DOCUMENT RESUME ?ED 221 402 SE 039 214 AUTHOR Carnegie, John W. TITLE Turbidity. Operational Control Tests for Wastewater Treatment Facilities. Instructor's Manual [and] Student Workbook. INSTITUTION Linn-Benton Commycity Coll., Albany, Oreg. SPONS AGENCY Office of Water Program Operations (EPA), Cincinnati, Ohio. Nationale Training and Operational Technology Center PUB DATE Aug 81 GRANT. EPA-900953010 NOTE 34p.; Slide/tape program which accompanies this module is also available from Linn-Benton Community College. /MEM. AVAILABLE FROMLinn-Benton Community College, 6500 S.W. Pacific Blvd., Albany, OR 97321 ($1. student workbook, $2. instructor's guide). EDRS PRICE MF01 Plus Postage. PC Not Available from EDRS. DESCRIPTORS Instructional Materials; *Laboratory Procedures; Postsecondary Education; Sludge; Solid-Wastes; Teaching Guides; *Training Methods; *Waste Water; *Water Treatment IDENTIFIERS Turbidity ABSTRACT Designed f individuals who have completed National Pollutant Discharge Elimi ation System (NPDES) level 1 laboratory training skills, this mo ule provides waste water treatment plant operators with the basic skills and information needed to: (1) standardize a nephelometric turbidimeter; (2) Aetermine the turbidity of a ,sample; and (3) calculate turbidity for tests requiring sample dilution. The instructor's manual contains a statement of instructional Tials, lists of instructor/student activities and instructional,materials, narrative of the slide/tape program used with the module, overhead transparency masters, and ptudent worksheet (with answeri). The student workbook contains objectives, prerequisite slRills needed before the module is started, lis't of Environmental Piotection Agency (EPA) approved nephelometric turbidimeters, sample problem, laboratory procedures for the- nephelometric method of measuring turbidity, and worksheet. (Author/JN) ********************14************************************************* * Reproductions supplied by EDRS are the best that can be made * * * w from the original documpnt. **************************************************ft******************** Appi4r..074.eq.read( ql:Qt .11 L Th Operational.Control Tests for. Wastewater TreatmentFacilities U S DSPARTMENT OF EDUCATION NATIONAL INSTITUTE OF EDUCATION IDUI AT IONAI RESOUR( ES INFORMATION ENTER IERICI /Thisdot rotretrIhas bornor)rorfor orI re, ervol horn tho Person or orgatozahon torrpoollori 11 hArrlor tootles have horn nod.. If, IIIPIIIVC 1111(111,V Porots of ,row oprorons slated or this fit/I II 1,1011110 Frio Fret Irss.rohr rApresenl "TN iI NIE oosroorr poIrr y 4/,ti.)4.:1-zi ."'-"faAi'''1A" 3/s .)J y. /12 k://, Wi- el-cfr ) if`;',4;.11 , _'±: p.22/1rrof `.5.-/) 9, .: , Turbidity. Th R.7; O.,LI4)4 -,::, I,-i ,,/, _>, V,. *c 1...CrA 1 r1/40.1 vo ( Instructor's Manual "PERMISSION TO REPRODUCE THIS MATERIAL INMICROFICHE ONLY HAS BEEN GRANTED BY 01 TO THE EDUCATIONAL RESOURCES INFORMATION CENTER (ERPIC)" Linn-Benton Community,Cojlege 44 Albany, Oregon TbRBID.ITY A, S. kr a./ Written Oy: V .,John W. Carnegie, Ph.D. Linn-Benton Community College Albany, Oregon Instructional Design: Priscilla Hardin CorVallis, Oregon Projec't Management: John W. Carnegie, Ph.D. Linn-Benton Community College Albany, Oregon Project Officer: Lynn S. Marshall United States ErNironmental Protection Agency National .Training and OperationailTechnology Center Cincinnati, Ohio Developed Under: EPA Grant #90095300 August, 1981 AI. 4 , $ . TURBIDITY CONTENTS r , , ,Subject Page 'Instructional Goal Tti-1 Instructional Activities Tb-14 Student Activities Tb-2 Instructional Materials List A Tb-2 , Narrative , Th-3 Appendix A Tb-7 ) , Tb-8 Overhead #1 J r Overhead.#2 Tb-9 ) Answers to Worksheet W-Tb-1 i Student Materials S-Tb-1 thru 10 SW-Tb-1 thru 3 ( .. \ , 1 * 04 0 .1 , Tb-i J 8/81 INSTRUCTIONAL GOALS I 7- , Upon completion-of this module the student should be able to stan-- dardize a nephelometric turbidimeter an4 successfully determinethe turbiditg of a sample. The student should also be able to calculate . iturbidity for tests requiring sample dilutio r . INSTRUcTOR ACTIVITIES The following sequence isrecoMmhded foe best use-of this material: Activity, Time 1. Review Objectives with students. 3 minutes 2. Have students read through the procedure. .10 minutes 3. View and listen to the slide/tape program. 14 minutes 15 minutes 4. 1/4Demons.trate the procedure. 5. Assign the worksheet. 10 minutes 6. Correct the worksheet. 5 minutes 7. Have students perform the test. 20 minutes OTHER ACTIVITIES r Items to emphasize during the demonstration should include: 1. Be sure instUment is warmed up properly. 2. Use a standard in the same range as thesample."' 3. Stress the need for clean sample cell. No fingerprints, water spots, dusi or scratches. -- , 4. Remind students to let air bubbles escape. 5. Keep fingers off of sides.of sample cell. 6. Be careful to read correct scale and be awareoescale selection knob position. You shoUld encourage students to read thoroughly theinstruction manual for their particular brand of instrument. Discuss the problems of reading the scales. Describe "paralax"; eyes mus-t be directly in frontof needle.. Most errors in this test result from misreading thescale. Sealed standards should be .scarded after one year. Laboratory prepared sta-n dards are good,for o te week. Samples with turbidity greater than 40 NTU # should be diluted. k) Tb-1 of 9 8/81, -7 STUDENT ACTIVITIES I. Read objectives. _2. Read procedure.- program. 3. Listen to and view slide/tape 4. Observe demonstration. 5. Complete worksheet. 6. Perform test. INSTRUCTIONAL MATERIALSLIST I. Instructor's Guide for Turbidity 2. Student Workbook for Turbidity 3. 35mm projector automatic synchronization 4. *Cassette tape playssoith 5. Projector screen 6. Overhead projector 7. Equipment listed in labpi-ocedure various brands of instruments 8. Copies of instruction for f) various brands of instruments(optional) 9. Demonstration models for Tb-2 of 9 8/81 TURBIDITY NARRATIVE ....) Slide # The heory of the test, the 1. This lesson covers the turbidity test. , test procedure itself, and the caltulationS e all addresspj. 2. The lesson was written by Dr. John W. Carnegie. Dr. Carnegie was also the project manager. Instructional design was done by Priscilla Hardin. P 3. Potable water and treated wastewater both contain somesuspended mater, ials. Operators can judge treatment efficiency by measuring how muchof the suspended material has been removed. 1 . : which is referred to 4. This suspended material causes a cloudy appearance as t4ir4idity; Technically, turbidity is an expression of the optical properties which cau e-light to be scattered and absorbed. (- and the turbidity 5. Very cloudy water scatt s a larger altount of light value is high. Clear water scatters less light and the turbidityvalue is lower. 6. The nephelometriciiiethod,of citermining turbidity measures the light scattered at a 900 angle to a beam of light. method is expressed as NTU's 7. Turbity determined by the nephelometric or Nephelometricturbidity units. In the potable watertiTatment industry, turbidity is often expressed simply asTU's or turbidity/ i uni ts. glass sample tube, a 8. The nephelometer consists of a light source,ta phototube or other li.ght sensitive deviceand,a meter to visually display the intensity of the scatteredlight. scattered,/ and transmitted. 9. Light enters the sample and is absorbed, A portion being scattered at900 is picked up by the light sensing device. The light ensing device measures th.e'intensity of the scattered light and the instrument convertsthe light energy to an electric signal which is displayed by .themeter. n and unscratched so as notto 10. The glass sample tube musL be cl interfere with the path dfthe ight, The tube is placed in a compartment with a ligilt-tight lid or cap sothat outside licht ' will not enter the sample and interferein the results. .* intensity of the light scattered by thesample is displayed on 1 ILT-hek, which allows use . the meter. The meter may have more than one scale, with a wide range of sample turbidities. High range scales allow measurement of turbidity as high as1,000 NTU's The lower scales are used to obtain greater accuracyon less turbidsamples. The Tb-3 of 9 -.8/81 range selector sets the instrument to read onthe appropriate scale. Experience with different samples will4elp you determinewhich scale to use. and when- 12. The instrument must be standardized each time a test is run ever switching from one scale rangetofanother. Restandardization it . accomplished by placing a standard of known turbidity inthe instrument and setting the meter to read the correct valueby adjusting the standardization knob. 13. Several nephelometric turbidimeters are available and meetEPA specifi- cations. These include Hach Chemical Co., HF Instruments, Turner Designs, and LaMotte Chemical Co. Sample tubes are usually supplied with the instruments. A.. / a 14. Running the turbidity test involves the preliminary stepsof solution preparation and sample collection, the main procedureitself, followed by calculations and, of course, clean7up. A turbidity 15. Let's first take a look at the two required solutions. standard,and turbidity-free water are the onlysolutions requrred. 'Tur- bidity-free water is used to prepare the standardand dilute the sample. suspension are used 16. Turbidity standards.solution made from a Formazin to standardize the instrument. Thesestandards may be purchased from chemical suppliers or they may be prepared tn thelaboratory from dry reagents.