Chlorine And Disinfection CEU Course

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Modern Disinfection CEU Training Course $200.00 48 HOUR RUSH ORDER PROCESSING FEE ADDITIONAL $50.00

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I understand State laws and rules change on a frequent basis and I believe this course is currently accepted in my State for CEU or contact hour credit, if it is not, I will not hold Technical Learning College responsible.

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Grading Information In order to maintain the integrity of our courses we do not distribute test scores, percentages or questions missed.

Our exams are based upon pass/fail criteria with the benchmark for successful completion set at 70%. Once you pass the exam, your record will reflect a successful completion and a certificate will be issued to you.

2 Modern Disinfection 9/1/2016 Assignment Modern Disinfection CEU Course Answer Key

Name ______Telephone # ______

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Please select one answer. You can circle, underline, bold or X the answer.

1. A B C D E F 21. A B C D E F 41. A B C D E F 2. A B C D E F 22. A B C D E F 42. A B C D E F 3. A B C D E F 23. A B C D E F 43. A B C D E F 4. A B C D E F 24. A B C D E F 44. A B C D E F 5. A B C D E F 25. A B C D E F 45. A B C D E F 6. A B C D E F 26. A B C D E F 46. A B C D E F 7. A B C D E F 27. A B C D E F 47. A B C D E F 8. A B C D E F 28. A B C D E F 48. A B C D E F 9. A B C D E F 29. A B C D E F 49. A B C D E F 10. A B C D E F 30. A B C D E F 50. A B C D E F 11. A B C D E F 31. A B C D E F 51. A B C D E F 12. A B C D E F 32. A B C D E F 52. A B C D E F 13. A B C D E F 33. A B C D E F 53. A B C D E F 14. A B C D E F 34. A B C D E F 54. A B C D E F 15. A B C D E F 35. A B C D E F 55. A B C D E F 16. A B C D E F 36. A B C D E F 56. A B C D E F 17. A B C D E F 37. A B C D E F 57. A B C D E F 18. A B C D E F 38. A B C D E F 58. A B C D E F 19. A B C D E F 39. A B C D E F 59. A B C D E F 20. A B C D E F 40. A B C D E F 60. A B C D E F

3 Modern Disinfection 9/1/2016 Assignment 61. A B C D E F 96. A B C D E F 131. A B C D E F 62. A B C D E F 97. A B C D E F 132. A B C D E F 63. A B C D E F 98. A B C D E F 133. A B C D E F 64. A B C D E F 99. A B C D E F 134. A B C D E F 65. A B C D E F 100. A B C D E F 135. A B C D E F 66. A B C D E F 101. A B C D E F 136. A B C D E F 67. A B C D E F 102. A B C D E F 137. A B C D E F 68. A B C D E F 103. A B C D E F 138. A B C D E F 69. A B C D E F 104. A B C D E F 139. A B C D E F 70. A B C D E F 105. A B C D E F 140. A B C D E F 71. A B C D E F 106. A B C D E F 141. A B C D E F 72. A B C D E F 107. A B C D E F 142. A B C D E F 73. A B C D E F 108. A B C D E F 143. A B C D E F 74. A B C D E F 109. A B C D E F 144. A B C D E F 75. A B C D E F 110. A B C D E F 145. A B C D E F 76. A B C D E F 111. A B C D E F 146. A B C D E F 77. A B C D E F 112. A B C D E F 147. A B C D E F 78. A B C D E F 113. A B C D E F 148. A B C D E F 79. A B C D E F 114. A B C D E F 149. A B C D E F 80. A B C D E F 115. A B C D E F 150. A B C D E F 81. A B C D E F 116. A B C D E F 151. A B C D E F 82. A B C D E F 117. A B C D E F 152. A B C D E F 83. A B C D E F 118. A B C D E F 153. A B C D E F 84. A B C D E F 119. A B C D E F 154. A B C D E F 85. A B C D E F 120. A B C D E F 155. A B C D E F 86. A B C D E F 121. A B C D E F 156. A B C D E F 87. A B C D E F 122. A B C D E F 157. A B C D E F 88. A B C D E F 123. A B C D E F 158. A B C D E F 89. A B C D E F 124. A B C D E F 159. A B C D E F 90. A B C D E F 125. A B C D E F 160. A B C D E F 91. A B C D E F 126. A B C D E F 161. A B C D E F 92. A B C D E F 127. A B C D E F 162. A B C D E F 93. A B C D E F 128. A B C D E F 163. A B C D E F 94. A B C D E F 129. A B C D E F 164. A B C D E F 95. A B C D E F 130. A B C D E F 165. A B C D E F

6 Modern Disinfection 9/1/2016 Assignment 376. A B C D E F 385. A B C D E F 394. A B C D E F 377. A B C D E F 386. A B C D E F 395. A B C D E F 378. A B C D E F 387. A B C D E F 396. A B C D E F 379. A B C D E F 388. A B C D E F 397. A B C D E F 380. A B C D E F 389. A B C D E F 398. A B C D E F 381. A B C D E F 390. A B C D E F 399. A B C D E F 382. A B C D E F 391. A B C D E F 400. A B C D E F 383. A B C D E F 392. A B C D E F 384. A B C D E F 393. A B C D E F

This course contains general EPA’s SDWA federal rule requirements. Please be aware that each state implements water / sampling procedures/safety/ environmental / building regulations that may be more stringent than EPA’s regulations. Check with your state environmental/health agency for more information. These rules change frequently and are often difficult to interpret and follow. Be careful to not be in non-compliance and do not follow this course for proper compliance.

Please fax the answer key to TLC (928) 272-0747 Always call to confirm that we received your paperwork.

7 Modern Disinfection 9/1/2016 Assignment 8 Modern Disinfection 9/1/2016 Assignment Please e-mail or fax this survey along with your final exam

MODERN DISINFECTION CEU TRAINING COURSE CUSTOMER SERVICE RESPONSE CARD

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PLEASE COMPLETE THIS FORM BY CIRCLING THE NUMBER OF THE APPROPRIATE ANSWER IN THE AREA BELOW.

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9 Modern Disinfection 9/1/2016 Assignment 10 Modern Disinfection 9/1/2016 Assignment Modern Disinfection CEU Course Assignment

The Modern Disinfection CEU Assignment is available in Word on the Internet for your Convenience, please visit www.ABCTLC.com and download the assignment and e mail it back to TLC.

You will have 90 days from the start of this course to complete in order to receive your Professional Development Hours (PDHs) or Continuing Education Unit (CEU). A score of 70 % is necessary to pass this course. If you should need any assistance, please email all concerns and the completed manual to [email protected].

I would prefer that you utilize the enclosed answer sheet in the front, but if you are unable to do so, type out your own answer key. Please include your name and address on your assignment and make copy for yourself.

Multiple Choice, please select only one answer per question. There are no intentional trick questions.

(S) means answer may be plural or singual in nature.

Chlorine Introduction Chlorine’s Appearance and Odor 1. Chlorine is a greenish-yellow gas with a characteristic pungent odor. It condenses to an amber liquid at approximately -34 degrees C (-29.2 degrees F) or at high pressures. Odor thresholds ranging from 0.08 to part per million (ppm) parts of air have been reported. ______may result in olfactory fatigue. A. Chlorine D. Spills B. Prolonged exposures E. Smelling C. Organic compounds F. None of the Above

Reactivity 2. Conditions Contributing to Instability: Cylinders of chlorine may burst when exposed to elevated temperatures. ______in solution forms a corrosive material. A. Combustible material(s) D. Few drops of acid B. Chlorine E. THMs C. Chlorine bleach F. None of the Above

3. Incompatibilities: Flammable gases and vapors form ______with chlorine. Contact between chlorine and many combustible substances (such as gasoline and petroleum products, hydrocarbons, turpentine, alcohols, acetylene, hydrogen, ammonia, and sulfur), reducing agents, and finely divided metals may cause fires and explosions. A. Hydrochloric acid D. Hypochlorous acid B. Chloric gas E. Hypochlorite solution C. Explosive mixtures F. None of the Above

4. Contact between ______and arsenic, bismuth, boron, calcium, activated carbon, carbon disulfide, glycerol, hydrazine, iodine, methane, oxomonosilane, potassium, propylene, and silicon should be avoided. A. Combustible material(s) D. Few drops of hydrochloric acid B. Chlorine E. Hypochlorous acid C. Corrosive material(s) F. None of the Above

11 Modern Disinfection 9/1/2016 Assignment 5. Chlorine reacts with ______and water to form hydrochloric acid, and it reacts with carbon monoxide and sulfur dioxide to form phosgene and sulfuryl chloride. Chlorine is also incompatible with moisture, steam, and water. A. Hydrogen sulfide D. Hypochlorous acid B. Chloric gas E. Hypochlorite solution C. Organic compounds F. None of the Above

Flammability 6. The National Fire Protection Association has assigned a flammability rating of 0 (no fire hazard) to chlorine; however, most combustible materials will burn in______. A. Hydrogen sulfide D. Hypochlorous acid B. Chlorine E. Hypochlorite solution C. Organic compounds F. None of the Above

7. Extinguishant: For small fires use water only; do not use dry chemical or carbon dioxide. Contain and let large fires involving ______burn. If fire must be fought, use water spray or fog. A. Chlorine D. Very reactive element B. Chlorine bleach E. Hydrochloric acid C. Organic compounds F. None of the Above

8. Fires involving ______should be fought upwind from the maximum distance possible. A. Combustible material(s) D. Few drops of hydrochloric acid B. Chlorine E. Ends of container(s) C. Corrosive material(s) F. None of the Above

9. Keep unnecessary people away; isolate the hazard area and deny entry. For a massive fire in a cargo area, use unmanned hose holders or monitor nozzles; if this is impossible, withdraw from the area and let the fire burn. Emergency personnel should stay out of low areas and ______before entering. A. Evacuate D. Ventilate closed spaces B. Allow the fire to burn E. Not ventilate C. Wear suits F. None of the Above

10. Containers of ______may explode in the heat of the fire and should be moved from the fire area if it is possible to do so safely. If this is not possible, cool fire exposed containers from the sides with water until well after the fire is out. A. Hydrochloric acid D. Hypochlorous acid B. Chloric gas E. Hypochlorite solution C. Chlorine F. None of the Above

11. Stay away from the ends of containers. Firefighters should wear a full set of protective clothing and self- contained breathing apparatus when fighting fires involving ______. A. Combustible material(s) D. Hydrochloric acid B. Chlorine E. Brine solution of sodium chloride C. Corrosive material(s) F. None of the Above

12. All three forms of chlorine produce ______(HOCl) when added to water. A. Calcium hypochlorite D. Sodium hydroxide B. Hypochlorous acid E. Sodium hypochlorite C. Hydrochloric acid F. None of the Above

12 Modern Disinfection 9/1/2016 Assignment 13. Hypochlorous acid is a weak acid but a strong disinfecting agent. The amount of hypochlorous acid depends on the pH and temperature of the water. Under normal water conditions, hypochlorous acid will also chemically react and break down into______. A. Chlorine D. Very reactive element B. A hypochlorite Ion E. Hydrochloric acid C. Organic compounds F. None of the Above

14. (OCl - ): ______H + + OCI – Also expressed HOCI → H + + OCI – (hypochlorous acid) (hydrogen) (hypochlorite ion) A. Calcium hypochlorite D. HOCI B. Hypochlorous acid E. Sodium hypochlorite C. Hydrochloric acid F. None of the Above

15. The hypochlorite ion is a much weaker disinfecting agent than ______, about 100 times less effective. A. Lower pH D. pH and temperature B. Hypochlorous acid E. The hypochlorite ion C. Higher water temperatures F. None of the Above

16. Let’s now look at how pH and temperature affect the ratio of hypochlorous acid to hypochlorite ions. As the temperature is decreased, the ______increases. A. Reduction Ratio D. "CT" disinfection concept B. CT actual E. Ratio of hypochlorous acid C. Free chlorine residual F. None of the Above

17. Temperature plays a small part in the acid ratio. Although the ratio of ______is greater at lower temperatures, pathogenic organisms are actually harder to kill. A. Hypochlorous acid D. Total chlorine B. The amount of chlorine E. pH value and temperature C. Chlorine Demand F. None of the Above

18. All other things being equal, ______and a lower pH are more conducive to chlorine disinfection. A. Lower pH D. pH and temperature B. Hypochlorous acid E. The hypochlorite ion C. Higher water temperatures F. None of the Above

Types of Residual 19. If water were pure, the measured amount of chlorine in the water should be the same as the amount added. But water is not 100% pure. There are always other substances (interfering agents) such as iron, manganese, turbidity, etc., which will combine chemically with the chlorine. This is called the ______. A. Chlorine residual D. Break-point chlorination B. Chlorine demand E. Total chlorine residual C. Pathogen reduction F. None of the Above

20. Naturally, once chlorine molecules are combined with these interfering agents, they are not capable of disinfection. It is ______that is much more effective as a disinfecting agent. A. Chlorine residual D. Break-point chlorination B. Chlorine demand E. Total chlorine residual C. Free chlorine F. None of the Above

(S) means answer may be plural or singual in nature.

13 Modern Disinfection 9/1/2016 Assignment 21. When a chlorine residual test is taken, either a total or a ______can be read. A. Chlorine residual D. Break-point chlorination B. Chlorine demand E. Total chlorine residual C. Free chlorine residual F. None of the Above

22. ______is all chlorine that is available for disinfection. A. Chlorine residual D. Break-point chlorination B. Chlorine demand E. Total chlorine C. Free chlorine F. None of the Above

23. Total chlorine residual = free +______. A. Chlorine residual D. Combined chlorine residual B. Chlorine demand E. Total chlorine residual C. Free chlorine F. None of the Above

24. ______is a much stronger disinfecting agent. Therefore, most water regulating agencies will require that your daily chlorine residual readings be of free chlorine residual. A. Free chlorine D. "CT" disinfection concept B. Total residual E. T10 of the process unit C. Free chlorine residual F. None of the Above

25. ______is where the chlorine demand has been satisfied, and any additional chlorine will be considered free chlorine. A. Chlorine residual D. Break-point chlorination B. Chlorine demand E. Total chlorine residual C. Free chlorine F. None of the Above

Residual Concentration/Contact Time (CT) Requirements 26. Disinfection to eliminate fecal and coliform bacteria may not be sufficient to adequately reduce pathogens such as Giardia or viruses to desired levels. Use of the ______is recommended to demonstrate satisfactory treatment, since monitoring for very low levels of pathogens in treated water is analytically very difficult. A. Free chlorine D. "CT" disinfection concept B. Total residual E. T10 of the process unit C. Free chlorine residual F. None of the Above

27. The______, as developed by the United States Environmental Protection Agency (Federal Register, 40 CFR, Parts 141 and 142, June 29, 1989), uses the combination of disinfectant residual concentration (mg/L) and the effective disinfection contact time (in minutes) to measure effective pathogen reduction. A. CT concept D. Total chlorine B. The amount of chlorine E. pH value and temperature C. Chlorine Demand F. None of the Above

28. ______is measured at the end of the process, and the contact time used is the T10 of the process unit (time for 10% of the water to pass). A. Free chlorine D. The residual B. Total residual E. T10 of the process unit C. Free chlorine residual F. None of the Above

29. ______= Concentration (mg/L) x Time (minutes) A. CT D. Total chlorine B. The amount of chlorine E. pH value and temperature C. Chlorine Demand F. None of the Above

14 Modern Disinfection 9/1/2016 Assignment 30. The effective reduction in pathogens can be calculated by reference to standard tables of required ______. A. Free chlorine D. "CT" s B. Total residual E. T10 of the process unit C. Free chlorine residual F. None of the Above

Required Giardia/Virus Reduction 31. All surface water treatment systems shall ensure a minimum reduction in pathogen levels: ______in Giardia; and 4-log reduction in viruses. These requirements are based on unpolluted raw water sources with Giardia levels of = 1 cyst/100 L, and a finished water goal of 1 cyst/100,000 L (equivalent to 1 in 10,000 risk of infection per person per year). A. Free chlorine D. "CT" disinfection concept B. 3-log reduction E. T10 of the process unit C. Free chlorine residual F. None of the Above

Calculation and Reporting of CT Data 32. ______shall be calculated daily, using either the maximum hourly flow and the disinfectant residual at the same time, or by using the lowest CT value if it is calculated more frequently. Actual CT values are then compared to required CT values. A. Free chlorine D. "CT" disinfection concept B. Total residual E. Disinfection CT values C. Free chlorine residual F. None of the Above

33. Results shall be reported as a reduction Ratio, along with the appropriate pH, temperature, and ______. A. Reduction Ratio D. Disinfectant residual B. CT actual E. T10 of the process unit C. Free chlorine residual F. None of the Above

34. The ______must be greater than 1.0 to be acceptable. A. Reduction Ratio D. "CT" disinfection concept B. CT actual E. T10 of the process unit C. Free chlorine residual F. None of the Above

35. Users may also calculate and record actual log reductions. Reduction Ratio = CT actual divide by ______. A. Reduction Ratio D. "CT" disinfection concept B. CT E. CT required C. Free chlorine residual F. None of the Above

Chlorine Review 36. Pre-chlorination: The addition of chlorine at the plant headworks or prior to other water treatment or groundwater production processes and mainly used for ______and control of tastes, odors, and aquatic growths. A. Organic amine(s) D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

37. Post-chlorination: The addition of chlorine after a process or adding chlorine downstream to meet a ______in the system. A. Chlorination D. Demand B. Value E. pH value and temperature C. Chlorine Demand F. None of the Above

15 Modern Disinfection 9/1/2016 Assignment 38. ______: Breakpoint chlorination means adding Cl2 to the water until the Cl2 demand is satisfied. Until all the microorganisms are killed. A. Organic amine(s) D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

39. ______: The minimum amount of chlorine needed to react in a water purification system; used as a monitoring measurement by system operators. A. Chlorination D. Total chlorine B. The amount of chlorine E. pH value and temperature C. Chlorine Demand F. None of the Above

40. ______: The concentration of chlorine in the water after the chlorine demand has been satisfied. The concentration is normally expressed in terms of total chlorine residual, which includes both the free and combined or chemically bound chlorine residuals. A. Chlorine Residual D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

41. ______: The amount of chlorine used up in a water purification system; used as a monitoring measurement by system operators. A. Chlorination D. Total chlorine B. The amount of chlorine E. Combined Chlorine Residual C. Chlorine Demand F. None of the Above

42. ______is defined as the residual chlorine existing in water in chemical combination with ammonia or organic amines which can be found in natural or polluted waters. A. Combined chlorine D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

43. Ammonia is sometimes deliberately added to chlorinated public water supplies to provide ______. A. Chlorination D. Total chlorine B. Inorganic chloramines E. pH value and temperature C. Chlorine Demand F. None of the Above

44. ______: Free chlorine is defined as the concentration of residual chlorine in water present as dissolved gas (Cl2), hypochlorous acid (HOCl), and/or hypochlorite ion (OCl-). The three forms of free chlorine exist together in equilibrium. A. Organic amine(s) D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

45. Their relative proportions are determined by the pH value and temperature. Regardless of whether pre-chloration is practiced or not, a free chlorine residual of at least 10 mg/L should be maintained in the clear well or distribution reservoir immediately downstream from ______and .2 mg/L in the distribution system to guard against backflow. A. Chlorination D. Total chlorine B. The amount of chlorine E. The point of post-chlorination C. Chlorine Demand F. None of the Above

16 Modern Disinfection 9/1/2016 Assignment 46. ______: The total of free residual and combined residual chlorine in a water purification system; used as a monitoring measurement by system operators. Total chlorine is the sum of free and combined chlorine. A. Organic amine(s) D. Breakpoint chlorination B. Disinfection E. Total Chlorine Residual C. Free chlorine F. None of the Above

47. When chlorinating most potable water supplies, total chlorine is essentially equal to ______since the concentration of ammonia or organic nitrogen compounds (needed to form combined chlorine) will be very low. A. Chlorination D. Total chlorine B. The amount of chlorine E. Free chlorine C. Chlorine Demand F. None of the Above

48. When chloramines are present in the municipal water supply, then total chlorine will be higher than ______. A. Organic amine(s) D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

49. ______: A method of water disinfection where gaseous, liquid, or dissolved chlorine is added to a water supply system. Water which has been treated with chlorine is effective in preventing the spread of disease. A. Chlorination D. Total chlorine B. The amount of chlorine E. Free chlorine C. Chlorine Demand F. None of the Above

50. The chlorination of public drinking supplies was originally met with resistance, as people were concerned about the health effects of the practice. The use of chlorine has greatly reduced the prevalence of waterborne disease as it is effective against almost all bacteria and viruses, as well as amoeba. ______kills everything. A. Sterilization D. Breakpoint chlorination B. Disinfection E. Total chlorine residual C. Free chlorine F. None of the Above

51. Physical and chemical properties of chlorine: A yellowish green, nonflammable and liquefied gas with an unpleasant and irritating smell. Can be readily compressed into a clear, amber-colored liquid, a noncombustible gas, and a______. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. An oxidizer E. Calcium hypochlorite C. Strong oxidizer F. None of the Above

52. ______is about 1.5 times heavier than water and gaseous chlorine is about 2.5 times heavier than air. Atomic number of chlorine is 17. Cl is the elemental symbol and Cl2 is the chemical formula. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. An oxidizer E. Calcium hypochlorite C. Solid chlorine F. None of the Above

53. ______reacts with bacteria as if it was very corrosive and burns the skin or covering killing the bacteria. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. Chlorine E. Calcium hypochlorite C. Solid chlorine F. None of the Above

54. Fusible plug is a safety device that melts. If the temperature of a full Cl2 cylinder is increased by 50 o F or 30o C, a rupture may occur. It will melt at 158 to 165 degrees F. It is found on the side of a 1-ton container and on top of the 150-pound cylinder and is located in the valve below the______. A. Cylinder valve outlet cap D. Valve seat 17 Modern Disinfection 9/1/2016 Assignment B. Cylinder valve E. Lead gasket C. Yoke F. None of the Above

55. Hook up the chlorinator to the container or cylinder with the chlorine valve turned off. Use the ______not the liquid if using a 1-ton container. A. Cylinder valve outlet cap D. Safety device B. Cylinder valve E. Gas side C. Yoke F. None of the Above

56. Remove the ______and check the valve face or damage. Clean with wire brush if necessary. If the valve face is smooth, clean proceed with hooking up the cylinder. A. Cylinder valve outlet cap D. Safety device B. Cylinder valve E. Lead gasket C. Yoke F. None of the Above

57. Check the ______of the chlorinator and clean if necessary. Place a new lead gasket on the chlorinator inlet, place the chlorinator on the cylinder valve, install the yoke clamp and slowly tighten the yoke clamp until the two faces are against the lead gasket. A. Cylinder valve outlet cap D. Inlet face B. Cylinder valve E. Gasket C. Yoke F. None of the Above

58. Tighten the ______, compressing the gasket one half to three quarters turn, do not over tighten. Replace the lead gasket with every change out. A. Cylinder valve outlet cap D. Safety device B. Cylinder valve E. Lead gasket C. Yoke F. None of the Above

Chlor-Alkali Membrane Process 59. The electrolysis occurs in a cell containing electrodes submerged in solutions called electrolytes. One electrode is referred to as the anode and is submerged in______. A. Chlorination D. Chlor-alkali membrane process B. Caustic soda E. A salt water solution C. Chlorine ion F. None of the Above

60. The second electrode is the cathode and is submerged in a ______solution. A. Oxidizing chemical(s) D. Sodium hydroxide (caustic soda) B. A salt water solution E. Sodium and chlorine ions C. Sodium F. None of the Above

61. ______is used to keep the two different solutions from mixing. This particular method of producing chlorine is called the chlor-alkali membrane process. A. A membrane D. Chlor-alkali membrane process B. Caustic soda E. Required contact time C. Chlorine ion F. None of the Above

62. When a low voltage direct current (DC) power supply is applied to the electrodes in the cell, the ______in the brine are attracted in opposite directions to the polarized electrodes. A. Oxidizing chemical(s) D. Caustic soda B. Sodium and chlorine ions E. Sodium and chlorine C. Sodium F. None of the Above 63. ______passes across an ion selective membrane leaving the chlorine ion to combine with a second chlorine ion, which makes a chlorine gas bubble at the anode (electrode). A. Chlorination D. Chlor-alkali membrane process B. Caustic soda E. The sodium ion C. Chlorine ion F. None of the Above

18 Modern Disinfection 9/1/2016 Assignment 64. When the sodium crosses the membrane, it combines with a hydroxyl ion at the cathode (electrode) making sodium hydroxide, or caustic soda (NaOH). The hydroxyl ion originates from the dissolution of water at the cathode where ______also develops. A. Hydrogen gas D. Caustic soda B. Chlorination E. Sodium and chlorine ions C. Sodium F. None of the Above

65. The membrane in the cell keeps the two solutions separate; otherwise, the chlorine gas bubble would immediately combine with the caustic soda forming______. This process, which uses a membrane to separate the two solutions, is called the chlor-alkali process. A. Chlorination D. Chlor-alkali membrane process B. Caustic soda E. Sodium hypochlorite, or bleach C. Chlorine ion F. None of the Above

Chlorine’s Effectiveness 66. The effectiveness of chlorination depends on the chlorine demand of the water, the concentration of the chlorine solution added, the time that ______is in contact with the organism, and water quality. A. Oxidizing chemical(s) D. Caustic soda B. Chlorine E. Sodium and chlorine ions C. Sodium F. None of the Above

67. These effects can be summarized in the following manner: As the concentration of the ______increases, the required contact time to disinfect decreases. A. Chlorination D. Chlor-alkali membrane process B. Caustic soda E. Required contact time C. Chlorine F. None of the Above

68. ______is more effective as water temperature increases. A. Oxidizing chemical(s) D. Caustic soda B. Chlorination E. Sodium and chlorine ions C. Sodium F. None of the Above

69. ______is less effective as the water's pH increases (becomes more alkaline). A. Chlorination D. Chlor-alkali membrane process B. Caustic soda E. Required contact time C. Chlorine ion F. None of the Above

70. ______is less effective in cloudy (turbid) water. A. Oxidizing chemical(s) D. Caustic soda B. Chlorination E. Sodium and chlorine ions C. Sodium F. None of the Above

71. When chlorine is added to the water supply, part of it combines with other chemicals in water (like iron, manganese, ______) and is not available for disinfection. A. Hydrogen sulfide, and ammonia D. Chlor-alkali membrane process B. Caustic soda E. Required contact time C. Chlorine ion F. None of the Above

19 Modern Disinfection 9/1/2016 Assignment 72. The amount of ______that reacts with the other chemicals plus the amount required to achieve disinfection is the chlorine demand of the water. A. Oxidizing chemical(s) D. Caustic soda B. Chlorine E. Sodium and chlorine ions C. Sodium F. None of the Above

73. The safest way to be sure that the amount of chlorine added is sufficient is to add a little more than is required. This will result in a ______that can be measured easily. This chlorine residual must be maintained for several minutes depending on chlorine level and water quality. A. Chlorination D. Total chlorine B. Free chlorine residual E. Free chlorine C. Chlorine Demand F. None of the Above

Oxidation Chemistry 74. Oxidation chemistry has long been an accepted and effective part of many water treatment programs. ______used in today's water treatment programs include: chlorine, chlorine dioxide, bromine, bromine/chlorine releasing compounds, ozone and hydrogen peroxide. A. Ozone D. Hypochlorite ion (OCl-) B. Oxidizing chemicals E. A number of compounds C. Chlorine dioxide F. None of the Above

75. ______are often found at the forefront of many cooling water treatment programs. In large volume or once-through cooling systems they are usually the primary biocide and often are the most cost-effective programs available to a plant. A. pH depression D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. Oxidizing microbiocides F. None of the Above

76. When selecting these economical and versatile chemicals, several factors should be considered before a technically sound program is implemented. Environmental and regulatory impact, system ______, process contamination, and equipment capital and maintenance expense all play a role in the decision-making process. A. Ozone D. Hypochlorite ion (OCl-) B. pH E. A number of compounds C. Chlorine dioxide F. None of the Above

77. The primary killing mechanism ______use is oxidizing protein groups within a microorganism. Proteins are the basic components of essential cellular enzymes that are necessary for life-sustaining cellular processes such as respiration. A. pH depression D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. These types of microbiocides C. OCl- F. None of the Above

78. The destruction of these proteins deprives the cell of its ability to carry out fundamental life functions and quickly kills it. One oxidant is ______, which appears to provide an additional killing mechanism. A. Ozone D. Hypochlorite ion (OCl-) B. The chloride ion (Cl-) E. Hydrochloric acid (HCl) C. Chlorine dioxide F. None of the Above

20 Modern Disinfection 9/1/2016 Assignment 79. ______is able to diffuse readily through hydrophobic lipid layers of an organism, allowing it to react with cellular amino acids, which directly inhibits protein synthesis. Since amino acids are the basic building blocks of all cellular proteins, destruction of these molecules has a devastating effect on the microorganism. A. Chlorine D. Hydrochloric acid (HCl) B. The chloride ion (Cl-) E. Chlorine dioxide C. HOCl F. None of the Above

Chlorine Gas Section 80. Chlorine is a yellowish-green gas at standard temperature and pressure. It is extremely reactive with most elements. Because its density is greater than that of air, the gas settles low to the ground. It is a respiratory irritant, and it burns the skin. Just a few breaths of it are fatal. ______does not occur naturally, although Chlorine can be found in a number of compounds. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Cl2 gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

81. ______is likely the most widely used oxidizing microbiocide. It has traditionally been the biocide of choice in many cooling water treatment systems. It is a strong oxidizer that is relatively easy to feed and is quite inexpensive. Upon introduction into the water stream, chlorine hydrolyzes into hypochlorous acid (HOCl) and hydrochloric acid (HCl). A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

82. This hydrolyzation provides the active toxicant, ______, which is pH-dependent. In alkaline cooling systems, it readily dissociates to form the hypochlorite ion (OCl-). A. Ozone D. Hypochlorite ion (OCl-) B. HOCl E. A number of compounds C. Chlorine dioxide F. None of the Above

83. This dissociation phenomenon is important to remember when working with systems that will operate at a higher pH. In alkaline conditions, ______becomes the predominant species and lacks the biocidal efficacy of the non-dissociated form. Considerably more HOCl is present at a pH of 7.0 than at pH 8.5. A. pH depression D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. OCl- F. None of the Above

84. It is also widely known that chlorine is non-selective, making it very sensitive to contamination from either cooling water makeup or from in-plant process leaks. Ammonia, organic acids and organic compounds, sulfides, iron and manganese all easily react with ______. A. Chlorine D. Hydrochloric acid (HCl) B. The chloride ion (Cl-) E. Chlorine dioxide C. HOCl F. None of the Above

85. The amount of chlorine needed to react with these contamination species is referred to as chlorine demand and it must be satisfied before active ______is available to provide a free chlorine residual. A. pH depression D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. HOCl E. Chlorine dioxide C. OCl- F. None of the Above

21 Modern Disinfection 9/1/2016 Assignment 86. The combination of high chlorine demand in process-contaminated systems and the dissociation process in alkaline systems creates the need for greater chlorine feed to obtain the same microbial efficacy. This results in a higher concentration of ______in the cooling system. A. Chlorine D. HCl B. The chloride ion (Cl-) E. Chlorine dioxide C. HOCl F. None of the Above

87. Since ______removes alkalinity, pH depression and system corrosion could occur. In low pH water the passive metal oxide layers protecting the metal may resolubulize, exposing the surface to corrosion. A. pH D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. HCl C. OCl- F. None of the Above

88. At free mineral acidity (pH <4.3), many passivating inhibitors become ineffective, and corrosion will proceed rapidly. Increased chloride may also have a negative impact on system corrosion. The ______ion (Cl-) can damage or penetrate the passive oxide layer, leading to localized damage of the metal surface. A. Chlorine D. Hydrochloric acid (HCl) B. Chloride E. Chlorine dioxide C. HOCl F. None of the Above

89. High ______concentrations have also been shown to directly attack traditional organic- based corrosion inhibitors. When these inhibitors are "deactivated," the metal surface would then be susceptible to corrosion. Process Safety Management (PSM) guidelines dictated by the U.S. Occupational Safety and Health Administration (OSHA), discharge problems related to chlorinated organic compounds such as trihalomethane (THM), dezincification of admiralty brass and delignification of cooling tower wood are other significant concerns associated with the use of chlorine. A. Chlorine D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. OCl- F. None of the Above

Pathophysiology 90. ______is a greenish-yellow, noncombustible gas at room temperature and atmospheric pressure. The intermediate water solubility of chlorine accounts for its effect on the upper airway and the lower respiratory tract. A. Chlorine D. Hydrochloric acid (HCl) B. The chloride ion (Cl-) E. Chlorine dioxide C. HOCl F. None of the Above

91. Exposure to ______may be prolonged because its moderate water solubility may not cause upper airway symptoms for several minutes. In addition, the density of the gas is greater than that of air, causing it to remain near ground level and increasing exposure time. A. Chlorine gas D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. OCl- F. None of the Above

92. The odor threshold for ______is approximately 0.3-0.5 parts per million (ppm); however, distinguishing toxic air levels from permissible air levels may be difficult until irritative symptoms are present. A. Chlorine D. Hydrochloric acid (HCl) B. The chloride ion (Cl-) E. Chlorine dioxide C. HOCl F. None of the Above

22 Modern Disinfection 9/1/2016 Assignment Solubility Effects 93. ______is highly soluble in water. The predominant targets of the acid are the epithelia of the ocular conjunctivae and upper respiratory mucus membranes. A. Hydrochloric acid D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. OCl- F. None of the Above

94. ______is also highly water soluble with an injury pattern similar to hydrochloric acid. A. Chlorine D. Hydrochloric acid (HCl) B. Hypochlorous acid E. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) C. HOCl F. None of the Above

95. ______may account for the toxicity of elemental chlorine and hydrochloric acid to the human body. A. Chlorine D. Hydrochloric acid (HCl) B. Hypochlorous acid E. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) C. HOCl F. None of the Above

Early Response to Chlorine Gas 96. Chlorine gas, when mixed with ammonia, reacts to form______. In the presence of water, chloramines decompose to ammonia and hypochlorous acid or hydrochloric acid. A. Chloramine gas D. Hypochlorous acid (HOCl) and hydrochloric acid (HCl) B. Active HOCl E. Chlorine dioxide C. OCl- F. None of the Above

97. The early response to chlorine exposure depends on the (1) concentration of chlorine gas, (2) duration of exposure, (3) water content of the tissues exposed, and (4)______. A. Chlorine gas toxicity D. Concentration of chlorine gas B. Plasma exudation E. Noncardiogenic pulmonary edema C. Individual susceptibility F. None of the Above

Immediate Effects 98. The immediate effects of chlorine gas toxicity include acute inflammation of the conjunctivae, nose, pharynx, larynx, trachea, and bronchi. ______leads to local edema secondary to active arterial and capillary hyperemia. A. Chlorine gas toxicity D. Irritation of the airway mucosa B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

99. ______results in filling the alveoli with edema fluid, resulting in pulmonary congestion. A. Chlorine gas toxicity D. Concentration of chlorine gas B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

Pathological Findings 100. Pathologic findings are nonspecific. They include severe pulmonary edema, pneumonia, hyaline membrane formation, multiple pulmonary thromboses, and______. A. Chlorine gas toxicity D. Ulcerative tracheobronchitis B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

23 Modern Disinfection 9/1/2016 Assignment 101. The hallmark of ______associated with chlorine toxicity is pulmonary edema, manifested as hypoxia. Noncardiogenic pulmonary edema is thought to occur when there is a loss of pulmonary capillary integrity. A. Chlorine gas toxicity D. Pulmonary injury B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

Sodium Hypochlorite Section Incompatibilities 102. ______react explosively or form explosive compounds with many common substances such as ammonia, amines, charcoal, or organic sulfides A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. Calcium or sodium hypochlorite C. Calcium carbonate F. None of the Above

Introduction 103. The world's most universal and reliable means of water and wastewater disinfection is chlorination. Two fundamental methods include gas chlorination (Cl2) and liquid chlorination (NaOCl) otherwise known as ______. A. Low pH corrosion D. The hypochlorite form of chlorine B. The NaOCl reaction E. Sodium Hypochlorite C. The HOCl F. None of the Above

104. ______is a solution made from reacting chlorine with a sodium hydroxide solution. These two reactants are the major co-products from most chlor-alkali cells. A. Chlorine gas D. Sodium hypochlorite (NaOCl) B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

105. ______has a variety of uses and is an excellent disinfectant/antimicrobial agent. Sodium hypochlorite also significantly increases the pH of the water. A. Low pH corrosion D. The hypochlorite form of chlorine B. The NaOCl reaction E. Sodium Hypochlorite C. The HOCl F. None of the Above

106. When ______is used, it must be counterbalanced by a strong acid like sodium bisulfate or muriatic acid to keep the pH within the ideal range. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

107. The hypochlorite form of chlorine has been used since 1850. The most widely used form of hypochlorite is the liquid, ______, with more than 150 tons per day consumed in the United States. A. Low pH corrosion D. The hypochlorite form of chlorine B. The NaOCl reaction E. Sodium hypochlorite (NaOCl) C. The HOCl F. None of the Above

108. ______application in cooling water is essentially the same as with gas chlorine; HOCl is produced as the active toxicant. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

24 Modern Disinfection 9/1/2016 Assignment 109. ______is equally susceptible to process contamination, has the same chlorine demand as gas chlorine and displays the same tendency to dissociate. A. Low pH corrosion D. The hypochlorite form of chlorine B. The NaOCl reaction E. Sodium Hypochlorite C. The HOCl F. None of the Above

110. ______differs from chlorine gas in two respects: method of feed and hydrolyzation properties. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

111. Sodium hypochlorite can either be gravity-fed or applied with a metering pump. The latter is generally recognized as a consistently more accurate method. The second difference, in hydrolysis, lies in the end products. The NaOCl reaction with water liberates______. A. Chlorine D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sodium hydroxide (NaOH) C. Explosive hydrogen gas F. None of the Above

112. The addition of ______differs in that it tends to add alkalinity to the water. In large concentrations it may artificially elevate pH, leading to precipitation of calcium carbonate. A. NaOH D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

113. While ______eliminates low pH corrosion as a concern, the use of large quantities in contaminated systems still introduces a high concentration of the chloride ion, which can be very aggressive to cooling system metals. Many of the other problems associated with chlorine remain present with sodium hypochlorite. A. Low pH corrosion D. The hypochlorite form of chlorine B. NaOCl E. Sodium Hypochlorite C. The HOCl F. None of the Above

Characteristics of Sodium hypochlorite 114. ______is a clear, slightly yellowish solution with a characteristic odor. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

115. ______has a relative density of is 1.1 (5.5% watery solution). A. Low pH corrosion D. The hypochlorite form of chlorine B. The NaOCl reaction E. Sodium Hypochlorite C. The HOCl F. None of the Above

116. As a bleaching agent for domestic use it usually contains ______(with a pH of around 11, it is irritating). If it is more concentrated, it contains a concentration 10-15% sodium hypochlorite (with a pH of around 13, it burns and is corrosive). A. 5% sodium hypochlorite D. Sodium hypochlorite B. NaOCl E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

25 Modern Disinfection 9/1/2016 Assignment 117. ______is unstable. Chlorine evaporates at a rate of 0,75-gram active chlorine per day from the solution. Then heated sodium hypochlorite disintegrates. This also happens when sodium hypochlorite comes in contact with acids, sunlight, certain metals and poisonous and corrosive gasses, including chlorine gas. A. Chlorine D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sulfuric acid C. Sodium hypochlorite F. None of the Above

118. ______is a strong oxidator and reacts with flammable compounds and reductors. A. 5% sodium hypochlorite D. Sodium B. Sodium hypochlorite E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

119. ______solution is a weak base that is inflammable. These characteristics must be kept in mind during transport, storage and use of sodium hypochlorite. A. Chlorine D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sulfuric acid C. Sodium hypochlorite F. None of the Above pH value When Sodium Hypochlorite is Added to Water 120. Due to the presence of caustic soda in sodium hypochlorite, the pH of the water is increased. When ______dissolves in water, two substances form, which play a role in oxidation and disinfection. A. Sodium hypochlorite D. Sodium B. pH E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

121. These are hypochlorous acid (HOCl) and the______. The pH of the water determines how much hypochlorous acid is formed. While sodium hypochlorite is used, hydrochloric (HCl) is used to lower the pH. A. Chlorine D. Less active hypochlorite ion (OCl-) B. Hypochlorite E. Sulfuric acid C. Explosive hydrogen gas F. None of the Above

122. ______can be used as an alternative for acetic acid. Less harmful gasses are produced when sulfuric acid is used. Sulfuric acid is a strong acid that strongly reacts with bases and is very corrosive. A. 5% sodium hypochlorite D. Sodium hypochlorite B. pH E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

How Can Sodium Hypochlorite be produced? 123. By dissolving salt in softened water, which results in a concentrated brine solution. The solution is electrolyzed and forms a sodium hypochlorite solution in water. This solution contains 150 g active ______per liter. During this reaction the explosive hydrogen gas is also formed. A. Chlorite D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sulfuric acid C. Chlorine (Cl2) F. None of the Above

26 Modern Disinfection 9/1/2016 Assignment Applications of Sodium Hypochlorite 124. Sodium hypochlorite is used on a large scale; for example, agriculture, chemical industries, paint- and lime industries, food industries, glass industries, paper industries, pharmaceutical industries, synthetics industries and waste disposal industries all use it. In the textile industry ______is used to bleach textile. It is sometimes added to industrial waste water--this is done to reduce odors. A. 5% sodium hypochlorite D. Sodium hypochlorite B. Chlorine E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

125. Hypochlorite neutralizes______. It is also used to detoxify cyanide baths in metal industries. Hypochlorite can be used to prevent algae and shellfish growth in cooling towers. In water treatment, hypochlorite is used to disinfect water. In households, hypochlorite is used frequently for the purification and disinfection of the house. A. Sulfur hydrogen gas (SH) and ammonia (NH3) D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sulfuric acid C. Explosive hydrogen gas F. None of the Above

How does Sodium Hypochlorite Disinfection Work? 126. Hypochlorous acid is divided into hydrochloric acid (HCl) and ______. The oxygen atom is a very strong oxidant. A. 5% sodium hypochlorite D. Sodium hypochlorite B. Hypochlorite E. Oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

127. Sodium hypochlorite is effective against bacteria, viruses and fungi. ______disinfects the same way as chlorine does. A. Chlorine D. Hypochlorous acid (HOCl) B. Hypochlorite E. Sulfuric acid C. Sodium hypochlorite F. None of the Above

128. There are various ways to use sodium hypochlorite. For on-site salt electrolysis, ______in water is applied. Sodium (Na+) and chloride (Cl-) ions are produced. A. 5% sodium hypochlorite D. Sodium hypochlorite B. A solution of salt (NaCl) E. Hydrochloric acid (HCl) and oxygen (O) C. Sulfuric acid (H2SO4) F. None of the Above

Salt Electrolysis System 129. The advantage of the salt electrolysis system is that no transport or storage of sodium hypochlorite is required. When ______is stored for a long time, it becomes inactive. Another advantage of the onsite process is that chlorine lowers the pH and no other acid is required to lower pH. A. pH D. Free chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

130. The hydrogen gas that is produced is explosive and as a result ventilation is required for explosion prevention. This system is slow and a buffer of extra hypochlorous acid needs to be used. The maintenance and purchase of the electrolysis system is much more expensive than ______. A. Ammonia D. Hypochlorous acid B. HOCl E. Hypochlorite ion state C. Sodium hypochlorite F. None of the Above

27 Modern Disinfection 9/1/2016 Assignment 131. When ______is used, acetic or sulfuric acid are added to the water. An overdose can produce poisonous gasses. If the dosage is too low, the pH becomes too high and can irritate the eyes. A. pH D. Free chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

132. Because sodium hypochlorite is used both to oxidize pollutants (urine, sweat, cosmetics) and to remove pathogenic microorganisms, the required concentration of sodium hypochlorite depends on the concentrations of these pollutions. Especially the amount of ______helps determine the required concentration. If the water is filtered before sodium hypochlorite is applied, less sodium hypochlorite is needed. A. Ammonia D. Hypochlorous acid B. HOCl E. Organic pollutants C. Chlorine gas F. None of the Above

Theory 133. Disinfection with ______is very popular in water and wastewater treatment because of its low cost, ability to form a residual, and its effectiveness at low concentrations. Although it is used as a disinfectant, it is a dangerous and potentially fatal chemical if used improperly. A. pH D. Chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

134. Despite the fact the disinfection process may seem simple, it is actually a quite complicated process. ______in wastewater treatment systems is a fairly complex science which requires knowledge of the plant's effluent characteristics. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Chlorination F. None of the Above

135. When ______is added to the water, it takes on various forms depending on the pH of the water. It is important to understand the forms of chlorine which are present because each has a different disinfecting capability. The acid form, HOCL, is a much stronger disinfectant than the hypochlorite ion, OCL-. A. Sodium hydroxide or lime D. Free chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

136. ______present in the effluent can also cause problems as chloramines are formed, which have very little disinfecting power. Some methods to overcome the types of chlorine formed are to adjust the pH of the water prior to chlorination or to simply add a larger amount of chlorine. A. Ammonia D. Hypochlorous acid B. HOCl E. Hypochlorite ion state C. Chlorine gas F. None of the Above

137. An adjustment in the pH would allow the operators to form the most desired form of chlorine, ______, which has the greatest disinfecting power. A. Chlorine gas D. Free chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

28 Modern Disinfection 9/1/2016 Assignment 138. Adding larger amounts of chlorine would be an excellent method to combat the chloramines because the ammonia present would bond to the chlorine but further addition of chlorine would stay in the ______state. A. Hypochlorus acid or hypochlorite ion D. Hypochlorous acid B. HOCl E. Hypochlorite ion state C. Chlorine gas F. None of the Above

139. Chlorine gas, when exposed to water reacts readily to form ______, HOCl, and hydrochloric acid. Cl2 + H2O -> HOCl + HCl A. Ammonia D. Hypochlorous acid B. HOCl2 E. Hypochlorite ion state C. Chlorine gas F. None of the Above

140. If the pH of the water is greater than 8, the ______will dissociate to yield hypochlorite ion. HOCl <-> H+ + OCl-- If however, the pH is much less than 7, and then HOCl will not dissociate. A. Ammonia D. Hypochlorous acid B. HOCl E. Hypochlorite ion state C. Chlorine gas F. None of the Above

141. If ammonia is present in the water effluent, then the ______will react to form one three types of chloramines depending on the pH, temperature, and reaction time. A. pH D. Free chlorine B. Sodium hypochlorite E. Hypochlorus acid C. Disinfection with chlorine F. None of the Above

Exposure 142.There is no threshold value for to sodium hypochlorite exposure. Various health effects occur after exposure to sodium hypochlorite. People are exposed to sodium hypochlorite by inhalation of aerosols. This causes coughing and a sore throat. After swallowing sodium hypochlorite, the effects are stomach ache, a burning sensation, coughing, diarrhea, a sore throat and vomiting. ______on skin or eyes causes redness and pain. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

143. After prolonged exposure, the skin can become sensitive. Sodium hypochlorite is poisonous for water organisms. It is mutagenic and very toxic when it comes in contact with______. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Ammonium salts E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

Routes of Exposure Inhalation 144. ______can liberate toxic gases such as chlorine. Chlorine's odor or irritant properties generally provide adequate warning of hazardous concentrations. However, prolonged, low-level exposures, such as those that occur in the workplace, can lead to olfactory fatigue and tolerance of chlorine's irritant effects. A. Air D. Sodium and calcium hypochlorite B. Hypochlorite solutions E. Household bleach C. Higher levels of chlorine F. None of the Above

29 Modern Disinfection 9/1/2016 Assignment 145. ______is heavier than air and may cause asphyxiation in poorly ventilated, enclosed, or low- lying areas. Children exposed to the same levels of gases as adults may receive a larger dose because they have greater lung surface area/body weight ratios and higher minute volumes/weight ratios. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

146. Children may be more vulnerable to ______than adults because of the smaller diameter of their airways. In addition, they may be exposed to higher levels than adults in the same location because of their short stature and the higher levels of chlorine found nearer to the ground. A. Corrosive agents D. Sodium and calcium hypochlorite B. Residual disinfectant E. Household bleach C. Higher levels of chlorine F. None of the Above

Skin/Eye Contact 147. Direct contact with ______causes severe chemical burns, leading to cell death and ulceration. Because of their relatively larger surface area/weight ratio, children are more vulnerable to toxicants affecting the skin. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

Ingestion 148. Ingestion of ______causes vomiting and corrosive injury to the gastrointestinal tract. Household bleaches (3 to 6% sodium hypochlorite) usually cause esophageal irritation, but rarely cause strictures or serious injury such as perforation. A. Hypochlorite solutions D. Sodium and calcium hypochlorite B. Residual disinfectant E. Household lime C. Higher levels of chlorine F. None of the Above

149. ______may contain higher concentrations of sodium hypochlorite and are more likely to cause serious injury. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

150. Metabolic acidosis is rare, but has been reported following the ingestion of ______. Pulmonary complications resulting from aspiration may also be seen after ingestion. A. Hypochlorous Acid (HOCl) D. Sodium and calcium B. Residual disinfectant E. Household bleach C. Higher levels of chlorine F. None of the Above

Sources/Uses 151. ______are manufactured by the chlorination of sodium hydroxide or lime. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Sodium and calcium hypochlorite F. None of the Above

152. ______are used primarily as oxidizing and bleaching agents or disinfectants. They are components of commercial bleaches, cleaning solutions, and disinfectants for drinking water and waste water purification systems and swimming pools. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Sodium and calcium hypochlorite F. None of the Above

Sodium Hypochlorite as a Disinfectant has the Following Advantages: 153. It can be easily stored and transported when it is produced on-site. Dosage is simple; transport and storage of ______are safe. 30 Modern Disinfection 9/1/2016 Assignment A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

154. ______is as effective as chlorine gas for disinfection. Sodium hypochlorite produces residual disinfectant. A. Sodium hypochlorite D. Calcium B. Residual disinfectant E. Household lime C. Hypochlorous Acid (HOCl) F. None of the Above

Disadvantages 155. ______is a dangerous and corrosive substance. While working with sodium hypochlorite, safety measures have to be taken to protect workers and the environment. A. Sodium hypochlorite D. Calcium B. Residual disinfectant E. Household lime C. Hypochlorous Acid (HOCl) F. None of the Above

156. Sodium hypochlorite should not come in contact with______, because that will cause it to disintegrate. Both sodium hypochlorite and chlorine do not deactivate Giardia Lambia and Cryptosporidium. A. Air D. Calcium B. Residual disinfectant E. Household lime C. Hypochlorous Acid (HOCl) F. None of the Above

157. The regulation for sodium hypochlorite is the same as the regulation considering chlorine. Household bleaches usually contain sodium hypochlorite in a 3% to 6% solution. Some sodium hydroxide (lye) is added to keep the pH high to avoid decomposition. If the solution is made more acidic, sodium hypochlorite will dissociate, producing chlorine gas and oxygen. It is made by bubbling ______through a solution of sodium hydroxide. In the environment, it breaks down into water, oxygen, and table salt. A. Sodium hypochlorite D. Sodium hydroxide or lime B. Chlorine gas E. Hypochlorite solutions, powder, or concentrated vapor C. Commercial bleach(es) F. None of the Above

Calcium Hypochlorite Section 158. There are two forms of ______: powder and tablets. Tablets range in size from 5 mg about the size of an Aspirin to 3 inch tablets. A. Calcium hypochlorite D. Chlorine B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

159. ______is generally available as a white powder, pellets, or flat plates; sodium hypochlorite is usually a greenish yellow, aqueous solution. Although not flammable, they may react explosively. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. An oxidizer E. Calcium hypochlorite C. Solid chlorine F. None of the Above

31 Modern Disinfection 9/1/2016 Assignment 160. ______decomposes in water to release chlorine and oxygen; sodium hypochlorite solutions can react with acids or ammonia to release chlorine or chloramine. Odor may not provide an adequate warning of hazardous concentrations. A. Calcium hypochlorite D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

Toxic 161. Both hypochlorites are toxic by the oral and dermal routes and can react to release chlorine or ______which can be inhaled. The toxic effects of sodium and calcium hypochlorite are primarily due to the corrosive properties of the hypochlorite moiety. Systemic toxicity is rare, but metabolic acidosis may occur after ingestion. A. Chlorine tablet(s) D. Sodium hypochlorite B. An oxidizer E. Hypochlorite ion C. Chloramine F. None of the Above

Description 162. ______stands alone as the safest form of chlorine disinfection. Requiring only minimal safety equipment for handling, users can breathe easy knowing our tablets are safe for both people and the environment. The elimination of costly scrubbers, containment, or hazard response capability, guarantees lower initial costs and reduced operating expense. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. An oxidizer E. Calcium hypochlorite C. Solid chlorine F. None of the Above

163. ______is generally available as a white powder, pellets, or flat plates. It decomposes readily in water or when heated, releasing oxygen and chlorine. It has a strong chlorine odor, but odor may not provide an adequate warning of hazardous concentrations. A. Calcium hypochlorite D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

164. ______is not flammable, but it acts as an oxidizer with combustible material and may react explosively with ammonia, amines, or organic sulfides. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. An oxidizer E. Calcium hypochlorite C. Solid chlorine F. None of the Above

165. Calcium hypochlorite should be stored in a dry, well-ventilated area at a temperature below 120ºF (50ºC) separated from acids, ammonia, amines, and______. A. Calcium hypochlorite D. Other chlorinating or oxidizing agents B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

Accuracy 166. Because of their stability, chlorine tablets are an accurate dose, always yielding the stated level of available chlorine in water or very slightly over, never under. ______strengths vary so widely and are mostly unknown (the container usually says "less than 5%") that it is impossible to make up accurate in-use solutions without access to laboratory equipment. A. Chlorine tablet(s) D. Sodium and calcium hypochlorite B. Liquid chlorine E. Calcium hypochlorite C. Solid chlorine F. None of the Above

32 Modern Disinfection 9/1/2016 Assignment Effectiveness 167. Both chlorine tablets and liquid Sodium hypochlorite produce Hypochlorous Acid (HOCl) and______. It has been postulated by Ortenzio and Stuart in 1959 and again by Trueman in 1971 that Hypochlorous Acid is the predominantly active species whilst Hypochlorite ion has little activity due to its negative charge impeding penetration of the cell wall and membrane. A. Calcium hypochlorite D. Hypochlorite ion (OCl-) in solution B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

168. The ratio of Hypochlorous Acid to ______increases with acidity. Chlorine tablets have a pH of 6.7 and liquid hypochlorite a pH of between 9 and 12. Ergo; tablets have a greater disinfection capacity and are less prone to inactivation due to soiling. A. Calcium hypochlorite D. Hypochlorite ion B. Hypochlorous Acid (HOCl) E. Hypochlorite C. Oxygen and chlorine F. None of the Above

Safety 169. Chlorine tablets in dry form will not leak or splash and do not damage clothing. ______can affect eyes, skin and mucous membranes; it is easily splashed and rots clothing. A. Chlorine tablet(s) D. Sodium dichloroisocyanurate (NaDCC) B. Hypochlorite E. Liquid chlorine C. Chloramine F. None of the Above

Corrosion 170. ______are much less corrosive than liquid chlorine, which is highly corrosive to most metals A. Calcium hypochlorite D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

Comparison 171. The final very important comparison to be made between ______and Sodium dichloroisocyanurate (NaDCC) is their neutralization by organic matter. A. Chlorine tablet(s) D. Sodium hypochlorite (NaOCL) B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

172. However, the degree of neutralization of NaOCL disinfectant is much greater than that of NaDCC disinfectant and the disparity increases with the concentration of serum. Hence, where there is a high concentration of organic material present, NaDCC will be very much more effective than______. A. Calcium hypochlorite D. NaOCL B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

Health Effects 173. Hypochlorite powder, solutions, and vapor are irritating and corrosive to the eyes, skin, and respiratory tract. Ingestion and skin contact produces injury to any exposed tissues. Exposure to gases released from ______may cause burning of the eyes, nose, and throat; cough as well as constriction and edema of the airway and lungs can occur. A. Hypochlorite D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

33 Modern Disinfection 9/1/2016 Assignment 174. ______produces tissue injury by liquefaction necrosis. Systemic toxicity is rare, but metabolic acidosis may occur after ingestion. A. Chlorine tablet(s) D. Sodium dichloroisocyanurate (NaDCC) B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

Acute Exposure 175. The toxic effects of ______are primarily due to the corrosive properties of the hypochlorite moiety. A. Calcium hypochlorite D. Sodium and calcium hypochlorite B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

176. ______causes tissue damage by liquefaction necrosis. Fats and proteins are saponified, resulting in deep tissue destruction. Further injury is caused by thrombosis of blood vessels. Injury increases with hypochlorite concentration and pH. Symptoms may be apparent immediately or delayed for a few hours. A. Chlorine tablet(s) D. Sodium dichloroisocyanurate (NaDCC) B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

177. Calcium hypochlorite decomposes in water releasing______. A. Chlorine gas D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Oxygen and chlorine F. None of the Above

Sodium Hypochlorite Solutions 178. Sodium hypochlorite solutions liberate the ______if mixed with acid or ammonia (this can occur when bleach is mixed with another cleaning product). Thus, exposure to hypochlorite may involve exposure to these gases. A. Chlorine tablet(s) D. Toxic gases chlorine or chloramine B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

Potential Sequelae 179. Exposure to toxic gases generated from ______can lead to reactive airways dysfunction syndrome (RADS), a chemical irritant-induced type of asthma. Chronic complications following ingestion of hypochlorite include esophageal obstruction, pyloric stenosis, squamous cell carcinoma of the esophagus, and vocal cord paralysis with consequent airway obstruction. A. Calcium hypochlorite D. Chlorine tablet(s) B. Hypochlorous Acid (HOCl) E. Hypochlorite ion C. Hypochlorite solutions F. None of the Above

Chronic Exposure 180. Chronic dermal exposure to ______can cause dermal irritation. A. Chlorine tablet(s) D. Sodium dichloroisocyanurate (NaDCC) B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

Chlorine-Based Disinfectants Chloramines 181. This process involves the addition of ammonia and chlorine compounds to a water filtration plant. When properly controlled, the mixture forms______. They are commonly used to maintain a residual in the distribution system following treatment with a stronger disinfectant, such as free chlorine. A. Free chlorine D. Chloramines B. Trichloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above Chloramine Disadvantages 182. Produces disinfection by-products (DBPs), including nitrogen-based compounds and chloral hydrate, which may be regulated as a DBP in the future. There is limited information on the toxicity of 34 Modern Disinfection 9/1/2016 Assignment chloramine DBPs. In an analysis of the health effects of alternatives, Bull states that "there is little information on which to base an estimate of the health hazard that ______poses." A. Free chlorine D. Monochloramine and dichloramine B. Chloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

183. Presents problems to individuals on dialysis machines. ______residuals in tap water can pass through membranes in dialysis machines and directly induce oxidant damage to red blood cells. A. Free chlorine D. Monochloramine B. Chloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

Chloramine Section 184. ______are formed in the pH range of 4.5 to 8.5, however, monochloramine is most common when the pH is above 8. When the pH of the water is below 4.5, the most common form of chloramine is trichloramine which produces a very foul odor. A. Free chlorine D. Monochloramine and dichloramine B. Chloramine(s) E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

185. ______: NH3 + HOCl -> NH2Cl + H2O A. Free chlorine D. Monochloramine B. Trichloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

186. ______: NH2Cl + 2HOCl -> NHCl2 + 2H2O A. Free chlorine D. Monochloramine B. Trichloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

187. ______: NHCl2 + 3HOCl -> NHCl3 + 3H2O A. Free chlorine D. Monochloramine B. Trichloramine E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

188. ______are an effective disinfectant against bacteria but not against viruses. As a result, it is necessary to add more chlorine to the wastewater to prevent the formation of chloramines and form other stronger forms of disinfectants. A. Free chlorine D. Monochloramine and dichloramine B. Chloramine(s) E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

189. The final step is that additional free chlorine reacts with the chloramine to produce hydrogen ion, water, and ______which will come out of solution. In the case of the monochloramine, the following reaction occurs: 2NH2Cl + HOCl -> N2 + 6HCl + H2O Thus, added free chlorine reduces the concentration of chloramines in the disinfection process. Instead the chlorine that is added is allowed to form the stronger disinfectant, hypochlorus acid. A. Free chlorine D. Nitrogen gas B. Chloramine(s) E. Ammonia and chlorine compounds C. Dichloramine F. None of the Above

35 Modern Disinfection 9/1/2016 Assignment Post Chlorination 190. Post chlorination is almost always done in______, but can be replaced with chlorine dioxide or chloramines. In this stage, chlorine is fed to the drinking water stream which is then sent to the chlorine contact basin to allow the chlorine a long enough detention time to kill all viruses, bacteria, and protozoa that were not removed and rendered inactive in the prior stages of treatment. A. Pressure D. Point of solution application B. This stage E. Water treatment C. Detention time F. None of the Above

191. Drinking water requires a large addition of chlorine because there must be a residual amount of chlorine in the water that will carry through the system until it reaches the tap of the user. After______, the water is retained in a clear well prior to distribution. A. Post chlorination D. Mechanical gas proportioning equipment B. The final step E. After post chlorination C. Manual chlorine feed systems F. None of the Above

Chlorination Equipment Requirement Section 192. For all water treatment facilities, chlorine gas under pressure shall not be permitted outside the chlorine room. A chlorine room is where chlorine gas cylinders and/or ton containers are______. A. Under pressure D. At the point of solution application B. In this stage E. Dosing enough chlorine C. Stored F. None of the Above

193. ______shall also be located inside the chlorine room. The chlorinator, which is the mechanical gas proportioning equipment, may or may not be located inside the chlorine room. A. Gas vacuum line D. Mechanical gas proportioning equipment B. Vacuum regulators E. Injectors C. Manual chlorine feed systems F. None of the Above

194. For new and upgraded facilities, from the chlorine room, chlorine gas vacuum lines should be run as close to the point of solution application as possible. ______should be located to minimize the length of pressurized chlorine solution lines. A. Gas vacuum line D. Mechanical gas proportioning equipment B. Vacuum regulators E. Injectors C. Manual chlorine feed systems F. None of the Above

195. ______shall be included in the gas vacuum line between the vacuum regulator(s) and the chlorinator(s) to ensure that pressurized chlorine gas does not enter the gas vacuum lines leaving the chlorine room. A. Gas vacuum line D. Mechanical gas proportioning equipment B. A gas pressure relief system E. Post chlorination C. Manual chlorine feed systems F. None of the Above

196. The gas pressure relief system shall vent pressurized gas to the atmosphere at a location that is not hazardous to plant personnel; vent line should be run in such a manner that moisture collecting traps are avoided. ______shall have positive shutdown in the event of a break in the downstream vacuum lines. A. Gas vacuum line D. Mechanical gas proportioning equipment B. A gas pressure relief system E. The vacuum regulating valve(s) C. Manual chlorine feed systems F. None of the Above

197. As an alternative to chlorine gas, it is permissible to use hypochlorite with positive displacement pumping. Anti-siphon valves shall be incorporated in the ______or in the discharge piping. A. Gas vacuum line D. Mechanical gas proportioning equipment B. A gas pressure relief system E. Pump heads C. Manual chlorine feed systems F. None of the Above Capacity 198. ______shall have the capacity to dose enough chlorine to overcome the demand and maintain the required concentration of the "free" or "combined" chlorine. 36 Modern Disinfection 9/1/2016 Assignment A. The chlorinator D. Automatic proportional controlled B. Constant flow rate(s) E. Constant pre-established dosage C. Uninterrupted chlorination F. None of the Above

Methods of Control 199. ______shall be automatic proportional controlled, automatic residual controlled, or compound loop controlled. A. A chlorine feed system D. Automatic proportional controlled B. Constant flow rate(s) E. Constant pre-established dosage C. Uninterrupted chlorination F. None of the Above

200. In the ______, the equipment adjusts the chlorine feed rate automatically in accordance with the flow changes to provide a constant pre-established dosage for all rates of flow. In the automatic residual controlled system, the chlorine feeder is used in conjunction with a chlorine residual analyzer which controls the feed rate of the chlorine feeders to maintain a particular residual in the treated water. A. Manual chlorine feed systems D. Automatic proportional controlled B. Constant flow rate(s) E. Constant pre-established dosage C. Uninterrupted chlorination F. None of the Above

201. In the______, the feed rate of the chlorinator is controlled by a flow proportional signal and a residual analyzer signal to maintain particular chlorine residual in the water. A. Gas vacuum line D. Mechanical gas proportioning equipment B. Compound loop control system E. After post chlorination C. Manual chlorine feed systems F. None of the Above

202. ______may be installed for groundwater systems with constant flow rates. A. Manual chlorine feed systems D. Automatic proportional controlled B. Constant flow rate(s) E. Constant pre-established dosage C. Uninterrupted chlorination F. None of the Above

Standby Provision 203. As a safeguard against______, standby chlorination equipment having the capacity to replace the largest unit shall be provided. A. Flow change(s) D. Malfunction and/or shut-down B. Constant flow rate(s) E. Constant pre-established dosage C. Uninterrupted chlorination F. None of the Above

204. For uninterrupted chlorination, ______shall be equipped with an automatic changeover system. In addition, spare parts shall be available for all chlorinators. A. Flow change(s) D. Automatic proportional controlled B. Constant flow rate(s) E. Constant pre-established dosage C. Gas chlorinators F. None of the Above

Weigh Scales 205. Scales for weighing cylinders shall be provided at all plants using chlorine gas to ______of total daily weight of chlorine used. At large plants, scales of the recording and indicating type are recommended. As a minimum, a platform scale shall be provided. Scales shall be of corrosion-resistant material. A. Permit an accurate reading D. Automatic chlorine leak detection B. Corrosion resistant E. Chlorine room ventilation system C. Securely positioned F. None of the Above

Securing Cylinders 206. ______shall be securely positioned to safeguard against movement. Tag the cylinder “empty” and store upright and chained. Ton containers may not be stacked. A. The chlorinator D. The chlorine gas leakage B. The facility E. Chlorine leak detection equipment C. All chlorine cylinders F. None of the Above 37 Modern Disinfection 9/1/2016 Assignment Chlorine Leak Detection 207. ______and related alarm equipment shall be installed at all water treatment plants using chlorine gas. Leak detection shall be provided for the chlorine rooms. A. Caustic soda solution reaction tanks D. Automatic chlorine leak detection B. Corrosion resistant E. Chlorine room ventilation system C. Securely positioned F. None of the Above

208. ______should be connected to a remote audible and visual alarm system and checked on a regular basis to verify proper operation. A. The chlorinator D. The chlorine gas leakage B. The facility E. Chlorine leak detection equipment C. All chlorine cylinders F. None of the Above

209. ______shall not automatically activate the chlorine room ventilation system in such a manner as to discharge chlorine gas. A. Caustic soda solution reaction tanks D. Automatic chlorine leak detection B. Corrosion resistant E. Chlorine room ventilation system C. Leak detection equipment F. None of the Above

210. During an emergency, if ______is unoccupied, the chlorine gas leakage shall be contained within the chlorine room itself in order to facilitate a proper method of clean-up. A. The chlorinator D. The chlorine room B. The facility E. Chlorine leak detection equipment C. All chlorine cylinders F. None of the Above

211. Consideration should also be given to the provision of ______for absorbing the contents of leaking one-ton cylinders where such cylinders are in use. A. Caustic soda solution reaction tanks D. Automatic chlorine leak detection B. Corrosion resistant E. Chlorine room ventilation system C. Securely positioned F. None of the Above

212. ______may not be required for very small chlorine rooms with an exterior door (e.g., floor area less than 3m2). A. Caustic soda solution reaction tanks D. Automatic chlorine leak detection B. Chlorine leak detection equipment E. Chlorine room ventilation system C. Securely positioned F. None of the Above

213. You can use a spray solution of ammonia or a rag soaked with ammonia to detect a small Cl 2 leak. If there is a leak, the ammonia will create a white colored smoke,______. A. Oxygen and nascent oxygen D. Ammonium chloride B. Air or oxygen E. Light blue gas C. Chloramine(s) F. None of the Above

38 Modern Disinfection 9/1/2016 Assignment Safety Equipment 214. ______shall be provided with personnel safety equipment including the following: Respiratory equipment; safety shower, eyewash, gloves, eye protection; protective clothing; cylinder and/or ton repair kits. A. The chlorinator D. The chlorine gas leakage B. The facility E. Chlorine leak detection equipment C. All chlorine cylinders F. None of the Above

Chlorine Room Design Requirements 215. Where gas chlorination is practiced, the gas cylinders and/or the ton containers up to the vacuum regulators shall be housed in a gas-tight, well illuminated, corrosion resistant and______. A. Mechanically ventilated enclosure D. Automatic chlorine leak detection B. Corrosion resistant E. Chlorine room ventilation system C. Securely positioned F. None of the Above

216. The chlorinator may or may not be located inside______. The chlorine room shall be located at the ground floor level. A. The chlorinator D. The chlorine room B. The facility E. Chlorine leak detection equipment C. All chlorine cylinders F. None of the Above

Ventilation 217. ______shall have entirely separate exhaust ventilation systems capable of delivering one (1) complete air change per minute during periods of chlorine room occupancy only. A. Gas chlorine rooms D. Automatic chlorine leak detection B. The chlorine room E. Chlorine room ventilation system C. The room F. None of the Above

218. ______from the room shall be 150 mm above the floor and the point of discharge located to preclude contamination of air inlets to buildings or areas used by people. The vents to the outside shall have insect screens. A. Gas chlorine room D. Automatic chlorine leak detection B. The chlorine room E. Chlorine room ventilation system C. The air outlet F. None of the Above

219. Air inlets should be louvered near______, the air being of such temperature as to not adversely affect the chlorination equipment. A. The ceiling D. Automatic chlorine leak detection B. The chlorine room E. Chlorine room ventilation system C. The room F. None of the Above

220. Separate switches for fans and lights shall be outside the room at all entrance or viewing points, and a clear wire-reinforced glass window shall be installed in such a manner as to allow the operator to inspect from the outside of ______. A. Gas chlorine room D. Automatic chlorine leak detection B. The chlorine room E. Chlorine room ventilation system C. The room F. None of the Above

Heating 221. ______shall have separate heating systems, if a forced air system is used to heat the building. The hot water heating system for the building will negate the need for a separate heating system for the chlorine room. The heat should be controlled at approximately 15oC. A. Gas chlorine room D. Automatic chlorine leak detection B. Chlorine rooms E. Chlorine room ventilation system C. The room F. None of the Above

222. Cylinders or containers shall be protected to ensure that the chlorine maintains its gaseous state when entering______. A. Gas chlorine room D. Automatic chlorine leak detection 39 Modern Disinfection 9/1/2016 Assignment B. The chlorine room E. The chlorinator C. The room F. None of the Above

Access 223. All access to the chlorine room shall only be from the exterior of the building. Visual inspection of the chlorination equipment from inside may be provided by the installation of glass window(s) in the walls of the chlorine room. Windows should be at least 0.20 m2 in area, and be made of clear wire reinforced glass. There should also be a ______on the inside of the chlorine room door for emergency exit. A. A panic button D. Chlorine gas storage room B. The chlorine room E. Chlorine cylinder storage room C. 'Panic bar' F. None of the Above

Storage of Chlorine Cylinders 224. If necessary, ______may be provided to simply store the chlorine gas cylinders, with no connection to the line. The chlorine cylinder storage room shall have access either to the chlorine room or from the plant exterior, and arranged to prevent the uncontrolled release of spilled gas. A. Cylinders or containers D. Uncontrolled release of spilled gas B. The outside of the room E. Air inlets C. A separate storage room F. None of the Above

225. ______shall have provision for ventilation at thirty air changes per hour. Viewing glass windows and a panic button on the inside of the door should also be provided. A. A panic button D. The chlorine gas storage room B. The chlorine room E. The chlorine cylinder storage room C. Scrubber(s) F. None of the Above

226. In very large facilities, entry into the ______may be through a vestibule from outside. A. Cylinders or containers D. Uncontrolled release of spilled gas B. The outside of the room E. Air inlets C. Chlorine rooms F. None of the Above

Scrubbers 227. For facilities located within residential or densely populated areas, consideration shall be given to provide scrubbers for______. A. A panic button D. The chlorine gas storage room B. The chlorine room E. The chlorine cylinder storage room C. Scrubber(s) F. None of the Above

Chlorine Demand 228. Chlorine combines with a wide variety of materials. These side reactions complicate the use of chlorine for disinfecting purposes. Their ______must be satisfied before chlorine becomes available to accomplish disinfection. A. Combined residual D. Total chlorine B. Free chlorine residual E. Free chlorine C. Demand for chlorine F. None of the Above

229. The amount of chlorine required to react on various water impurities before a residual is obtained. Also, it means the amount of chlorine required to produce a ______of 0.1 mg/l after a contact time of fifteen minutes as measured by iodmetic method of a sample at a temperature of twenty degrees in conformance with Standard methods. A. Combined residual D. Total chlorine B. Free chlorine residual E. Free chlorine C. Chlorine Demand F. None of the Above

40 Modern Disinfection 9/1/2016 Assignment Chlorine Health Hazard Section Signs and Symptoms of Exposure 230. Acute exposure: Acute exposure to low levels of chlorine results in eye, nose, and throat irritation, sneezing, ______, general excitement, and restlessness. A. Rambling D. Chronic exposure B. Laughing E. Immediate attention after inhalation C. Excessive salivation F. None of the Above

231. Higher concentrations causes difficulty in breathing, ______, nausea, vomiting, cyanosis, dizziness, headache, choking, laryngeal edema, acute tracheobronchitis, chemical pneumonia. Contact with the liquid can result in frostbite burns of the skin and eyes [Genium 1992]. A. Violent coughing D. Chronic exposure B. Laughing E. Immediate attention after inhalation C. Excessive salivation F. None of the Above

232. Chronic exposure: Chronic exposure to low levels of chlorine gas can result in a dermatitis known as chloracne, tooth enamel corrosion, coughing, ______, sore throat, hemoptysis and increased susceptibility to tuberculosis [Genium 1992]. A. Violent coughing D. Severe chest pain B. Laughing E. Immediate attention after inhalation C. Excessive salivation F. None of the Above

Inhalation 233. Immediately remove the exposed person upwind from the contaminated area and contact the poison control center. Inhalation can cause coughing, sneezing, shortness of breath, sensation of tightness in the chest, as well as severe restlessness or______. A. Chlorine gas toxicity D. Anxiety, nausea, and vomiting B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

234. The nose and throat may become irritated; a stinging and ______may be experienced. Immediate fatalities can occur as a result of suffocation. Delayed fatalities can occur as a result of pulmonary edema (fluid in the lungs). For this reason, rest and immediate attention after inhalation is important. A. Liquid and concentrated gas D. Chronic exposure to low levels of chlorine gas B. Pour a gentle stream of warm water E. Burning sensation C. General excitement F. None of the Above

235. Persons with known cardiovascular or lung problems should not risk______. If breathing has stopped, give artificial respiration; if breathing is difficult, give oxygen if equipment and trained personnel are available. If exposed person is breathing, place in a comfortable position and keep person warm and at rest until medical assistance becomes available. A. Chlorine exposure D. Chronic exposure to low levels of chlorine gas B. Plasma exudation E. Inhalation C. General excitement F. None of the Above

Eye/Skin Contact 236. Liquid and concentrated gas could produce severe______. A. Burns and injury on contact D. Chronic exposure to low levels of chlorine gas B. Plasma exudation E. Inhalation C. General excitement F. None of the Above 41 Modern Disinfection 9/1/2016 Assignment 42 Modern Disinfection 9/1/2016 Assignment Eye 237. Pour a gentle stream of ______through the affected eye for at least 15 minutes. Contact the poison control center, emergency room or physician right away as further treatment will be necessary. A. Liquid D. Salt water B. Warm water E. Cold water C. Milk F. None of the Above

Skin 238. Run ______over the affected area for 15 minutes. A mild soap may be used if available. Contact the poison control center, emergency room or physician right away as further treatment will be necessary. A. A gentle stream of water D. Salt water B. Warm water E. Cold water C. Milk F. None of the Above

Chronic 239. Repeated exposures can result in a loss of ability to detect the odor of chlorine. Long term exposures may cause damage to teeth and inflammation or______. A. Chlorine gas toxicity D. Ulceration of the nasal passages B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

Pre-hospital Management 240. Rescue personnel are at low risk of ______from victims who have been exposed only to gases released from hypochlorite solutions. However, clothing or skin soaked with industrial-strength bleach or similar solutions may be corrosive to rescuers and may release harmful gases. A. Chlorine gas toxicity D. Secondary contamination B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

241. Ingestion of hypochlorite solutions may cause pain in the mouth or throat, dysphagia, stridor, drooling, odynophagia, and vomiting. Hypochlorite irritates the skin and can cause ______. A. Chlorine gas toxicity D. Burning pain, inflammation, and blisters B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

242. Acute exposure to gases released from hypochlorite solutions can cause coughing, eye and nose irritation, ______, and a burning sensation in the chest. Airway constriction and noncardiogenic pulmonary edema may also occur. There is no specific antidote for hypochlorite poisoning. Treatment is supportive. A. Lacrimation D. Burning pain, inflammation, and blisters B. Plasma exudation E. Noncardiogenic pulmonary edema C. Pulmonary edema F. None of the Above

Hot Zone 243. Rescuers should be trained and appropriately attired before entering the______. If the proper equipment is not available, or if rescuers have not been trained in its use, assistance should be obtained from a local or regional HAZMAT team or other properly equipped response organization. A. Support Zone D. Decontamination area B. Warm zone E. Hot Zone C. Chemical-protective clothing area F. None of the Above 43 Modern Disinfection 9/1/2016 Assignment 44 Modern Disinfection 9/1/2016 Assignment Rescuer Protection 244. ______is irritating to the skin and eyes and in some cases may release toxic gases. A. Chlorine tablet(s) D. Sodium dichloroisocyanurate (NaDCC) B. Hypochlorite E. Hypochlorous Acid C. Chloramine F. None of the Above

245. Respiratory Protection: Positive-pressure, self-contained breathing apparatus (SCBA) is recommended in response to situations that involve exposure to potentially unsafe levels of ______. A. Chlorine tablet(s) D. Solid hypochlorite or concentrated solutions B. Hypochlorite E. Hypochlorous Acid C. Chlorine gas F. None of the Above

246. Skin Protection: Chemical-protective clothing should be worn due to the risk of skin irritation and burns from direct contact with ______. A. Chlorine tablet(s) D. Solid hypochlorite or concentrated solutions B. Hypochlorite E. Hypochlorous Acid C. Chlorine gas F. None of the Above

ABC Reminders 247. Quickly establish a ______, ensure adequate respiration and pulse. If trauma is suspected, maintain cervical immobilization manually and apply a cervical collar and a backboard when feasible. A. Support Zone D. Delay decontamination B. Patient airway E. Hot Zone to the Decontamination Zone C. Chemical-protective clothing F. None of the Above

Victim Removal 248. If victims can walk, lead them out of the ______. Victims who are unable to walk may be removed on backboards or gurneys; if these are not available, carefully carry or drag victims to safety. Consider appropriate management in victims with chemically-induced acute disorders, especially children who may suffer separation anxiety if separated from a parent or other adult. A. Decontamination area D. Chemically contaminated zone B. Hot Zone E. Hot Zone to the Decontamination Zone C. Chemical-free zone F. None of the Above

Decontamination Zone 249. Victims exposed only to chlorine gas released by hypochlorite who have no skin or eye irritation do not need decontamination. They may be transferred immediately to the ______. All others require decontamination as described below. A. Support Zone D. Decontamination area B. Patient Zone E. Hot Zone to the Decontamination Zone C. Chemical free zone F. None of the Above

Rescuer Protection 250. If exposure levels are determined to be safe, decontamination may be conducted by personnel wearing a lower level of protection than that worn in the ______. A. Support Zone D. Decontamination area B. Patient Zone E. Hot Zone C. Chemical free zone F. None of the Above

45 Modern Disinfection 9/1/2016 Assignment ABC Reminders 251. Quickly establish a ______, ensure adequate respiration and pulse. Stabilize the cervical spine with a collar and a backboard if trauma is suspected. Administer supplemental oxygen as required. Assist ventilation with a bag-valve-mask device if necessary. A. Support Zone D. Decontamination zone B. Patient airway E. Hot Zone C. Chemical-protective clothing dressing area F. None of the Above

Basic Decontamination 252. ______is critical. Victims who are able may assist with their own decontamination. Remove and double-bag contaminated clothing and personal belongings. Flush exposed skin and hair with copious amounts of plain tepid water. Use caution to avoid hypothermia when decontaminating victims, particularly children or the elderly. Use blankets or warmers after decontamination as needed. A. Decontamination D. Rapid decontamination B. Hot Zone E. Hot Zone to the Decontamination Zone C. Chemical-protective clothing F. None of the Above

In Cases of Ingestion, Do Not Induce Emesis or Offer Activated Charcoal. 253. Victims who are conscious and able to swallow should be given 4 to 8 ounces of ______; if the victim is symptomatic, delay decontamination until other emergency measures have been instituted. Dilultants are contraindicated in the presence of shock, upper airway obstruction, or in the presence of perforation. A. Liquid D. Water or milk B. Warm water E. Cold water C. Milk F. None of the Above

254. Consider appropriate ______of chemically contaminated children at the exposure site. Provide reassurance to the child during decontamination, especially if separation from a parent occurs. A. Decontamination D. Management B. Hot Zone E. Hot Zone to the Decontamination Zone C. Chemical-protective clothing F. None of the Above

Chlorine Dioxide Section 255. Chlorine dioxide is generated on-site at water treatment facilities. The popularity of ______as a water disinfectant increased in the 1970s when it was discovered that it did not promote THM formation. A. THM precursor(s) D. Sodium chlorate (NaClO3) and sulfuric acid B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

256. ______, long used in the paper industry, has been an acceptable and effective alternative to chlorination in cooling systems. A. Chlorine dioxide (ClO2) D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

257. Chlorine dioxide is a yellow-green gas with an irritating odor not unlike ______. It cannot be compressed and shipped in a container, so it must be generated on site. A. THM precursor(s) D. Sodium chlorate (NaClO3) and sulfuric acid B. Chlorine E. THM formation C. Chlorine dioxide F. None of the Above

46 Modern Disinfection 9/1/2016 Assignment 258. There are three proven methods of efficiently generating chlorine dioxide. The most common is the chlorine/chlorite or "one pump" method. ClO2 generation uses ______and chlorine gas. A. Chlorine dioxide (ClO2) D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

259. Chlorine gas is educted into a motive water stream in a ClO 2 generator forming ______Sodium chlorite is pumped into the stream and allowed to react in a generating column to produce ClO2. A. THM precursor(s) D. Sodium chlorate (NaClO3) and sulfuric acid B. HOCl and HCl E. THM formation C. Chlorine dioxide F. None of the Above

260. A second, common method of generation uses ______in place of chlorine gas. Also referred to as the "three pump" method of generation, this method is valuable to a facility that wants to eliminate gaseous chlorine. A. Chlorine dioxide (ClO2) D. NaOCl and HCl B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

261. A third, more recent method of generation uses ______and sulfuric acid. This differs from the other two methods in that ClO2 is generated in a vacuum and is then educted into the motive water stream. A. THM precursor(s) D. Sodium chlorate (NaClO3) B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

262. Chlorine dioxide holds many advantages over chlorine in cooling water systems. ______is considerably more selective than chlorine in the presence of various compounds, which allows it to be more effective in contaminated systems. A. ClO2 D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

263. Under certain conditions ClO2 may, in fact, be two-and-one-half times more reactive than chlorine. Under efficient ClO2 generation, THMs are not formed and ______are reduced. In one application, THM formation was reduced from 34 m g/l to 1 m g/l using ClO2. A. THM precursor(s) D. Sodium chlorate (NaClO3) and sulfuric acid B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

264. ______does not hydrolyze in water as does chlorine and there is no dissociation of ClO2. It remains fully active in a pH range far broader than chlorine or sodium hypochlorite. A. Chlorine dioxide D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

265. Since ClO2 remains a gas in water, it does not have the corrosive tendencies of chlorine gas. Its selectivity generally allows for lower dosages compared to chlorine, limiting the amount of aggressive ______available to attack passivated metal surfaces. Finally, ClO2 is much less aggressive to traditional corrosion inhibitors. A. THM precursor(s) D. Cl- B. Chlorine gas E. THM formation 47 Modern Disinfection 9/1/2016 Assignment C. Chlorine dioxide F. None of the Above

48 Modern Disinfection 9/1/2016 Assignment 266. Hypochlorous acid, whether formed from the dissolution of chlorine gas or sodium hypochlorite in water, has satisfactorily controlled microorganisms in cooling water systems. However, dissolution does yield a mineral acid or caustic soda which may adversely affect______, inhibitor passivation layers or metal surfaces. A. System pH D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

267. ______is heavily pH-dependent, because as system pH increases, there is a correspondingly rapid decrease in the concentration of the biocidally active species. It is also a non-specific oxidant which readily reacts with various organic and inorganic compounds that may be present in a cooling water system. Some of these reactions tend to yield undesirable by-products which are regulated or may be regulated in the future. A. Chlorine dioxide (ClO2) D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Sodium chlorate (NaClO3) and sulfuric acid C. Hypochlorous acid F. None of the Above

268. The effects of ______on hypochlorous acid and its reactivity with a variety of compounds both combine to vastly diminish its effectiveness in contaminated, high-pH cooling water systems. Conversely, chlorine dioxide remains completely pH-independent in the range where recirculating and once-through cooling systems are typically operated. A. THM precursor(s) D. pH B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

269. Since ______is a dissolved gas in water, there is no mineral acid or caustic soda formation as happens when using HOCl. Chlorine dioxide tends to be much less, if not totally non-reactive, with many organic and inorganic compounds. A. ClO2 D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

Water Disinfection Methods Review 270. Disinfection is an important step in ensuring that water is safe to drink. Water systems add ______to destroy microorganisms that can cause disease in humans. A. Alkalinity and Ph D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Disinfectants C. Hypochlorous acid F. None of the Above

271. The Surface Water Treatment Rule requires public water systems to disinfect water obtained from surface water supplies or groundwater sources under the influence of______. A. Alkalinity and Ph D. Oxidizing and biocidal properties B. Surface water E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

272. Primary methods of disinfection are chlorination, chloramines, zone, and ultraviolet light. Other disinfection methods include chlorine dioxide,______. A. Alkalinity and pH D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Potassium permanganate, and nanofiltration C. Hypochlorous acid F. None of the Above

49 Modern Disinfection 9/1/2016 Assignment 273. Since certain forms of chlorine react with ______naturally present in many water sources to form harmful chemical by-products, the U.S. Environmental Protection Agency has proposed maximum levels for these contaminants. A. Alkalinity and pH D. Oxidizing and biocidal properties B. Organic material E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

Physical Methods 274. Formation of ______in water and wastewater effluent treated with chlorine has prompted research to seek alternative disinfecting methods that would minimize environmental and public health impacts. The technology, based on nonchemical methods, is undergoing rapid development. A. Alkalinity D. Oxidizing and biocidal properties B. Mutagenic and carcinogenic agents E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

Chemical Methods 275. Chemical methods depend mostly on selected chemicals with oxidizing and biocidal properties. Their practical applications range from removing ______to disinfecting water supplies, wastewater treatment effluent, or industrial waters. A. Alkalinity and pH D. Oxidizing and biocidal properties B. Undesirable constituents E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

276. The most commonly used chemicals include______, chlorine and some of its compounds, potassium permanganate, and hydrogen peroxide. A. Chlorine dioxide (ClO2) D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Ozone C. Hypochlorous acid F. None of the Above

277. There is some evidence that it forms smaller amounts of ______when employed to treat polluted waters or wastewater effluent than either chlorine or chlorine dioxide. However, its potential for producing other equally toxic substances is still not clearly defined (Glaze 1987). A. Alkalinity D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

278. Ozonation has become popular in North America partly because of its superiority over chlorination. It enhances the ______despite its inherent weakness in leaving practically no residual in the distribution system. A. Effectiveness and cost D. Coagulation process B. Protecting public health E. Superiority over chlorination C. Mode of disinfection F. None of the Above

279. Interhalogen compounds, formed from two different halogens, resemble their parent substances in properties and germicidal characteristics. The interhalogens BrCl, ICl, and IBr have recently been investigated as possible alternative disinfectants for water and wastewater effluent. Added to water, they rapidly hydrolyze to the corresponding hypohalous acids, which are stronger oxidants and disinfectants than hypochlorous acid. For instance, BrCl is hydrolyzed to ______A. HCl and HOBr D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

50 Modern Disinfection 9/1/2016 Assignment 280. However, their improved germicidal activity is counterbalanced by the formation of haloforms. They react with humates in water or wastewater effluent by the haloform reaction (HOBr, for example, reacts with humates yielding bromoform). In this context, hypobromite would be formed in ______by reaction of the natural bromides with hypochlorites in chlorinated wastewater effluent or cooling waters from power plants. A. Seawater D. Chlorinated wastewater effluent B. Protecting public health E. Superiority over chlorination C. Mode of disinfection F. None of the Above

281. Using ______for water disinfection began in the 1950s in Eastern Europe. Although it has been well known for its high oxidative and germicidal activity, its application as a water disinfectant has not gained wide acceptance. A. Alkalinity and pH D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

Chlorination and Dechlorination 282. The use of ______will continue as an integral part of the disinfection process in water and wastewater treatment. This also applies to developing countries, where this mode of disinfection is fairly well established. A. Chlorine and some of its derivatives D. Chlorinated wastewater effluent B. Protecting public health E. Superiority over chlorination C. Disinfection F. None of the Above pH Scale 283. Alkalinity is the capacity of water to neutralize acids. This capacity is caused by the water's content of carbonate, bicarbonate, hydroxide and occasionally borate, silicate and phosphate. pH is an expression of the intensity of the basic or acid condition of a liquid. EPA has a suggested range of 6.5 to 8.5 for pH (called a secondary maximum contaminant level or SMCL). Furthermore, ______are different because water does not have to be strongly basic (high pH) to have a high alkalinity. A. Alkalinity and pH D. Oxidizing and biocidal properties B. Hydrogen peroxide E. Hazardous trihalomethanes (THM) C. Hypochlorous acid F. None of the Above

Disinfection Rule Review 284. In the past 25 years, the Safe Drinking Water Act (SDWA) has been highly effective in protecting public health and has also evolved to respond to new and emerging threats to safe drinking water. Disinfection of drinking water is one of the major public health advances in the 20th century. One hundred years ago, typhoid and cholera epidemics were common through American cities; ______was a major factor in reducing these epidemics. A. Disinfection D. Chlorinated wastewater effluent B. Protecting public health E. Superiority over chlorination C. Mode of disinfection F. None of the Above

285. However, the disinfectants themselves can react with naturally-occurring materials in the water to form unintended byproducts which may pose health risks. In addition, in the past ten years, we have learned that there are specific microbial pathogens, such as______, which can cause illness and is resistant to traditional disinfection practices. A. TTHM and HAA5 D. Disinfection byproducts (DBPs) B. DBP MCLs E. Trihalomethanes and haloacetic acids C. Cryptosporidium F. None of the Above 51 Modern Disinfection 9/1/2016 Assignment 52 Modern Disinfection 9/1/2016 Assignment 286. ______is the most widely used water disinfectant due to its effectiveness and cost. Using chlorine as a drinking water disinfectant has prevented millions of water borne diseases, such as typhoid, cholera, dysentery, and diarrhea. Most states require community water systems to use chlorination. However, research shows that chlorine has side effects. It reacts with organic matter present in water and forms a series of compounds that have been linked to cancer in animals. A. Chlorine D. Sodium hypochlorite B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

These compounds are called disinfection by-products (DBPs). All disinfectants form DBPs in one of two reactions: 287. Chorine and chlorine-based compounds (halogens) react with organics in water causing the chlorine atom to substitute other atoms resulting in______. A. Chlorine D. Halogenated by-products B. Organic sulfide(s) E. HOCl C. Calcium carbonate F. None of the Above

288. Oxidation reactions, where chlorine oxidizes ______present in water. Secondary by-products are also formed when multiple disinfectants are used. A. Carbon D. Chorine and chlorine-based compounds (halogens) B. Surface water E. Secondary by-products C. Compounds F. None of the Above

289. All living organisms have carbon as an essential element in their cells. When trees shed their leaves, they start decomposing and are ultimately broken down by bacteria into______. A. Carbon D. Chorine and chlorine-based compounds (halogens) B. Carbon-containing compounds E. Secondary by-products C. Compounds F. None of the Above

290. The EPA ______requires systems using public water supplies from either surface water or groundwater under the direct influence of surface water to disinfect. A. TTHM and HAA5 Rule D. Disinfection byproducts (DBPs) Rule B. DBP MCLs Rule E. Surface Water Treatment Rule (SWTR) C. A community water system (CWS) F. None of the Above

291. Since some disinfectants produce chemical by-products, the dual objective of disinfection is to provide the required level of organism destruction and remain within the maximum contaminant level (MCL) for the SWTR disinfection set by EPA. At this time, an MCL is set for only ______, and proposed for additional disinfection byproducts. A. TTHM and HAA5 Rule D. Disinfection byproducts (DBPs) Rule B. DBP MCLs Rule E. Total Trihalomethanes C. A community water system (CWS) F. None of the Above

292. The ______rules apply to all community and non-community water systems using a disinfectant such as chlorine, chloramines, ozone and chlorine dioxide. A. TTHM and HAA5 Rule D. Disinfection byproducts (DBPs) Rule B. DBP MCLs Rule E. Disinfectants and Disinfection Byproducts (DBP) C. A community water system (CWS) F. None of the Above 53 Modern Disinfection 9/1/2016 Assignment 293. The Long Term 2 Enhanced Surface Water Treatment Rule (LT2) rule applies to all water systems using ______under the influence of a surface water, as well as groundwater/surface water blends. A. Surface water, groundwater D. Disinfection byproducts (DBPs) Rule B. DBP MCLs Rule E. Total Trihalomethanes C. A community water system (CWS) F. None of the Above

294. ______began in 2006 with the characterization of raw water Cryptosporidium and E. coli levels. Systems serving <10,000 monitor for E. coli only every two weeks for one year. Compliance with the LT2 requirements begin in April 2013. A. DBPs requirements D. Stage 1 Disinfectant and Disinfection Byproduct Rule B. Disinfectants requirements E. The LT2 requirements C. SDWA in 1996 F. None of the Above

295. ______applies to all public water systems using groundwater. The GWR requirements begin in March 2009 with 6-months investigative monitoring (IM) for source water E. coli, for systems currently applying disinfection only. All other requirements for the GWR began back in Dec 2009. A. Groundwater Rule (GWR) D. Long Term 2 Enhanced Surface Water Treatment Rule (LT2) B. Compliance E. Interim Enhanced Surface Water Treatment Rule C. SDWA in 1996 F. None of the Above

296. ______require EPA to develop rules to balance the risks between microbial pathogens and disinfection byproducts (DBPs). It is important to strengthen protection against microbial contaminants, especially Cryptosporidium, and at the same time, reduce potential health risks of DBPs. A. Amendments to the SDWA in 1996 D. Stage 1 Disinfectant and Disinfection Byproduct Rule B. Disinfectants E. The LT2 requirements C. SDWA in 1996 F. None of the Above

297. The Stage 1 Disinfectants and Disinfection Byproducts Rule and ______, announced in December 1998, are the first of a set of rules under the 1996 SDWA Amendments. This fact sheet focuses on the Stage 1 Disinfectants and Disinfection Byproducts Rule. A separate fact sheet focuses on the Interim Enhanced Surface Water Treatment Rule (EPA 815-F-98-009). A. Groundwater Rule (GWR) D. Long Term 2 Enhanced Surface Water Treatment Rule (LT2) B. Compliance E. Interim Enhanced Surface Water Treatment Rule C. SDWA in 1996 F. None of the Above

Public Health Concerns 298. While disinfectants are effective in controlling many microorganisms, they react with natural organic and inorganic matter in source water and distribution systems to form ______. Results from toxicology studies have shown several DBPs (e.g., bromodichloromethane, bromoform, chloroform, dichloroacetic acid, and bromate) to be carcinogenic in laboratory animals. A. DBPs D. Classes of DBPs B. Chlorine and chloramine E. Ultraviolet light C. Stage 2 DBPR F. None of the Above

54 Modern Disinfection 9/1/2016 Assignment 299. Other ______(e.g., chlorite, bromodichloromethane, and certain haloacetic acids) have also been shown to cause adverse reproductive or developmental effects in laboratory animals. A. DBPs D. Classes of DBPs B. Chlorine and chloramine E. Ultraviolet light C. Stage 2 DBPR F. None of the Above

300. Several epidemiology studies have suggested a weak association between certain cancers (e.g., bladder) or reproductive and developmental effects, and exposure to chlorinated surface water. More than 200 million people consume water that has been disinfected. Because of the large population exposed, health risks associated with ______, even if small, need to be taken seriously. A. DBPs D. Classes of DBPs B. Chlorine and chloramine E. Ultraviolet light C. Stage 2 DBPR F. None of the Above

55 Modern Disinfection 9/1/2016 Assignment 301. ______and Disinfection Byproducts Rule applies to all community and nontransient non-community water systems that treat their water with a chemical disinfectant for either primary or residual treatment. A. Groundwater Rule (GWR) D. Long Term 2 Enhanced Surface Water Treatment Rule (LT2) B. The Stage 1 Disinfectants E. Interim Enhanced Surface Water Treatment Rule C. SDWA in 1996 F. None of the Above

302. ______and Disinfection Byproduct Rule updates and supersedes the 1979 regulations for total trihalomethanes. In addition, it will reduce exposure to three disinfectants and many disinfection byproducts. A. DBPs D. Stage 1 Disinfectant and Disinfection Byproduct Rule B. The Stage 1 Disinfectant E. The LT2 requirements C. SDWA in 1996 F. None of the Above

Stage 2 DBP Rule Federal Register Notices 303. ______is one part of the Microbial and Disinfection Byproducts Rules (MDBPs), which are a set of interrelated regulations that address risks from microbial pathogens and disinfectants/disinfection byproducts. A. Groundwater Rule (GWR) D. Long Term 2 Enhanced Surface Water Treatment Rule (LT2) B. Compliance E. Interim Enhanced Surface Water Treatment Rule C. The Stage 2 DBP rule F. None of the Above

304. ______focuses on public health protection by limiting exposure to DBPs, specifically total trihalomethanes (TTHM) and five haloacetic acids (HAA5), which can form in water through disinfectants used to control microbial pathogens. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. DBP exposure E. Traditional disinfection practices C. The Stage 2 DBP rule F. None of the Above

305. This rule will apply to all community water systems and nontransient non- community water systems that add a primary or residual disinfectant other than ______or deliver water that has been disinfected by a primary or residual disinfectant other than UV. A. Ultraviolet (UV) light D. UV source B. The open-channel system E. UV radiation C. UV rather than ozone F. None of the Above

306. In the past 30 years, the ______has been highly effective in protecting public health and has also evolved to respond to new and emerging threats to safe drinking water. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. DBP exposure E. Safe Drinking Water Act (SDWA) C. The Stage 2 DBP rule F. None of the Above

307. ______is one of the major public health advances in the 20th century. One hundred years ago, typhoid and cholera epidemics were common through American cities; disinfection was a major factor in reducing these epidemics. A. Major public health advances D. Amendments to the SDWA in 1996 B. The Stage 2 DBPR E. Primary or residual disinfectant C. Disinfection of drinking water F. None of the Above

56 Modern Disinfection 9/1/2016 Assignment 308. However, the disinfectants themselves can react with naturally-occurring materials in the water to form byproducts, which may pose health risks. In addition, in the past 10 years, we have learned that there are specific microbial pathogens, such as______, which can cause illness, and are highly resistant to traditional disinfection practices. A. Enteric virus(es) D. C. perfringens B. Oocyst(s) E. E. coli host culture C. Cryptosporidium F. None of the Above

57 Modern Disinfection 9/1/2016 Assignment 309. Amendments to the SDWA in 1996 require EPA to develop rules to balance the risks between microbial pathogens and disinfection byproducts (DBPs). The Stage 1 Disinfectants and Disinfection Byproducts Rule and______, promulgated in December 1998, were the first phase in a rulemaking strategy required by Congress as part of the 1996 Amendments to the Safe Drinking Water Act. A. Major public health advances D. Amendments to the SDWA in 1996 B. The Stage 2 DBPR E. Interim Enhanced Surface Water Treatment Rule C. This final rule F. None of the Above

310. The Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) builds upon the ______to address higher risk public water systems for protection measures beyond those required for existing regulations. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. DBP exposure E. Traditional disinfection practices C. Stage 1 DBPR F. None of the Above

311. ______and the Long Term 2 Enhanced Surface Water Treatment Rule are the second phase of rules required by Congress. These rules strengthen protection against microbial contaminants, especially Cryptosporidium, and at the same time, reduce potential health risks of DBPs. A. Major public health advances D. Amendments to the SDWA in 1996 B. The Stage 2 DBPR E. Primary or residual disinfectant C. This final rule F. None of the Above

312. The ______will reduce potential cancer and reproductive and developmental health risks from disinfection byproducts (DBPs) in drinking water, which form when disinfectants are used to control microbial pathogens. Over 260 million individuals are exposed to DBPs. A. Stage 1 DBPR D. Long Term 2 Enhanced Surface Water Rule B. DBP exposure E. Traditional disinfection practices C. Stage 2 Disinfection Byproducts Rule F. None of the Above

313. ______strengthens public health protection for customers by tightening compliance monitoring requirements for two groups of DBPs, trihalomethanes (TTHM) and haloacetic acids (HAA5). A. Major public health advances D. Amendments to the SDWA in 1996 B. The Stage 3 DBPR E. Primary or residual disinfectant C. This final rule F. None of the Above

314. ______targets systems with the greatest risk and builds incrementally on existing rules. This regulation will reduce DBP exposure and related potential health risks and provide more equitable public health protection. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. The rule E. Traditional disinfection practices C. The Stage 1 DBP rule F. None of the Above

315. ______is being promulgated simultaneously with the Long Term 2 Enhanced Surface Water Treatment Rule to address concerns about risk tradeoffs between pathogens and DBPs. A. Major public health advances D. Amendments to the SDWA in 1996 B. The Stage 2 DBPR E. Primary or residual disinfectant C. This final rule F. None of the Above 58 Modern Disinfection 9/1/2016 Assignment 59 Modern Disinfection 9/1/2016 Assignment What does the rule require? 316. Under the ______, systems will conduct an evaluation of their distribution systems, known as an Initial Distribution System Evaluation (IDSE), to identify the locations with high disinfection byproduct concentrations. These locations will then be used by the systems as the sampling sites for Stage 2 DBPR compliance monitoring. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. DBP exposure E. Traditional disinfection practices C. The Stage 1 DBP rule F. None of the Above

317. Compliance with the maximum contaminant levels for two groups of disinfection byproducts (TTHM and HAA5) will be calculated for each monitoring location in the distribution system. This approach, referred to as the______, differs from current requirements, which determine compliance by calculating the running annual average of samples from all monitoring locations across the system. A. TTHM and HAA5 D. Disinfection byproducts (DBPs) B. DBP MCLs E. Trihalomethanes and haloacetic acids C. Locational running annual average (LRAA)) F. None of the Above

318. The ______also requires each system to determine if they have exceeded an operational evaluation level, which is identified using their compliance monitoring results. A. Stage 2 DBPR D. Long Term 2 Enhanced Surface Water Treatment Rule B. DBP exposure E. Traditional disinfection practices C. The Stage 1 DBP rule F. None of the Above

319. The operational evaluation level provides an early warning of possible future MCL violations, which allows the system to take proactive steps to remain in compliance. A system that exceeds an operational evaluation level is required to review their operational practices and submit a report to their state that identifies actions that may be taken to mitigate future high______, particularly those that may jeopardize their compliance with the DBP MCLs. A. TTHM and HAA5 D. Disinfection byproducts (DBPs) B. DBP MCLs E. Trihalomethanes and haloacetic acids C. DBP levels F. None of the Above

Who must comply with the rule? 320. Entities potentially regulated by the ______are community and nontransient noncommunity water systems that produce and/or deliver water that is treated with a primary or residual disinfectant other than ultraviolet light. A. DBPs from chlorination D. Classes of DBPs B. Chlorine and chloramine E. TTHM and HAA5 C. Stage 2 DBPR F. None of the Above

321. ______is a public water system that serves year-round residents of a community, subdivision, or mobile home park that has at least 15 service connections or an average of at least 25 residents. A. Trailer park D. A nontransient non-community water system (NTNCWS) B. A non-community water system E. A nontransient water system C. A community water system (CWS) F. None of the Above

60 Modern Disinfection 9/1/2016 Assignment 322. ______is a water system that serves at least 25 of the same people more than six months of the year, but not as primary residence, such as schools, businesses, and day care facilities. A. Trailer park D. A nontransient non-community water system (NTNCWS) B. A non-community water system E. A nontransient water system C. A community water system (CWS) F. None of the Above

61 Modern Disinfection 9/1/2016 Assignment What are disinfection byproducts (DBPs)? 323. Disinfectants are an essential element of drinking water treatment because of the barrier they provide against waterborne disease-causing microorganisms. ______form when disinfectants used to treat drinking water react with naturally occurring materials in the water (e.g., decomposing plant material). A. TTHM and HAA5 D. Disinfection byproducts (DBPs) B. DBP MCLs E. Trihalomethanes and haloacetic acids C. DBPs from chlorination F. None of the Above

324. Total trihalomethanes (TTHM - chloroform, bromoform, bromodichloromethane, and dibromochloromethane) and haloacetic acids (HAA5 - monochloro-, dichloro-, trichloro-, monobromo-, dibromo-) are widely occurring ______formed during disinfection with chlorine and chloramine. A. DBPs from chlorination D. Classes of DBPs B. Chlorine and chloramine E. Trihalomethanes and haloacetic acids C. Stage 2 DBPR F. None of the Above

325. The amount of ______in drinking water can change from day to day, depending on the season, water temperature, amount of disinfectant added, the amount of plant material in the water, and a variety of other factors. A. DBPs from chlorination D. Classes of DBPs B. Chlorine and chloramine E. Trihalomethanes and haloacetic acids C. Stage 2 DBPR F. None of the Above

Are THMs and HAAs the only disinfection byproducts? 326. The four THMs (TTHM) and five HAAs (HAA5) measured and regulated in the Stage 2 DBPR act as indicators for DBP occurrence. There are many other known DBPs, in addition to the possibility of unidentified DBPs present in disinfected water. ______typically occur at higher levels than other known and unknown DBPs. A. TTHM and HAAs D. Disinfection byproducts (DBPs) B. DBP MCLs E. Trihalomethanes and haloacetic acids C. Classes of DBPs F. None of the Above

327. The presence of ______is representative of the occurrence of many other chlorination DBPs; thus, a reduction in the TTHM and HAA5 generally indicates a reduction of DBPs from chlorination. A. DBPs from chlorination D. Classes of DBPs B. Chlorine and chloramine E. TTHM and HAA5 C. Stage 2 DBPR F. None of the Above

Alternative Disinfectants Ultraviolet Disinfection 328. This process involves exposing water to______, which inactivates various microorganisms. The technique has enjoyed increased application in wastewater treatment but very limited application in potable water treatment. A. Ballast(s) D. UV source B. The open-channel system E. Ultraviolet (UV) radiation C. UV rather than ozone F. None of the Above

329. The enormous temperatures on the sun create ______in great amounts, and this radiation is so powerful that all life on earth would be destroyed if these rays were not scattered by the atmosphere and filtered out by the layers of ozone gas that float some 20 miles above the earth. A. UV array(s) D. Infiltration B. UV rather than ozone E. Ultraviolet (UV) rays C. Non-contact design F. None of the Above

62 Modern Disinfection 9/1/2016 Assignment 330. This radiation can be artificially produced by sending strong electric currents through various substances. A sun lamp, for example, sends out ______that, when properly controlled, result in a suntan. Of course, too much will cause sunburn. A. UV rays D. UV source B. The open-channel system E. UV radiation C. UV rather than ozone F. None of the Above

331. The UV lamp that can be used for the disinfection of water depends upon the low-pressure mercury vapor lamp to produce the ultraviolet energy. ______is one in which an electric arc is passed through an inert gas. This in turn will vaporize the mercury contained in the lamp; and it is a result of this vaporization that UV rays are produced. A. UV array(s) D. A mercury vapor lamp B. Lamp(s) E. Quartz tube C. Non-contact design F. None of the Above

332. The lamp itself does not come in to contact with water, the lamp is placed inside a quartz tube, and the water is in contact with the outside of the______. A. UV array(s) D. A mercury vapor lamp B. Lamp(s) E. Quartz tube C. Non-contact design F. None of the Above

333. Quartz is used in this case since practically none of the UV rays are absorbed by the quartz, allowing all of the rays to reach the water. ______cannot be used since it will absorb the UV rays, leaving little for disinfection. A. UV array(s) D. Ordinary glass B. Lamp(s) E. Quartz tube C. Non-contact design F. None of the Above

334. The ______will consist of a various number of lamps and tubes, depending upon the quantity of water to be treated. As water enters the sterilizer, it is given a tangential flow pattern so that the water spins over and around the quartz sleeves. A. Ballast(s) D. UV source B. UV sterilizer E. UV radiation C. UV rather than ozone F. None of the Above

335. In this way the microorganisms spend maximum time and contact with the outside of the quartz tube and the source of the______. The basic design flow of water of certain UV units is in the order of 2.0 gpm for each inch of the lamp. Further, the units are designed so that the contact or retention time of the water in the unit is not less than 15 seconds. A. UV array(s) D. Infiltration B. Lamp(s) E. Quartz tube C. UV rays F. None of the Above

336. UV disinfection transfers electromagnetic energy from a mercury arc lamp to a pathogen's DNA material, thus affecting its ability to replicate itself. UV's effectiveness depends on the characteristics of the wastewater, the intensity of the UV radiation being emitted, the length of time that the ater comes in contact with the UV radiation, and the arrangement of the______. A. Ballast(s) D. UV source B. The open-channel system E. UV radiation C. UV reactor F. None of the Above

63 Modern Disinfection 9/1/2016 Assignment 337. UV has the advantage of being effective at inactivating viruses and, because it's a physical process rather than______, there are no residual constituents remaining in the treated wastewater after exposure to UV. A. UV array(s) D. Infiltration B. Lamp(s) E. A chemical process C. Non-contact design F. None of the Above

338. The contact time for the wastewater with the ______is the shortest of any of the disinfectant strategies, lasting no longer than 20 to 30 seconds. A. Ballast(s) D. UV source B. The open-channel system E. UV radiation C. UV rather than ozone F. None of the Above

339. Disadvantages include the effects of turbidity in the water reducing the infiltration and therefore the effectiveness of UV and the need to provide an effective cleaning and replacement program for ______. A. UV array(s) D. The UV components B. Lamp(s) E. Quartz tube C. Non-contact design F. None of the Above

340. "If you just need pure disinfection you probably would tend towards ______". "The cost of the UV just for disinfection is usually less than ozone, and the amount of equipment needed is less. But every water treatment has to be looked at individually in order to get what you want. Sometimes you cannot use UV because the waste treatment is too turbid; if you can filter it to get the turbidity levels down, maybe you'll use UV." A. Ballast(s) D. UV source B. The open-channel system E. UV radiation C. UV rather than ozone F. None of the Above

341. Primarily, there are two designs for UV systems. One system involves a non- contact design in which the UV-light system is suspended away from______. A. UV array(s) D. Infiltration B. Lamp(s) E. Quartz tube C. Contact with the water F. None of the Above

342. The second system is the ______in which the lamps are encased in a quartz sleeve that is submerged in the water. This contact-type system is further separated by whether it is an open- or closed-channel system. A. Ballast(s) D. UV source B. The open-channel system E. UV radiation C. Contact reactor-type design F. None of the Above

343. ______submerges the lamps in either a horizontal or vertical arrangement. A closed-channel system is within a sealed chamber that can be used in a pressurized system. The open-channel system is mostly used in wastewater treatment. A. Ballast(s) D. The closed-channel system B. The open-channel system E. UV radiation C. UV rather than ozone F. None of the Above

344. Ensuring that the ______maintains good contact with the water requires control of the water level within the channel to ensure that the UV is making total contact at the designed depths. A. UV D. Infiltration B. Lamp(s) E. Quartz tube 64 Modern Disinfection 9/1/2016 Assignment C. Non-contact design F. None of the Above

345. Because of the heat generated by the electric components of the system, adequate ventilation and cooling must be applied to the ______to reduce heat build-up, otherwise the ballasts could fail. A. Ballast(s) D. UV source B. UV arrays E. UV radiation C. UV rather than ozone F. None of the Above

346. UV lamps have a rated life of up to 14,000 hours, and should be routinely replaced at 12,000 hours or roughly every 1.5 years of continuous operation. The electrical consumption of this system, combined with the cost of routine replacement of______, should be considered against other systems. A. UV array(s) D. Infiltration B. Lamp(s) E. Quartz tube C. Ballasts and shields F. None of the Above

Strongest Oxidizing Agent 347. Ozone (O3) is probably the strongest oxidizing agent available for water treatment. Although it is widely used throughout the world, is has not found much application in the United States. ______is obtained by passing a flow of air or oxygen between two electrodes that are subjected to an alternating current in the order of 10,000 to 20,000 volts. A. Oxygen and nascent oxygen D. Strongest oxidizing agent B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

348. ______is very unstable and can readily explode. As a result, it is not shipped and must be manufactured on-site. Ozone is a light blue gas at room temperature. A. Oxygen and nascent oxygen D. Strongest oxidizing agent B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

349. It has a self-policing pungent odor similar to that sometimes noticed during and after heavy electrical storms. In use, ozone breaks down into ______. A. Oxygen and nascent oxygen D. Strong oxidizing agent B. Air or oxygen E. Light blue gas C. Chloramine(s) F. None of the Above

350. It is the ______that produces the high oxidation and disinfections, and even sterilization. Each water has its own ozone demand, in the order of 0.5 ppm to 5.0 ppm. Contact time, temperature, and pH of the water are factors to be determined. A. Oxygen and nascent oxygen D. Strongest oxidizing agent B. Air or oxygen E. Light blue gas C. Nascent oxygen F. None of the Above

351. ______acts as a complete disinfectant. It is an excellent aid to the flocculation and coagulation process, and will remove practically all color, taste, odor, iron, and manganese. It does not form chloramines or THMs, and while it may destroy some THMs, it may produce others when followed by chlorination. A. Oxygen and nascent oxygen D. Strongest oxidizing agent B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

65 Modern Disinfection 9/1/2016 Assignment 352. ______is not practical for complete removal of chlorine or chloramines, or of THM and other inorganics. Further, because of the possibility of formation of other carcinogens (such as aldehydes or phthalates) it falls into the same category as other disinfectants in that it can produce DBPs. A. Oxygen and nascent oxygen D. Strongest oxidizing agent B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

Alternate Disinfectants Section Summary Chloramines 353. ______is a very weak disinfectant for Giardia and virus reduction. It is recommended that it be used in conjunction with a stronger disinfectant. It is best utilized as a stable distribution system disinfectant. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. Chloramine C. Calcium carbonate F. None of the Above

354. In the production of chloramines, the ______in the finished water, when fed in excess of stoichiometric amount needed, should be limited to inhibit growth of nitrifying bacteria. A. Chlorine gas D. Sodium hypochlorite B. Organic sulfide(s) E. Ammonia residuals C. Calcium carbonate F. None of the Above

Chlorine Dioxide 355. ______may be used for either taste and odor control or as a pre- disinfectant. Total residual oxidants (including chlorine dioxide and chlorite, but excluding chlorate) shall not exceed 0.30 mg/L during normal operation or 0.50 mg/L (including chlorine dioxide, chlorite and chlorate) during periods of extreme variations in the raw water supply. A. Chlorine dioxide D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

356. ______provides good Giardia and virus protection but its use is limited by the restriction on the maximum residual of 0.5 mg/L ClO2/chlorite/chlorate allowed in finished water. This limits usable residuals of chlorine dioxide at the end of a process unit to less than 0.5 mg/L. A. THM precursor(s) D. Sodium chlorate (NaClO3) and sulfuric acid B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

357. Where chlorine dioxide is approved for use as an oxidant, the preferred method of generation is to entrain chlorine gas into a packed reaction chamber with a 25% aqueous solution of ______. A. Chlorine dioxide (ClO2) D. NaOCl and HCl in place of chlorine gas B. Sodium chlorite (NaClO2) E. Heavily pH-dependent C. Hypochlorous acid F. None of the Above

358. Warning: ______is explosive and can cause fires in feed equipment if leaking solutions or spills are allowed to dry out. A. Dry sodium chlorite D. Sodium chlorate (NaClO3) and sulfuric acid B. Chlorine gas E. THM formation C. Chlorine dioxide F. None of the Above

66 Modern Disinfection 9/1/2016 Assignment Ozone 359. ______is a very effective disinfectant for both Giardia and viruses. Ozone CT (Contact time) values must be determined for the ozone basin alone; an accurate T10 value must be obtained for the contact chamber, residual levels measured through the chamber and an average ozone residual calculated. A. Oxygen and nascent oxygen D. Chlorine B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

360. ______does not provide a system residual and should be used as a primary disinfectant only in conjunction with free and/or combined chlorine. A. Oxygen and nascent oxygen D. Chlorine B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

361. ______does not produce chlorinated byproducts (such as trihalomethanes) but it may cause an increase in such byproduct formation if it is fed ahead of free chlorine; ozone may also produce its own oxygenated byproducts such as aldehydes, ketones, or carboxylic acids. A. Oxygen and nascent oxygen D. Chlorine B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

362. Any installed ozonation system must include adequate ozone leak detection alarm systems, and an ozone off-gas destruction system. ______may also be used as an oxidant for removal of taste and odor, or may be applied as a pre- disinfectant. A. Oxygen and nascent oxygen D. Chlorine B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

UV 363. The germicidal effect of ______is thought to be associated with its absorption by various organic components essential to the cell’s functioning. For effective use of ultraviolet, the water to be disinfected must be clean and free of any suspended solids. The water must also be colorless and must be free of any colloids, iron, manganese, taste, and odor. These are conditions that must be met. A. UV D. Chlorine B. Liquid ozone E. Ozone C. Chloramine(s) F. None of the Above

Laboratory Analysis Sample Procedures 364. Samples need to be kept on ice and shipped to a central laboratory for analysis of coliphage, ______and enteric viruses by the current analytical methods. The single-agar layer (SAL), direct plating method with induction of β-galactosidase (Ijzerman and Hagedorn, 1992) is recommended for detection of somatic and F- specific coliphage in streamwater samples. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. C. perfringens, Cryptosporidium, Giardia, C. The plates F. None of the Above

365. In this method, 100-mL sample volumes are mixed with an agar medium, ______host culture, chemicals that induce the β-galactosidase enzyme, and appropriate antibiotics. The mixtures are poured into four 150- x 15-mm plates and incubated at 35°C. 67 Modern Disinfection 9/1/2016 Assignment A. Enteric virus(es) D. C. perfringens B. Oocyst(s) E. E. coli C. Viral plaques F. None of the Above

366. Upon infection by coliphage in the water sample, the ______host cells are lysed and stable indolyl product that is dark blue is visible within each plaque. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Coliphage C. E. coli F. None of the Above

367. Viral plaques are easily identified and enumerated by the distinct blue circle. Because of contamination by naturally occurring bacteria in streamwater samples, antibiotic- resistant host-culture strains, E. coli CN-13 (resistant to nalidixic acid) and ______(resistant to streptomycin and ampicillin) are used as hosts for somatic and F-specific coliphage, respectively. A. Enteric virus(es) D. C. perfringens B. E. Coli F-amp E. E. coli host culture C. Viral plaques F. None of the Above

368. ______, such as 1-L volumes or greater, are recommended for detection of coliphage in ground water. Because the SAL method is impractical for sample volumes above 100 mL, an alternative method should be used for groundwater sample analysis. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Coliphage C. The plates F. None of the Above

369. One example, currently being tested by USEPA, is a two-step enrichment presence-absence method (U.S. Environmental Protection Agency, 1999e). Samples for enumeration of ______are analyzed by use of the mCP agar method (U.S. Environmental Protection Agency, 1996c). A. Enteric virus(es) D. C. perfringens B. Oocyst(s) E. E. coli host culture C. Viral plaques F. None of the Above

370. Standard MF techniques are used, and ______are incubated anaerobically for 24 hours at 44.5°C. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Coliphage C. The plates F. None of the Above

371. After incubation, the plates are exposed to ammonium hydroxide, and all straw- colored colonies that turn dark pink to magenta are counted as ______. A. Enteric virus(es) D. C. perfringens B. Oocyst(s) E. E. coli host culture C. Viral plaques F. None of the Above

372. In the laboratory, ______analyses are done on 100-, 30-, and 10-mL volumes of streamwater. In the case of a high-flow or high-turbidity streamwater sample, lower sample volumes may be plated. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Coliphage C. The plates F. None of the Above

373. Method 1623 (U.S. Environmental Protection Agency, 1999c) is recommended for detection of ______in water. The oocysts are 68 Modern Disinfection 9/1/2016 Assignment concentrated on a capsule filter from a 10-L water sample, eluted from the capsule filter with buffer, and concentrated by centrifugation. Immunomagnetic separation (IMS) is used to separate the oocysts from other particulates in the sample. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Cryptosporidium oocysts and Giardia cysts C. The plates F. None of the Above

374. In IMS, the ______are magnetized by attachment of magnetic beads conjugated to an antibody and then are separated from sediment and debris by means of a magnet. A. Oocyst(s) D. Large sample volumes B. C. perfringens E. Cryptosporidium oocysts and Giardia cysts C. The plates F. None of the Above

375. Fluorescently labeled antibodies and vital dye are used to make the final microscopic identification of______. The reverse-transcriptase, polymerase chain reaction (RT-PCR) and cell-culture methods are recommended for detection of enteric viruses in water samples (G. Shay Fout, U.S. Environmental Protection Agency, written commun., 1997; U.S. Environmental Protection Agency, 1996c). A. Enteric virus(es) D. Oocysts and cysts B. Oocyst(s) E. E. coli host culture C. Viral plaques F. None of the Above

376. To prepare samples for RT-PCR and cell culture, ______are eluted from a 1MDS filter with beef extract (pH 9.5), concentrated using celite (pH 4.0), and eluted with sodium phosphate (pH 9.5). A. Oocyst(s) D. Attached viruses B. C. perfringens E. Coliphage C. The plates F. None of the Above

QA/QC Activities and Measures 377. QA/QC activities and measures to take to reduce contamination. Use a sterilization indicator, such as autoclave tape, in preparing ______and other equipment for collection of microbiological samples to determine whether adequate temperatures and pressures have been attained during autoclaving. A. Enteric virus(es) D. Sample bottles B. Sterile equipment E. E. coli host culture C. Viral plaques F. None of the Above

378. Prepare a separate set of ______for microbiological sampling at each site. A. Enteric virus(es) D. Sample bottles B. Sterile equipment E. E. coli host culture C. Viral plaques F. None of the Above

379. Before processing samples in the field vehicle, wipe down the area with a disinfectant (such as isopropyl alcohol) to ensure a sterile working surface. Monitor the incubators daily to ensure temperatures are appropriate for______. A. Equipment blank(s) D. Appropriate laboratory equipment B. MF procedure blank(s) E. The methods used C. Sterile working surface F. None of the Above

380. For bacteria samples, membrane-filtration (MF) equipment and MF procedure blanks are used to estimate______. 69 Modern Disinfection 9/1/2016 Assignment A. Equipment blank(s) D. Appropriate laboratory equipment B. Analytical bias E. Prepare a MF procedure blank C. Sterile working surface F. None of the Above

Field personnel should do the following: 381. Prepare ______, a 50- to 100-mL aliquot of sterile buffered water plated before thesample—for every sample by field personnel for total coliform, E. coli, and enterococci analyses to determine the sterility of equipment and supplies. A. Reagent water quality D. Protozoan Giardia and virus(es) B. An environmental sample E. Microbiological sampling C. An MF equipment blank F. None of the Above

382. Prepare a ______, a 50- to 100-mL aliquot of sterile buffered water plated after the sample— for every fourth sample to measure the effectiveness of the analyst’s rinsing technique or presence of incidental contamination of the buffered water. A. Equipment blank(s) D. Appropriate laboratory equipment B. MF procedure blank(s) E. Prepare a MF procedure blank C. Sterile working surface F. None of the Above

383. If contamination from a MF equipment or ______is found, results are suspect and are qualified or not reported. Proper and consistent procedures for counting and identifying target colonies will be followed, as described in Myers and Sylvester (1997). A. Reagent water quality D. Protozoan Giardia and virus(es) B. An environmental sample E. Procedure blank C. An MF equipment blank F. None of the Above

384. For coliphage, Cryptosporidium, Giardia, and enteric virus samples, equipment and field blanks are used to determine sampling and analytical bias. ______for these analyses are different from the MF equipment blanks for bacterial analysis. A. Equipment blank(s) D. Appropriate laboratory equipment B. MF procedure blank(s) E. Prepare a MF procedure blank C. sterile working surface F. None of the Above

385. An equipment blank is a blank solution (sterile buffered water) subjected to the same aspects of sample collection, processing, storage, transportation, and laboratory handling as an environmental sample, but it is processed in an office or laboratory. ______are the same as equipment blanks except that they are generated under actual field conditions. A. Reagent water quality D. Field blanks B. An environmental sample E. Microbiological sampling C. An MF equipment blank F. None of the Above

Quality Assurance and Quality Control in the Laboratory 386. The following criteria may be used to evaluate each production analytical laboratory: (1) appropriate, approved, and published methods, (2) documented standard operating procedures, (3) approved quality-assurance plan, (4) types and amount of quality-control data fully documented and technical defensible, (5) participation in the standard reference sample project (6) scientific capability of personnel, and (7______. A. Equipment blank(s) D. Appropriate laboratory equipment B. MF procedure blank(s) E. Prepare a MF procedure blank C. sterile working surface F. None of the Above

70 Modern Disinfection 9/1/2016 Assignment 387. The microbiology laboratories must follow good laboratory practices— cleanliness, safety practices, procedures for______, specifications for reagent water quality—as set forth by American Public Health Association (1998) and Britton and Greeson (1989). A. Reagent water quality D. Media preparation B. An environmental sample E. Microbiological sampling C. An MF equipment blank F. None of the Above

Understanding Chlorine Residual 388. The amount of available chlorine present in water after a given contact time (20 minutes at peak flow; 30 minutes at average flow), and under specific conditions including______. A. Ammonia D. Free residual chlorination B. CT E. Free available residual C. pH and temperature F. None of the Above

71 Modern Disinfection 9/1/2016 Assignment 389. For effective water treatment, the water supply industry has recognized the need for adequate exposure to the disinfectant and sufficient disinfectant dosage for a certain amount of time. In the 1980s, the two functions were combined with the development of the ______values for various disinfectants. A. Ammonia D. Free residual chlorination B. CT E. Free available residual C. Nitrogen compound(s) F. None of the Above

390. ______represents the combination of the disinfectant dosage and the length of time water has been exposed to a minimum amount of the disinfectant residual. A. Ammonia D. Free residual chlorination B. CT E. Free available residual C. Nitrogen compound(s) F. None of the Above

391. In an assessment of disinfection effectiveness, two types of organisms have been chosen as disinfection surrogates –______. CT values established for disinfection of surface waters require treatment plants to achieve a three-log or 99.9% reduction in Giardia and a four-log or 99.99% virus reduction. A. Reagent water quality D. The protozoan Giardia and viruses B. An environmental sample E. Microbiological sampling C. An MF equipment blank F. None of the Above

392. It is important to recognize that the use of ______as the disinfectant is only one part of the treatment process. Equally important is the need for improved filtration to remove organisms. A. Ammonia D. Free residual chlorination B. Chlorine E. Free available residual C. Free available chlorine F. None of the Above

393. A combination of proper ______is most effective in providing safe drinking water. Recent experiments in controlling Cryptosporidium also suggest the effectiveness of filtration in the water treatment process. A. Alkalinity D. Oxidizing and biocidal properties B. Mutagenic and carcinogenic agents E. Hazardous trihalomethanes (THM) C. Disinfection and filtration F. None of the Above

394. ______involves the application of chlorine to water to produce-- either directly or by first destroying any naturally present ammonia--a free available chlorine residual and to maintain this residual through part or all of the water treatment plant and distribution system. A. Ammonia D. Free residual chlorination B. CT E. Free available residual C. Nitrogen compound(s) F. None of the Above

395. ______forms have higher oxidation potentials than combined available chlorine forms and are more effective as disinfectants. A. Ammonia D. Free residual chlorination B. CT E. Free available residual C. Nitrogen compound(s) F. None of the Above

When free available chlorine residuals are desired, the characteristics of the water will determine how this will be accomplished. This may have to be considered:

72 Modern Disinfection 9/1/2016 Assignment 396. If the water contains no ammonia or______, any application of chlorine will yield a free residual once it has reacted with any bacteria, virus and other microorganisms present in the water. A. Other nitrogen compounds D. Amount of chlorine B. More chlorine E. Iron, manganese, organic matter C. Taste and odor F. None of the Above

Breakpoint Chlorination 397. Breakpoint chlorination is the name of the process of adding chlorine to water until the chlorine demand has been satisfied. ______equals the amount of chlorine used up before a free available chlorine residual is produced. A. Free available residual D. No disinfection B. Free available chlorine E. No residual C. Chlorine demand F. None of the Above

398. Further additions of chlorine will result in a chlorine residual that is directly proportional to the amount of chlorine added beyond the______. Public water supplies normally chlorinate past the breakpoint. A. Free available residual D. No disinfection B. Free available chlorine E. No residual C. Breakpoint F. None of the Above

Principles of Modern Chemistry 399. The current model of atomic structure is the quantum mechanical model. ______starts with the study of elementary particles, atoms, molecules, substances, metals, crystals and other aggregates of matter. This matter can be studied in solid, liquid, or gas states, in isolation or in combination. A. Nuclear chemistry D. Analytical chemistry B. Neurochemistry E. Traditional chemistry C. Organic chemistry F. None of the Above

400. The interactions, reactions and transformations that are studied in chemistry are usually the result of interactions between atoms, leading to rearrangements of the ______which hold atoms together. Such behaviors are studied in a chemistry laboratory. A. Chemical bonds D. Chemical compound B. Chemical substance(s) E. Physical chemistry C. Chemical(s) F. None of the Above

73 Modern Disinfection 9/1/2016 Assignment