DOCSLIB.ORG

Taste and Odor-Causing Compounds in Drinking Water Fact Sheet

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Taste and Odor-Causing Compounds in Drinking Water Fact Sheet FACTSHEET TASTE AND ODOR Environmental Contaminant Treatment Taste and Odor -Causing Compounds in Drinking Water The primary sources of taste and odor problems common name “blue-green algae” has remained. Man-Made Chemicals in drinking water are algae and bacteria. However, Cyanobacteria are photosynthetic bacteria. In Man-made chemicals are another source of other anthropogenic sources such as wastewater addition to the blue-green color of many inferred taste and odor-causing chemicals in drinking discharges and chemical spills also act as sources by the name, other species can be red, brown, or water. For example, methyl tertiary butyl ether of chemicals that cause off tastes and odors. yellow. Cyanobacteria are most commonly found (MTBE), a gasoline additive persistent in Such chemicals can affect both groundwater and in eutrophic waters (waters with high levels of groundwater and recreational surface waters, surface water. nutrients) and shallow reservoirs, and can occur has an odor threshold as low as 5 parts per as surface scum, benthic (bottom) mats, and on billion. Dissolved in water, it smells oily and like TYPES OF TASTE AND aquatic weeds (Hoehn, 2002). In the 1960’s turpentine. Industrial phenols can create odor and 1970’s, it was discovered that cyanobacteria problems. Hydrocarbons and volatile organic ODOR PROBLEMS produce geosmin and MIB as intracellular by- compounds such as fuels and solvents produce products. As a bloom progresses, bacteria die, oily, paint-like, and medicinal odors. There are four basic taste types: sour, sweet, salty releasing these odorous chemicals into the water. and bitter. There are also a variety of odor types including earthy, musty, chemical, and chlorinous. ALGAE AND BACTERIA Actinomycetes The table on the reverse side lists several taste Actinomycetes are spore-forming bacteria that BLOOM PATTERNS and odor types and their potential causes. grow as branching filaments in water. Closely A bloom occurs in a surface water body when related to cyanobacteria, they have simple cells. light, temperature, and nutrient conditions are THE CAUSES OF TASTE AND Actinomycetes also live in soil. In fact, it is the favorable for one type of algae or bacteria over geosmin-producing soil variety that causes soil to ODOR PROBLEMS another. This combination allows one organism to smell “earthy.” Other species produce antibiotics. become dominant. It is an ecological imbalance Some species of algae and bacteria naturally Aquatic actinomycetes grow in aerobic mud, on often triggered by pollution. Nitrates, organic produce odorous chemicals inside their cells. decaying vegetation, and in the excrement phosphorus and ammonia are discharged into the Geosmin (trans-1, 10-dimethyl-trans-9-decalol) of zebra mussels. The bacteria help to degrade water body from water treatment plants or are and MIB (2-methylisoborneol) are common cellulose and other plant parts, and for this carried in by watershed runoff (including runoff odorous chemicals. The earthy and musty odors reason thrive as a result of an algae bloom from pig and cattle feed lots and fertilizer from generated by geosmin and MIB are detectable by (Hoehn, 2002). Actinomycetes, like cyanobacteria, agricultural fields). The conditions favorable to many people at concentrations of 5 to 10 parts produce geosmin and MIB. blooms are seasonal. Spring and winter conditions per trillion. When large numbers of algae and favor golden brown algae and fishy, cucumber bacteria flourish in a water body (an “algae bloom”), Other Algal and Natural Sources odors. Summer and fall conditions favor geosmin taste and odor-compound concentrations increase Green algae blooms in a reservoir can produce and MIB-producing bacteria and earthy and musty to levels above this threshold and cause taste a grassy or fishy odor. Golden-brown algae, odors. Generally, the most common bloom month and odor problems. particularly the species Synura, can produce a is September. cucumber, melon, or fishy odor. Biological activity Cyanobacteria (Blue-Green Algae) in surface waters can produce 2,4-heptadienal Cyanobacteria are known by several names, and decadienal, which have a fishy, rancid odor. MEASUREMENT AND including “blue-green algae”, “blue greens”, In addition, dissolved metals such as zinc, REGULATION OF TASTE AND and “cyanophyta”. To the biologist, they are not manganese, copper, and iron can produce a ODOR QUALITY technically algae (a multi-celled plant), but metallic taste. bacteria. This was not known until the advent There are several methods of taste and odor of high-powered microscopes, however, the quality measurement and very few regulations. TASTE OR ODOR SOURCE FACTSHEET Earthy Geosmin Musty MIB, isopropylmethoxypyrazine (IPMP), isobutylmethoxypyrazine (IBMP) Turpentine, oily Methyl tertiary butyl ether (MTBE) Fishy/rancid 2,4-Heptadienal, decandienal, octanal The most frequently used measuring system is Chlorinous Chlorine the Total Odor Number (TON), a method based Medicinal Chlorophenols, iodoform on the persistence of an odor after dilution. Oily, gas-like, paint Hydrocarbons, volatile organic compounds (VOCs) Other methods include Flavor Profile Analysis Metallic Iron, copper, zinc, manganese and analytical measurement of chemical Grassy Green algae concentrations. Regulatory limits are few. The United States Environmental Protection Agency (USEPA) has issued a secondary maximum concentration limit (MCL) limiting the TON to 3. larger utilities. Chlorine is widely used for the For over 30 years, Trojan has specialized in UV Iron, manganese, copper, and zinc have USEPA oxidation of taste and odor-causing chemicals, applications for water treatment and wastewater MCLs ranging from 0.5 to 5 parts per million. but itself can produce chlorinous odors and disinfection. Over 6,500 Trojan UV systems are However, the primary regulator with respect to disinfection by-products such as THMs and HAAs. treating municipal wastewater in more than 80 taste and odor is the consumer. Ozonation is also used, but is expensive, complex countries around the world. Tens of thousands to operate, and can form bromate, a harmful by- of industrial and residential Trojan UV treatment ALGAL TOXINS product. However, UV-photolysis and UV-oxidation systems are in operation in industries and using UV light and hydrogen peroxide is a cost- households worldwide. Now, Trojan offers the In addition to producing chemicals that impact effective alternative for treating a wide variety of industry standard in Environmental Contaminant the aesthetic quality of water, certain species taste and odor problems. MIB, geosmin, MTBE, Treatment (ECT). Trojan’s UV-photolysis and UV- of cyanobacteria produce toxins (“cyanotoxins”) phenols, VOCs, and many others contaminants oxidation systems are capable of cost-effectively that can cause harm to animals and humans. can be treated with UV-oxidation. This technology removing environmental contaminants from a Toxic cyanobacteria are indistinguishable from requires the photolysis of hydrogen peroxide variety of water streams. With its optimized non-toxic cyanobacteria under a microscope and with UV light to generate hydroxyl radicals. The technology, Trojan is the leader in ECT, offering both types may be present in a bloom. Multiple hydroxyl radical is one of the most powerful the most cost effective, highest quality UV classes of cyanotoxins exist, including microcystin, oxidizing agents known and reacts rapidly with solutions available. cylindrospermopsin, and anatoxin-a. Cyanotoxins organic constituents in the water, including taste can be present wherever blooms occur and as a and odor compounds, breaking them down into result, several regulating agencies worldwide have their elemental, non-odorous components. Trojan’s issued guidance regulations. Research in the U.S. UV-oxidation reactors provide a reliable barrier and Canada has shown that a high percentage of to taste and odor compounds and do not form raw water taken from water supplies undergoing bromate. In addition, the same UV system used a cyanobacteria bloom contained cyanotoxins, for taste and odor control simultaneously performs in addition to other taste and odor-causing disinfection. This reduces or eliminates the source chemicals (Carmichael, 2001). In the U.S., the of unpleasant chlorinous odors resulting from the USEPA has listed freshwater cyanobacteria and use of chlorine as a primary disinfectant. their toxins on the Contaminant Candidate List. In addition, New Zealand, Germany, and the World TREATING MULTIPLE Health Organization (WHO) have established CONTAMINANTS WITH ONE microcystin guidelines of 1.0 ppb, while Canada Cyanobacteria Bloom in Lake Manatee, Florida has established a 1.5 ppb guideline. UV SYSTEM (Photo courtesy of Bruce MacLeod) As a further benefit to taste and odor control and TREATMENT ALTERNATIVES – microbial disinfection, the Trojan UV system will References: UV LIGHT A KEY disinfect Cryptosporidium and Giardia. The process Hoehn, R.C. 2002. Odor Production by Algae. Conference will also treat many other dissolved organic Workshop Presentation: Understanding and Controlling Many utilities use powdered activated carbon compounds present in the water, including the Taste and Odor of Drinking Water. AWWA Annual (PAC) to treat taste and odor problems. However, endocrine disruptors, N-nitrosodimethylamine Conference, New Orleans. June 16, 2002. Carmichael, W. W. 2001. Assessment of Blue-Green large doses of PAC are required to treat geosmin (NDMA), pesticides, and algal toxins. Algal Toxins in Raw and Finished Drinking Water. AWWA and MIB, making it impractical, especially for Research Foundation, Denver. 179 pgs. North America T. 519.457.3400 F. 519.457.3030 www.trojanuv.com Europe (please contact our UK office) T. +44 (1905) 771117 F. +44 (1905) 772270 ©Copyright 2010. Trojan Technologies, London, Ontario, Canada. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means without the written permission of Trojan Technologies. ECT-1110.
Load more

Recommended publications
  • Medical Review Officer Manual
    Department of Health and Human Services Substance Abuse and Mental Health Services Administration Center for Substance Abuse Prevention Medical Review Officer Manual for Federal Agency Workplace Drug Testing Programs EFFECTIVE OCTOBER 1, 2010 Note: This manual applies to Federal agency drug testing programs that come under Executive Order 12564 dated September 15, 1986, section 503 of Public Law 100-71, 5 U.S.C. section 7301 note dated July 11, 1987, and the Department of Health and Human Services Mandatory Guidelines for Federal Workplace Drug Testing Programs (73 FR 71858) dated November 25, 2008 (effective October 1, 2010). This manual does not apply to specimens submitted for testing under U.S. Department of Transportation (DOT) Procedures for Transportation Workplace Drug and Alcohol Testing Programs (49 CFR Part 40). The current version of this manual and other information including MRO Case Studies are available on the Drug Testing page under Medical Review Officer (MRO) Resources on the SAMHSA website: http://www.workplace.samhsa.gov Previous Versions of this Manual are Obsolete 3 Table of Contents Chapter 1. The Medical Review Officer (MRO)........................................................................... 6 Chapter 2. The Federal Drug Testing Custody and Control Form ................................................ 7 Chapter 3. Urine Drug Testing ...................................................................................................... 9 A. Federal Workplace Drug Testing Overview..................................................................
    [Show full text]
  • Evaluation of Ozonation on Levels of the Off-Flavor Compounds Geosmin and 2-Methylisoborneol in Water and Rainbow Trout Oncorhyn
    Aquacultural Engineering 43 (2010) 46–50 Contents lists available at ScienceDirect Aquacultural Engineering journal homepage: www.elsevier.com/locate/aqua-online Evaluation of ozonation on levels of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout Oncorhynchus mykiss from recirculating aquaculture systems Kevin K. Schrader a,∗, John W. Davidson b, Agnes M. Rimando a, Steven T. Summerfelt b a United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, National Center for Natural Products Research, Post Office Box 8048, University, MS 38677-8048, USA View metadata, citation and similar papers at core.ac.uk brought to you by CORE b The Conservation Fund Freshwater Institute, 1098 Turner Road, Shepherdstown, WV 25443, USA provided by Elsevier - Publisher Connector article info abstract Article history: Common “off-flavors” in fish cultured in recirculating aquaculture systems (RAS) are “earthy” and “musty” Received 29 January 2010 due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Accepted 17 May 2010 Previously, ozone addition has been applied to RAS at relatively low doses to break refractory organic molecules (i.e., reducing color), microflocculate fine particulate matter (i.e., increasing solids removal), Keywords: and oxidize nitrite to nitrate, but the effect of ozone addition at these dosing rates on levels of off-flavor Aquaculture compounds was unknown. Ozonation has been used in municipal drinking water facilities to reduce the Geosmin levels of these compounds, to improve water taste, and to subsequently reduce consumer complaints. In 2-Methylisoborneol Off-flavor this study, the effects of ozone addition to the inlet water of the RAS culture tanks on levels of geosmin Ozone and MIB in the culture water and fish flesh were evaluated.
    [Show full text]
  • Geosmin and 2-MIB Removal by Full-Scale Drinking Water Treatment Processes in the Republic of Korea
    water Article Geosmin and 2-MIB Removal by Full-Scale Drinking Water Treatment Processes in the Republic of Korea Keug Tae Kim 1 and Yong-Gyun Park 2,* 1 Department of Environmental & Energy Engineering, Suwon University, 17 Wauan-gil, Bongdam-eup, Hwaseong-si 18323, Korea; [email protected] 2 Pioneer Team Research Institute, GS Engineering &Construction, 33, Jong-ro, Jongro-gu, Seoul 03159, Korea * Correspondence: [email protected] Abstract: Due to climate change, population growth, industrialization, urbanization, and water contamination, it is becoming more difficult to secure and supply clean and safe drinking water. One of the challenges many water utilities often face is the taste and odor (T&O) problem in drinking water treatment plants, mostly associated with geosmin and 2-MIB. These representative T&O compounds are mainly produced by the metabolism of blue-green algae (cyanobacteria), especially in summer. In this study, the correlation between algae blooms and T&O compounds was identified in the intake and raw water of a large-scale water treatment plant in the Republic of Korea. The removal efficiency of geosmin and 2-MIB by each treatment process was intensively evaluated. According to the obtained results, ozonation and granular activated carbon (GAC) adsorption were more effective for removing the troublesome compounds compared to other water treatment processes, such as coagulation/flocculation, filtration, and chlorination. Because of their seasonal concentration variation and different removal rates, optimal operation methods need to be developed and implemented for drinking water treatment plants to solve the T&O problems. Citation: Kim, K.T.; Park, Y.-G.
    [Show full text]
  • Color, Taste, and Odor: What You Should Know
    Color, Taste, and Odor: What you should know From time to time the MassDEP receives consumer questions or complaints regarding the look, taste or the odor of drinking water. Listed below are common problems with drinking water and their most common causes. Please note that a particular problem in your drinking water may be the result of a cause not listed here; the only way to confirm a cause is to have a certified lab analyze the water and discuss the results with drinking water professional. If you receive water from a public drinking water system it is important to contact the Public Water Supply (PWS) before having a laboratory analyze the water. Information on private water testing is available. Filtering or treating the water may remedy persistent problems; however MassDEP does not recommend filtering or treating your water supply if your water is supplied by a MassDEP- approved PWS. MassDEP also does not regulate or recommend specific treatment systems for private home use. If you decide to use a filtration or treatment device in your home, the Department strongly encourages you to contact National Sanitation Foundation (NSF) for a list of approved devices. If you purchase a treatment device for private home use MassDEP also strongly recommends that it is maintained and provide active maintenance according to the manufacturer's instructions. Failure to maintain the equipment properly may make treatment ineffective and/or may create the potential for contamination. Common problems with drinking water are grouped into three categories: Color problems Taste / odor problems Particles in water If the problem with your water is not described here, if you are on a public water system please contact the public water department in your city or town or the MassDEP Drinking Water Program at your nearest regional MassDEP office.
    [Show full text]
  • Water Quality and Relation to Taste-And-Odor Compounds in the North Fork Ninnescah River and Cheney Reservoir South-Central Kans
    Prepared in cooperation with the City of Wichita, Kansas Water Quality and Relation to Taste-and-Odor Compounds in the North Fork Ninnescah River and Cheney Reservoir, South-Central Kansas, 1997–2003 Scientific Investigations Report 2006−5095 U.S. Department of the Interior U.S. Geological Survey Water Quality and Relation to Taste-and- Odor Compounds in the North Fork Ninnescah River and Cheney Reservoir, South-Central Kansas, 1997–2003 By Victoria G. Christensen, Jennifer L. Graham, Chad R. Milligan, Larry M. Pope, and Andrew C. Ziegler Prepared in cooperation with the City of Wichita, Kansas Scientific Investigations Report 2006–5095 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior P. Lynn Scarlett, Acting Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia: 2006 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 For more information about the USGS and its products: Telephone: 1-888-ASK-USGS World Wide Web: http://www.usgs.gov/ Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Christensen, V.G., Graham, J.L., Milligan, C.R., Pope, L.M., and Ziegler, A.C., 2006, Water quality and relation to taste- and-odor compounds in the North Fork Ninnescah River and Cheney Reservoir, south-central Kansas, 1997–2003: U.S.
    [Show full text]
  • Safety Data Sheet
    SAFETY DATA SHEET According to JIS Z 7253:2019 Revision Date 16-Feb-2021 Version 7.01 Section 1: PRODUCT AND COMPANY IDENTIFICATION Product name (±)-Geosmin-d3 Standard Solution (1mg/mL Methanol Solution) Product code 072-06081 Manufacturer FUJIFILM Wako Pure Chemical Corporation 1-2 Doshomachi 3-Chome Chuo-ku, Osaka 540-8605, Japan Phone: +81-6-6203-3741 Fax: +81-6-6203-5964 Supplier FUJIFILM Wako Pure Chemical Corporation 1-2 Doshomachi 3-Chome, Chuo-ku, Osaka 540-8605, Japan Phone: +81-6-6203-3741 Fax: +81-6-6203-2029 Emergency telephone number +81-6-6203-3741 / +81-3-3270-8571 Recommended uses and For research use only restrictions on use Section 2: HAZARDS IDENTIFICATION GHS classification Classification of the substance or mixture Flammable liquids Category 2 Acute toxicity - Oral Category 4 Serious eye damage/eye irritation Category 2A Reproductive Toxicity Category 1B Specific target organ toxicity (single exposure) Category 1, Category 3 Category 1 central nervous system, Visual organ, systemic toxicity Category 3 Narcotic effects Specific target organ toxicity (repeated exposure) Category 1 Category 1 central nervous system, Visual organ Pictograms Signal word Danger Hazard statements H225 - Highly flammable liquid and vapor H319 - Causes serious eye irritation H302 - Harmful if swallowed H360 - May damage fertility or the unborn child H336 - May cause drowsiness or dizziness H370 - Causes damage to the following organs: central nervous system, Visual organ, systemic toxicity H372 - Causes damage to the following organs through
    [Show full text]
  • STD Glossary of Terms
    STD 101 In A Box- STD Glossary of Terms Abstinence Not having sexual intercourse Acquired A disease of the human immune system caused by the Human Immunodeficiency Virus (HIV). HIV/AIDS represents the entire range of Immunodeficiency disease caused by the HIV virus from early infection to late stage Syndrome (AIDS) symptoms. Anal Intercourse Sexual contact in which the penis enters the anus. Antibiotic A medication that either kills or inhibits the growth of a bacteria. Antiviral A medication that either kills or inhibits the growth of a virus. A thinning of tissue modified by the location. In epidermal atrophy, the epidermis becomes transparent with a loss of skin texture and cigarette Atrophic paper-like wrinkling. In dermal atrophy, there is a loss of connective tissue and the lesion is depressed. A polymicrobial clinical syndrome resulting from replacement of the Bacterial Vaginosis normal hydrogen peroxide producing Lactobacillus sp. in the vagina with (BV) high concentrations of anaerobic bacteria. The common symptom of BV is abnormal homogeneous, off-white, fishy smelling vaginal discharge. Cervical Motion A sign found on pelvic examination suggestive of pelvic pathology; when Tenderness (CMT) movement of the cervix during the bimanual exam elicits pain. The lower, cylindrical end of the uterus that forms a narrow canal Cervix connecting the upper (uterus) and lower (vagina) parts of a woman's reproductive tract. The most common sexually transmitted bacterial infection in the U.S., caused by the bacteria Chlamydia trachomatis. Often no symptoms are present, especially in women. Untreated chlamydia can cause sterility, Chlamydia Pelvic Inflammatory Disease (PID), and increase the chances for life- threatening tubal pregnancies.
    [Show full text]
  • A Pheromone Antagonist Liberates Female Sea Lamprey from a Sensory Trap to Enable Reliable Communication
    A pheromone antagonist liberates female sea lamprey from a sensory trap to enable reliable communication Tyler J. Buchingera,1, Anne M. Scotta,1, Skye D. Fissettea, Cory O. Branta,2, Mar Huertasa,3,KeLia,4, Nicholas S. Johnsonb, and Weiming Lia,5 aDepartment of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824; and bHammond Bay Biological Station, US Geological Survey, Millersburg, MI 49759 Edited by John G. Hildebrand, University of Arizona, Tucson, AZ, and approved February 21, 2020 (received for review December 12, 2019) The evolution of male signals and female preferences remains a subsequent preference evolution precludes a full understanding central question in the study of animal communication. The sensory of how receiver biases shape communication. trap model suggests males evolve signals that mimic cues used Sea lamprey (Petromyzon marinus) are a useful model to track in nonsexual contexts and thus manipulate female behavior to the evolutionary trajectory of communication that originated via generate mating opportunities. Much evidence supports the sen- a sensory trap. Chemical cues and pheromones guide sea lam- sory trap model, but how females glean reliable information from prey behavior throughout their complex life history, especially both mimetic signals and their model cues remains unknown. We during the terminal reproductive phase (21). After parasitizing discovered a mechanism whereby a manipulative male signal guides fish in lakes or the Atlantic Ocean, prespawning sea lamprey reliable communication in sea lamprey (Petromyzon marinus). Mi- migrate into streams following chemical cues released by larvae gratory sea lamprey follow a larval cue into spawning streams; once residing in nursery habitats near spawning grounds.
    [Show full text]
  • Chapter I : General Introduction
    Sorbonne Université Ecole doctorale 129 Science de l’environnement INRA UMR 1402 ECOSYS Écologie fonctionnelle et écotoxicologie des agroécosystèmes Study of the effect of organic waste products amendments and microbial diversity on volatile organic compounds emissions by soil Par Letizia ABIS Thèse de doctorat de Science de l’environnement Dirigée par Benjamin Loubet Présentée et soutenue publiquement le 1 Février 2019 Devant un jury composé de : Rapporteur Michael Staudt HDR CEFE/CRNS Montpellier Rapporteur Françoise Binet HDR ECOBIO Rennes Examinatrice Engracia Madejón DR IRNAS-CSIC Séville Examinateur Thomas Eglin IR ADEME Angers Examinateur Jean-Marie Mouchel PR UPMC Paris Directeur de thèse Benjamin Loubet HDR INRA Grignon Co-directrice de thèse Sophie Bourgeteau-Sadet MC AgrosupDijon/INRA Dijon A mia madre, con tutto l’amore del mondo Acknowledgements Summary BACKGROUND 1 CHAPTER I 3 I. GENERAL INTRODUCTION 5 I.1 What are Volatile Organic Compounds (VOCs)? 5 I.2 The regulatory context 6 I.2.1 VOCs affect human health and crop productions 6 I.2.2 The regulatory context 6 I.3 The role of VOCs in air pollution and climate change 7 I.3.1 The atmosphere composition 7 I.3.2 Tropospheric air pollution 8 I.3.2.1 VOCs lifetime 8 I.3.2.2 The role of VOCs in ozone formation 9 I.3.2.3 VOCs as precursor of particulate matter (or secondary organic aerosol – SOA) 11 I.3.2.3 VOCs effects on air quality and climate change 12 I.4 Biogenic Volatile Organic Compounds 13 I.4.1 Main sources and sinks 13 I.4.2 Feedbacks effects of bVOC on climate 14
    [Show full text]
  • Evaluation of the Impact of Nitrate-Nitrogen Levels in Recirculating Aquaculture Systems on Concentrations of the Off-Flavor
    Aquacultural Engineering 57 (2013) 126–130 View metadata, citation and similar papers at core.ac.uk brought to you by CORE Contents lists available at ScienceDirect provided by Elsevier - Publisher Connector Aquacultural Engineering journal homepage: www.elsevier.com/locate/aqua-online Short communication Evaluation of the impact of nitrate-nitrogen levels in recirculating aquaculture systems on concentrations of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout (Oncorhynchus mykiss) Kevin K. Schrader a,∗, John W. Davidson b, Steven T. Summerfelt b a United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, National Center for Natural Products Research, Post Office Box 8048, University, MS 38677-8048, USA b The Conservation Fund Freshwater Institute, 1098 Turner Road, Shepherdstown, WV 25443, USA article info abstract Article history: Aquatic animals raised in recirculating aquaculture systems (RAS) can develop preharvest “off-flavors” Received 19 May 2013 such as “earthy” or “musty” which are caused by the bioaccumulation of the odorous compounds geosmin Accepted 16 July 2013 or 2-methylisoborneol (MIB), respectively, in their flesh. Tainted aquatic products cause large economic losses to producers due to the inability to market them. Certain species of actinomycetes, a group of fila- Keywords: mentous bacteria, have been attributed as the main sources of geosmin and MIB in RAS. Previous studies Actinomycetes have demonstrated that certain nutritional factors can stimulate or inhibit bacterial biomass and geosmin Geosmin production by certain actinomycetes. In the current study, the effects of two nitrate-nitrogen (NO −-N) 2-Methylisoborneol 3 Nitrate levels (20–40 mg/L and 80–100 mg/L) on geosmin and MIB levels in culture water and the flesh of rainbow Off-flavor trout (Oncorhynchus mykiss) raised in RAS were monitored.
    [Show full text]
  • Taste and Odor Control, but Use As a Control Chemical Must Be Evaluated Carefully Due to the Formation of Thms and Chlorophenol When Organics Are Present
    Taste and Odor Most customers judge the quality of drinking water by taste and odor. If the customer is satisfied with these qualities, it is assumed the water is safe to drink. Many harmful contaminants in water cannot be detected due to taste or smell and many of the contaminants found in drinking water that have a detectable taste or odor are not harmful. Sources of taste and odor problems can be found in surface water and groundwater. Source water protection involves the prevention of contaminants from entering the source. Surface water or groundwater may become contaminated by pollutants such as gasoline, industrial solvents or a wide variety of volatile organics. The removal of contaminants from surface water or groundwater is costly and may involve the use of aeration, powdered activated carbon, or both. If taste and odor must be controlled at the treatment plant, oxidation, aeration and adsorption can be effective in reducing taste and odor, and improved coagulation filtration. ODOR MEASUREMENTS One of the most common methods for measuring odor in water is the threshold odor test. It involves a series of flasks presented to an observer, who is told that some of the samples contain odors and that the series is arranged in order of increasing concentrations. The observer is also given a known odor-free blank for reference during the test. The observer compares the flasks in ascending order with the blank and then notes whether an odor is detected in any sample flask. Individuals vary in their reactions to certain types of odors. An odor stimulus that is agreeable to one may be disagreeable to another.
    [Show full text]
  • Cracking the Odor Code: Molecular and Cellular Deconstruction of the Olfactory Circuit of Drosophila Larvae Kenta Asahina
    Rockefeller University Digital Commons @ RU Student Theses and Dissertations 2008 Cracking the Odor Code: Molecular and Cellular Deconstruction of the Olfactory Circuit of Drosophila Larvae Kenta Asahina Follow this and additional works at: http://digitalcommons.rockefeller.edu/ student_theses_and_dissertations Part of the Life Sciences Commons Recommended Citation Asahina, Kenta, "Cracking the Odor Code: Molecular and Cellular Deconstruction of the Olfactory Circuit of Drosophila Larvae" (2008). Student Theses and Dissertations. Paper 196. This Thesis is brought to you for free and open access by Digital Commons @ RU. It has been accepted for inclusion in Student Theses and Dissertations by an authorized administrator of Digital Commons @ RU. For more information, please contact [email protected]. Cracking the Odor Code: Molecular and Cellular Deconstruction of the Olfactory Circuit of Drosophila Larvae A Thesis Presented to the Faculty of The Rockefeller University in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy By Kenta Asahina June 2008 © Copyright by Kenta Asahina 2008 CRACKING THE ODOR CODE: MOLECULAR AND CELLULAR DECONSTRUCTION OF THE OLFACTORY CIRCUIT OF DROSOPHILA LARVAE Kenta Asahina, Ph.D. The Rockefeller University 2008 The Drosophila larva offers a powerful model system to investigate the general principles by which the olfactory system processes behaviorally relevant sensory stimuli. The numerically reduced larval olfactory system relieves the formidable molecular and cellular complexity found in other organisms. This thesis presents a study in four parts that investigates molecular and neuronal mechanisms of larval odor coding. First, the larval odorant receptor (OR) repertoire was characterized. ORs define the olfactory receptive range of an animal.
    [Show full text]