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Sample records for water disinfection byproducts

  1. Water disinfection agents and disinfection by-products

    Science.gov (United States)

    Ilavský, J.; Barloková, D.; Kapusta, O.; Kunštek, M.

    2017-10-01

    The aim of this work is to describe factors of water quality change in the distribution network and legislative requirements in Slovakia for disinfectants and disinfection byproducts (DBPs). In the experimental part, the time dependence of the application of the chlorine dioxide and sodium hypochlorite on the formation of some by-products of disinfection for drinking water from WTP Hriňová is studied. We monitored trihalomethanes, free chlorine, chlorine dioxide and chlorites.

  2. Studies on Disinfection By-Products and Drinking Water

    Science.gov (United States)

    Rostad, Colleen E.

    2007-01-01

    Drinking water is disinfected with chemicals to remove pathogens, such as Giardia and Cryptosproridium, and prevent waterborne diseases such as cholera and typhoid. During disinfection, by-products are formed at trace concentrations. Because some of these by-products are suspected carcinogens, drinking water utilities must maintain the effectiveness of the disinfection process while minimizing the formation of by-products.

  3. Biological Treatment of Water Disinfection Byproducts using ...

    Science.gov (United States)

    Major disinfection by-products (DBPs) from the chlorination process of drinking water include trihalomethanes (THMs) and haloacetic acides (HAA5). THMs mainly consist of chloroform, and other harsh chemicals. Prolonged consumptions of drinking water containing high levels of THMs has been linked with diseases of the liver, kidneys, bladder, or central nervous system and may increase likelihood of cancer. A risk also exists for THMs exposure via inhalation while showering, bathing or washing clothes and dishes. Due to these risks, the U.S. EPA regulate THMs content in drinking water. This research investigates biological degradation of THM using chloroform as a model compound. The study aims to decrease possible risks of THMs through filtration. Throughout this year’s presentations, there is a common theme of health and safety concerns. UC researchers are working hard to clean water ways of naturally occurring contaminates as well as man-made toxins found in our waterways. The significance of these presentations translates into the promise of safer environments, and more importantly saved lives, as UC’s faculty continues to produce real-world solutions to problems threatening the world around us. A biotech process has been developed and demonstrated that effectively remove and treat volatile disinfection by-products from drinking water. The process strips low concentration disinfection by-products, such as trihalomethanes, that are formed during the chlori

  4. IDENTIFICATION OF TI02/UV DISINFECTION BYPRODUCTS IN DRINKING WATER

    Science.gov (United States)

    Due to concern over the presence of trihalomethanes (THMs) and other chlorinated byproducts in chlorinated drinking water, alternative disinfection methods are being explored. One of the alternative treatment methods currently being evaluated for potential use with small systems ...

  5. Chlorine dioxine DBPs (disinfection by-products in drinking water

    Directory of Open Access Journals (Sweden)

    C. Lasagna

    2013-01-01

    Full Text Available Since the 1970s it has been well known that, though water for human consumption is generally disinfected before being distributed along the network, the use of chemicals results in the formation of many different Disinfection By-Products (DBPs. In the case of chlorine dioxide, the most important and represented DBPs are chlorite and chlorate: after an introduction concerning the current Italian regulation on this subject, in the experimental part the results of a 7-year minitoring campaign, concerning water of different origin collected from taps in various Italian regions, are shown. The analytical technique used for the determination of chlorite and chlorate was Ion Chromatography. The result obtained are finally discussed.

  6. Disinfection Methods for Swimming Pool Water: Byproduct Formation and Control

    Directory of Open Access Journals (Sweden)

    Huma Ilyas

    2018-06-01

    Full Text Available This paper presents a comprehensive and critical comparison of 10 disinfection methods of swimming pool water: chlorination, electrochemically generated mixed oxidants (EGMO, ultraviolet (UV irradiation, UV/chlorine, UV/hydrogen peroxide (H2O2, UV/H2O2/chlorine, ozone (O3/chlorine, O3/H2O2/chlorine, O3/UV and O3/UV/chlorine for the formation, control and elimination of potentially toxic disinfection byproducts (DBPs: trihalomethanes (THMs, haloacetic acids (HAAs, haloacetonitriles (HANs, trihaloacetaldehydes (THAs and chloramines (CAMs. The statistical comparison is carried out using data on 32 swimming pools accumulated from the reviewed studies. The results indicate that O3/UV and O3/UV/chlorine are the most promising methods, as the concentration of the studied DBPs (THMs and HANs with these methods was reduced considerably compared with chlorination, EGMO, UV irradiation, UV/chlorine and O3/chlorine. However, the concentration of the studied DBPs including HAAs and CAMs remained much higher with O3/chlorine compared with the limits set by the WHO for drinking water quality. Moreover, the enhancement in the formation of THMs, HANs and CH with UV/chlorine compared with UV irradiation and the increase in the level of HANs with O3/UV/chlorine compared with O3/UV indicate the complexity of the combined processes, which should be optimized to control the toxicity and improve the quality of swimming pool water.

  7. ANALYTICAL METHODS FOR WATER DISINFECTION BY-PRODUCTS IN FOODS AND BEVERAGES

    Science.gov (United States)

    The determination of exposure to drinking water disinfection byproducts (DBPs) requires an understanding of how drinking waters come into contact with the human through multiple pathways. The most significant pathway is the ingestion of drinking water. However, ingestion can oc...

  8. Integrated Disinfection By-Products Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection By-Products from Water Disinfected by Chlorination and Ozonation/Postchlorination

    Science.gov (United States)

    To conduct the health-effect studies described in subsequent articles in this series, concentrated aqueous mixtures of disinfection by-products were required for the two water treatment trains described in the preceding article (Miltner et al., 2008). To accomplish this, the fini...

  9. Chloraminated Concentrated Drinking Water for Disinfection Byproduct Mixtures Research: Evaluating Free Chlorine Contact Times

    Science.gov (United States)

    Complex mixtures of disinfection by-products (DBPs) are formed when the disinfectant oxidizes constituents (e.g., natural organic matter (NOM) and organic pollutants) present in the source water. Since 1974, over 600 DBPs have been identified in drinking water, yet a large portio...

  10. Chloramination of Concentrated Drinking Water for Disinfection Byproduct Mixtures Creation- Indianapolis

    Science.gov (United States)

    Complex mixtures of disinfection by-products (DBPs) are formed when the disinfectant oxidizes constituents (e.g., natural organic matter (NOM) and organic pollutants) found in the source water. Since 1974, over 600 DBPs have been identified in drinking water. Despite intense iden...

  11. Chloramination of Concentrated Drinking Water: Evaluation of Disinfection Byproduct Formation and Dosing Scenarios - Portland

    Science.gov (United States)

    Complex mixtures of disinfection by-products (DBPs) are formed when the disinfectant oxidizes constituents (e.g., natural organic matter (NOM) and organic pollutants) found in the source water. Since 1974, over 600 DBPs have been identified in drinking water. Despite intense iden...

  12. ANALYTICAL METHODS FOR WATER DISINFECTION BY-PRODUCTS IN FOODS AND BEVERAGES

    Science.gov (United States)

    The determination of exposure to drinking water disinfection byproducts (DBPs) requires an understanding of how drinking water comes in contact with humans through multiple pathways. In order to facilitate the investigation of human exposure to DBPs via foods and beverages, analy...

  13. Secondary formation of disinfection by-products by UV treatment of swimming pool water

    DEFF Research Database (Denmark)

    Spiliotopoulou, Aikaterini; Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus

    2015-01-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile...

  14. Disinfection by-products and extractable organic compounds in South African tap water

    Directory of Open Access Journals (Sweden)

    Carien Nothnagel

    2008-04-01

    Full Text Available An important step in urban purification of drinking water is disinfection by e.g. chlorination where potential pathogenic micro-organisms in the water supply are killed. The presence of organic material in natural water leads to the formation of organic by- products during disinfection. Over 500 of these disinfection by-products (DBPs have been identified and many more are estimated to form during the disinfection step. Several DBPs such as trihalomethanes (THMs, which is carcinogenic, poses serious health risks to the community. There is very few quantitative data available which realizes the actual levels of these compounds present in drinking water. The levels of four THMs present in drinking water were measured. It included chloroform, bromodichloromethane, chlorodibromomethane and bromoform. Although microbiological parameters are considered to get more attention than disinfection by-products, the measurement of the levels of these compounds in South-African drinking water is essential together with establishing minimum acceptable concentration levels. The target range for total trihalomethanes (TTHMs established by the US EPA at the end of 2003 is 0-0.08ug/mL. The aim of this paper is to create an awareness of the problem as well as presenting preliminary results obtained with the method of analysis. Preliminary results indicate that urgent attention must be given to the regulation and monitoring of DBPs in South African drinking water.

  15. MUTAGENICITY AND DISINFECTION BY-PRODUCTS IN SURFACE DRINKING WATER DISINFECTED WITH PERACETIC ACID

    Science.gov (United States)

    The aims of this research were to study the influence of peracetic acid (PAA) on the formation of mutagens in surface waters used for human consumption and to assess its potential application for the disinfection of drinking water. The results obtained using PAA were compared to ...

  16. Formation of nitrogenous disinfection by-products in 10 chlorinated and chloraminated drinking water supply systems.

    Science.gov (United States)

    Liew, Deborah; Linge, Kathryn L; Joll, Cynthia A

    2016-09-01

    The presence of nitrogenous disinfection by-products (N-DBPs) in drinking water supplies is a public health concern, particularly since some N-DBPs have been reported to be more toxic than the regulated trihalomethanes and haloacetic acids. In this paper, a comprehensive evaluation of the presence of N-DBPs in 10 drinking water supply systems in Western Australia is presented. A suite of 28 N-DBPs, including N-nitrosamines, haloacetonitriles (HANs), haloacetamides (HAAms) and halonitromethanes (HNMs), were measured and evaluated for relationships with bulk parameters in the waters before disinfection. A number of N-DBPs were frequently detected in disinfected waters, although at generally low concentrations (water, N-DBP concentrations were significantly correlated with dissolved organic carbon (DOC) and ammonia, and these, in addition to high bromide in one of the waters, led to elevated concentrations of brominated HANs (26.6 μg/L of dibromoacetonitrile). There were significant differences in the occurrence of all classes of N-DBPs between chlorinated and chloraminated waters, except for HNMs, which were detected at relatively low concentrations in both water types. Trends observed in one large distribution system suggest that N-DBPs can continue to form or degrade within distribution systems, and redosing of disinfectant may cause further by-product formation.

  17. Seasonal evaluation of disinfection by-products throughout two full-scale drinking water treatment plants.

    Science.gov (United States)

    Zhong, Xin; Cui, Chongwei; Yu, Shuili

    2017-07-01

    Carbonyl compounds can occur alpha-hydrogens or beta-diketones substitution reactions with disinfectants contributed to halogenated by-products formation. The objective of this research was to study the occurrence and fate of carbonyl compounds as ozonation by-products at two full-scale drinking water treatment plants (DWTPs) using different disinfectants for one year. The quality of the raw water used in both plants was varied according to the season. The higher carbonyl compounds concentrations were found in raw water in spring. Up to 15 (as the sum of both DWTPs) of the 24 carbonyl compounds selected for this work were found after disinfection. The dominant carbonyl compounds were formaldehyde, glyoxal, methyl-glyoxal, fumaric, benzoic, protocatechuic and 3-hydroxybenzoic acid at both DWTPs. In the following steps in each treatment plant, the concentration patterns of these carbonyl compounds differed depending on the type of disinfectant applied. Benzaldehyde was the only aromatic aldehyde detected after oxidation with ozone in spring. As compared with DWTP 1, five new carbonyl compounds were formed (crotonaldehyde, benzaldehyde, formic, oxalic and malonic acid) disinfection by ozone, and the levels of the carbonyl compounds increased. In addition, pre-ozonation (PO) and main ozonation (OZ) increased the levels of carbonyl compounds, however coagulation/flocculation (CF), sand filtration (SF) and granular activated carbon filtration (GAC) decreased the levels of carbonyl compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Disinfection aboard cruise liners and naval units: formation of disinfection by-products using chlorine dioxide in different qualities of drinking water.

    Science.gov (United States)

    Ufermann, Petra; Petersen, Hauke; Exner, Martin

    2011-12-01

    The world-wide deployment of cruise liners and naval units has caused an increased need for the disinfection of drinking water. The main cause for this is the unknown quality of drinking water in foreign harbours--besides the formation of bio-films due to the climatically disadvantageous conditions in the operational area. Water conduits on board are currently disinfected with calcium hypochlorite in case of microbiological contamination. Chemical and physical analyses after disinfection with calcium hypochlorite have shown that organic by-products consisting of trihalomethanes develop in considerable amounts during disinfection. Furthermore, the method is susceptible to handling errors and thus often leads to insufficient disinfection results. Hitherto, the use of other disinfection methods allowed by government regulations, especially chlorine dioxide, is not widely spread. Unlike disinfection with calcium hypochlorite, chlorine dioxide does not lead to the formation of trihalomethanes. Typical disinfection by-products (DBP) are the anions chlorite and chlorate, which are formed in oxidative processes. The formation conditions of these anions have not yet been elucidated. For this reason, the probability of the generation of inorganic by-products after disinfection with chlorine dioxide has been determined, and their occurrence in drinking water on board has been examined with respect to a possible correlation between water quality and the formation of chlorate and chlorite. Therefore, a chromatographic method was developed and validated in order to determine the periodical development of chlorate and chlorite from chorine dioxide in purified water at different pH-values as well as in actual drinking water samples from water conduits on board. The formation of the by-products chlorite and chlorate after disinfection with chlorine dioxide is influenced neither by pH-value nor by chemical properties of the disinfected water. Considering the examined conditions

  19. Disinfection Byproduct Formation in Reverse-Osmosis Concentrated and Lyophilized Natural Organic Matter from a Drinking Water Source

    Science.gov (United States)

    Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking wa...

  20. Halogenated by-products of disinfecting ozonised recreational waters; Subproductos halaogenados de desinfeccion en aguas recreacionales ozonizadas

    Energy Technology Data Exchange (ETDEWEB)

    Goma i Huguet, A.; Quintana i Comte, J.; Soler i Vilaro, J.

    2005-07-01

    Recreational water like the present in swimming pools suffers, more than water from supply, formation of certain by-products in the local disinfection system because a mechanism of accumulation. Using advanced oxidation process, like onization, drives to a reduction of such an effect. Assessment of the presence of these disinfection by-products with and without onization, as well as the discussion of certain key aspects of how to ozonate, are the aim of this paper. (Author) 7 refs.

  1. Models for predicting disinfection byproduct (DBP) formation in drinking waters: a chronological review.

    Science.gov (United States)

    Chowdhury, Shakhawat; Champagne, Pascale; McLellan, P James

    2009-07-01

    Disinfection for the supply of safe drinking water forms a variety of known and unknown byproducts through reactions between the disinfectants and natural organic matter. Chronic exposure to disinfection byproducts through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. Since their discovery in drinking water in 1974, numerous studies have presented models to predict DBP formation in drinking water. To date, more than 48 scientific publications have reported 118 models to predict DBP formation in drinking waters. These models were developed through laboratory and field-scale experiments using raw, pretreated and synthetic waters. This paper aims to review DBP predictive models, analyze the model variables, assess the model advantages and limitations, and to determine their applicability to different water supply systems. The paper identifies the current challenges and future research needs to better control DBP formation. Finally, important directions for future research are recommended to protect human health and to follow the best management practices.

  2. Socioeconomic status and exposure to disinfection by-products in drinking water in Spain

    Directory of Open Access Journals (Sweden)

    Serra Consol

    2011-03-01

    Full Text Available Abstract Background Disinfection by-products in drinking water are chemical contaminants that have been associated with cancer and other adverse effects. Exposure occurs from consumption of tap water, inhalation and dermal absorption. Methods We determined the relationship between socioeconomic status and exposure to disinfection by-products in 1271 controls from a multicentric bladder cancer case-control study in Spain. Information on lifetime drinking water sources, swimming pool attendance, showering-bathing practices, and socioeconomic status (education, income was collected through personal interviews. Results The most highly educated subjects consumed less tap water (57% and more bottled water (33% than illiterate subjects (69% and 17% respectively, p-value = 0.003. These differences became wider in recent time periods. The time spent bathing or showering was positively correlated with attained educational level (p Conclusions The most highly educated subjects were less exposed to chlorination by-products through ingestion but more exposed through dermal contact and inhalation in pools and showers/baths. Health risk perceptions and economic capacity may affect patterns of water consumption that can result in differences in exposure to water contaminants.

  3. Do Iodine Contrast Media Compounds Used for Medical Imaging Contribute to the Formation of Iodinated Disinfection By-Products in Drinking Water?

    Science.gov (United States)

    Iodinated disinfection byproducts (DBPs) have recently gained attention due to their cyto- and genotoxicity and increased formation in drinking water treated with chloramine, which has become an increasingly popular disinfectant in the United States. One of these—iodoacetic acid...

  4. Effect of drinking water disinfection by-products in human peripheral blood lymphocytes and sperm.

    Science.gov (United States)

    Ali, Aftab; Kurzawa-Zegota, Malgorzata; Najafzadeh, Mojgan; Gopalan, Rajendran C; Plewa, Michael J; Anderson, Diana

    2014-12-01

    Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses. Copyright © 2014. Published by Elsevier B.V.

  5. The Occurrence and Comparative Toxicity of Haloacetaldehyde Disinfection Byproducts in Drinking Water

    Science.gov (United States)

    The introduction of drinking water disinfection greatly reduced the incidence of waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water can lead to an unintended consequence, which is the formation of drinking water disinfe...

  6. Comparison of permanganate preoxidation and preozonation on algae containing water: cell integrity, characteristics, and chlorinated disinfection byproduct formation.

    Science.gov (United States)

    Xie, Pengchao; Ma, Jun; Fang, Jingyun; Guan, Yinghong; Yue, Siyang; Li, Xuchun; Chen, Liwei

    2013-12-17

    Aqueous suspensions of Microcystis aeruginosa were preoxidized with either ozone or permanganate and then subjected to chlorination under conditions simulating drinking water purification. The impacts of the two oxidants on the algal cells and on the subsequent production of dissolved organic matter and disinfection byproducts were investigated. Preozonation dramatically increased disinfection byproduct formation during chlorination, especially the formation of haloaldehydes, haloacetonitriles, and halonitromethanes. Preoxidation with permanganate had much less effect on disinfection byproduct formation. Preozonation destroyed algal cell walls and cell membranes to release intracellular organic matter (IOM), and less than 2.0% integrated cells were left after preozonation with the dosage as low as 0.4 mg/L. Preoxidation with permanganate mainly released organic matter adsorbed on the cells' surface without causing any damage to the cells' integrity, so the increase in byproduct formation was much less. More organic nitrogen and lower molecular weight precursors were produced in a dissolved phase after preozonation than permanganate preoxidation, which contributes to the significant increase of disinfection byproducts after preozonation. The results suggest that permanganate is a better choice than ozone for controlling algae derived pollutants and disinfection byproducts.

  7. Characterization of soluble microbial products as precursors of disinfection byproducts in drinking water supply.

    Science.gov (United States)

    Liu, Jin-Lin; Li, Xiao-Yan; Xie, Yue-Feng; Tang, Hao

    2014-02-15

    Water pollution by wastewater discharge can cause the problem of disinfection byproducts (DBPs) in drinking water supply. In this study, DBP formation characteristics of soluble microbial products (SMPs) as the main products of wastewater organic biodegradation were investigated. The results show that SMPs can act as DBP precursors in simulated wastewater biodegradation process. Under the experimental conditions, stabilized SMPs had DBPFP (DBP formation potential) yield of around 5.6 μmol mmol(-1)-DOC (dissolved organic carbon) and DBP speciation profile different from that of the conventional precursor, natural organic matter (NOM). SMPs contained polysaccharides, proteins, and humic-like substances, and the latter two groups can act as reactive DBP precursors. SMP fraction with molecular weight of water treatment processes, more efforts are needed to control wastewater-derived DBP problem in water resource management. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Reproductive toxicity of a mixture of regulated drinking-water disinfection by-products in a multigenerational rat bioassay

    Science.gov (United States)

    BACKGROUND:Trihalomethanes (THMs) and haloaretic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.OBJECTIVE: We aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs ...

  9. Formation and occurrence of new polar iodinated disinfection byproducts in drinking water.

    Science.gov (United States)

    Pan, Yang; Li, Wenbin; An, Hao; Cui, Hao; Wang, Ying

    2016-02-01

    During drinking water disinfection, iodinated disinfection byproducts (I-DBPs) can be generated through reactions between iodide, disinfectants, and natural organic matter. Drinking water I-DBPs have been increasingly attracting attention as emerging organic pollutants as a result of their significantly higher toxicity and growth inhibition than their chloro- and bromo-analogues. In this study, by adopting ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry precursor ion scan, multiple reaction monitoring, and product ion scan analyses, 11 new polar I-DBPs with confirmed structures and eight new polar I-DBPs with proposed structures were detected in simulated drinking water samples. Chloramination of simulated raw waters containing natural organic matter with higher aromaticity produced higher levels of new phenolic I-DBPs. Formation of new polar I-DBPs and total organic iodine (TOI) was most favored in chloramination, followed by chlorine dioxide treatment, and relatively minor in chlorination. Lower pH in chloramination substantially enhanced the formation of new polar I-DBPs and TOI. NH2Cl and dissolved organic nitrogen could be important nitrogen sources and precursors for formation of the two new nitrogenous phenolic I-DBPs. Notably, in tap water samples collected from nine major cities located in the Yangtze River Delta region of China, seven of the 11 new polar I-DBPs with confirmed structures were detected at levels from 0.11 to 28 ng/L, and the two new nitrogenous phenolic I-DBPs were ubiquitous with concentrations from 0.12 to 24 ng/L, likely due to the relatively high dissolved organic nitrogen levels in regional source waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Nitrogenous disinfection byproducts in English drinking water supply systems: Occurrence, bromine substitution and correlation analysis.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Mokhtar Kamal, Nurul Hana; Graham, Nigel; Kanda, Rakesh

    2015-11-15

    Despite the recent focus on nitrogenous disinfection byproducts in drinking water, there is limited occurrence data available for many species. This paper analyses the occurrence of seven haloacetonitriles, three haloacetamides, eight halonitromethanes and cyanogen chloride in 20 English drinking water supply systems. It is the first survey of its type to compare bromine substitution factors (BSFs) between the haloacetamides and haloacetonitriles. Concentrations of the dihalogenated haloacetonitriles and haloacetamides were well correlated. Although median concentrations of these two groups were lower in chloraminated than chlorinated surface waters, median BSFs for both in chloraminated samples were approximately double those in chlorinated samples, which is significant because of the higher reported toxicity of the brominated species. Furthermore, median BSFs were moderately higher for the dihalogenated haloacetamides than for the haloacetonitriles. This indicates that, while the dihalogenated haloacetamides were primarily generated from hydrolysis of the corresponding haloacetonitriles, secondary formation pathways also contributed. Median halonitromethane concentrations were remarkably unchanging for the different types of disinfectants and source waters: 0.1 μg · mgTOC(-1) in all cases. Cyanogen chloride only occurred in a limited number of samples, yet when present its concentrations were higher than the other N-DBPs. Concentrations of cyanogen chloride and the sum of the halonitromethanes were not correlated with any other DBPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Kinetic model for the radical degradation of tri-halonitromethane disinfection byproducts in water

    International Nuclear Information System (INIS)

    Mezyk, Stephen P.; Mincher, Bruce J.; Cooper, William J.; Kirkham Cole, S.; Fox, Robert V.; Gardinali, Piero R.

    2012-01-01

    The halonitromethanes (HNMs) are byproducts of the ozonation and chlorine/chloramine treatment of drinking waters. Although typically occurring at low concentrations HNMs have high cytotoxicity and mutagenicity, and may therefore represent a significant human health hazard. In this study, we have investigated the radical based mineralization of fully-halogenated HNMs in water using the congeners bromodichloronitromethane and chlorodibromonitromethane. We have combined absolute reaction rate constants for their reactions with the hydroxyl radical and the hydrated electron as measured by electron pulse radiolysis and analytical measurements of stable product concentrations obtained by 60 Co steady-state radiolysis with a kinetic computer model that includes water radiolysis reactions and halide/nitrogen oxide radical chemistry to fully elucidate the reaction pathways of these HNMs. These results are compared to our previous similar study of the fully chlorinated HNM chloropicrin. The full optimized computer model, suitable for predicting the behavior of this class of compounds in irradiated drinking water, is provided. - Highlights: ► Radical-based mineralization of aqueous halonitromethane disinfection byproducts. ► Constructed kinetic computer model for tri-halogenated halonitromethane removal. ► Model predicted that superoxide reaction is unimportant for halonitromethanes. ► Measured superoxide reaction with chloropicrin was negligibly slow, 4 M −1 s −1 . ► Determined that superoxide reaction with nitrate also insignificant at ∼10 4 M −1 s −1 .

  12. Ozone and hydrogen peroxide applications for disinfection by-products control in drinking water

    International Nuclear Information System (INIS)

    Collivignarelli, C.; Sorlini, S.; Riganti, V.

    2001-01-01

    A great interest has been developed during the last years for ozone in drinking water treatments thanks to its strong oxidant and disinfectant power and for its efficiency in disinfection by-products (DBPs) precursors removal. However ozonization produces some specific DBPs, such as aldehydes and ketones; moreover, the presence of bromide in raw water engages ozone in a complex cycle in which both organic bromide and inorganic bromate are end products. In this paper the combination of hydrogen peroxide with ozone (known as peroxone process) and the ozone alone process were experimented on one surface water coming from the lake of Brugneto (Genova) in order to investigate bromate formation and trihalomethanes precursors removal during the oxidation process. The results show that the advanced peroxone process can be applied for bromate reduction (about 30-40%) with better results in comparison with the ozone alone process, while no advantages are shown for THMs precursors removal. The addition of in-line filtration step after pre-oxidation improves both bromate and THMs precursors removal, particularly with increasing hydrogen peroxide/ozone ratio in the oxidation step [it

  13. Evidence of arsenic release promoted by disinfection by-products within drinking-water distribution systems.

    Science.gov (United States)

    Andra, Syam S; Makris, Konstantinos C; Botsaris, George; Charisiadis, Pantelis; Kalyvas, Harris; Costa, Costas N

    2014-02-15

    Changes in disinfectant type could trigger a cascade of reactions releasing pipe-anchored metals/metalloids into finished water. However, the effect of pre-formed disinfection by-products on the release of sorbed contaminants (arsenic-As in particular) from drinking water distribution system pipe scales remains unexplored. A bench-scale study using a factorial experimental design was performed to evaluate the independent and interaction effects of trihalomethanes (TTHM) and haloacetic acids (HAA) on arsenic (As) release from either scales-only or scale-biofilm conglomerates (SBC) both anchored on asbestos/cement pipe coupons. A model biofilm (Pseudomonas aeruginosa) was allowed to grow on select pipe coupons prior experimentation. Either TTHM or HAA individual dosing did not promote As release from either scales only or SBC, detecting water. In the case of scales-only coupons, the combination of the highest spike level of TTHM and HAA significantly (pwater in pipe networks remains to be investigated in the field. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Predictive model for disinfection by-product in Alexandria drinking water, northern west of Egypt.

    Science.gov (United States)

    Abdullah, Ali M; Hussona, Salah El-dien

    2013-10-01

    Chlorine has been utilized in the early stages of water treatment processes as disinfectant. Disinfection for drinking water reduces the risk of pathogenic infection but may pose a chemical threat to human health due to disinfection residues and their by-products (DBP) when the organic and inorganic precursors are present in water. In the last two decades, many modeling attempts have been made to predict the occurrence of DBP in drinking water. Models have been developed based on data generated in laboratory-scale and field-scale investigations. The objective of this paper is to develop a predictive model for DBP formation in the Alexandria governorate located at the northern west of Egypt based on field-scale investigations as well as laboratory-controlled experimentations. The present study showed that the correlation coefficient between trihalomethanes (THM) predicted and THM measured was R (2)=0.88 and the minimum deviation percentage between THM predicted and THM measured was 0.8 %, the maximum deviation percentage was 89.3 %, and the average deviation was 17.8 %, while the correlation coefficient between dichloroacetic acid (DCAA) predicted and DCAA measured was R (2)=0.98 and the minimum deviation percentage between DCAA predicted and DCAA measured was 1.3 %, the maximum deviation percentage was 47.2 %, and the average deviation was 16.6 %. In addition, the correlation coefficient between trichloroacetic acid (TCAA) predicted and TCAA measured was R (2)=0.98 and the minimum deviation percentage between TCAA predicted and TCAA measured was 4.9 %, the maximum deviation percentage was 43.0 %, and the average deviation was 16.0 %.

  15. Occurrence of nitrogenous and carbonaceous disinfection byproducts in drinking water distributed in Shenzhen, China.

    Science.gov (United States)

    Huang, Huang; Zhu, Haihui; Gan, Wenhui; Chen, Xue; Yang, Xin

    2017-12-01

    A 12-month sampling program was conducted throughout a drinking water distribution system in Shenzhen and the data from 251 samples provide a comprehensive picture of the spatial and seasonal variability of 17 species disinfection by-products (DBPs) in a city with subtropical monsoon climate. The carbonaceous disinfection by-product (C-DBPs) included four trihalomethanes (THMs), three trihaloacetaldehydes (THAs) and two haloketones (HKs). Their median concentrations over the entire period were 19.9 μg/L, 3.4 μg/L and 1.4 μg/L, respectively. The nitrogenous DBPs (N-DBPs) monitored were four haloacetonitriles (HANs) and four haloacetamides (HAcAms). Their median levels were 2.0 μg/L and 1.5 μg/L, respectively. Low levels of brominated DBP species (bromine substitution factors ≤ 0.5) were observed. The BSF of each DBP class followed the trend: THMs ≈ DHAcAms > DHANs > THAs. All the DBP concentrations showed clear seasonal variations with the highest average concentrations in spring. Correlation analyses showed that the THMs and CH levels in Shenzhen drinking water could be used as statistical indicators of the levels of unregulated N-DBPs (0.4 water in China, and provide an important reference data set for DBP occurrence in cities with a subtropical monsoon climate around the world. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. EPIDEMIOLOGIC EVALUATION OF THE POTENTIAL ASSOCIATION BETWEEN EXPOSURE TO DRINKING WATER DISINFECTION BY-PRODUCTS (DBP) AND SEMEN QUALITY

    Science.gov (United States)

    Epidemiologic Evaluation of the Potential Association between Exposure to Drinking Water Disinfection By-Products and Semen Quality*Morris, R; +Olshan, A; +Lansdell, L; *Jeffay, S; *Strader, L; *Klinefelter, G; *Perreault, S.* U.S. EPA/ORD/NHEERL/RTD/GEEBB, Research ...

  17. Analysis, Occurrence and Toxicity of Haloacetaldehydes in Drinking Waters: Iodacetaldehyde as an Emerging Disinfection ByProduct.

    Science.gov (United States)

    Chlorinated and brominated haloacetaldehydes (HALs) are consideredthe 3rd largest class of disinfection by-products (DBPs) by weight. The iodinatedHAL, iodoacetaldehyde, has been recently reported as an emerging DBP infinished drinking waters. Overall, iodinated DBPs, e.g., iodoa...

  18. Combining Mass Spectrometry and Toxicology for a Multi-Country European Epidemiologic Study on Drinking Water Disinfection By-Products

    Science.gov (United States)

    The HiWATE (Health Impacts of long-term exposure to disinfection by-products in drinking WATEr) project is the first systematic analysis that combines the epidemiology on adverse pregnancy outcomes with analytical chemistry and analytical biology in the European Union. This study...

  19. Detection of genotoxic effects of drinking water disinfection by-products using Vicia faba bioassay.

    Science.gov (United States)

    Hu, Yu; Tan, Li; Zhang, Shao-Hui; Zuo, Yu-Ting; Han, Xue; Liu, Na; Lu, Wen-Qing; Liu, Ai-Lin

    2017-01-01

    Plant-based bioassays have gained wide use among the toxicological and/or ecotoxicological assessment procedures because of their simplicity, sensitivity, low cost, and reliability. The present study describes the use of Vicia faba (V. faba) micronucleus (MN) test and V. faba comet assay in the evaluation of the genotoxic potential of disinfection by-products (DBPs) commonly found in chlorine-disinfected drinking water. Five haloacetic acids and three halogenated acetonitriles were chosen as representatives of DBPs in this study because they are of potentially great public health risk. Results of the MN test indicated that monochloroacetic acid (MCA), monobromoacetic acid (MBA), dichloroacetic acid (DCA), dibromoacetic acid (DBA), trichloroacetic acid (TCA), and trichloroacetonitrile (TCAN) caused a statistically significant increase in MN frequency in V. faba root tip cells. However, no genotoxic response was observed for dichloroacetonitrile (DCAN) and dibromoacetonitrile (DBAN). Results of the comet assay showed that all tested DBPs induced a statistically significant increase in genomic DNA damage to V. faba root tip cells. On considering the capacity to detect genomic damage of a different nature, we suggest that a combination of V. faba MN test and V. faba comet assay is a useful tool for the detection of genotoxic effects of DBPs. It is worthy of assessing the feasibility of using V. faba comet assay combined with V. faba MN test to screen for the genotoxic activity of chlorinated drinking water in future work.

  20. The determination and fate of disinfection by-products from ozonation of polluted raw water

    International Nuclear Information System (INIS)

    Huang, W.-J.; Fang, G.-C.; Wang, C.-C.

    2005-01-01

    The major disinfection by-products (DBPs) resulting from ozone treatment of polluted surface water were investigated. By-products of either health concern or which may contribute to biological instability of treated drinking water were investigated. The major DBPs were analyzed in two fractions: carbonyl compounds and brominated organic compounds. The natural organic matter (NOM) was also isolated and fractionated from polluted water for subsequent ozonation and DBPs identification under conditions of typical drinking treatment. The main identified carbonyl compounds were low molecular weight carboxylic acids, benzoic compounds, aliphatic aldehydes and odorous aldehydes, respectively. Brominated organics were also found in ozonated water, including bromoform (CHBr 3 ), monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), 2,4-dibromophenol (2,4-DBP) and dibromoacetonitrile (DBAN), respectively. It was also found that the characteristic of organic precursors have significant influences on brominated organic by-products formation. Humic acid demonstrated the highest CHBr 3 , DBAA and 2,4-DBP formations, whereas hydrophilic neutral produced less CHBr 3 and 2,4-DBP than the rest of the organic fractions but produced the highest amount of DBAN. In addition to the other target compounds, a total of 59 different organic compounds were detected by means of gas chromatograph/high-resolution electron-impact mass spectrometry (GC/EI-MS) detection and tentatively identified using mass spectral library searching, mainly aromatics, acids/esters, alcohols, aldehydes, phthalates and amines/amino acids were analyzed. The percentage of elimination or formation levels reached during ozonation is also discussed in this study

  1. Hazard assessment of three haloacetic acids, as byproducts of water disinfection, in human urothelial cells.

    Science.gov (United States)

    Marsà, Alicia; Cortés, Constanza; Hernández, Alba; Marcos, Ricard

    2018-04-07

    Disinfection by-products (DBPs) are compounds produced in the raw water disinfection processes. Although increased cancer incidence has been associated with exposure to this complex mixture, the carcinogenic potential of individual DBPs remains not well known; thus, further studies are required. Haloacetic acids (HAAs) constitute an important group among DBPs. In this study, we have assessed the in vitro carcinogenic potential of three HAAs namely chloro-, bromo-, and iodoacetic acids. Using a long-term (8 weeks) and sub-toxic doses exposure scenario, different in vitro transformation markers were evaluated using a human urothelial cell line (T24). Our results indicate that long-term exposure to low doses of HAAs did not reproduce the genotoxic effects observed in acute treatments, where oxidative DNA damage was induced. No changes in the transformation endpoints analyzed were observed, as implied by the absence of significant morphological, cell growth rate and anchorage-independent cell growth pattern modifications. Interestingly, HAA-long-term exposed cells developed resistance to oxidative stress damage, what would explain the observed differences between acute and long-term exposure conditions. Accordingly, data obtained under long-term exposure to sub-toxic doses of HAAs could be more accurate, in terms of risk assessment, than under acute exposure scenarios. Copyright © 2018. Published by Elsevier Inc.

  2. Risk analysis of drinking water microbial contamination versus disinfection by-products (DBPs)

    International Nuclear Information System (INIS)

    Ashbolt, Nicholas John

    2004-01-01

    Managing the provision of safe drinking water has a renewed focus in light of the new World Health Organization (WHO) water safety plans. Risk analysis is a necessary component to assist in selecting priority hazards and identifying hazardous scenarios, be they qualitative to quantitative assessments. For any approach, acute diarrhoeal pathogens are often the higher risk issue for municipal water supplies, no matter how health burden is assessed. Furthermore, potential sequellae (myocarditis, diabetes, reactive arthritis and cancers) only further increase the potential health burden of pathogens; despite the enormous uncertainties in determining pathogen exposures and chemical dose-responses within respective microbial and chemical analyses. These interpretations are currently being improved by Bayesian and bootstrapping approaches to estimate parameters for stochastic assessments. A case example, covering the health benefits of ozonation for Cryptosporidium inactivation versus potential cancers from bromate exposures, illustrated the higher risks from a pathogen than one of the most likely disinfection by-products (DBPs). Such analyses help justify the industries long-held view of the benefits of multiple barriers to hazards and that microbial contamination of water supplies pose a clear public health risk when treatment is inadequate. Therefore, efforts to reduce potential health risks from DBP must not compromise pathogen control, despite socio-political issues

  3. Drinking water disinfection byproduct iodoacetic acid induces tumorigenic transformation of NIH3T3 cells.

    Science.gov (United States)

    Wei, Xiao; Wang, Shu; Zheng, Weiwei; Wang, Xia; Liu, Xiaolin; Jiang, Songhui; Pi, Jingbo; Zheng, Yuxin; He, Gengsheng; Qu, Weidong

    2013-06-04

    Iodoacetic acid (IAA) and iodoform (IF) are unregulated iodinated disinfection byproducts (DBPs) found in drinking water. Their presence in the drinking water of China has not been documented. Recently, the carcinogenic potential of IAA and IF has been a concern because of their mutagenicity in bacteria and genotoxicity in mammalian cells. Therefore, we measured their concentrations in Shanghai drinking water and assessed their cytotoxicity, genotoxicity, and ability to transform NIH3T3 cells to tumorigenic lines. The concentrations of IAA and IF in Shanghai drinking water varied between summer and winter with maximum winter levels of 2.18 μg/L IAA and 0.86 μg/L IF. IAA with a lethal concentration 50 (LC50) of 2.77 μM exhibited more potent cytotoxicity in NIH3T3 cells than IF (LC50 = 83.37 μM). IAA, but not IF, induced a concentration-dependent DNA damage measured by γ-H2AX staining and increased tail moment in single-cell gel electrophoresis. Neither IAA nor IF increased micronucleus frequency. Prolonged exposure of NIH3T3 cells to IAA increased the frequencies of transformed cells with anchorage-independent growth and agglutination with concanavalin A. IAA-transformed cells formed aggressive fibrosarcomas after inoculation into Balb/c nude mice. This study demonstrated that IAA has a biological activity that is consistent with a carcinogen and human exposure should be of concern.

  4. Disinfection byproduct formation in drinking water sources: A case study of Yuqiao reservoir.

    Science.gov (United States)

    Zhai, Hongyan; He, Xizhen; Zhang, Yan; Du, Tingting; Adeleye, Adeyemi S; Li, Yao

    2017-08-01

    This study investigated the potential formation of disinfection byproducts (DBPs) during chlorination and chloramination of 20 water samples collected from different points of Yuqiao reservoir in Tianjin, China. The concentrations of dissolved organic matter and ammonia decreased downstream the reservoir, while the specific UV absorbance (SUVA: the ratio of UV 254 to dissolved organic carbon) increased [from 0.67 L/(mg*m) upstream to 3.58 L/(mg*m) downstream]. The raw water quality played an important role in the formation of DBPs. During chlorination, haloacetic acids (HAAs) were the major DBPs formed in most of the water samples, followed by trihalomethanes (THMs). CHCl 3 and CHCl 2 Br were the major THM species, while trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) were the major HAA species. Chloramination, on the other hand, generally resulted in lower concentrations of THMs (CHCl 3 ), HAAs (TCAA and DCAA), and haloacetonitriles (HANs). All the species of DBPs formed had positive correlations with the SUVA values, and HANs had the highest one (R 2  = 0.8). The correlation coefficients between the analogous DBP yields and the SUVA values in chlorinated samples were close to those in chloraminated samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Toxicity of drinking water disinfection byproducts: cell cycle alterations induced by the monohaloacetonitriles.

    Science.gov (United States)

    Komaki, Yukako; Mariñas, Benito J; Plewa, Michael J

    2014-10-07

    Haloacetonitriles (HANs) are a chemical class of drinking water disinfection byproducts (DBPs) that form from reactions between disinfectants and nitrogen-containing precursors, the latter more prevalent in water sources impacted by algae bloom and municipal wastewater effluent discharge. HANs, previously demonstrated to be genotoxic, were investigated for their effects on the mammalian cell cycle. Treating Chinese hamster ovary (CHO) cells with monoHANs followed by the release from the chemical treatment resulted in the accumulation of abnormally high DNA content in cells over time (hyperploid). The potency for the cell cycle alteration followed the order: iodoacetonitrile (IAN) > bromoacetonitrile (BAN) ≫ chloroacetonitrile (CAN). Exposure to 6 μM IAN, 12 μM BAN and 900 μM CAN after 26 h post-treatment incubation resulted in DNA repair; however, subsequent cell cycle alteration effects were observed. Cell proliferation of HAN-treated cells was suppressed for as long as 43 to 52 h. Enlarged cell size was observed after 52 h post-treatment incubation without the induction of cytotoxicity. The HAN-mediated cell cycle alteration was mitosis- and proliferation-dependent, which suggests that HAN treatment induced mitosis override, and that HAN-treated cells proceeded into S phase and directly into the next cell cycle. Cells with multiples genomes would result in aneuploidy (state of abnormal chromosome number and DNA content) at the next mitosis since extra centrosomes could compromise the assembly of bipolar spindles. There is accumulating evidence of a transient tetraploid state proceeding to aneuploidy in cancer progression. Biological self-defense systems to ensure genomic stability and to eliminate tetraploid cells exist in eukaryotic cells. A key tumor suppressor gene, p53, is oftentimes mutated in various types of human cancer. It is possible that HAN disruption of the normal cell cycle and the generation of aberrant cells with an abnormal number of

  6. In Vitro Cytotoxicity and Adaptive Stress Responses to Selected Haloacetic Acid and Halobenzoquinone Water Disinfection Byproducts.

    Science.gov (United States)

    Procházka, Erik; Escher, Beate I; Plewa, Michael J; Leusch, Frederic D L

    2015-10-19

    The process of disinfecting drinking water inadvertently leads to the formation of numerous disinfection byproducts (DBPs). Some of these are mutagenic, genotoxic, teratogenic, and cytotoxic, as well as potentially carcinogenic both in vivo and in vitro. We investigated the in vitro biological activity of five DBPs: three monohaloacetic acids (monoHAAs) [chloroacetic acid (CAA), bromoacetic acid (BAA), and iodoacetic acid (IAA)] and two novel halobenzoquinones (HBQs) [2,6-dichloro-p-benzoquinone (DCBQ) and 2,6-dibromo-p-benzoquinone]. We focused particularly on cytotoxicity and induction of two adaptive stress response pathways: the oxidative stress responsive Nrf2/ARE and DNA-damage responsive p53 pathways. All five DBPs were cytotoxic to the Caco-2 cell line after a 4 h exposure, and all DBPs induced both of the adaptive stress response pathways, Nrf2/ARE and p53, in the micromolar range, as measured by two β-lactamase-based reporter gene assays. The decreasing order of potency for all three endpoints for the five DBPs was IAA ∼ BAA > DCBQ ∼ DBBQ > CAA. Induction of oxidative stress was previously proposed to be the molecular initiating event (MIE) for both classes of DBPs. However, comparing the levels of activation of the two pathways uncovered that the Nrf2/ARE pathway was the more sensitive endpoint for HAAs, whereas the p53 pathway was more sensitive in the case of HBQs. Therefore, the DNA damage-responsive p53 pathway may be an important piece of information to fill in a gap in the adverse outcome pathway framework for the assessment of HBQs. Finally, we cautiously compared the potential risk of the two novel HBQs using a benchmarking approach to that of the well-studied CAA, which suggested that their relative risk may be lower than that of BAA and IAA.

  7. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Science.gov (United States)

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-07

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  8. Disinfection byproduct formation during biofiltration cycle: Implications for drinking water production.

    Science.gov (United States)

    Delatolla, R; Séguin, C; Springthorpe, S; Gorman, E; Campbell, A; Douglas, I

    2015-10-01

    The goal of this study was to investigate the potential of biofiltration to reduce the formation potential of disinfection byproducts (DBPs). Particularly, the work investigates the effect of the duration of the filter cycle on the formation potential of total trihalomethanes (TTHM) and five species of haloacetic acids (HAA5), dissolved oxygen (DO), organic carbon, nitrogen and total phosphorous concentrations along with biofilm coverage of the filter media and biomass viability of the attached cells. The study was conducted on a full-scale biologically active filter, with anthracite and sand media, at the Britannia water treatment plant (WTP), located in Ottawa, Ontario, Canada. The formation potential of both TTHMs and HAA5s decreased due to biofiltration. However the lowest formation potentials for both groups of DBPs and or their precursors were observed immediately following a backwash event. Hence, the highest percent removal of DBPs was observed during the early stages of the biofiltration cycle, which suggests that a higher frequency of backwashing will reduce the formation of DBPs. Variable pressure scanning electron microscopy (VPSEM) analysis shows that biofilm coverage of anthracite and sand media increases as the filtration cycle progressed, while biomass viability analysis demonstrates that the percentage of cells attached to the anthracite and sand media also increases as the filtration cycle progresses. These results suggest that the development and growth of biofilm on the filters increases the DPB formation potential. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Precursors of nitrogenous disinfection by-products in drinking water--A critical review and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Tom [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Templeton, Michael R.; Graham, Nigel [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The proportion of N-DBP formation attributable to specific precursors was calculated. Black-Right-Pointing-Pointer Precursor concentrations are typically insufficient to account for observed N-DBP formation, except CNX and NDMA. Black-Right-Pointing-Pointer Amino acid precursors are easier to remove during water treatment than suggested by laboratory studies. - Abstract: In recent years research into the formation of nitrogenous disinfection by-products (N-DBPs) in drinking water - including N-nitrosodimethylamine (NDMA), the haloacetonitriles (HANs), haloacetamides (HAcAms), cyanogen halides (CNX) and halonitromethanes (HNMs) - has proliferated. This is partly due to their high reported toxicity of N-DBPs. In this review paper information about the formation yields of N-DBPs from model precursors, and about environmental precursor occurrence, has been employed to assess the amount of N-DBP formation that is attributable to known precursors. It was calculated that for HANs and HAcAms, the concentrations of known precursors - mainly free amino acids are insufficient to account for the observed concentrations of these N-DBP groups. However, at least in some waters, a significant proportion of CNX and NDMA formation can be explained by known precursors. Identified N-DBP precursors tend to be of low molecular weight and low electrostatic charge relative to bulk natural organic matter (NOM). This makes them recalcitrant to removal by water treatment processes, notably coagulation, as confirmed by a number of bench-scale studies. However, amino acids have been found to be easier to remove during water treatment than would be suggested by the known molecular properties of the individual free amino acids.

  10. Desalinated and blended water in Saudi Arabia: human exposure and risk analysis from disinfection byproducts

    Directory of Open Access Journals (Sweden)

    Chowdhury Imran Rahman

    2017-01-01

    Full Text Available Saudi Arabia produces the largest amount of desalinated water as a single country. The desalinated water is typically blended with treated groundwater, pH adjusted and chlorinated prior to supply to the communities. The desalinated seawater and/or blended water contains various types of disinfection byproducts (DBPs, some of which may induce cancer risks to human through lifetime exposure. In this study, occurrences of trihalomethanes (THMs in desalinated and blended water in Saudi Arabia were investigated and their exposure and risks were predicted. The chronic daily intakes of CHCl3, BDCM, DBCM and CHBr3 were estimated to be 8.38×10−5, 7.57×10−5, 2.54×10−5 and 4.32×10−4 mg/kg-day respectively. The overall cancer risk was 1.78×10−5 with the range of 7.40×10−7 – 9.26×10−5 and the average hazard index was 3.49×10−2 with the range of 1.20×10−3 – 2.34×10−1. The loss of disability adjusted life years (DALY were estimated to be 25.1 per year and the average cancer risk had 8.48×10−7 DALY per person per year. The financial burden was estimated to be US$2.72 million with the range of US$2.52–2.91 million. The findings may assist in better understanding and reducing cancer risks from DBPs in desalinated and blended water.

  11. Nano-silver in drinking water and drinking water sources: stability and influences on disinfection by-product formation.

    Science.gov (United States)

    Tugulea, A-M; Bérubé, D; Giddings, M; Lemieux, F; Hnatiw, J; Priem, J; Avramescu, M-L

    2014-10-01

    Nano-silver is increasingly used in consumer products from washing machines and refrigerators to devices marketed for the disinfection of drinking water or recreational water. The nano-silver in these products may be released, ending up in surface water bodies which may be used as drinking water sources. Little information is available about the stability of the nano-silver in sources of drinking water, its fate during drinking water disinfection processes, and its interaction with disinfection agents and disinfection by-products (DBPs). This study aims to investigate the stability of nano-silver in drinking water sources and in the finished drinking water when chlorine and chloramines are used for disinfection and to observe changes in the composition of DBPs formed when nano-silver is present in the source water. A dispersion of nano-silver particles (10 nm; PVP-coated) was used to spike untreated Ottawa River water, treated Ottawa River water, organic-free water, and a groundwater at concentrations of 5 mg/L. The diluted dispersions were kept under stirred and non-stirred conditions for up to 9 months and analyzed weekly using UV absorption to assess the stability of the nano-silver particles. In a separate experiment, Ottawa River water containing nano-silver particles (at 0.1 and 1 mg/L concentration, respectively) was disinfected by adding sodium hypochlorite (a chlorinating agent) in sufficient amounts to maintain a free chlorine residual of approximately 0.4 mg/L after 24 h. The disinfected drinking water was then quenched with ascorbic acid and analyzed for 34 neutral DBPs (trihalomethanes, haloacetonitriles, haloacetaldehydes, 1,1 dichloro-2-propanone, 1,1,1 trichloro-2-propanone, chloropicrin, and cyanogen chloride). The results were compared to the profile of DBPs obtained under the same conditions in the absence of nano-silver and in the presence of an equivalent concentration of Ag(+) ions (as AgNO3). The stability of the nano-silver dispersions in

  12. The Occurrence and Toxicity of Disinfection Byproducts in European Drinking Waters in Relation with the HIWATE Epidemiology Study

    Science.gov (United States)

    Jeong, Clara H.; Wagner, Elizabeth D.; Siebert, Vincent R.; Anduri, Sridevi; Richardson, Susan D.; Daiber, Eric J.; McKague, A. Bruce; Kogevinas, Manolis; Villanueva, Cristina M.; Goslan, Emma H.; Luo, Wentai; Isabelle, Lorne M.; Pankow, James F.; Grazuleviciene, Regina; Cordier, Sylvaine; Edwards, Susan C.; Righi, Elena; Nieuwenhuijsen, Mark J.; Plewa, Michael J.

    2012-01-01

    The HIWATE (Health Impacts of long-term exposure to disinfection byproducts in drinking WATEr) project was a systematic analysis that combined the epidemiology on adverse pregnancy outcomes and other health effects with long term exposure to low levels of drinking water disinfection byproducts (DBPs) in the European Union. The present study focused on the relationship of the occurrence and concentration of DBPs with in vitro mammalian cell toxicity. Eleven drinking water samples were collected from 5 European countries. Each sampling location corresponded with an epidemiological study for the HIWATE program. Over 90 DBPs were identified; the range in the number of DBPs and their levels reflected the diverse collection sites, different disinfection processes, and the different characteristics of the source waters. For each sampling site, chronic mammalian cell cytotoxicity correlated highly with the numbers of DBPs identified and the levels of DBP chemical classes. Although there was a clear difference in the genotoxic responses among the drinking waters, these data did not correlate as well with the chemical analyses. Thus, the agents responsible for the genomic DNA damage observed in the HIWATE samples may be due to unresolved associations of combinations of identified DBPs, unknown emerging DBPs that were not identified, or other toxic water contaminants. This study represents the first to integrate quantitative in vitro toxicological data with analytical chemistry and human epidemiologic outcomes for drinking water DBPs. PMID:22958121

  13. What's in The Pool? A Comprehensive Identification Of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

    Science.gov (United States)

    Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. We performed a compreh...

  14. What's in the pool? A comprehensive identification of disinfection by-products and assessment of mutagenicity of chlorinated and brominated swimming pool water

    NARCIS (Netherlands)

    Richardson, S.D.; Demarini, D.M.; Kogevinas, M.; Fernandez, P.; Marco, E.; Lourencetti, C.; Balleste, C.; Heederik, D.|info:eu-repo/dai/nl/072910542; Meliefste, K.; McKague, A.B.; Marcos, R.; Font-Ribera, L.; Grimalt, J.O.; Villanueva, C.M.

    2010-01-01

    BACKGROUND: Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. OBJECTIVES: We performed a

  15. Fingerprinting the reactive toxicity pathways of 50 drinking water disinfection by-products.

    Science.gov (United States)

    Stalter, Daniel; O'Malley, Elissa; von Gunten, Urs; Escher, Beate I

    2016-03-15

    A set of nine in vitro cellular bioassays indicative of different stages of the cellular toxicity pathway was applied to 50 disinfection by-products (DBPs) to obtain a better understanding of the commonalities and differences in the molecular mechanisms of reactive toxicity of DBPs. An Eschericia coli test battery revealed reactivity towards proteins/peptides for 64% of the compounds. 98% activated the NRf2-mediated oxidative stress response and 68% induced an adaptive stress response to genotoxic effects as indicated by the activation of the tumor suppressor protein p53. All DBPs reactive towards DNA in the E. coli assay and activating p53 also induced oxidative stress, confirming earlier studies that the latter could trigger DBP's carcinogenicity. The energy of the lowest unoccupied molecular orbital ELUMO as reactivity descriptor was linearly correlated with oxidative stress induction for trihalomethanes (r(2)=0.98) and haloacetamides (r(2)=0.58), indicating that potency of these DBPs is connected to electrophilicity. However, the descriptive power was poor for haloacetic acids (HAAs) and haloacetonitriles (r(2) (0.80, indicating that HAAs' potency is connected to both, electrophilicity and speciation. Based on the activation of oxidative stress response and the soft electrophilic character of most tested DBPs we hypothesize that indirect genotoxicity-e.g., through oxidative stress induction and/or enzyme inhibition-is more plausible than direct DNA damage for most investigated DBPs. The results provide not only a mechanistic understanding of the cellular effects of DBPs but the effect concentrations may also serve to evaluate mixture effects of DBPs in water samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Glutathione-mediated detoxification of halobenzoquinone drinking water disinfection byproducts in T24 cells.

    Science.gov (United States)

    Li, Jinhua; Wang, Wei; Zhang, Hongquan; Le, X Chris; Li, Xing-Fang

    2014-10-01

    Halobenzoquinones (HBQs) are a new class of drinking water disinfection byproducts (DBPs) and are capable of producing reactive oxygen species and causing oxidative damage to proteins and DNA in T24 human bladder carcinoma cells. However, the exact mechanism of the cytotoxicity of HBQs is unknown. Here, we investigated the role of glutathione (GSH) and GSH-related enzymes including glutathione S-transferase (GST) and glutathione peroxidase (GPx) in defense against HBQ-induced cytotoxicity in T24 cells. The HBQs are 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), 2,3,6-trichloro-1,4-benzoquinone (TriCBQ), and 2,6-dibromobenzoquinone (DBBQ). We found that depletion of cellular GSH could sensitize cells to HBQs and extracellular GSH supplementation could attenuate HBQ-induced cytotoxicity. HBQs caused significant cellular GSH depletion and increased cellular GST activities in a concentration-dependent manner. Our mass spectrometry study confirms that HBQs can conjugate with GSH, explaining in part the mechanism of GSH depletion by HBQs. The effects of HBQs on GPx activity are compound dependent; DCMBQ and DBBQ decrease cellular GPx activities, whereas DCBQ and TriCBQ have no significant effects. Pearson correlation analysis shows that the cellular GSH level is inversely correlated with ROS production and cellular GST activity in HBQ-treated cells. These results support a GSH and GSH-related enzyme-mediated detoxification mechanism of HBQs in T24 cells. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Secondary formation of disinfection by-products by UV treatment of swimming pool water

    Energy Technology Data Exchange (ETDEWEB)

    Spiliotopoulou, Aikaterini [Water ApS, Farum Gydevej 64, 3520 Farum (Denmark); Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark); Hansen, Kamilla M.S., E-mail: kmsh@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark); Andersen, Henrik R. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark)

    2015-07-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  18. Secondary formation of disinfection by-products by UV treatment of swimming pool water

    International Nuclear Information System (INIS)

    Spiliotopoulou, Aikaterini; Hansen, Kamilla M.S.; Andersen, Henrik R.

    2015-01-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  19. Assessment of air and water contamination by disinfection by-products at 41 indoor swimming pools.

    Science.gov (United States)

    Tardif, Robert; Catto, Cyril; Haddad, Sami; Simard, Sabrina; Rodriguez, Manuel

    2016-07-01

    This study was aimed at assessing the profiles (occurrence and speciation) of disinfection by-product (DBP) contamination in air and water of a group of 41 public indoor swimming pools in Québec (Canada). The contaminants measured in the water included the traditional DBPs [i.e., four trihalomethanes (THMs), six haloacetic acids (HAAs)] but also several emergent DBPs [i.e., halonitriles, halonitromethanes, haloketones and nitrosodimethylamine (NDMA)]. Those measured in the air comprised THMs and chloramines (CAMs). Overall, extremely variable DBP levels were found from one pool to another (both quantitatively and in terms of speciation). For instance, in water, among the four THMs, chloroform was usually the most abundant compound (37.9±25.7µg/L). Nevertheless, the sum of the three other brominated THMs represented more than 25% of total THMs at almost half the facilities visited (19 cases). In 13 of them, the levels of brominated THMs (66±24.2µg/L) even greatly outweighed the levels of chloroform (15.2±6.31µg/L). Much higher levels of HAAs (294.8±157.6µg/L) were observed, with a consistent preponderance of brominated HAAs in the swimming pools with more brominated THMs. NDMA levels which were measured in a subset of 8 pools ranged between 2.8ng/L and 105ng/L. With respect to air, chloroform was still the most abundant THM globally (119.4±74.2µg/m(3)) but significant levels of brominated THMs were also observed in various cases, particularly in the previously evoked group of 13 swimming pools with preponderant levels of brominated THMs in water. CAM levels (0.23±0.15mg/m(3)) varied highly, ranging from not detected to 0.56mg/m(3). Overall, the levels were generally relatively high compared to current guidelines or reference values from several countries, and they point to a relatively atypical presence of brominated compounds, and to significant levels of emergent DBPs for which health risk is less documented. Copyright © 2016 Elsevier Inc. All rights

  20. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    International Nuclear Information System (INIS)

    Barber, Larry B.; Hladik, Michelle L.; Vajda, Alan M.; Fitzgerald, Kevin C.; Douville, Chris

    2015-01-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m 3 d −1 design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L −1 ; n = 5) and 10 HDBPs (mean total concentration = 4.5 μg L −1 ), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L −1 ) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative

  1. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Larry B. [U.S. Geological Survey, 3215 Marine St., Boulder, CO 80303 (United States); Hladik, Michelle L. [U.S. Geological Survey, 6000 J Street Placer Hall, Sacramento, CA 95819 (United States); Vajda, Alan M. [University of Colorado, Department of Integrative Biology, CB 171, Denver, CO 80217 (United States); Fitzgerald, Kevin C. [U.S. Geological Survey, 3215 Marine St., Boulder, CO 80303 (United States); AECOM, 500 West Jefferson St., Ste. 1600, Louisville, KY 40202 (United States); Douville, Chris [City of Boulder, 4049 75th Street, Boulder, CO 80301 (United States)

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m{sup 3} d{sup −1} design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L{sup −1}; n = 5) and 10 HDBPs (mean total concentration = 4.5 μg L{sup −1}), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L{sup −1}) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had

  2. Identification and characterization of phenylacetonitrile as a nitrogenous disinfection byproduct derived from chlorination of phenylalanine in drinking water.

    Science.gov (United States)

    Ma, Xiaoyan; Deng, Jing; Feng, Jiao; Shanaiah, Narasimhamurthy; Smiley, Elizabeth; Dietrich, Andrea M

    2016-10-01

    Unregulated disinfection byproducts (DBPs), including nitrogenous disinfection byproducts (N-DBPs), originating from chlorination of the precursor amino acid phenylalanine in aqueous systems, were identified in laboratory reactions and distributed tap. The major N-DBP identified was phenylacetonitrile, and minor DBPs of benzyl chloride, phenylacetaldehyde, 2-chlorobenzyl cyanide, and 2, 6-diphenylpyridine were also formed. Phenylacetonitrile was generated through decarboxylation, dechlorination and/or hydrolysis processes. With an aromatic structure, phenylacetonitrile has an unpleasant odor of various descriptors and an odor threshold concentration of 0.2 ppt-v as measured through gas chromatography-olfactometry. The half-life of phenylacetonitrile in reagent water and chlorinated water at 19 °C were 121 h and 792 h, respectively. The occurrence of phenylacetonitrile as an N-DBP in tap water was investigated for the first time; the results revealed that μg/L concentrations were present in nine different distributed drinking waters in China and the United States. Phenylacetonitrile deteriorates the aesthetic quality of drinking water and may present risk due to its prolonged existence in drinking water, especially in the presence of residual chlorine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Evaluation of associations between lifetime exposure to drinking water disinfection by-products and bladder cancer in dogs.

    Science.gov (United States)

    Backer, Lorraine C; Coss, Angela M; Wolkin, Amy F; Flanders, W Dana; Reif, John S

    2008-06-01

    To assess the risk of bladder cancer in dogs from exposure to drinking water disinfection by-products and determine whether dogs could serve as sentinels for human bladder cancer associated with such exposures. Case-control study. 100 dogs with cancer of the urinary bladder and 100 control dogs. Case and control dogs were frequency-matched by age (within 2 years) and sex. Owners of dogs enrolled provided verbal informed consent and were interviewed by telephone. The telephone questionnaire included a complete residence history for each dog. Each dog's total exposure history to trihalomethanes was reconstructed from its residence history and corresponding drinking water utility company data. No association was detected between increasing years of exposure to chlorinated drinking water and risk of bladder cancer. Dogs with bladder cancer were exposed to higher total trihalomethanes concentrations than control dogs; however, the difference was not significant. Although humans and their dogs live in the same household, the activity patterns of dogs may lead to lower exposures to household tap water. Thus, although exposure to disinfection by-products in tap water may be a risk factor for human bladder cancer, this may not be true for canine bladder cancer at the concentrations at which dogs are exposed.

  4. The study of interrelationship between raw water quality parameters, chlorine demand and the formation of disinfection by-products

    Science.gov (United States)

    Abdullah, Md. Pauzi; Yee, Lim Fang; Ata, Sadia; Abdullah, Abass; Ishak, Basar; Abidin, Khairul Nidzham Zainal

    Disinfection is the most crucial process in the treatment of drinking water supply and is the final barrier against bacteriological impurities in drinking water. Chlorine is the primary disinfectant used in the drinking water treatment process throughout Malaysia. However, the occurrence of various disinfection by-products such as trihalomethanes (THM) and haloacetic acids created a major issue on the potential health hazards which may pose adverse health effects in both human and animals. To simulate real water treatment conditions and to represent the conditions inherent in a tropical country, this study was performed at an urbanized water treatment plant with a daily production of about 549,000 m 3 of treated water. The purpose of this work is to examine the relationship between the water quality parameters in the raw water with chlorine demand and the formation of disinfection by-products. This study also investigated the possibility of the statistical model applications for the prediction of chlorine demand and the THM formation. Two models were developed to estimate the chlorine demand and the THM formation. For the statistical evaluation, correlation and simple linear regression analysis were conducted using SPSS. The results of Kolmogorov-Smirnov test for the estimation of goodness-of-fit of the dependent variables of the models to the normal distribution showed that all the dependent variables followed the normal distribution at significance level of 0.05. Good linear correlations were observed between the independent parameters and formation of THM and the chlorine demand. This study also revealed that ammonia and the specific ultraviolet absorbent (SUVA) were the function of chlorine consumption in the treatment process. Chlorine dosage and SUVA increase the yield of THM. Chlorine demand and THM formation was moderately sensitive, but significant to the pH. The level of significance ( α) for the statistical tests and the inclusion of a variable in the

  5. A comparison of disinfection by-products formation during sequential or simultaneous disinfection of surface waters with chlorine dioxide and chlor(am)ine.

    Science.gov (United States)

    Shi, Yanwei; Ling, Wencui; Qiang, Zhimin

    2013-01-01

    The effect of chlorine dioxide (ClO2) oxidation on the formation of disinfection by-products (DBPs) during sequential (ClO2 pre-oxidation for 30 min) and simultaneous disinfection processes with free chlorine (FC) or monochloramine (MCA) was investigated. The formation of DBPs from synthetic humic acid (HA) water and three natural surface waters containing low bromide levels (11-27 microg/L) was comparatively examined in the FC-based (single FC, sequential ClO2-FC, and simultaneous ClO2/FC) and MCA-based (single MCA, ClO2-MCA, and ClO2/MCA) disinfection processes. The results showed that much more DBPs were formed from the synthetic HA water than from the three natural surface waters with comparative levels of dissolved organic carbon. In the FC-based processes, ClO2 oxidation could reduce trihalomethanes (THMs) by 27-35% and haloacetic acids (HAAs) by 14-22% in the three natural surface waters, but increased THMs by 19% and HAAs by 31% in the synthetic HA water after an FC contact time of 48 h. In the MCA-based processes, similar trends were observed although DBPs were produced at a much lower level. There was an insignificant difference in DBPs formation between the sequential and simultaneous processes. The presence of a high level of bromide (320 microg/L) remarkably promoted the DBPs formation in the FC-based processes. Therefore, the simultaneous disinfection process of ClO2/MCA is recommended particularly for waters with a high bromide level.

  6. The effect of inorganic precursors on disinfection byproduct formation during UV-chlorine/chloramine drinking water treatment.

    Science.gov (United States)

    Lyon, Bonnie A; Dotson, Aaron D; Linden, Karl G; Weinberg, Howard S

    2012-10-01

    Ultraviolet (UV) disinfection is being increasingly used in drinking water treatment. It is important to understand how its application to different types of water may influence finished water quality, particularly as anthropogenic activity continues to impact the quality of source waters. The objective of this study was to evaluate the effect of inorganic precursors on the formation of regulated and unregulated disinfection byproducts (DBPs) during UV irradiation of surface waters when combined with chlorination or chloramination. Samples were collected from three drinking water utilities supplied by source waters with varying organic and inorganic precursor content. The filtered samples were treated in the laboratory with a range of UV doses delivered from low pressure (LP, UV output at 253.7 nm) and medium pressure (MP, polychromatic UV output 200-400 nm) mercury lamps followed by chlorination or chloramination, in the presence and absence of additional bromide and nitrate. The regulated trihalomethanes and haloacetic acids were not affected by UV pretreatment at disinfection doses (40-186 mJ/cm²). With higher doses (1000 mJ/cm²), trihalomethane formation was increased 30-40%. While most effects on DBPs were only observed with doses much higher than typically used for UV disinfection, there were some effects on unregulated DBPs at lower doses. In nitrate-spiked samples (1-10 mg N/L), chloropicrin formation doubled and increased three- to six-fold with 40 mJ/cm² MP UV followed by chloramination and chlorination, respectively. Bromopicrin formation was increased in samples containing bromide (0.5-1 mg/L) and nitrate (1-10 mg N/L) when pretreated with LP or MP UV (30-60% with 40 mJ/cm² LP UV and four- to ten-fold increase with 40 mJ/cm² MP UV, after subsequent chlorination). The formation of cyanogen chloride doubled and increased three-fold with MP UV doses of 186 and 1000 mJ/cm², respectively, when followed by chloramination in nitrate-spiked samples but

  7. Destruction of disinfection byproducts and their precursors in swimming pool water by combined UV treatment and ozonation

    DEFF Research Database (Denmark)

    Cheema, Waqas Akram; Kaarsholm, Kamilla Marie Speht; Andersen, Henrik Rasmus

    Both UV treatment and ozonation are used to reduce different types of disinfection byproducts (DBP) in swimming pools. UV treatment is most common as it is particularly efficient in removing the repulsive chlorine like smelling chloramines (combined chlorine). UV treatment of a pool water increased...... chlorine reactivity and formation of chlor-organic DBP such as trihalomethanes. Based on the similar selective reactivity of ozone and chlorine we hypothesized that the created reactivity towards chlorine by UV treatment of dissolved organic matter in pool water might also be expressed as an increased...... reactivity towards ozone and that ozonation might saturate the chlorine reactivity created by UV treatment and mitigate the increased DBP formation. By experimentally treating pool water samples, we found that UV treatment makes pool water highly reactive to ozone. The created reactivity towards chlorine...

  8. The impact of iodinated X-ray contrast agents on formation and toxicity of disinfection by-products in drinking water.

    Science.gov (United States)

    Jeong, Clara H; Machek, Edward J; Shakeri, Morteza; Duirk, Stephen E; Ternes, Thomas A; Richardson, Susan D; Wagner, Elizabeth D; Plewa, Michael J

    2017-08-01

    The presence of iodinated X-ray contrast media (ICM) in source waters is of high concern to public health because of their potential to generate highly toxic disinfection by-products (DBPs). The objective of this study was to determine the impact of ICM in source waters and the type of disinfectant on the overall toxicity of DBP mixtures and to determine which ICM and reaction conditions give rise to toxic by-products. Source waters collected from Akron, OH were treated with five different ICMs, including iopamidol, iopromide, iohexol, diatrizoate and iomeprol, with or without chlorine or chloramine disinfection. The reaction product mixtures were concentrated with XAD resins and the mammalian cell cytotoxicity and genotoxicity of the reaction mixture concentrates was measured. Water containing iopamidol generated an enhanced level of mammalian cell cytotoxicity and genotoxicity after disinfection. While chlorine disinfection with iopamidol resulted in the highest cytotoxicity overall, the relative iopamidol-mediated increase in toxicity was greater when chloramine was used as the disinfectant compared with chlorine. Four other ICMs (iopromide, iohexol, diatrizoate, and iomeprol) expressed some cytotoxicity over the control without any disinfection, and induced higher cytotoxicity when chlorinated. Only iohexol enhanced genotoxicity compared to the chlorinated source water. Copyright © 2017. Published by Elsevier B.V.

  9. Drinking Water Disinfection By-products, Genetic Polymorphisms, and Birth Outcomes in a European Mother-Child Cohort Study.

    Science.gov (United States)

    Kogevinas, Manolis; Bustamante, Mariona; Gracia-Lavedán, Esther; Ballester, Ferran; Cordier, Sylvaine; Costet, Nathalie; Espinosa, Ana; Grazuleviciene, Regina; Danileviciute, Asta; Ibarluzea, Jesus; Karadanelli, Maria; Krasner, Stuart; Patelarou, Evridiki; Stephanou, Euripides; Tardón, Adonina; Toledano, Mireille B; Wright, John; Villanueva, Cristina M; Nieuwenhuijsen, Mark

    2016-11-01

    We examined the association between exposure during pregnancy to trihalomethanes, the most common water disinfection by-products, and birth outcomes in a European cohort study (Health Impacts of Long-Term Exposure to Disinfection By-Products in Drinking Water). We took into account exposure through different water uses, measures of water toxicity, and genetic susceptibility. We enrolled 14,005 mothers (2002-2010) and their children from France, Greece, Lithuania, Spain, and the UK. Information on lifestyle- and water-related activities was recorded. We ascertained residential concentrations of trihalomethanes through regulatory records and ad hoc sampling campaigns and estimated route-specific trihalomethane uptake by trimester and for whole pregnancy. We examined single nucleotide polymorphisms and copy number variants in disinfection by-product metabolizing genes in nested case-control studies. Average levels of trihalomethanes ranged from around 10 μg/L to above the regulatory limits in the EU of 100 μg/L between centers. There was no association between birth weight and total trihalomethane exposure during pregnancy (β = 2.2 g in birth weight per 10 μg/L of trihalomethane, 95% confidence interval = 3.3, 7.6). Birth weight was not associated with exposure through different routes or with specific trihalomethane species. Exposure to trihalomethanes was not associated with low birth weight (odds ratio [OR] per 10 μg/L = 1.02, 95% confidence interval = 0.95, 1.10), small-for-gestational age (OR = 0.99, 0.94, 1.03) and preterm births (OR = 0.98, 0.9, 1.05). We found no gene-environment interactions for mother or child polymorphisms in relation to preterm birth or small-for-gestational age. In this large European study, we found no association between birth outcomes and trihalomethane exposures during pregnancy in the total population or in potentially genetically susceptible subgroups. (See video abstract at http://links.lww.com/EDE/B104.).

  10. Anaerobic effluent disinfection using ozone: Byproducts formation

    NARCIS (Netherlands)

    Silva, G.H.R.; Daniel, L.A.; Bruning, H.; Rulkens, W.H.

    2010-01-01

    This research was aimed at studying oxidation processes, coliform inactivation effectiveness and disinfection byproducts (DBPs) associated with the disinfection of anaerobic sanitary wastewater effluent with ozone applied at doses of 5.0, 8.0 and 10.0mg O(3)L(-1) for contact times of 5, 10 and 15

  11. Models for estimation of the presence of non-regulated disinfection by-products in small drinking water systems.

    Science.gov (United States)

    Guilherme, Stéphanie; Rodriguez, Manuel J

    2017-10-23

    Among all the organic disinfection by-products (DBPs), only trihalomethanes (THMs) and haloacetic acids (HAAs) are regulated in drinking water, while most DBPs are not. Very little information exists on the occurrence of non-regulated DBPs, particularly in small water systems (SWS). Paradoxically, SWS are more vulnerable to DBPs because of a low capacity to implement adequate treatment technologies to remove DBP precursors. Since DBP analyses are expensive, usually SWS have difficulties to implement a rigorous characterization of these contaminants. The purpose of this study was to estimate non-regulated DBP levels in SWS from easy measurements of relevant parameters regularly monitored. Since no information on non-regulated DBPs in SWS was available, a sampling program was carried out in 25 SWS in two provinces of Canada. Five DBP families were investigated: THMs, HAAs, haloacetonitriles (HANs), halonitromethanes (HNMs), and haloketones (HKs). Multivariate linear mixed regression models were developed to estimate HAN, HK, and HNM levels from water quality characteristics in the water treatment plant, concentrations of regulated DBPs, and residual disinfectant levels. The models obtained have a good explanatory capacity since R 2 varies from 0.77 to 0.91 according to compounds and conditions for application (season and type of treatment). Model validation with an independent database suggested their ability for generalization in similar SWS in North America.

  12. Modelling formation of disinfection by-products in water distribution: Optimisation using a multi-objective evolutionary algorithm

    KAUST Repository

    Radhakrishnan, Mohanasundar; Pathirana, Assela; Ghebremichael, Kebreab A.; Amy, Gary L.

    2012-01-01

    Concerns have been raised regarding disinfection by-products (DBPs) formed as a result of the reaction of halogen-based disinfectants with DBP precursors. In order to appreciate the chemical and biological tradeoffs, it is imperative to understand the formation trends of DBPs and their spread in the distribution network. However, the water at a point in a complex distribution system is a mixture from various sources, whose proportions are complex to estimate and requires advanced hydraulic analysis. To understand the risks of DBPs and to develop mitigation strategies, it is important to understand the distribution of DBPs in a water network, which requires modelling. The goal of this research was to integrate a steady-state water network model with a particle backtracking algorithm and chlorination as well as DBPs models in order to assess the tradeoffs between biological and chemical risks in the distribution network. A multi-objective optimisation algorithm was used to identify the optimal proportion of water from various sources, dosages of alum, and dosages of chlorine in the treatment plant and in booster locations to control the formation of chlorination DBPs and to achieve a balance between microbial and chemical risks. © IWA Publishing 2012.

  13. Modelling formation of disinfection by-products in water distribution: Optimisation using a multi-objective evolutionary algorithm

    KAUST Repository

    Radhakrishnan, Mohanasundar

    2012-05-01

    Concerns have been raised regarding disinfection by-products (DBPs) formed as a result of the reaction of halogen-based disinfectants with DBP precursors. In order to appreciate the chemical and biological tradeoffs, it is imperative to understand the formation trends of DBPs and their spread in the distribution network. However, the water at a point in a complex distribution system is a mixture from various sources, whose proportions are complex to estimate and requires advanced hydraulic analysis. To understand the risks of DBPs and to develop mitigation strategies, it is important to understand the distribution of DBPs in a water network, which requires modelling. The goal of this research was to integrate a steady-state water network model with a particle backtracking algorithm and chlorination as well as DBPs models in order to assess the tradeoffs between biological and chemical risks in the distribution network. A multi-objective optimisation algorithm was used to identify the optimal proportion of water from various sources, dosages of alum, and dosages of chlorine in the treatment plant and in booster locations to control the formation of chlorination DBPs and to achieve a balance between microbial and chemical risks. © IWA Publishing 2012.

  14. Removal of soluble microbial products as the precursors of disinfection by-products in drinking water supplies.

    Science.gov (United States)

    Liu, Jin-Lin; Li, Xiao-Yan

    2015-01-01

    Water pollution worsens the problem of disinfection by-products (DBPs) in drinking water supply. Biodegradation of wastewater organics produces soluble microbial products (SMPs), which can be important DBP precursors. In this laboratory study, a number of enhanced water treatment methods for DBP control, including enhanced coagulation, ozonation, and activated carbon adsorption, were evaluated for their effectiveness in treating SMP-containing water for the DBP reduction purpose. The results show that enhanced coagulation with alum could remove SMPs only marginally and decrease the DBP formation potential (DBPFP) of the water by less than 20%. Although ozone could cause destruction of SMPs in water, the overall DBPFP of the water did not decrease but increased after ozonation. In contrast, adsorption by granular activated carbon could remove the SMP organics from water by more than 60% and reduce the DBPFP by more than 70%. It is apparent that enhanced coagulation and ozonation are not suitable for the removal of SMPs as DBP precursors from polluted water, although enhanced coagulation has been commonly used to reduce the DBP formation caused by natural organic matter. In comparison, activated carbon adsorption is shown as a more effective means to remove the SMP content from water and hence to control the wastewater-derived DBP problem in water supply.

  15. Effect of pH on the formation of disinfection byproducts in swimming pool water – Is less THM better?

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Willach, Sarah; Antoniou, Maria

    2012-01-01

    This study investigated the formation and predicted toxicity of different groups of disinfection byproducts (DBPs) from human exudates in relation to chlorination of pool water at different pH values. Specifically, the formation of the DBP groups trihalomethanes (THMs), haloacetic acids (HAAs......), haloacetonitriles (HANs) and trichloramine (NCl3), resulting from the chlorination of body fluid analog, were investigated at 6.0 ≤ pH ≤ 8.0. Either the initial concentration of active chorine or free chlorine was kept constant in the tested pH range. THM formation was reduced by decreasing pH but HAN, and NCl3...... formation was investigated and found to follow the same pH dependency as without bromide present, with the overall DBP formation increasing, except for HAAs. Estimation of genotoxicity and cytotoxicity of the chlorinated human exudates showed that among the quantified DBP groups, HAN formation were...

  16. Identification of developmentally toxic drinking water disinfection byproducts and evaluation of data relevant to mode of action

    International Nuclear Information System (INIS)

    Colman, Joan; Rice, Glenn E.; Wright, J. Michael; Hunter, E. Sidney; Teuschler, Linda K.; Lipscomb, John C.; Hertzberg, Richard C.; Simmons, Jane Ellen; Fransen, Margaret; Osier, Mark; Narotsky, Michael G.

    2011-01-01

    Reactions between chemicals used to disinfect drinking water and compounds present in source waters produce chemical mixtures containing hundreds of disinfection byproducts (DBPs). Although the results have been somewhat inconsistent, some epidemiological studies suggest associations may exist between DBP exposures and adverse developmental outcomes. The potencies of individual DBPs in rodent and rabbit developmental bioassays suggest that no individual DBP can account for the relative risk estimates reported in the positive epidemiologic studies, leading to the hypothesis that these outcomes could result from the toxicity of DBP mixtures. As a first step in a mixtures risk assessment for DBP developmental effects, this paper identifies developmentally toxic DBPs and examines data relevant to the mode of action (MOA) for DBP developmental toxicity. We identified 24 developmentally toxic DBPs and four adverse developmental outcomes associated with human DBP exposures: spontaneous abortion, cardiovascular defects, neural tube defects, and low birth weight infancy. A plausible MOA, involving hormonal disruption of pregnancy, is delineated for spontaneous abortion, which some epidemiologic studies associate with total trihalomethane and bromodichloromethane exposures. The DBP data for the other three outcomes were inadequate to define key MOA steps.

  17. Determination of the minor disinfection by-products formed in the water plant of Sant Joan Despi (Barcelona, Spain); Determinacion de los subproductos de desinfeccion minoritarios formados en la planta de Sant Joan Despi (Barcelona)

    Energy Technology Data Exchange (ETDEWEB)

    Cancho, B.; Galceran, M.T. [Universitat de Barcelona (Spain); Ventura, F. [AGBAR. Societat General d` Aigues de Barcelona, S.A. (Spain)

    1997-09-01

    Chlorine is widely used in drinking water disinfection due to be a powerful and not expense disinfection. Although the benefits of disinfection, the formation of stable disinfection by-products of the health concern, is the result of the interaction of aqueous chlorine with natural organic matter presents in water. Disinfection by-products generated in major concentration are trihalomethane and haloacetic acids. Disinfection by-products generated in minor concentration are haloacetonitriles, haloketones,chloral hydrate and chloropicrin and some new groups such as cyanogen halides and trihaloacetaldydes. In this work two analytical methods.: headspace/gas chromatography/electron capture detector and liquid-liquid microextraction/gas chromatography/electron capture detector are studied and compared to determine the minor by-products and to establish finally, a systematic control of them in the different stages of the Water Treatment Plant of San Joan Despi (Barcelona, Spain). (Author) 12 refs.

  18. Evaluating Evidence for Association of Human Bladder Cancer with Drinking-Water Chlorination Disinfection By-Products.

    Science.gov (United States)

    Hrudey, Steve E; Backer, Lorraine C; Humpage, Andrew R; Krasner, Stuart W; Michaud, Dominique S; Moore, Lee E; Singer, Philip C; Stanford, Benjamin D

    2015-01-01

    Exposure to chlorination disinfection by-products (CxDBPs) is prevalent in populations using chlorination-based methods to disinfect public water supplies. Multifaceted research has been directed for decades to identify, characterize, and understand the toxicology of these compounds, control and minimize their formation, and conduct epidemiologic studies related to exposure. Urinary bladder cancer has been the health risk most consistently associated with CxDBPs in epidemiologic studies. An international workshop was held to (1) discuss the qualitative strengths and limitations that inform the association between bladder cancer and CxDBPs in the context of possible causation, (2) identify knowledge gaps for this topic in relation to chlorine/chloramine-based disinfection practice(s) in the United States, and (3) assess the evidence for informing risk management. Epidemiological evidence linking exposures to CxDBPs in drinking water to human bladder cancer risk provides insight into causality. However, because of imprecise, inaccurate, or incomplete estimation of CxDBPs levels in epidemiologic studies, translation from hazard identification directly to risk management and regulatory policy for CxDBPs can be challenging. Quantitative risk estimates derived from toxicological risk assessment for CxDBPs currently cannot be reconciled with those from epidemiologic studies, notwithstanding the complexities involved, making regulatory interpretation difficult. Evidence presented here has both strengths and limitations that require additional studies to resolve and improve the understanding of exposure response relationships. Replication of epidemiologic findings in independent populations with further elaboration of exposure assessment is needed to strengthen the knowledge base needed to better inform effective regulatory approaches.

  19. Evaluating Evidence for Association of Human Bladder Cancer with Drinking-Water Chlorination Disinfection By-Products

    Science.gov (United States)

    Hrudey, Steve E.; Backer, Lorraine C.; Humpage, Andrew R.; Krasner, Stuart W.; Michaud, Dominique S.; Moore, Lee E.; Singer, Philip C.; Stanford, Benjamin D.

    2015-01-01

    Exposure to chlorination disinfection by-products (CxDBPs) is prevalent in populations using chlorination-based methods to disinfect public water supplies. Multifaceted research has been directed for decades to identify, characterize, and understand the toxicology of these compounds, control and minimize their formation, and conduct epidemiologic studies related to exposure. Urinary bladder cancer has been the health risk most consistently associated with CxDBPs in epidemiologic studies. An international workshop was held to (1) discuss the qualitative strengths and limitations that inform the association between bladder cancer and CxDBPs in the context of possible causation, (2) identify knowledge gaps for this topic in relation to chlorine/chloramine-based disinfection practice(s) in the United States, and (3) assess the evidence for informing risk management. Epidemiological evidence linking exposures to CxDBPs in drinking water to human bladder cancer risk provides insight into causality. However, because of imprecise, inaccurate, or incomplete estimation of CxDBPs levels in epidemiologic studies, translation from hazard identification directly to risk management and regulatory policy for CxDBPs can be challenging. Quantitative risk estimates derived from toxicological risk assessment for CxDBPs currently cannot be reconciled with those from epidemiologic studies, notwithstanding the complexities involved, making regulatory interpretation difficult. Evidence presented here has both strengths and limitations that require additional studies to resolve and improve the understanding of exposure response relationships. Replication of epidemiologic findings in independent populations with further elaboration of exposure assessment is needed to strengthen the knowledge base needed to better inform effective regulatory approaches. PMID:26309063

  20. Effect of medium-pressure UV-lamp treatment on disinfection by-products in chlorinated seawater swimming pool waters

    DEFF Research Database (Denmark)

    Cheema, Waqas Akram; Manasfi, Tarek; Kaarsholm, Kamilla Marie Speht

    2017-01-01

    Several brominated disinfection by-products (DBPs) are formed in chlorinated seawater pools, due to the high concentration of bromide in seawater. UV irradiation is increasingly employed in freshwater pools, because UV treatment photodegrades harmful chloramines. However, in freshwater pools it has...

  1. THE OCCURRENCE OF DISINFECTION BY-PRODUCTS OF HEALTH CONCERN IN DRINKING WATER: RESULTS OF A NATIONWIDE DBP OCCURRENCE STUDY

    Science.gov (United States)

    The motivation for this Nationwide Disinfection By-product (DBP) Occurrence Study was two-fold: First, more than 500 DBPs have been reported in the literature, yet there is almost no quantitative occurrence information for most. As a result, there is significant uncertainty ove...

  2. Evaluation of Drinking Water Disinfectant Byproducts Compliance Data as an Indirect Measure for Short-Term Exposure in Humans.

    Science.gov (United States)

    Parvez, Shahid; Frost, Kali; Sundararajan, Madhura

    2017-05-20

    In the absence of shorter term disinfectant byproducts (DBPs) data on regulated Trihalomethanes (THMs) and Haloacetic acids (HAAs), epidemiologists and risk assessors have used long-term annual compliance (LRAA) or quarterly (QA) data to evaluate the association between DBP exposure and adverse birth outcomes, which resulted in inconclusive findings. Therefore, we evaluated the reliability of using long-term LRAA and QA data as an indirect measure for short-term exposure. Short-term residential tap water samples were collected in peak DBP months (May-August) in a community water system with five separate treatment stations and were sourced from surface or groundwater. Samples were analyzed for THMs and HAAs per the EPA (U.S. Environmental Protection Agency) standard methods (524.2 and 552.2). The measured levels of total THMs and HAAs were compared temporally and spatially with LRAA and QA data, which showed significant differences ( p water stations showed higher levels than LRAA or QA. Significant numbers of samples in surface water stations exceeded regulatory permissible limits: 27% had excessive THMs and 35% had excessive HAAs. Trichloromethane, trichloroacetic acid, and dichloroacetic acid were the major drivers of variability. This study suggests that LRAA and QA data are not good proxies of short-term exposure. Further investigation is needed to determine if other drinking water systems show consistent findings for improved regulation.

  3. Drinking-Water Disinfection By-products and Semen Quality: A Cross-Sectional Study in China

    Science.gov (United States)

    Zeng, Qiang; Wang, Yi-Xin; Xie, Shao-Hua; Xu, Liang; Chen, Yong-Zhe; Li, Min; Yue, Jing; Li, Yu-Feng; Liu, Ai-Lin

    2014-01-01

    Background: Exposure to disinfection by-products (DBPs) has been demonstrated to impair male reproductive health in animals, but human evidence is limited and inconsistent. Objective: We examined the association between exposure to drinking-water DBPs and semen quality in a Chinese population. Methods: We recruited 2,009 men seeking semen analysis from the Reproductive Center of Tongji Hospital in Wuhan, China, between April 2011 and May 2012. Each man provided a semen sample and a urine sample. Semen samples were analyzed for sperm concentration, sperm motility, and sperm count. As a biomarker of exposure to drinking-water DBPs, trichloroacetic acid (TCAA) was measured in the urine samples. Results: The mean (median) urinary TCAA concentration was 9.58 (7.97) μg/L (interquartile range, 6.01–10.96 μg/L). Compared with men with urine TCAA in the lowest quartile, increased adjusted odds ratios (ORs) were estimated for below-reference sperm concentration in men with TCAA in the second and fourth quartiles (OR = 1.79; 95% CI: 1.19, 2.69 and OR = 1.51; 95% CI: 0.98, 2.31, respectively), for below-reference sperm motility in men with TCAA in the second and third quartiles (OR = 1.46; 95% CI: 1.12, 1.90 and OR = 1.30; 95% CI: 1.00, 1.70, respectively), and for below-reference sperm count in men with TCAA in the second quartile (OR 1.62; 95% CI: 1.04, 2.55). Nonmonotonic associations with TCAA quartiles were also estimated for semen parameters modeled as continuous outcomes, although significant negative associations were estimated for all quartiles above the reference level for sperm motility. Conclusion: Our findings suggest that exposure to drinking-water DBPs may contribute to decreased semen quality in humans. Citation: Zeng Q, Wang YX, Xie SH, Xu L, Chen YZ, Li M, Yue J, Li YF, Liu AL, Lu WQ. 2014. Drinking-water disinfection by-products and semen quality: a cross-sectional study in China. Environ Health Perspect 122:741–746; http://dx.doi.org/10.1289/ehp

  4. The effects of chemical additives on the production of disinfection byproducts and ecotoxicity in simulated ballast water

    Science.gov (United States)

    Park, Chul; Cha, Hyung-Gon; Lee, Ji-Hyun; Choi, Tae Seop; Lee, Jungsuk; Kim, Young-Hee; Bae, Minjung; Shin, Kyoungsoon; Choi, Keun-Hyung

    2017-11-01

    The management of ship ballast water is essential to stemming the introduction of non-indigenous species. Approval for onboard installation of a system to treat ballast water requires rigorous land-based testing as dictated in the G8 guideline by the International Maritime Organization. However, this testing lacks standardization-most notably augmentation of organic carbon for influent water by adding chemical additives. Electrochlorination is a popular treatment method for ballast water, in which chlorinated oxidants react with organisms and organic matter in water. The additives could thus affect the treatment efficacy of the ballast water. Here, we examined the effects of several candidates of organic carbon additives on the consumption of total residual oxidant (TRO), the production of disinfection byproducts (DBPs), plankton survival, and ecotoxicity. The TRO consumption over five days of storage was higher in electrochlorinated seawater amended with lignin and Metamucil when compared with seawaters with other organic carbon compounds. DBP production varied by almost two orders of magnitude as a function of the various additives. This was largely attributed to the production of tribromomethane and dibromoacetic acid. The survival of Artemia franciscana was significantly different across waters of different organic carbon additives. Algal toxicity testing with the marine haptophyte Isochrysis galbana significantly reduced growth in lignin- and Metamucil-treated seawaters, but not with other organic carbon compounds. Bioluminescence in Vibrio fischeri sharply declined in electrochlorinated seawaters with all types of organic carbon compounds, but no toxicity was manifested once the electrochlorinated seawaters were neutralized with sodium thiosulfate. The varying degrees of outcome suggest that it might be better to eliminate the requirements of adding organic carbon to test water as long as natural water was used for land-based testing of BWMS. If needed, the

  5. Genotoxicity of a Low-Dose Nitrosamine Mixture as Drinking Water Disinfection Byproducts in NIH3T3 Cells.

    Science.gov (United States)

    Wang, Hai-Yan; Qin, Ming; Dong, Lei; Lv, Jia-Ying; Wang, Xia

    2017-01-01

    N - nitrosamines (NAms), which can arise as byproducts of disinfection agents, are reportedly found in drinking water, and their potential carcinogenicity is a concern; however, little research exists regarding the genotoxicity or carcinogenicity of NAms exposure as a low-dose mixture. The three most common NAms components in China's drinking water are N -nitrosodimethylamine (NDMA), N -nitrosodiethylamine (NDEA) and N -nitrosomethylethylamine (NMEA). Thus, we measured the genotoxic and carcinogenic potential of these compounds and measured the cell cycle and gene expression. The data show that exposure to the NAms-mixture doubled the revertants in the TA98 and TA100 S. typhimurium strains and increased the DNA double-strand breaks and the micronuclear frequency in the NIH3T3 cells compared to a single exposure. After long-term NAms mixture exposure, a malignant transformation of NIH3T3 and a significantly increased G2/M distribution were observed. Furthermore, P53, CDK1, P38, CDC25A and CyclinB expressions were down-regulated in the NAms-mixture exposure group; however, P21 and GADD45A genes were up-regulated. Interestingly, the CHK1/CHK2 and CDC25A genes had two responses, depending on the NAms concentrations. Thus, we observed mutagenic, genotoxic and carcinogenic effects after a low-dose NAms-mixture exposure in drinking water, and DNA repair and apoptosis pathways may contribute to these adverse effects.

  6. The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

    Directory of Open Access Journals (Sweden)

    Glòria Carrasco-Turigas

    2013-01-01

    Full Text Available Disinfection by-products (DBPs are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4 (chloroform (TCM, bromodichloromethane (BDCM, dibromochloromethane (DBCM, and bromoform (TBM, MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97% and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.

  7. Disinfection byproduct formation in reverse-osmosis concentrated and lyophilized natural organic matter from a drinking water source.

    Science.gov (United States)

    Pressman, Jonathan G; McCurry, Daniel L; Parvez, Shahid; Rice, Glenn E; Teuschler, Linda K; Miltner, Richard J; Speth, Thomas F

    2012-10-15

    Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking water research has been limited because the selected NOM sources are atypical of most drinking water sources. The purpose of this research was to demonstrate that reconstituted NOM from a lyophilized reverse-osmosis (RO) concentrate of a typical drinking water source closely represents DBP formation in the original NOM. A preliminary experiment assessed DBP formation kinetics and yields in concentrated NOM, which demonstrated that chlorine decays faster in concentrate, in some cases leading to altered DBP speciation. Potential changes in NOM reactivity caused by lyophilization were evaluated by chlorination of lyophilized and reconstituted NOM, its parent RO concentrate, and the source water. Bromide lost during RO concentration was replaced by adding potassium bromide prior to chlorination. Although total measured DBP formation tended to decrease slightly and unidentified halogenated organic formation tended to increase slightly as a result of RO concentration, the changes associated with lyophilization were minor. In lyophilized NOM reconstituted back to source water TOC levels and then chlorinated, the concentrations of 19 of 21 measured DBPs, constituting 96% of the total identified DBP mass, were statistically indistinguishable from those in the chlorinated source water. Furthermore, the concentrations of 16 of 21 DBPs in lyophilized NOM reconstituted back to the RO concentrate TOC levels, constituting 86% DBP mass, were statistically indistinguishable from those in the RO concentrate. This study suggests that lyophilization can be used to preserve concentrated NOM without substantially altering the precursors to DBP formation. Published by Elsevier Ltd.

  8. Pyruvate remediation of cell stress and genotoxicity induced by haloacetic acid drinking water disinfection by-products.

    Science.gov (United States)

    Dad, Azra; Jeong, Clara H; Pals, Justin A; Wagner, Elizabeth D; Plewa, Michael J

    2013-10-01

    Monohaloacetic acids (monoHAAs) are a major class of drinking water disinfection by-products (DBPs) and are cytotoxic, genotoxic, mutagenic, and teratogenic. We propose a model of toxic action based on monoHAA-mediated inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a target cytosolic enzyme. This model predicts that GAPDH inhibition by the monoHAAs will lead to a severe reduction of cellular ATP levels and repress the generation of pyruvate. A loss of pyruvate will lead to mitochondrial stress and genomic DNA damage. We found a concentration-dependent reduction of ATP in Chinese hamster ovary cells after monoHAA treatment. ATP reduction per pmol monoHAA followed the pattern of iodoacetic acid (IAA) > bromoacetic acid (BAA) > chloroacetic acid (CAA), which is the pattern of potency observed with many toxicological endpoints. Exogenous supplementation with pyruvate enhanced ATP levels and attenuated monoHAA-induced genomic DNA damage as measured with single cell gel electrophoresis. These data were highly correlated with the SN 2 alkylating potentials of the monoHAAs and with the induction of toxicity. The results from this study strongly support the hypothesis that GAPDH inhibition and the possible subsequent generation of reactive oxygen species is linked with the cytotoxicity, genotoxicity, teratogenicity, and neurotoxicity of these DBPs. Copyright © 2013 Wiley Periodicals, Inc.

  9. Spatial variations in the occurrence of potentially genotoxic disinfection by-products in drinking water distribution systems in China.

    Science.gov (United States)

    Li, Chunmei; Wang, Donghong; Xu, Xiong; Xu, Meijia; Wang, Zijian

    2017-12-01

    We investigated the occurrence of disinfection by-products (DBPs) with genotoxic potential in plant effluent and distribution water samples from four drinking water treatment plants in two Chinese cities using comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry. We tested the samples for 37 DBPs with genotoxic potential, which we had previously identified and prioritized in water under controlled laboratory conditions. Thirty of these DBPs were found in the water samples at detection frequencies of between 10% and 100%, and at concentrations between 3.90 and 1.77 × 10 3  ng/L. Of the DBPs detected, the concentrations of 1,1,1-trichloropropan-2-one were highest, and ranged from 299 to 1.77 × 10 3  ng/L with an average of 796 ng/L. The concentrations of 6-chloro-2-N-propan-2-yl-1,3,5-triazine-2,4-diamine and 2,6-ditert-butylcyclohexa-2,5-diene-1,4-dione were also much higher, and ranged from 107 to 721 ng/L, and from 152 to 504 ng/L, respectively. Concentrations of 1,1,1-trichloropropan-2-one, 2-chloro-1-phenylethanone, 2,2-dichloro-1-phenylethanone and 6-chloro-2-N-propan-2-yl-1,3,5-triazine-2,4-diamine were highest at or near the treatment plants and decreased with increasing distance from the plants. Patterns in the concentrations of benzaldehyde, 2-phenylpropan-2-ol, and 1-methylnaphthalene differed between plants. The levels of DBPs such as 4-ethylbenzaldehyde, (E)-non-2-enal, and 1-phenylethanone were relatively constant within the distribution systems, even at the furthest sampling points (20 km drinking water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Detection, formation and occurrence of 13 new polar phenolic chlorinated and brominated disinfection byproducts in drinking water.

    Science.gov (United States)

    Pan, Yang; Wang, Ying; Li, Aimin; Xu, Bin; Xian, Qiming; Shuang, Chendong; Shi, Peng; Zhou, Qing

    2017-04-01

    Recently, 13 new polar phenolic chlorinated and brominated disinfection byproducts (Cl- and Br-DBPs) were identified and quantified in simulated chlorinated drinking water by adopting product ion scan, precursor ion scan, and multiple reaction monitoring (MRM) analyses using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry (UPLC/ESI-tqMS). The 13 new DBPs have been drawing increasing concern not only because they possess significantly higher growth inhibition, developmental toxicity, and chronic cytotoxicity than commonly known aliphatic DBPs, but also because they act as intermediate DBPs that can decompose to form the U.S. EPA regulated DBPs. In this study, through MS parameter optimization of the UPLC/ESI-tqMS MRM analysis, the instrument detection and quantitation limits of the 13 new DBPs were substantially lowered to 0.42-6.44 and 1.35-16.51 μg/L, respectively. The total levels of the 13 new DBPs formed in chlorination were much higher than those formed in chloramination within a contact time of 3 d. In chlorination, the 13 new DBPs formed quickly and decomposed rapidly, and their total concentration kept on decreasing with contact time. In chloramination, the levels of the dominant species (i.e., trihalo-phenols) firstly increased and then decreased with contact time, whereas the levels of the other new DBPs were relatively low and kept on increasing with contact time. An increasing of pH from 6.0 to 9.0 decreased the formation of the 13 new DBPs by 57.8% and 62.3% in chlorination and chloramination, respectively. Gallic acid was found to be present in various simulated and real source water samples and was demonstrated to be a precursor of the 13 new DBPs with elucidated formation pathways. Furthermore, 12 of the 13 new DBPs were detected in 16 tap water samples obtained from major cities in East China, at total levels from 9.5 to 329.8 ng/L. The concentrations of the new DBPs were higher in samples

  11. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    Science.gov (United States)

    Barber, Larry B.; Hladik, Michelle; Vajda, Alan M.; Fitzgerald, Kevin C.; Douville, Chris

    2015-01-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m3 d−1 design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L−1; n=5) and 10 HDBPs (mean total concentration = 4.5 μg L−1), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L−1) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative

  12. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    International Nuclear Information System (INIS)

    Serrano, Maria; Montesinos, Isabel; Cardador, M.J.; Silva, Manuel; Gallego, Mercedes

    2015-01-01

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  13. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Maria; Montesinos, Isabel; Cardador, M.J.; Silva, Manuel; Gallego, Mercedes, E-mail: mercedes.gallego@uco.es

    2015-06-01

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  14. Disinfection by-product formation of UV treated swimming pool water

    DEFF Research Database (Denmark)

    Spiliotopoulou, Aikaterini; Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus

    2015-01-01

    Water samples from 3 indoor swimming pool facilities were tested to evaluate UV-induced effects on swimming pool water chemistry. Concentration change of several DBPs was investigated in experiments including medium pressure UV treatment with and without chlorine and post-UV chlorination. Post-UV...

  15. The alkaline comet assay used in evaluation of genotoxic damage of drinking water disinfection by-products (bromoform and chloroform

    Directory of Open Access Journals (Sweden)

    Messaouda Khallef

    2015-06-01

    Full Text Available The alkaline comet assay (pH 12.3 is a useful method for monitoring genotoxic effects of environmental pollutants in the root nuclei of Allium cepa and various plants; it allows the detection of single- and double-strand breaks, incomplete excision-repair sites and cross-links. It has been introduced to detect even small changes in DNA structure. It is a technically simple, highly sensitive, fast and economic test which detects in vitro and in vivo genotoxicity (DNA integrity and packing mode in any cell types examined, and requires just a few cells for its execution (Liman et al., 2011; Yıldız et al., 2009. Chloroform and bromoform are the most important trihalomethanes found in drinking water. Different concentrations of bromoform (25, 50, 75and 100µg/ml and chloroform (25, 50, 100 and 200 µg/ml were introduced to onion tuber roots. Distilled water was used as a negative control and methyl methansulfonate (MMS-10 µg/ml as positive control. All obtained data were subjected to statistical analyses by using SPSS 15.0 for Windows software. For comparison purposes, Duncan multiple range tests using one-way analysis of variance (ANOVA were employed and p<0.05 was accepted as the test of significance. Comet assay results showed that DNA damage was significant at p <0.05 for the different concentrations of chloroform and bromoform compared to the negative control which has a damage rate equal to 3.5 ± 0.7 and the positive control which has damage rate equal to 13.5 ± 2.12. The exposure of root tip cells to these disinfection by-products increases DNA damage. All concentrations examined in this study of bromoform and chloroform cause significant harm, which could be due to DNA damage induced by oxidative stress. The measurement of DNA damage in the nuclei of higher plant tissues is a new area of study with SCGE. This assay could be incorporated into in situ monitoring of atmosphere, water and soil: the comet assay allows a fast detection without

  16. Drinking water disinfection by-products during pregnancy and child neuropsychological development in the INMA Spanish cohort study.

    Science.gov (United States)

    Villanueva, Cristina M; Gracia-Lavedan, Esther; Julvez, Jordi; Santa-Marina, Loreto; Lertxundi, Nerea; Ibarluzea, Jesús; Llop, Sabrina; Ballester, Ferran; Fernández-Somoano, Ana; Tardón, Adonina; Vrijheid, Martine; Guxens, Mònica; Sunyer, Jordi

    2018-01-01

    Disinfection by-products (DBPs) constitute a complex mixture of prevalent chemicals in drinking water and there is evidence of neurotoxicity for some of them. We evaluated the association between estimates of DBP exposure during pregnancy and child neuropsychological outcomes at 1 and 4-5years of age. We conducted a population-based mother-child cohort study in Spain with recruitment at first trimester of gestation (INMA Project, 2003-2008). Neuropsychological development was measured at 1year of age using the Bayley Scales of Infant Development and at 4-5years with the McCarthy Scales of Children's Abilities. Modeled tap water concentrations of trihalomethanes (THM) were combined with personal ingestion, showering and bathing habits to estimate exposure as ingestion uptake, all route (showering, bathing, ingestion) uptake (μg/day) and crude levels (μg/l) in the residence. Chloroform, brominated THMs (bromodichloromethane, dibromochloromethane, bromoform) and total THMs (chloroform and brominated THMs) were analysed separately. Nine haloacetic acids levels were available in one of the areas. Linear regression was used to estimate associations in 1855 subjects adjusting for covariables. The median concentration of total THMs, chloroform, brominated THMs, total haloacetic acids, dichloroacetic acid, and trichloroacetic acid were, respectively 30.3μg/L, 9.4μg/L, 11.6μg/L, 10.5μg/L, 2.7μg/L, and 3.1μg/L. The associations between THM exposure and neuropsychological outcomes were null, except for total and brominated THM uptake though all routes and the general cognitive score at 4-5years, with a decrease in -0.54 points (95%CI -1.03, -0.05) and -0.64 (95%CI -1.16, -0.12), respectively, for doubling total and brominated THM uptake. A positive association found between dichloroacetic acid and the mental score at 1year did not persist at 4-5years. Minor associations observed between DBP exposure during gestation and child neuropsychological development at 1year

  17. Modelling of Disinfection by-products formation via UV irradiation of the water from Tajan River (source water for Sari drinking water, Iran

    Directory of Open Access Journals (Sweden)

    Allahbakhsh Javid

    2013-11-01

    Full Text Available Background & Aims of the Study Irradiation with ultraviolet light (UV is used for the disinfection of bacterial contaminants in the production of potable water. The main objective of the study was to investigate and model Disinfection By-Products (DBPs formation due to the UV Irradiation of the Tajan River water under different Irradiation conditions. Materials & Methods:  Water samples were collected throughout September 2011 to August 2013. Transportation of the sample to the laboratory was done on ice in a cooler, and physiochemical analysis was conducted immediately within one day. Dissolved organic carbon (DOC was determined by a TOC analyzer. Irradiation experiments were conducted in a series of 25 mL glass serum bottles with Teflon septa. The present study adopts an orthogonal design. The design involved irradiation with UV at a UV/DOC ratio of 0.5–3.0 and incubating (headspace-free storage for 5–25 sec. A 1 mM phosphate buffer maintained the pH at 6, 7, or 8 respectively, and an incubator maintained the temperature (Temp at 15, 20, or 25 °C respectively. The development of empirical models for DBPs formation used a multivariate regression procedure (stepwise which applied the SPSS System for Windows (Version 16.0. Results:  The results showed that the total DBPs formation ranged between 12.3 and 67.4 mg/l and that control of the levels was primarily due to the reaction time and the dissolved organic carbon level (DOC in the water. Conclusions:  Reaction time and level of DOC concentrations in water exerted a dominant influence on the formation of DBPs during the UV irradiation of water from the Tajan River. The relationships between the measured and predicted values were satisfactory with R 2 values ranging from 0.89 (for Octanal–0.92 (for Formaldehydes. The DOC level in water is the key factor in controlling DBPs formation.

  18. Free Radical Chemistry of Disinfection Byproducts 1: Kinetics of Hydrated Electron and Hydroxyl Radical Reactions with Halonitromethanes in Water

    International Nuclear Information System (INIS)

    B. J. Mincher; R. V. Fox; S. P. Mezyk; T. Helgeson; S. K. Cole; W. J. Cooper; P. R. Gardinali

    2006-01-01

    Halonitromethanes are disinfection-byproducts formed during ozonation and chlorine/chloramine treatment of waters that contain bromide ion and natural organic matter. In this study, the chemical kinetics of the free-radical-induced degradations of a series of halonitromethanes were determined. Absolute rate constants for hydroxyl radical, OH, and hydrated electron, e aq - , reaction with both chlorinated and brominated halonitromethanes were measured using the techniques of electron pulse radiolysis and transient absorption spectroscopy. The bimolecular rate constants obtained, k (M -1 s -1 ), for e aq - /OH, respectively, were the following: chloronitromethane (3.01 ± 0.40) x 10 10 /(1.94 ± 0.32) x 10 8 ; dichloronitromethane (3.21 ± 0.17) x 10 10 /(5.12 ± 0.77) x 10 8 ; bromonitromethane (3.13 ± 0.06) x 10 10 /(8.36 ± 0.57) x 107; dibromonitromethane (3.07 ± 0.40) x 10 10 /(4.75 ± 0.98) x 10 8 ; tribromonitromethane (2.29 ± 0.39) x 10 10 /(3.25 ± 0.67) x 10 8 ; bromochloronitromethane (2.93 ± 0.47) x 10 10 /(4.2 ± 1.1) x 10 8 ; bromodichloronitromethane (2.68 ± 0.13) x 10 10 /(1.02 ± 0.15) x 10 8 ; and dibromochloronitromethane (2.95 ± 0.43) x 10 10 /(1.80 ± 0.31) x 10 8 at room temperature and pH ∼7. Comparison data were also obtained for hydroxyl radical reaction with bromoform (1.50 ± 0.05) x 10 8 , bromodichloromethane (7.11 ± 0.26) x 10 7 , and chlorodibromomethane (8.31 ± 0.25) x 10 7 M -1 s -1 , respectively. These rate constants are compared to recently obtained data for trichloronitromethane and bromonitromethane, as well as to other established literature data for analogous compounds

  19. The shadow of dichloroacetonitrile (DCAN), a typical nitrogenous disinfection by-product (N-DBP), in the waterworks and its backwash water reuse.

    Science.gov (United States)

    Tan, Yiwen; Lin, Tao; Jiang, Fuchun; Dong, Jian; Chen, Wei; Zhou, Dongju

    2017-08-01

    Dichloroacetonitrile (DCAN) is one of nitrogenous disinfection by-products (N-DBPs) with strong cytotoxicity and genotoxicity. In this study, the formation potential (FP) of DCAN was investigated in the samples of six important water sources located in the Yangtze River Delta. The highest formation concentration of DCAN was 9.05 μg/L in the water sample taken from Taihu Lake with the lowest SUVA value. After the NOM fractionation, the conversion rate of hydrophilic fraction to DCAN was found the highest. Subsequently, a waterworks using Taihu Lake as water source was chosen to research the FP variations of DCAN in the treatment process and backwash water. The results showed that, compared to the conventional treatment process, O/biological activated carbon (BAC) process increased the removal efficiency of DCAN from 21.89% to 50.58% by removing aromatic protein and soluble biological by-products as main precursors of DCAN. The DCAN FP in the effluent of BAC filters using old granular activated carbon was higher than that in the influent and the DCAN FP of its backwash water was lower than that in raw water. In the backwash water of sand filters, the DCAN FP higher than raw water required the recycle ratio less than 5% to avoid the accumulation of DCAN. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Formation of trihalomethanes as disinfection byproducts in herbal spa pools.

    Science.gov (United States)

    Fakour, Hoda; Lo, Shang-Lien

    2018-04-09

    Herbal spa treatments are favorite recreational activities throughout the world. The water in spas is often disinfected to control pathogenic microorganisms and guarantee hygiene. However, chlorinated water may cause the formation of disinfection byproducts (DBPs). Although there have been many studies on DBP formation in swimming pools, the role of organic matter derived from herbal medicines applied in herbal spa water has been largely neglected. Accordingly, the present study investigated the effect of herbal medicines on the formation of trihalomethanes (THMs) in simulated herbal spa water. Water samples were collected from a spa pool, and then, disinfection and herbal addition experiments were performed in a laboratory. The results showed that the organic molecules introduced by the herbal medicines are significant precursors to the formation of THMs in spa pool water. Since at least 50% of THMs were produced within the first six hours of the reaction time, the presence of herbal medicines in spa water could present a parallel route for THM exposure. Therefore, despite the undeniable benefits of herbal spas, the effect of applied herbs on DBP formation in chlorinated water should be considered to improve the water quality and health benefits of spa facilities.

  1. Effect of medium-pressure UV-lamp treatment on disinfection by-products in chlorinated seawater swimming pool waters.

    Science.gov (United States)

    Cheema, Waqas A; Manasfi, Tarek; Kaarsholm, Kamilla M S; Andersen, Henrik R; Boudenne, Jean-Luc

    2017-12-01

    Several brominated disinfection by-products (DBPs) are formed in chlorinated seawater pools, due to the high concentration of bromide in seawater. UV irradiation is increasingly employed in freshwater pools, because UV treatment photodegrades harmful chloramines. However, in freshwater pools it has been reported that post-UV chlorination promotes the formation of other DBPs. To date, UV-based processes have not been investigated for DBPs in seawater pools. In this study, the effects of UV, followed by chlorination, on the concentration of three groups of DBPs were investigated in laboratory batch experiments using a medium-pressure UV lamp. Chlorine consumption increased following post-UV chlorination, most likely because UV irradiation degraded organic matter in the pool samples to more chlorine-reactive organic matter. Haloacetic acid (HAA) concentrations decreased significantly, due to photo-degradation, but the concentrations of trihalomethanes (THMs) and haloacetonitriles (HANs) increased with post-UV chlorination. Bromine incorporation in HAAs was significantly higher in the control samples chlorinated without UV irradiation but decreased significantly with UV treatment. Bromine incorporation was promoted in THM and HAN after UV and chlorine treatment. Overall, the accumulated bromine incorporation level in DBPs remained essentially unchanged in comparison with the control samples. Toxicity estimates increased with single-dose UV and chlorination, mainly due to increased HAN concentrations. However, brominated HANs are known in the literature to degrade following further UV treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. CONTROL OF MICROBIAL CONTAMINANTS AND DISINFECTION BY-PRODUCTS (DBPS): COST AND PERFORMANCE

    Science.gov (United States)

    The USEPA is in the process of developing a sophisticated regulatory strategy in an attempt to balance the complex trade-offs in risks associated with controlling disinfectants and disinfection by-products (D/DBPs) in drinking water. EPA first attempted to control DBPs in 1974, w...

  3. The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product, in drinking water treatment process and its toxicity on zebrafish.

    Science.gov (United States)

    Lin, Tao; Zhou, Dongju; Yu, Shilin; Chen, Wei

    2016-09-01

    The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product (DBP) in conventional drinking water treatment plant (C-DWTP) and advanced DWTP (ADWTP) was studied with newly maximum formation potential (MFP) process. It was demonstrated that the advanced treatment displayed greater removal efficiency towards DCAcAm formation potential (MFP) than the conventional treatment. The hydrophilic natural organic matter and natural organic matter with molecular weight 10 kDa leaded to more DCAcAm formation, and the aromatic protein was inferred as one part of DCAcAm precursor. DCAcAm was found to cause delayed development and malformation to zebrafish embryos at embryonic growth stage. Compared with heart toxicity, it caused a significant neuron toxicity. It also could cause the acute DNA damage to adult zebrafish, which should be extremely cautioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Chemical degradation of drinking water disinfection byproducts by millimeter-sized particles of iron-silicon and magnesium-aluminum alloys.

    Science.gov (United States)

    Li, Tianyu; Chen, Yongmei; Wan, Pingyu; Fan, Maohong; Yang, X Jin

    2010-03-03

    The candidature of Fe-Si and Mg-Al alloys at millimeter-scale particle sizes for chemical degradation of disinfection byproducts (DBPs) in drinking water systems was substantiated by their enhanced corrosion resistance and catalytic effect on the degradation. The Mg-Al particles supplied electrons for reductive degradation, and the Fe-Si particles acted as a catalyst and provided the sites for the reaction. The alloy particles are obtained by mechanical milling and stable under ambient conditions. The proposed method for chemical degradation of DBPs possesses the advantages of relatively constant degradation performance, long-term durability, no secondary contamination, and ease of handling, storage and maintenance in comparison with nanoparticle systems.

  5. Bioanalytical assessment of adaptive stress responses in drinking water: A predictive tool to differentiate between micropollutants and disinfection by-products.

    Science.gov (United States)

    Hebert, Armelle; Feliers, Cedric; Lecarpentier, Caroline; Neale, Peta A; Schlichting, Rita; Thibert, Sylvie; Escher, Beate I

    2018-04-01

    Drinking water can contain low levels of micropollutants, as well as disinfection by-products (DBPs) that form from the reaction of disinfectants with organic and inorganic matter in water. Due to the complex mixture of trace chemicals in drinking water, targeted chemical analysis alone is not sufficient for monitoring. The current study aimed to apply in vitro bioassays indicative of adaptive stress responses to monitor the toxicological profiles and the formation of DBPs in three drinking water distribution systems in France. Bioanalysis was complemented with chemical analysis of forty DBPs. All water samples were active in the oxidative stress response assay, but only after considerable sample enrichment. As both micropollutants in source water and DBPs formed during treatment can contribute to the effect, the bioanalytical equivalent concentration (BEQ) approach was applied for the first time to determine the contribution of DBPs, with DBPs found to contribute between 17 and 58% of the oxidative stress response. Further, the BEQ approach was also used to assess the contribution of volatile DBPs to the observed effect, with detected volatile DBPs found to have only a minor contribution as compared to the measured effects of the non-volatile chemicals enriched by solid-phase extraction. The observed effects in the distribution systems were below any level of concern, quantifiable only at high enrichment and not different from bottled mineral water. Integrating bioanalytical tools and the BEQ mixture model for monitoring drinking water quality is an additional assurance that chemical monitoring is not overlooking any unknown chemicals or transformation products and can help to ensure chemically safe drinking water. Copyright © 2017. Published by Elsevier Ltd.

  6. Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams

    Science.gov (United States)

    Hladik, Michelle; Focazio, Michael J.; Engle, Mark

    2014-01-01

    Fluids co-produced with oil and gas production (produced waters) are often brines that contain elevated concentrations of bromide. Bromide is an important precursor of several toxic disinfection by-products (DBPs) and the treatment of produced water may lead to more brominated DBPs. To determine if wastewater treatment plants that accept produced waters discharge greater amounts of brominated DBPs, water samples were collected in Pennsylvania from four sites along a large river including an upstream site, a site below a publicly owned wastewater treatment plant (POTW) outfall (does not accept produced water), a site below an oil and gas commercial wastewater treatment plant (CWT) outfall, and downstream of the POTW and CWT. Of 29 DBPs analyzed, the site at the POTW outfall had the highest number detected (six) ranging in concentration from 0.01 to 0.09 μg L− 1 with a similar mixture of DBPs that have been detected at POTW outfalls elsewhere in the United States. The DBP profile at the CWT outfall was much different, although only two DBPs, dibromochloronitromethane (DBCNM) and chloroform, were detected, DBCNM was found at relatively high concentrations (up to 8.5 μg L− 1). The water at the CWT outfall also had a mixture of inorganic and organic precursors including elevated concentrations of bromide (75 mg L− 1) and other organic DBP precursors (phenol at 15 μg L− 1). To corroborate these DBP results, samples were collected in Pennsylvania from additional POTW and CWT outfalls that accept produced waters. The additional CWT also had high concentrations of DBCNM (3.1 μg L− 1) while the POTWs that accept produced waters had elevated numbers (up to 15) and concentrations of DBPs, especially brominated and iodinated THMs (up to 12 μg L− 1 total THM concentration). Therefore, produced water brines that have been disinfected are potential sources of DBPs along with DBP precursors to streams wherever these wastewaters are discharged.

  7. Peracetic acid oxidation of saline waters in the absence and presence of H ₂O ₂: secondary oxidant and disinfection byproduct formation.

    Science.gov (United States)

    Shah, Amisha D; Liu, Zheng-Qian; Salhi, Elisabeth; Höfer, Thomas; von Gunten, Urs

    2015-02-03

    Peracetic acid (PAA) is a disinfectant considered for use in ballast water treatment, but its chemical behavior in such systems (i.e., saline waters) is largely unknown. In this study, the reactivity of PAA with halide ions (chloride and bromide) to form secondary oxidants (HOCl, HOBr) was investigated. For the PAA-chloride and PAA-bromide reactions, second-order rate constants of (1.47 ± 0.58) × 10(-5) and 0.24 ± 0.02 M(-1) s(-1) were determined for the formation of HOCl or HOBr, respectively. Hydrogen peroxide (H2O2), which is always present in PAA solutions, reduced HOCl or HOBr to chloride or bromide, respectively. As a consequence, in PAA-treated solutions with [H2O2] > [PAA], the HOBr (HOCl) steady-state concentrations were low with a limited formation of brominated (chlorinated) disinfection byproducts (DBPs). HOI (formed from the PAA-iodide reaction) affected this process because it can react with H2O2 back to iodide. H2O2 is thus consumed in a catalytic cycle and leads to less efficient HOBr scavenging at even low iodide concentrations (acid (MBAA), dibromoacetic acid (DBAA), and tribromoacetic acid (TBAA) formed at up to 260, 106, 230, and 89 μg/L, respectively for doses of 2 mM (ca. 150 mg/L) PAA and [H2O2] acid concentrations.

  8. Characteristics of water obtained by dewatering cyanobacteria-containing sludge formed during drinking water treatment, including C-, N-disinfection byproduct formation.

    Science.gov (United States)

    Xu, Hangzhou; Pei, Haiyan; Jin, Yan; Xiao, Hongdi; Ma, Chunxia; Sun, Jiongming; Li, Hongmin

    2017-03-15

    This is the first study to systematically investigate the characteristics of the water obtained by dewatering cyanobacteria-containing sludge generated in the drinking water treatment plant, including formation of C- and N-disinfection by-products (DBPs). Results showed that this 'dewatering water' (DW) had different properties when the sludge was stored at different times. The content of dissolved organic matter (DOM) and microcystins (MCs) in the DW were low when the sludge was treated or disposed of within 4 days; correspondingly, the C-, N-DBP production was also low. However, due to the damage of algal cells to some extent, the DOM and MC levels increased significantly for storage time longer than 4 days; the production of C-, N-DBPs also increased. There were also obvious differences in the characteristics of the DW from sludges generated with different coagulant species. Due to the better protective effect of FeCl 3 and polymeric aluminium ferric chloride (PAFC) flocs, the DOM and MC levels and the production of C-, N-DBPs in the DW with FeCl 3 and PAFC coagulation were lower than those with AlCl 3 coagulation, even though the sludges were stored for the same amount of time. Furthermore, because of the formation of Al and Fe hydroxides, precipitated onto the surface of flocs, the soluble Al and Fe in the DW decreased with increased storage time, especially in the first four days. Overall, this study revealed the trends in variation of DW quality for cyanobacteria-containing sludges formed with different coagulants, then FeCl 3 and PAFC coagulants are recommended and sludge should be treated or disposed of within 4 days. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria.

    Science.gov (United States)

    Benson, Nsikak U; Akintokun, Oyeronke A; Adedapo, Adebusayo E

    2017-01-01

    Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950  μ g/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10 -2  mg/kg-day), while the ingestion in children (3.99 × 10 -2  mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

  10. MODERATING INFLUENCE OF THE DRINKING WATER DISINFECTION BY-PRODUCT DIBROMOACETIC ACID ON A DITHIOCARBAMATE-INDUCED SUPPRESSION OF THE LUTEINIZING HORMONE SURGE IN FEMALE RATS.

    Science.gov (United States)

    The disinfection by-product dibromoacetic acid (DBA) has been found in female rats to increase circulating concentrations of both estradiol (E2) and estrone (E1). This effect is apparently due, at least in part, to a suppression in hepatic catabolism. The present study investigat...

  11. Optical monitoring of Disinfection By-product Precursors with Fluorescence Excitation-Emission Mapping (F-EEM): Practical Application Issues for Drinking, Waste and Reuse Water Industry

    Science.gov (United States)

    Gilmore, A. M.

    2012-12-01

    Drinking water, wastewater and reuse plants must deal with regulations associated with bacterial contamination and halogen disinfection procedures that can generate harmful disinfection by-products (DBPs) including trihalomethanes (THMs), haloacetic acids (HOAAs) and other compounds. The natural fluorescent chromophoric dissolved organic matter (CDOM) is regulated as the major DBP precursor. This study outlines the advantages and current limitations associated with optical monitoring of water treatment processes using tcontemporary Fluorescence Excitation-Emission Mapping (F-EEM). The F-EEM method coupled with practical peak indexing and multi-variate analyses is potentially superior in terms of cost, speed and sensitivity over conventional total organic carbon (TOC) meters and specific UV-absorbance (SUVA) measurements. Hence there is strong interest in developing revised environmental regulations around the F-EEM technique instruments which can incidentally simultaneously measure the SUVA and DOC parameters. Importantly, the F-EEM technique, compared to the single-point TOC and SUVA signals can resolve CDOM classes distinguishing those that strongly cause DBPs. The F-EEM DBP prediction method can be applied to surface water sources to evaluate DBP potential as a function of the point sources and reservoir depth profiles. It can also be applied in-line to rapidly adjust DOC removal processes including sedimentation-flocculation, microfiltration, reverse-osmosis, and ozonation. Limitations and interferences for F-EEMs are discussed including those common to SUVA and TOC in contrast to the advantages including that F-EEMs are less prone to interferences from inorganic carbon and metal contaminations and require little if any chemical preparation. In conclusion, the F-EEM method is discussed in terms of not only the DBP problem but also as a means of predicting (concurrent to DBP monitoring) organic membrane fouling in water-reuse and desalination plants.

  12. Reducing Volatile Disinfection By-Products in Treated Drinking Water Using Aeration Technologies (WaterRF Report 4441)

    Science.gov (United States)

    The primary objective of this project was to evaluate cost-effective aeration technology solutions to address TTHM compliance at a water treatment plant clearwell. The project team worked closely with EPA Region 6 and the EPA Office of Research and Development (ORD) to identify a...

  13. Removal of the precursors of N-nitrosodiethylamine (NDEA), an emerging disinfection byproduct, in drinking water treatment process and its toxicity to adult zebrafish (Danio rerio).

    Science.gov (United States)

    Zheng, Jian; Lin, Tao; Chen, Wei

    2018-01-01

    N-nitrosodiethylamine (NDEA) is one of the emerging nitrogenous disinfection byproducts with probable cytotoxicity, genotoxicity, and carcinogenesis. Its potential toxicological effects have received extensive attention but remain to be poorly understood. In this study, changes in NDEA precursors in drinking water treatment process were studied using the trial of its formation potential (FP), and the toxicity induced by NDEA to adult zebrafish was investigated. NDEA FP in the raw water of Taihu Lake ranged from 46.9 to 68.3 ng/L. The NDEA precursors were removed effectively by O 3 /BAC process. Hydrophilic fraction and low-molecular-weight fraction (stress and antioxidant defense to zebrafish metabolism system at concentrations over 5 μg/L. After a 42-day exposure, a significant DNA damage was observed in zebrafish liver cells at NDEA concentrations beyond 500 μg/L. This study investigated NDEA properties in both engineering prospective and toxicity evaluation, thus providing comprehensive information on its control in drinking water treatment process and its toxicity effect on zebrafish as a model animal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Detection of chlorinated and brominated byproducts of drinking water disinfection using electrospray ionization-high-field asymmetric waveform ion mobility spectrometry-mass spectrometry.

    Science.gov (United States)

    Ells, B; Barnett, D A; Froese, K; Purves, R W; Hrudey, S; Guevremont, R

    1999-10-15

    The lower limit of detection for low molecular weight polar and ionic analytes using electrospray ionization-mass spectrometry (ESI-MS) is often severely compromised by an intense background that obscures ions of trace components in solution. Recently, a new technique, referred to as high-field asymmetric waveform ion mobility spectrometry (FAIMS), has been shown to separate gas-phase ions at atmospheric pressure and room temperature. A FAIMS instrument is an ion filter that may be tuned, by control of electrical voltages, to continuously transmit selected ions from a complex mixture. This capability offers significant advantages when FAIMS is coupled with ESI, a source that generates a wide variety of ions, including solvent clusters and salt adducts. In this report, the tandem arrangement of ESI-FAIMS-MS is used for the analysis of haloacetic acids, a class of disinfection byproducts regulated by the US EPA. FAIMS is shown to effectively discriminate against background ions resulting from the electrospray of tap water solutions containing the haloacetic acids. Consequently, mass spectra are simplified, the selectivity of the method is improved, and the limits of detection are lowered compared with conventional ESI-MS. The detection limits of ESI-FAIMS-MS for six haloacetic acids ranged between 0.5 and 4 ng/mL in 9:1 methanol/tap water (5 and 40 ng/mL in the original tap water samples) with no preconcentration, derivatization, or chromatographic separation prior to analysis.

  15. Source Water Management for Disinfection By-Product Control using New York City's Operations Support Tool and On-Line Monitoring

    Science.gov (United States)

    Weiss, W. J.; Becker, W.; Schindler, S.

    2012-12-01

    The United States Environmental Protection Agency's 2006 Stage 2 Disinfectant / Disinfection Byproduct Rule (DBPR) for finished drinking waters is intended to reduce overall DBP levels by limiting the levels of total trihalomethanes (TTHM) and five of the haloacetic acids (HAA5). Under Stage 2, maximum contaminant levels (MCLs), 80 μg/L for TTHM and 60 μg/L for HAA5, are based on a locational running annual average for individual sites instead of as the system-wide quarterly running annual average of the Stage 1 DBPR. This means compliance will have to be met at sampling locations of peak TTHM and HAA5 concentrations rather than an average across the entire system. Compliance monitoring under the Stage 2 DBPR began on April 1, 2012. The New York City (NYC) Department of Environmental Protection (DEP) began evaluating potential impacts of the Stage 2 DBPR on NYC's unfiltered water supply in 2002 by monitoring TTHM and HAA5 levels at various locations throughout the distribution system. Initial monitoring indicated that HAA5 levels could be of concern in the future, with the potential to intermittently violate the Stage 2 DBPR at specific locations, particularly those with high water age. Because of the uncertainty regarding the long-term prospect for compliance, DEP evaluated alternatives to ensure compliance, including operational changes (reducing chlorine dose, changing flow configurations to minimize water age, altering pH, altering source water withdrawals); changing the residual disinfectant from free chlorine to chloramines; and engineered treatment alternatives. This paper will discuss the potential for using DEP's Operations Support Tool (OST) and enhanced reservoir monitoring to support optimization of source water withdrawals to minimize finished water DBP levels. The OST is a state-of-the-art decision support system (DSS) to provide computational and predictive support for water supply operations and planning. It incorporates a water supply system

  16. Disinfection of drinking water

    International Nuclear Information System (INIS)

    Ensenauer, P.

    1977-01-01

    Some methods for disinfecting drinking water are described, e.g. UV irradiation (optimal wavelength 210-250mm) with the advantage of constant water composition and the resulting danger of re-infection. (AJ) [de

  17. Disinfection of drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Ensenauer, P

    1977-01-01

    Some methods for disinfecting drinking water are described, e.g. UV irradiation (optimal wavelength 210-250mm) with the advantage of constant water composition and the resulting danger of re-infection.

  18. Effects of conventional ozonation and electro-peroxone pretreatment of surface water on disinfection by-product formation during subsequent chlorination.

    Science.gov (United States)

    Mao, Yuqin; Guo, Di; Yao, Weikun; Wang, Xiaomao; Yang, Hongwei; Xie, Yuefeng F; Komarneni, Sridhar; Yu, Gang; Wang, Yujue

    2018-03-01

    The electro-peroxone (E-peroxone) process is an emerging ozone-based electrochemical advanced oxidation process that combines conventional ozonation with in-situ cathodic hydrogen peroxide (H 2 O 2 ) production for oxidative water treatment. In this study, the effects of the E-peroxone pretreatment on disinfection by-product (DBP) formation from chlorination of a synthetic surface water were investigated and compared to conventional ozonation. Results show that due to the enhanced transformation of ozone (O 3 ) to hydroxyl radicals (OH) by electro-generated H 2 O 2 , the E-peroxone process considerably enhanced dissolved organic carbon (DOC) abatement and significantly reduced bromate (BrO 3 - ) formation compared to conventional ozonation. However, natural organic matter (NOM) with high UV 254 absorbance, which is the major precursors of chlorination DBPs, was less efficiently abated during the E-peroxone process than conventional ozonation. Consequently, while both conventional ozonation and the E-peroxone process substantially reduced the formation of DBPs (trihalomethanes and haloacetic acids) during post-chlorination, higher DBP concentrations were generally observed during chlorination of the E-peroxone pretreated waters than conventional ozonation treated. In addition, because of conventional ozonation or the E-peroxone treatment, DBPs formed during post-chlorination shifted to more brominated species. The overall yields of brominated DBPs exhibited strong correlations with the bromide concentrations in water. Therefore, while the E-peroxone process can effectively suppress bromide transformation to bromate, it may lead to higher formation of brominated DBPs during post-chlorination compared to conventional ozonation. These results suggest that the E-peroxone process can lead to different DBP formation and speciation during water treatment trains compared to conventional ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Four groups of new aromatic halogenated disinfection byproducts: effect of bromide concentration on their formation and speciation in chlorinated drinking water.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru

    2013-02-05

    Bromide is naturally present in source waters worldwide. Chlorination of drinking water can generate a variety of chlorinated and brominated disinfection byproducts (DBPs). Although substantial efforts have been made to examine the effect of bromide concentration on the formation and speciation of halogenated DBPs, almost all previous studies have focused on trihalomethanes and haloacetic acids. Given that about 50% of total organic halogen formed in chlorination remains unknown, it is still unclear how bromide concentration affects the formation and speciation of the new/unknown halogenated DBPs. In this study, chlorinated drinking water samples with different bromide concentrations were prepared, and a novel approach-precursor ion scan using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry-was adopted for the detection and identification of polar halogenated DBPs in these water samples. With this approach, 11 new putative aromatic halogenated DBPs were identified, and they were classified into four groups: dihalo-4-hydroxybenzaldehydes, dihalo-4-hydroxybenzoic acids, dihalo-salicylic acids, and trihalo-phenols. A mechanism for the formation of the four groups of new aromatic halogenated DBPs was proposed. It was found that increasing the bromide concentration shifted the entire polar halogenated DBPs as well as the four groups of new DBPs from being less brominated to being more brominated; these new aromatic halogenated DBPs might be important intermediate DBPs formed in drinking water chlorination. Moreover, the speciation of the four groups of new DBPs was modeled: the speciation patterns of the four groups of new DBPs well matched those determined from the model equations, and the reactivity differences between HOBr and HOCl in reactions forming the four groups of new DBPs were larger than those in reactions forming trihalomethanes and haloacetic acids.

  20. DOES MICRO LC/MS OFFER ADVANTAGES OVER CONVENTIONAL LC/MS IN IDENTIFYING DISINFECTION BY-PRODUCTS

    Science.gov (United States)

    Lower maximum contaminant levels (MCLs) of disinfection by-products were set for drinking water municipalities by the Stage 1 DBP Rule in November, 1998. With these new regulations, additional water treatment plants are expected to choose alternative disinfectants to chlorine. Al...

  1. Emergency Disinfection of Drinking Water

    Science.gov (United States)

    How to boil and disinfect water to kill most disease-causing microorganisms during emergency situations where regular water service has been interrupted and local authorities recommend using only bottled water, boiled water, or disinfected water.

  2. Genotoxic Effects in Swimmers Exposed to Disinfection By-products in Indoor Swimming Pool

    Science.gov (United States)

    BACKGROUND: Exposure to disinfection by-products (DBPs) in drinking water has been associated with cancer risk, and a recent study found an increased bladder cancer risk among subjects attending swimming pools. OBJECTIVES: To evaluate whether swimming in pools is associated with ...

  3. Environmental and personal determinants of the uptake of disinfection by-products during swimming

    NARCIS (Netherlands)

    Font-Ribera, Laia; Kogevinas, Manolis; Schmalz, Christina; Zwiener, Christian; Marco, Esther; Grimalt, Joan O; Liu, Jiaqi; Zhang, Xiangru; Mitch, William; Critelli, Rossana; Naccarati, Alessio; Heederik, Dick; Spithoven, Jack; Arjona, Lourdes; de Bont, Jeroen; Gracia-Lavedan, Esther; Villanueva, Cristina M

    BACKGROUND: Trihalomethanes (THMs) in exhaled breath and trichloroacetic acid (TCAA) in urine are internal dose biomarkers of exposure to disinfection by-products (DBPs) in swimming pools. OBJECTIVE: We assessed how these biomarkers reflect the levels of a battery of DBPs in pool water and

  4. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao; Croue, Jean-Philippe

    2015-01-01

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  5. Comparative cytotoxic and genotoxic potential of 13 drinking water disinfection by-products using a microplate-based cytotoxicity assay and a developed SOS/umu assay.

    Science.gov (United States)

    Zhang, Shao-Hui; Miao, Dong-Yue; Tan, Li; Liu, Ai-Lin; Lu, Wen-Qing

    2016-01-01

    The implications of disinfection by-products (DBPs) present in drinking water are of public health concern because of their potential mutagenic, carcinogenic and other toxic effects on humans. In this study, we selected 13 main DBPs found in drinking water to quantitatively analyse their cytotoxicity and genotoxicity using a microplate-based cytotoxicity assay and a developed SOS/umu assay in Salmonella typhimurium TA1535/pSK1002. With the developed SOS/umu test, eight DBPs: 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-fura3-chloro-4-(dichloromethyl)-5-hydroxy-2-[5H]-furanone (MX), dibromoacetonitrile (DBN), iodoacetic acid (IA), bromochloroacetonitrile (BCN), bromoacetic acid (BA), trichloroacetonitrile (TCN), dibromoacetic acid (DBA) and dichloroacetic acid (DCA) were significantly genotoxic to S. typhimurium. Three DBPs: chloroacetic acid (CA), trichloroacetic acid (TCA) and dichloroacetonitrile (DCN) were weakly genotoxic, whereas the remaining DBPs: chloroacetonitrile (CN) and chloral hydrate (CH) were negative. The rank order in decreasing genotoxicity was as follows: MX > DBN > IA > BCN > BA > TCN > DBA > DCA > CA, TCA, DCN > CN, CH. MX was approximately 370 000 times more genotoxic than DCA. In the microplate-based cytotoxicity assay, cytotoxic potencies of the 13 DBPs were compared and ranked in decreasing order as follows: MX > IA > DBN > BCN > BA > TCN > DCN > CA > DCA > DBA > CN > TCA > CH. MX was approximately 19 200 times more cytotoxic than CH. A statistically significant correlation was found between cytotoxicity and genotoxicity of the 13 DBPs in S. typhimurium. Results suggest that microplate-based cytotoxicity assay and the developed SOS/umu assay are feasible tools for analysing the cytotoxicity and genotoxicity of DBPs, particularly for comparing their toxic intensities quantitatively. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e

  6. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao

    2015-12-02

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  7. Effect of ozonation of swimming pool water on formation of volatile disinfection by-products - A laboratory study

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram

    2016-01-01

    Ozonation experiments were performed using unchlorinated tap water used for filling municipal swimming pools, actual pool water and pool water polluted by addition of fresh tap water and artificial body fluid to evaluate ozone kinetics and water quality effects on formation of volatile disinfecti...

  8. Genotoxicity of the disinfection by-products resulting from peracetic acid- or hypochlorite-disinfected sewage wastewater.

    Science.gov (United States)

    Crebelli, R; Conti, L; Monarca, S; Feretti, D; Zerbini, I; Zani, C; Veschetti, E; Cutilli, D; Ottaviani, M

    2005-03-01

    Wastewater disinfection is routinely carried out to prevent the spread of human pathogens present in wastewater effluents. To this aim, chemical and physical treatments are applied to the effluents before their emission in water bodies. In this study, the influence of two widely used disinfectants, peracetic acid (PAA) and sodium hypochlorite (NaClO), on the formation of mutagenic by-products was investigated. Wastewater samples were collected before and after disinfection, in winter and in summer, at a pilot plant installed in a municipal wastewater-treatment plant. Samples were adsorbed using silica C18 cartridges and the concentrates were tested for mutagenicity in the Salmonella typhimurium reversion test with strains TA98 and TA100. Non-concentrated water samples were tested with two plant genotoxicity assays (the Allium cepa root anaphase aberration test and the Tradescantia/micronucleus test). Mutagenicity assays in bacteria and in Tradescantia showed borderline mutagenicity in some of the wastewater samples, independent of the disinfection procedure applied. Negative results were obtained in the A. cepa anaphase aberration test. These results indicate that, in the conditions applied, wastewater disinfection with PAA and NaClO does not lead to the formation of significant amounts of genotoxic by-products.

  9. The Use of Normal Colon Cell Culture to Assess Toxicities and Cancer Molecular Pathway Alterations Induced by Disinfection Byproducts.

    Science.gov (United States)

    Recent Epidemiological studies have linked the consumption of disinfected surface waters to an increased risk of colorectal cancer (Bove, GE, Jr et al., Int. J. Health Geogr., 6:18, 2007). Approximately 600 disinfection byproducts (DBP) have been identified. Because it would be...

  10. Understanding the Impacts and Meaning of Maintaining Detectable Disinfection Residuals in Drinking Water Distribution Systems: Controlling Waterborne Pathogens, Disinfection Byproducts, Organic Chloramines, and Nitrification

    Science.gov (United States)

    : EPA Region 6, in collaboration with the Office of Research and Development and Office of Water (OW) in Cincinnati, Ohio, and the Louisiana Department of Health and Hospitals (LDHH), proposes a drinking water research project to understand how maintaining various drinking water...

  11. Potential for formation of disinfection by-products from storage of chlorinated surface water in the Basalt aquifer near Fallon, Nevada

    Science.gov (United States)

    Fram, Miranda S.; Maurer, Douglas K.; Lico, Michael S.

    2005-01-01

    Increased pumpage from a basalt aquifer near Fallon, Nevada, has caused its water levels to decline and has induced changes in the quality of water pumped from the basalt. The aquifer is the sole source of water for municipal supply to the city of Fallon, the Naval Air Station Fallon, and the Fallon Paiute-Shoshone Tribe. These changes may be mitigated by storage of surface water in the basalt for subsequent use. Because chlorination of the surface water may be required for storage, the U.S. Geological Survey, in cooperation with the Fallon Paiute-Shoshone Tribe, made laboratory tests using laboratory carbon-organic-free water, surface-water, ground-water, and basaltic-rock samples to determine the potential for formation of disinfection by-products. Experiments with water samples only (no rock and no chlorine) indicated no change in dissolved-organic-carbon (DOC) concentrations over a 20-day reaction period; whereas, all experiments using rock, water, and no chlorine indicated an increase in DOC concentrations. The greatest increase in DOC concentrations for all three water samples occurred in experiments with the rock samples from outcrops on Rattlesnake Hill. Experiments with water only and chlorine yielded a total trihalomethane (THM) concentration of 97.4 ?g/L for the ground-water sample and 347 ?g/L for the surface-water sample. Experiments with mixtures of water, rocks, and chlorine indicated that reactions with the rock consumed chlorine and released significant amounts of organic carbon from the rock, increasing the DOC concentration in the water. The organic carbon in the rocks likely is associated with the secondary clay minerals that line vesicles and fractures in the rocks. THM concentrations were greatest, from 335 to 909 ?g/L, for surface water equilibrated with rock samples from Rattlesnake Hill. However, the concentration of chlorine required to produce these high THM concentrations ranged from 18 to 84 mg/L. The results of the experiments suggest

  12. Formation and Occurrence of N-Chloro-2,2-dichloroacetamide, a Previously Overlooked Nitrogenous Disinfection Byproduct in Chlorinated Drinking Waters.

    Science.gov (United States)

    Yu, Yun; Reckhow, David A

    2017-02-07

    Haloacetamides (HAMs) are a class of newly identified nitrogenous disinfection byproducts (N-DBPs) whose occurrence in drinking waters has recently been reported in several DBP surveys. As the most prominent HAM species, it is commonly acknowledged that 2,2-dichloroacetamide (DCAM) is mainly generated from dichloroacetonitrile (DCAN) hydrolysis because the concentrations of these two compounds are often well correlated. Instead of DCAM, a previously unreported N-DBP, N-chloro-2,2-dichloroacetamide (N-Cl-DCAM), was confirmed in this study as the actual DCAN degradation product in chlorinated drinking waters. It is suspected that N-Cl-DCAM has been erroneously identified as DCAM, because its nitrogen-bound chlorine is readily reduced by most commonly used quenching agents. This hypothesis is supported by kinetic studies that indicate almost instantaneous N-chlorination of DCAM even at low chlorine residuals. Therefore, it is unlikely that DCAM can persist as a long-lived DCAN decomposition product in systems using free chlorine as a residual disinfectant. Instead, chlorination of DCAM will lead to the formation of an equal amount of N-Cl-DCAM by forming a hydrogen bond between hypochlorite oxygen and amino hydrogen. Alternatively, N-Cl-DCAM can be produced directly from DCAN chlorination via nucleophilic addition of hypochlorite on the nitrile carbon. Due to its relatively low pK a value, N-Cl-DCAM tends to deprotonate under typical drinking water pH conditions, and the anionic form of N-Cl-DCAM was found to be very stable in the absence of chlorine. N-Cl-DCAM can, however, undergo acid-catalyzed decomposition to form the corresponding dichloroacetic acid (DCAA) when chlorine is present, although those acidic conditions that favor N-Cl-DCAM degradation are generally atypical for finished drinking waters. For these reasons, N-Cl-DCAM is predicted to have very long half-lives in most distribution systems that use free chlorine. Furthermore, an analytical method using

  13. Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

    Science.gov (United States)

    Kolb, Chelsea; Francis, Royce A; VanBriesen, Jeanne M

    2017-08-01

    Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM 3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. Copyright © 2017. Published by Elsevier B.V.

  14. Evaluation of the water disinfection by-product dichloroacetonitrile-induced biochemical, oxidative, histopathological, and mitochondrial functional alterations: Subacute oral toxicity in rats.

    Science.gov (United States)

    Dong, Ying; Li, Fang; Shen, Haijun; Lu, Rongzhu; Yin, Siqi; Yang, Qi; Li, Zhuangfa; Wang, Suhua

    2018-03-01

    Dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product, is more genotoxic and cytotoxic than the currently regulated carbonaceous disinfection by-products such as haloacetic acids. Few mechanistic studies have been conducted on the hepatic and renal toxicities of DCAN. This study examined the clinical biochemical, hematological, histopathological, oxidative, and mitochondrial functional alterations to evaluate the systematic toxicity after subacute oral exposure of 11 or 44 mg/kg/day in rats for 28 days. Body and spleen weights were lower, and organ-to-body weight ratios of the liver and kidney were higher in rats administered 44-mg/kg DCAN than in controls. The activities of serum alanine aminotransferase and alkaline phosphatase, and concentrations of blood serum urea nitrogen and retinol-binding protein were increased in rats administered 44-mg/kg DCAN compared with those of controls, thereby indicating hepatic and renal damage in this group. This was confirmed by histopathological alterations, including hepatic sinus dilation, extensive hemorrhage, vacuolar degeneration in the liver and glomerulus hemorrhage, and renal tubular swelling, in DCAN-exposed rats. Exposure to 44-mg/kg DCAN induced hepatic oxidative damage shown by the significant increase in malonaldehyde levels, a poisonous product of lipid peroxidation. Exposure to 44-mg/kg DCAN significantly increased hepatic glutathione content and mitochondrial bioenergy as noted by the elevation of mitochondrial membrane potential and cytochrome c oxidase activity, which might be attributed to compensatory pathophysiologic responses to DCAN-induced hepatic mitochondrial damage.

  15. Application of effect-directed analysis to identify mutagenic nitrogenous disinfection by-products of advanced oxidation drinking water treatment

    NARCIS (Netherlands)

    Vughs, D.; Baken, K.A.; Kolkman, A.; Martijn, A.J.; de Voogt, P.

    Advanced oxidation processes are important barriers for organic micropollutants in (drinking) water treatment. It is however known that medium pressure UV/H2O2 treatment may lead to mutagenicity in the Ames test, which is no longer present after granulated activated carbon (GAC) filtration. Many

  16. Predictive QSAR Models for the Toxicity of Disinfection Byproducts

    Directory of Open Access Journals (Sweden)

    Litang Qin

    2017-10-01

    Full Text Available Several hundred disinfection byproducts (DBPs in drinking water have been identified, and are known to have potentially adverse health effects. There are toxicological data gaps for most DBPs, and the predictive method may provide an effective way to address this. The development of an in-silico model of toxicology endpoints of DBPs is rarely studied. The main aim of the present study is to develop predictive quantitative structure–activity relationship (QSAR models for the reactive toxicities of 50 DBPs in the five bioassays of X-Microtox, GSH+, GSH−, DNA+ and DNA−. All-subset regression was used to select the optimal descriptors, and multiple linear-regression models were built. The developed QSAR models for five endpoints satisfied the internal and external validation criteria: coefficient of determination (R2 > 0.7, explained variance in leave-one-out prediction (Q2LOO and in leave-many-out prediction (Q2LMO > 0.6, variance explained in external prediction (Q2F1, Q2F2, and Q2F3 > 0.7, and concordance correlation coefficient (CCC > 0.85. The application domains and the meaning of the selective descriptors for the QSAR models were discussed. The obtained QSAR models can be used in predicting the toxicities of the 50 DBPs.

  17. Predictive QSAR Models for the Toxicity of Disinfection Byproducts.

    Science.gov (United States)

    Qin, Litang; Zhang, Xin; Chen, Yuhan; Mo, Lingyun; Zeng, Honghu; Liang, Yanpeng

    2017-10-09

    Several hundred disinfection byproducts (DBPs) in drinking water have been identified, and are known to have potentially adverse health effects. There are toxicological data gaps for most DBPs, and the predictive method may provide an effective way to address this. The development of an in-silico model of toxicology endpoints of DBPs is rarely studied. The main aim of the present study is to develop predictive quantitative structure-activity relationship (QSAR) models for the reactive toxicities of 50 DBPs in the five bioassays of X-Microtox, GSH+, GSH-, DNA+ and DNA-. All-subset regression was used to select the optimal descriptors, and multiple linear-regression models were built. The developed QSAR models for five endpoints satisfied the internal and external validation criteria: coefficient of determination ( R ²) > 0.7, explained variance in leave-one-out prediction ( Q ² LOO ) and in leave-many-out prediction ( Q ² LMO ) > 0.6, variance explained in external prediction ( Q ² F1 , Q ² F2 , and Q ² F3 ) > 0.7, and concordance correlation coefficient ( CCC ) > 0.85. The application domains and the meaning of the selective descriptors for the QSAR models were discussed. The obtained QSAR models can be used in predicting the toxicities of the 50 DBPs.

  18. UV disinfection of water

    International Nuclear Information System (INIS)

    Skipperud, E.; Johansen; Myhrstad, J.A.

    1978-01-01

    UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW)

  19. Determination of several common disinfection by-products in frozen foods.

    Science.gov (United States)

    Cardador, Maria Jose; Gallego, Mercedes

    2018-01-01

    Disinfected water and/or disinfectants are commonly used by the freezing industry in such processes as sanitising, washing, blanching, cooling and transporting the final product. For this reason, disinfection by-products (DBPs) can be expected in frozen foods. This study focused on the presence of DBPs in a wide variety of frozen vegetables, meats and fish. For this purpose, the 14 halogenated DBPs more prevalent in disinfected water were selected (four trihalomethanes, seven haloacetic acids, two haloacetonitriles and trichloronitromethane). Up to seven DBPs were found in vegetables, whereas only four DBPs were present in meats and fish, and at lower concentrations, since their contact with disinfected water is lower than in frozen vegetables. It is important to emphasise that trichloronitromethane (the most abundant nitrogenous DBP in disinfected water) was found for the first time in foods. Finally, it was concluded that the freezing process can keep the compounds stable longer than other preservation processes (viz. sanitising, canning) and, therefore, frozen foods present higher DBP concentrations than other food categories (minimally processed vegetables, or canned vegetables and meats).

  20. Water-Quality Constituents, Dissolved-Organic-Carbon Fractions, and Disinfection By-Product Formation in Water from Community Water-Supply Wells in New Jersey, 1998-99

    Science.gov (United States)

    Hopple, Jessica A.; Barringer, Julia L.; Koleis, Janece

    2007-01-01

    Water samples were collected from 20 community water-supply wells in New Jersey to assess the chemical quality of the water before and after chlorination, to characterize the types of organic carbon present, and to determine the disinfection by-product formation potential. Water from the selected wells previously had been shown to contain concentrations of dissolved organic carbon (DOC) that were greater than 0.2 mg/L. Of the selected wells, five are completed in unconfined (or semi-confined) glacial-sediment aquifers of the Piedmont and Highlands (New England) Physiographic Provinces, five are completed in unconfined bedrock aquifers of the Piedmont Physiographic Province, and ten are completed in unconsolidated sediments of the Coastal Plain Physiographic Province. Four of the ten wells in the Coastal Plain are completed in confined parts of the aquifers; the other six are in unconfined aquifers. One or more volatile organic compounds (VOCs) were detected in untreated water from all of the 16 wells in unconfined aquifers, some at concentrations greater than maximum contaminant levels. Those compounds detected included aliphatic compounds such as trichloroethylene and 1,1,1-trichloroethane, aromatic compounds such as benzene, the trihalomethane compound, chloroform, and the gasoline additive methyl tert-butyl ether (MTBE). Concentrations of sodium and chloride in water from one well in a bedrock aquifer and sulfate in water from another exceeded New Jersey secondary standards for drinking water. The source of the sulfate was geologic materials, but the sodium and chloride probably were derived from human inputs. DOC fractions were separated by passing water samples through XAD resin columns to determine hydrophobic fractions from hydrophilic fractions. Concentrations of hydrophobic acids were slightly lower than those of combined hydrophilic acids, neutral compounds, and low molecular weight compounds in most samples. Water samples from the 20 wells were adjusted

  1. CHO cell cytotoxicity and genotoxicity analyses of disinfection by-products: An updated review

    Institute of Scientific and Technical Information of China (English)

    Elizabeth D.Wagner; Michael J.Plewa

    2017-01-01

    The disinfection of drinking water is an important public health service that generates high quality,safe and palatable tap water.The disinfection of drinking water to reduce waterborne disease was an outstanding public health achievement of the 20th century.An unintended consequence is the reaction of disinfectants with natural organic matter,anthropogenic contaminants and bromide/iodide to form disinfection by-products (DBPs).A large number of DBPs are cytotoxic,neurotoxic,mutagenic,genotoxic,carcinogenic and teratogenic.Epidemiological studies demonstrated low but significant associations between disinfected drinking water and adverse health effects.The distribution of DBPs in disinfected waters has been well defined by advances in high precision analytical chemistry.Progress in the analytical biology and toxicology of DBPs has been forthcoming.The objective of this review was to provide a detailed presentation of the methodology for the quantitative,comparative analyses on the induction of cytotoxicity and genotoxicity of 103 DBPs using an identical analytical biological platform and endpoints.A single Chinese hamster ovary cell line was employed in the assays.The data presented are derived from papers published in the literature as well as additional new data and represent the largest direct quantitative comparison on the toxic potency of both regulated and emerging DBPs.These data may form the foundation of novel research to define the major forcing agents of DBP-mediated toxicity in disinfected water and may play an important role in achieving the goal of making safe drinking water better.

  2. The toxicity of a new disinfection by-product, 2,2-dichloroacetamide (DCAcAm), on adult zebrafish (Danio rerio) and its occurrence in the chlorinated drinking water.

    Science.gov (United States)

    Yu, Shilin; Lin, Tao; Chen, Wei; Tao, Hui

    2015-11-01

    The detection method of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product (DBP) in chlorinated drinking water, was established using a gas chromatograph coupled with a micro-electron capture detector. The chlorinated water samples were taken from ten drinking water treatment plants around Yangtze River or Taihu Lake in China. The concentration of DCAcAm was detected ranging from 0.5 to 1.8μg/L in the waterworks around Yangtze River, and 1.5-2.6μg/L around Taihu Lake. The toxicity of DCAcAm on adult zebrafish was assessed by investigating the metabolism damage with multiple metabolic biomarkers and the accumulation capability with bio-concentration factor. The results showed that DCAcAm could cause the acute metabolism damage and was easily accumulated in zebrafish, and should be extremely cautioned. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Disinfection byproduct formation from chlorination of pure bacterial cells and pipeline biofilms.

    Science.gov (United States)

    Wang, Jun-Jian; Liu, Xin; Ng, Tsz Wai; Xiao, Jie-Wen; Chow, Alex T; Wong, Po Keung

    2013-05-15

    Disinfection byproduct (DBP) formation is commonly attributed to the reaction between natural organic matters and disinfectants, yet few have considered the contribution from disinfecting bacterial materials - the essential process of water disinfection. Here, we explored the DBP formation from chlorination and chloramination of Escherichia coli and found that most selected DBPs were detectable, including trihalomethanes, haloacetonitriles, chloral hydrate, chloropicrin, and 1,1,1-trichloro-2-propanone. A positive correlation (P = 0.08-0.09) between DBP formation and the log reduction of E. coli implied that breaking down of bacterial cells released precursors for DBP formation. As Pseudomonas aeruginosa is a dominant bacterial species in pipeline biofilms, the DBP formation potentials (DBPFPs) from its planktonic cells and biofilms were characterized. Planktonic cells formed 7-11 times greater trihalomethanes per carbon of those from biofilms but significantly lower (P biofilms on polyvinyl chloride compared to that on galvanized zinc. This study revealed both the in situ disinfection of bacterial planktonic cells in source water and ex situ reaction between biofilms and residual chlorine in pipeline networks as hitherto unknown DBP sources in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A Summary of Publications on the Development of Mode-of-Action Information and Statistical Tools for Evaluating Health Outcomes from Drinking Water Disinfection By-Product (DBP) Exposures

    Science.gov (United States)

    Chemical contaminants are formed as a consequence of chemical disinfection of public drinking waters. Chemical disinfectants, which are used to kill harmful microorganisms, react with natural organic matter (NOM), bromide, iodide, and other compounds, forming complex mixtures...

  5. Sources and characteristics of organic matter in the Clackamas River, Oregon, related to the formation of disinfection by-products in treated drinking water

    Science.gov (United States)

    Carpenter, Kurt D.; Kraus, Tamara E.C.; Goldman, Jami H.; Saraceno, John Franco; Downing, Bryan D.; Bergamaschi, Brian A.; McGhee, Gordon; Triplett, Tracy

    2013-01-01

    This study characterized the amount and quality of organic matter in the Clackamas River, Oregon, to gain an understanding of sources that contribute to the formation of chlorinated and brominated disinfection by-products (DBPs), focusing on regulated DBPs in treated drinking water from two direct-filtration treatment plants that together serve approximately 100,000 customers. The central hypothesis guiding this study was that natural organic matter leaching out of the forested watershed, in-stream growth of benthic algae, and phytoplankton blooms in the reservoirs contribute different and varying proportions of organic carbon to the river. Differences in the amount and composition of carbon derived from each source affects the types and concentrations of DBP precursors entering the treatment plants and, as a result, yield varying DBP concentrations and species in finished water. The two classes of DBPs analyzed in this study-trihalomethanes (THMs) and haloacetic acids (HAAs)-form from precursors within the dissolved and particulate pools of organic matter present in source water. The five principal objectives of the study were to (1) describe the seasonal quantity and character of organic matter in the Clackamas River; (2) relate the amount and composition of organic matter to the formation of DBPs; (3) evaluate sources of DBP precursors in the watershed; (4) assess the use of optical measurements, including in-situ fluorescence, for estimating dissolved organic carbon (DOC) concentrations and DBP formation; and (5) assess the removal of DBP precursors during treatment by conducting treatability "jar-test" experiments at one of the treatment plants. Data collection consisted of (1) monthly sampling of source and finished water at two drinking-water treatment plants; (2) event-based sampling in the mainstem, tributaries, and North Fork Reservoir; and (3) in-situ continuous monitoring of fluorescent dissolved organic matter (FDOM), turbidity, chlorophyll-a, and

  6. Spiral-shaped reactor for water disinfection

    KAUST Repository

    Soukane, Sofiane; Ait-Djoudi, Fariza; Naceur, Wahib M.; Ghaffour, NorEddine

    2016-01-01

    Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria

  7. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry

    International Nuclear Information System (INIS)

    Wang, Xin; Wang, Juan; Zhang, Yahe; Shi, Quan; Zhang, Haifeng; Zhang, Yu; Yang, Min

    2016-01-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AI mod ), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water. - Highlights: • The formulas of 206 iodinated DBPs in chloraminated drinking water were proposed. • More than 68% of the I-DBPs might have aromatic or polycyclic aromatic structures. • Precursors with high aromaticity is preferential to form iodinated DBPs.

  8. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Wang, Juan [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhang, Yahe; Shi, Quan [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhang, Haifeng; Zhang, Yu [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Yang, Min, E-mail: yangmin@rcees.ac.cn [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-06-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AI{sub mod}), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water. - Highlights: • The formulas of 206 iodinated DBPs in chloraminated drinking water were proposed. • More than 68% of the I-DBPs might have aromatic or polycyclic aromatic structures. • Precursors with high aromaticity is preferential to form iodinated DBPs.

  9. Oxidation of diclofenac by aqueous chlorine dioxide: identification of major disinfection byproducts and toxicity evaluation.

    Science.gov (United States)

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai

    2014-03-01

    Diclofenac (DCF), a synthetic non-steroidal anti-inflammatory drug, is one of the most frequently detected pharmaceuticals in the aquatic environment. In this work, the mechanism and toxicity of DCF degradation by ClO2 under simulated water disinfection conditions were investigated. Experimental results indicate that rapid and significant oxidation of DCF occurred within the first few minutes; however, its mineralization process was longer than its degradation process. UPLC-MS and (1)H NMR spectroscopy were performed to identify major disinfection byproducts that were generated in three tentative degradation routes. The two main routes were based on initial decarboxylation of DCF on the aliphatic chain and hydroxylation of the phenylacetic acid moiety at the C-4 position. Subsequently, the formed aldehyde intermediates were the starting point for further multistep degradation involving decarboxylation, hydroxylation, and oxidation reactions of CN bond cleavage. The third route was based on transient preservation of chlorinated derivatives resulting from electrophilic attack by chlorine on the aromatic ring, which similarly underwent CN bond cleavage. Microtox bioassay was employed to evaluate the cytotoxicity of solutions treated by ClO2. The formation of more toxic mid-byproducts during the ClO2 disinfection process poses a potential risk to consumers. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Recent advances in drinking water disinfection: successes and challenges.

    Science.gov (United States)

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    Drinking water is the most important single source of human exposure to gastroenteric diseases, mainly as a result of the ingestion of microbial contaminated water. Waterborne microbial agents that pose a health risk to humans include enteropathogenic bacteria, viruses, and protozoa. Therefore, properly assessing whether these hazardous agents enter drinking water supplies, and if they do, whether they are disinfected adequately, are undoubtedly aspects critical to protecting public health. As new pathogens emerge, monitoring for relevant indicator microorganisms (e.g., process microbial indicators, fecal indicators, and index and model organisms) is crucial to ensuring drinking water safety. Another crucially important step to maintaining public health is implementing Water Safety Plans (WSPs), as is recommended by the current WHO Guidelines for Drinking Water Quality. Good WSPs include creating health-based targets that aim to reduce microbial risks and adverse health effects to which a population is exposed through drinking water. The use of disinfectants to inactivate microbial pathogens in drinking water has played a central role in reducing the incidence of waterborne diseases and is considered to be among the most successful interventions for preserving and promoting public health. Chlorine-based disinfectants are the most commonly used disinfectants and are cheap and easy to use. Free chlorine is an effective disinfectant for bacteria and viruses; however, it is not always effective against C. parvum and G. lamblia. Another limitation of using chlorination is that it produces disinfection by-products (DBPs), which pose potential health risks of their own. Currently, most drinking water regulations aggressively address DBP problems in public water distribution systems. The DBPs of most concern include the trihalomethanes (THMs), the haloacetic acids (HAAs), bromate, and chlorite. However, in the latest edition of the WHO Guidelines for Drinking Water Quality

  11. Monte-Carlo and multi-exposure assessment for the derivation of criteria for disinfection byproducts and volatile organic compounds in drinking water: Allocation factors and liter-equivalents per day.

    Science.gov (United States)

    Akiyama, Megumi; Matsui, Yoshihiko; Kido, Junki; Matsushita, Taku; Shirasaki, Nobutaka

    2018-06-01

    The probability distributions of total potential doses of disinfection byproducts and volatile organic compounds via ingestion, inhalation, and dermal exposure were estimated with Monte Carlo simulations, after conducting physiologically based pharmacokinetic model simulations to takes into account the differences in availability between the three exposures. If the criterion that the 95th percentile estimate equals the TDI (tolerable daily intake) is regarded as protecting the majority of a population, the drinking water criteria would be 140 (trichloromethane), 66 (bromodichloromethane), 157 (dibromochloromethane), 203 (tribromomethane), 140 (dichloroacetic acid), 78 (trichloroacetic acid), 6.55 (trichloroethylene, TCE), and 22 μg/L (perchloroethylene). The TCE criterion was lower than the Japanese Drinking Water Quality Standard (10 μg/L). The latter would allow the intake of 20% of the population to exceed the TDI. Indirect inhalation via evaporation from water, especially in bathrooms, was the major route of exposure to compounds other than haloacetic acids (HAAs) and accounted for 1.2-9 liter-equivalents/day for the median-exposure subpopulation. The ingestion of food was a major indirect route of exposure to HAAs. Contributions of direct water intake were not very different for trihalomethanes (30-45% of TDIs) and HAAs (45-52% of TDIs). Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Ultraviolet disinfection of potable water

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, R. L. [Metropolitan Water District of Southern California, Los Angeles, CA (United States)

    1990-06-15

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection.

  13. Ultraviolet disinfection of potable water

    International Nuclear Information System (INIS)

    Wolfe, R.L.

    1990-01-01

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection

  14. Health impact of disinfection by-products in swimming pools

    Directory of Open Access Journals (Sweden)

    Cristina M. Villanueva

    2012-12-01

    Full Text Available This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemiological study suggested an increased risk of bladder cancer with swimming pool attendance, although evidence is inconclusive. A higher prevalence of respiratory symptoms including asthma is found among swimming pool workers and elite swimmers, although the causality of this association is unclear. The body of evidence in children indicates that asthma is not increased by swimming pool attendance. Overall, the available knowledge suggests that the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimising potential risks.

  15. Occurrence of disinfection byproducts in United States wastewater treatment plant effluents

    KAUST Repository

    Krasner, Stuart W.

    2009-11-01

    Effluents from wastewater treatment plants (WWTPs) contain disinfection byproducts (DBPs) of health concern when the water is utilized downstream as a potable water supply. The pattern of DBP formation was strongly affected by whether or not the WWTP achieved good nitrification. Chlorine addition to poorly nitrified effluents formed low levels of halogenated DBPs, except for (in some cases) dihalogenated acetic acids, but often substantial amounts of N-nitrosodimethyamine (NDMA). Chlorination of well-nitrified effluent typically resulted in substantial formation of halogenated DBPs but much less NDMA. For example, on a median basis after chlorine addition, the well-nitrified effluents had 57 μg/L of trihalomethanes [THMs] and 3 ng/L of NDMA, while the poorly nitrified effluents had 2 μg/L of THMs and 11 ng/L of NDMA. DBPs with amino acid precursors (haloacetonitriles, haloacetaldehydes) formed at substantial levels after chlorination of well-nitrified effluent. The formation of halogenated DBPs but not that of NDMA correlated with the formation of THMs in WWTP effluents disinfected with free chlorine. However, THM formation did not correlate with the formation of other DBPs in effluents disinfected with chloramines. Because of the relatively high levels of bromide in treated wastewater, bromine incorporation was observed in various classes of DBPs. © 2009 American Chemical Society.

  16. Occurrence of disinfection byproducts in United States wastewater treatment plant effluents

    KAUST Repository

    Krasner, Stuart W.; Westerhoff, Paul K.; Chen, Baiyang; Rittmann, Bruce E.; Amy, Gary L.

    2009-01-01

    Effluents from wastewater treatment plants (WWTPs) contain disinfection byproducts (DBPs) of health concern when the water is utilized downstream as a potable water supply. The pattern of DBP formation was strongly affected by whether or not the WWTP achieved good nitrification. Chlorine addition to poorly nitrified effluents formed low levels of halogenated DBPs, except for (in some cases) dihalogenated acetic acids, but often substantial amounts of N-nitrosodimethyamine (NDMA). Chlorination of well-nitrified effluent typically resulted in substantial formation of halogenated DBPs but much less NDMA. For example, on a median basis after chlorine addition, the well-nitrified effluents had 57 μg/L of trihalomethanes [THMs] and 3 ng/L of NDMA, while the poorly nitrified effluents had 2 μg/L of THMs and 11 ng/L of NDMA. DBPs with amino acid precursors (haloacetonitriles, haloacetaldehydes) formed at substantial levels after chlorination of well-nitrified effluent. The formation of halogenated DBPs but not that of NDMA correlated with the formation of THMs in WWTP effluents disinfected with free chlorine. However, THM formation did not correlate with the formation of other DBPs in effluents disinfected with chloramines. Because of the relatively high levels of bromide in treated wastewater, bromine incorporation was observed in various classes of DBPs. © 2009 American Chemical Society.

  17. Ames and random amplified polymorphic DNA tests for the validation of the mutagenic and/or genotoxic potential of the drinking water disinfection by-products chloroform and bromoform.

    Science.gov (United States)

    Khallef, Messaouda; Cenkci, Süleyman; Akyil, Dilek; Özkara, Arzu; Konuk, Muhsin; Benouareth, Djamel Eddine

    2018-01-28

    Chloroform and Bromoform are two abundant trihalomethanes found in Algerian drinking water. The investigation of the mutagenic hazard of these disinfection by-products was studied by Ames test as prokaryotic bioassay to show their mutagenic effects. For this, Salmonella typhimurium TA98 and TA100 strains were employed. Both chloroform and bromoform showed a direct mutagenic effect since the number of revertant colonies gradually increase in dose-dependent manner with all concentrations tested with the two bacterial strains and these were both in the absence and presence of S9 metabolic activation. The genotoxic hazard was also studied by random amplified polymorphic DNA test on the root cells of Allium cepa as eukaryotic bioassay. DNA extracted from the roots of the onion were incubated at different concentrations of chloroform and bromoform and then amplified by polymerase chain reaction. This was based on demonstrating a major effect of disappearance of bands compared to roots incubated in the negative control (distilled water). The results showed that these two compounds affected genomic DNA by breaks although by mutations.

  18. Effect of Permanganate Preoxidation to Natural Organic Matter and Disinfection by-Products Formation Potential Removal

    Science.gov (United States)

    Hidayah, E. N.; Yeh, H. H.

    2018-01-01

    Laboratory scale experiments was conducted to examine effect of permanganate (KMnO4) peroxidation in characterizing and to remove natural organic matter (NOM) in source water. The experimental results shows that increasing permanganate dosage could decreased aromatic matter, as indicated by decreasing UV254 and SUVA value about 23% and 28%, respectively. It seems that permanganate preoxidation caused the breakdown of high molecular weight (MW) organics into low MW ones, as represented by increasing NPDOC about 10%. Further, disinfection by-products formation potential (DBPFP) in terms of trihalomethanes formation potential (THMFP) and haloacetic acid formation potential (HAAP) decreased about 15% and 23%, respectively. HAAFP removal is higher than THMFP removal and that DPBFP removal is consistent with UV254 and NPDOC removal.

  19. Tracing disinfection byproducts in full-scale desalination plants

    KAUST Repository

    Le Roux, Julien

    2015-03-01

    The aim of this study was to assess the formation and the behavior of halogenated byproducts (regulated THMs and HAAs, as well as nitrogenous, brominated and iodinated DBPs including the emerging iodo-THMs) along the treatment train of full-scale desalination plants. One thermal multi-stage flash distillation (MSF) plant and two reverse osmosis (RO) plants located on the Red Sea coast of Saudi Arabia. DBPs formed during the prechlorination step were efficiently removed along the treatment processes (MSF or RO). Desalination plants fed with good seawater quality and using intermittent chlorine injection did not show high DBP formation and discharge. One RO plant with a lower raw water quality and using continuous chlorination at the intake formed more DBPs. In this plant, some non-regulated DBPs (e.g., dibromoacetonitrile and iodo-THMs) reached the product water in low concentrations (< 1.5 μg/L). Regulated THMs and HAAs were far below their maximum contamination levels set by the US Environmental Protection Agency. Substantial amounts of DBPs are disposed to the sea; low concentrations of DBPs were indeed detected in the water on shore of the desalination plants.

  20. DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON

    Science.gov (United States)

    The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by–products (DBPs) including total organic halide, trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along ...

  1. Bench-Scale Evaluation of Peracetic Acid and Twin Oxide ™ as Disinfectants in Drinking Water

    Science.gov (United States)

    Chlorine is widely used as an inexpensive and potent disinfectant in the United States for drinking water. However, chlorine has the potential for forming carcinogenic and mutagenic disinfection by-products (DBPs). In this study, bench scale experiments were conducted at the U.S...

  2. Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-)

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

    2017-01-01

    Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should......: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO2) as well as two by-products of their use: hydrogen peroxide (H2O2) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC50 values ranged from 0.16 to 2.9 mg...

  3. Disinfection of grey water

    OpenAIRE

    Winward, Gideon Paul

    2007-01-01

    The reuse of grey water, for applications such as toilet flushing and irrigation, represents a potential sustainable solution to water shortages experienced by regions worldwide. Although reused grey water is not intended for potable use, the potential for transmission of waterborne pathogens by aerosol inhalation, topical contact, or indirect ingestion is a key concern for grey water reuse. This thesis explores the pathogen content of grey water and investigates pathogen remov...

  4. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    International Nuclear Information System (INIS)

    Das, Suvarthi; Kumar, Ashutosh; Seth, Ratanesh Kumar; Tokar, Erik J.; Kadiiska, Maria B.; Waalkes, Michael P.; Mason, Ronald P.; Chatterjee, Saurabh

    2013-01-01

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates protein

  5. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    Energy Technology Data Exchange (ETDEWEB)

    Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Seth, Ratanesh Kumar [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Tokar, Erik J. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Waalkes, Michael P. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Mason, Ronald P. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

    2013-06-15

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates

  6. UV disinfection in drinking water supplies.

    Science.gov (United States)

    Hoyer, O

    2000-01-01

    UV disinfection has become a practical and safely validatable disinfection procedure by specifying the requirements for testing and monitoring in DVGW standard W 294. A standardized biodosimetric testing procedure and monitoring with standardized UV sensors is introduced and successfully applied. On-line monitoring of irradiance can be counterchecked with handheld reference sensors and makes it possible that UV systems can be used for drinking water disinfection with the same level of confidence and safety as is conventional chemical disinfection.

  7. Origin of low-molecular mass aldehydes as disinfection by-products in beverages.

    Science.gov (United States)

    Serrano, María; Gallego, Mercedes; Silva, Manuel

    2017-09-01

    A novel, simple and automatic method based on static headspace-gas chromatography-mass spectrometry has been developed to determine 10 low-molecular mass aldehydes that can be found in beverages, coming from the treated water used in their production. These aldehydes are the most frequently found in treated water as water disinfection by-products, so they can be used as indicators of the addition of treated water to beverages. The study covered a large number of fruit juices and soft drinks. The presence of the whole array of analytes is related to the contact with treated water during beverage production, mainly by the addition of treated water as ingredient. In particular, propionaldehyde, valeraldehyde and benzaldehyde can be used as indicators of the addition of treated water in these kinds of beverages. Among the ten aldehydes, only formaldehyde and acetaldehyde are naturally present in all kinds of fruit, and their concentrations are related to stage of the ripening of the fruit.

  8. Formation of Toxic Iodinated Disinfection By-Products from Compounds Used in Medical Imaging

    Science.gov (United States)

    Iodinated X-ray contrast media (ICM) were investigated as a source of iodine in the formation of iodo-trihalomethane (iodo-THM) and iodo-acid disinfection byproducts (DBPs), both of which are highly genotoxic and/or cytotoxic in mammalian cells. ICM are widely used at medical cen...

  9. Silver disinfection in water distribution systems

    Science.gov (United States)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  10. Zinc oxide nanoparticles for water disinfection

    Directory of Open Access Journals (Sweden)

    Emelita Asuncion S. Dimapilis

    2018-03-01

    Full Text Available The world faces a growing challenge for adequate clean water due to threats coming from increasing demand and decreasing supply. Although there are existing technologies for water disinfection, their limitations, particularly the formation of disinfection-by-products, have led to researches on alternative methods. Zinc oxide, an essential chemical in the rubber and pharmaceutical industries, has attracted interest as antimicrobial agent. In nanoscale, zinc oxide has shown antimicrobial properties which make its potential great for various applications. This review discusses the synthesis of zinc oxide with focus on precipitation method, its antimicrobial property and the factors affecting it, disinfection mechanisms, and the potential application to water disinfection.

  11. Biomarkers of end of shift exposure to disinfection byproducts in nurses.

    Science.gov (United States)

    Ioannou, Solomon; Andrianou, Xanthi D; Charisiadis, Pantelis; Makris, Konstantinos C

    2017-08-01

    Increased disinfectant use commonly takes place in hospitals and other health care settings. A cross-sectional study among active nurses in two Cypriot public hospitals (n=179) was conducted to examine the prevalence of exposure to disinfection byproducts (DBPs), such as trihalomethanes (THMs) using both self-reported information and biomarker measurements. The objectives of this study were to: i) quantify the magnitude and variability of occupational exposure to disinfectants/DBPs in nurses, ii) generate job exposure matrices (JEM) and job task exposure matrices (JTEM) for disinfectants, and iii) assess the major determinants of urinary THMs in nurses. End of shift urinary total THM values showed high variability among the nurses, but did not differ between hospitals. The disinfectant group of alcohols/phenols was used by >98% of nurses, followed by octenidine (82%), iodine and chlorine (39%, each), chlorhexidine (25%), formaldehyde (12%), hydrogen peroxide (11%), and peracetic acid/ammonia/quaternary ammonium compounds (QACs), all being Nurses were exposed to nearly double the levels of TTHMs and BrTHMs (median and IQR, 1027 [560, 2475] ng/g and 323 [212, 497] ng/g, respectively) when compared to those of the general population (552 [309,989] ng/g and 152 [87,261] ng/g, respectively). This was the first occupational health dataset reporting measurements of biomarkers of end of shift exposures to disinfectants/DBPs. Copyright © 2017. Published by Elsevier B.V.

  12. Induction of bacterial antibiotic resistance by mutagenic halogenated nitrogenous disinfection byproducts

    International Nuclear Information System (INIS)

    Lv, Lu; Yu, Xin; Xu, Qian; Ye, Chengsong

    2015-01-01

    Halogenated nitrogenous disinfection byproducts (N-DBPs) raise concerns regarding their mutagenicity and carcinogenicity threatening public health. However, environmental consequence of their mutagenicity has received less attention. In this study, the effect of halogenated N-DBPs on bacterial antibiotic resistance (BAR) was investigated. After exposure to bromoacetamide (BAcAm), trichloroacetonitrile (TCAN) or tribromonitromethane (TBNM), the resistance of Pseudomonas aeruginosa PAO1 to both individual and multiple antibiotics (ciprofloxacin, gentamicin, polymyxin B, rifampin, tetracycline, ciprofloxacin + gentamicin and ciprofloxacin + tetracycline) was increased, which was predominantly ascribed to the overexpression of efflux pumps. The mechanism of this effect was demonstrated to be mutagenesis through sequencing and analyzing antibiotic resistance genes. The same induction phenomena also appeared in Escherichia coli, suggesting this effect may be universal to waterborne pathogens. Therefore, more attention should be given to halogenated N-DBPs, as they could increase not only genotoxicological risks but also epidemiological risks of drinking water. - Highlights: • The halogenated N-DBPs could induce bacterial antibiotic resistance. • Both individual and multiple resistances could be induced. • Efflux mechanism played an important role in the induced antibiotic resistance. • The halogenated N-DBPs induced bacterial antibiotic resistance via mutagenesis. • Effects of N-DBPs on antibiotic resistance may be universal to waterborne pathogens. - Halogenated N-DBPs could increase antibiotic resistance, even multidrug resistance via mutagenesis, contributing to the enrichment of antibiotic resistant bacteria in drinking water

  13. Enhanced coagulation with powdered activated carbon or MIEX secondary treatment: a comparison of disinfection by-product formation and precursor removal.

    Science.gov (United States)

    Watson, Kalinda; Farré, Maria José; Knight, Nicole

    2015-01-01

    The removal of both organic and inorganic disinfection by-product (DBP) precursors prior to disinfection is important in mitigating DBP formation, with halide removal being particularly important in salinity-impacted water sources. A matrix of waters of variable alkalinity, halide concentration and dissolved organic carbon (DOC) concentration were treated with enhanced coagulation (EC) followed by anion exchange (MIEX resin) or powdered activated carbon (PAC) and the subsequent disinfection by-product formation potentials (DBP-FPs) assessed and compared to DBP-FPs for untreated samples. Halide and DOC removal were also monitored for both treatment processes. Bromide and iodide adsorption by MIEX treatment ranged from 0 to 53% and 4-78%, respectively. As expected, EC and PAC treatments did not remove halides. DOC removal by EC/PAC was 70 ± 10%, while EC/MIEX enabled a DOC removal of 66 ± 12%. Despite the halide removals achieved by MIEX, increases in brominated disinfection by-product (Br-DBP) formation were observed relative to untreated samples, when favourable Br:DOC ratios were created by the treatment. However, the increases in formation were less than what was observed for the EC/PAC treated waters, which caused large increases in Br-DBP formation when high Br-DBP-forming water quality conditions occurred. The formation potential of fully chlorinated DBPs decreased after treatment in all cases.

  14. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    Science.gov (United States)

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  15. Photochemical Transformation and Bacterial Utilization of Dissolved Organic Matter and Disinfection Byproduct Precursors from Foliar Litter

    Science.gov (United States)

    Chow, A. T.; Wong, P.; O'Geen, A. T.; Dahlgren, R. A.

    2009-12-01

    Foliar litter is an important terrestrial source of dissolved organic matter (DOM) in surface water. DOM is a public health concern since it is a precursor of carcinogenic disinfection byproducts (DBPs) during drinking water treatment. Chemical characterization of in-situ water samples for their impact on water treatment may be misleading because DOM characteristics can be altered from their original composition during downstream transport to water treatment plants. In this study, we collected leachate from four fresh litters and decomposed duffs from four dominant vegetation components of California oak woodlands: blue oak (Quercus douglassi), live oak (Quercus wislizenii), foothill pine (Pinus sabiniana), and annual grasses to evaluate their DOM degradability and the reactivity of altered DOM towards DBP formation. Samples were filtered through a sterilized membrane (0.2 micron) and exposed to natural sunlight and Escherichia coli K-12 independently for 14 days. Generally speaking, leachate from decomposed duff was relatively resistant towards biodegradation compared to that from fresh litter, but the former was more susceptible to photo-transformation. Photo-bleaching caused a 30% decrease in ultra-violet absorbance at 254 nm (UVA) but no significant changes in dissolved organic carbon (DOC) concentration. This apparent loss of aromatic carbon in DOM, in terms of specific UVA, did not result in a decrease of specific trihalomethane (THM) formation potential, although aromatic carbon is considered as a major reactive site for THM formation. In addition, there were significant increases (p < 0.05) of chloral hydrate after the 14-day exposure, suggesting that the photolytic products could be a precursor of chloral hydrate. In contrast, samples inoculated with E. coli did not show a significant effect on the DOC concentration, UVA or DBP formation, although the colony counts indicated a 2-log cell growth during the 14-day incubation. Results suggest photolysis is a

  16. Monitoring natural organic matter and disinfection by-products at ...

    African Journals Online (AJOL)

    COD) and conductivity. Water samples were collected from two water treatment plants in South Africa, namely Sedibeng (Balkfontein) and Midvaal. The overall TOC reduction after the water treatment processes was 33% and 30% at Midvaal and ...

  17. Removal of disinfection by-product precursors by coagulation and an innovative suspended ion exchange process.

    Science.gov (United States)

    Metcalfe, David; Rockey, Chris; Jefferson, Bruce; Judd, Simon; Jarvis, Peter

    2015-12-15

    This investigation aimed to compare the disinfection by-product formation potentials (DBPFPs) of three UK surface waters (1 upland reservoir and 2 lowland rivers) with differing characteristics treated by (a) a full scale conventional process and (b) pilot scale processes using a novel suspended ion exchange (SIX) process and inline coagulation (ILCA) followed by ceramic membrane filtration (CMF). Liquid chromatography-organic carbon detection analysis highlighted clear differences between the organic fractions removed by coagulation and suspended ion exchange. Pretreatments which combined SIX and coagulation resulted in significant reductions in dissolved organic carbon (DOC), UV absorbance (UVA), trihalomethane and haloacetic acid formation potential (THMFP, HAAFP), in comparison with the SIX or coagulation process alone. Further experiments showed that in addition to greater overall DOC removal, the processes also reduced the concentration of brominated DBPs and selectively removed organic compounds with high DBPFP. The SIX/ILCA/CMF process resulted in additional removals of DOC, UVA, THMFP, HAAFP and brominated DBPs of 50, 62, 62, 62% and 47% respectively compared with conventional treatment. Copyright © 2015. Published by Elsevier Ltd.

  18. Ingested Nitrate, Disinfection By-products, and Kidney Cancer Risk in Older Women.

    Science.gov (United States)

    Jones, Rena R; Weyer, Peter J; DellaValle, Curt T; Robien, Kim; Cantor, Kenneth P; Krasner, Stuart; Beane Freeman, Laura E; Ward, Mary H

    2017-09-01

    N-nitroso compounds formed endogenously after nitrate/nitrite ingestion are animal renal carcinogens. Previous epidemiologic studies of drinking water nitrate did not evaluate other potentially toxic water contaminants, including the suspected renal carcinogen chloroform. In a cohort of postmenopausal women in Iowa (1986-2010), we used historical measurements to estimate long-term average concentrations of nitrate-nitrogen (NO3-N) and disinfection by-products (DBP) in public water supplies. For NO3-N and the regulated DBP (total trihalomethanes [THM] and the sum of five haloacetic acids [HAA5]), we estimated the number of years of exposure above one-half the current maximum contaminant level (>½-MCL NO3-N; >5 mg/L). Dietary intakes were assessed via food frequency questionnaire. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) with Cox models, and evaluated interactions with factors influencing N-nitroso compound formation. We identified 125 incident kidney cancers among 15,577 women reporting using water from public supplies >10 years. In multivariable models, risk was higher in the 95th percentile of average NO3-N (HRp95vsQ1 = 2.3; CI: 1.2, 4.3; Ptrend = 0.33) and for any years of exposure >½-MCL; adjustment for total THM did not materially change these associations. There were no independent relationships with total THM, individual THMs chloroform and bromodichloromethane, or with haloacetic acids. Dietary analyses yielded associations with high nitrite intake from processed meats but not nitrate or nitrite overall. We found no interactions. Relatively high nitrate levels in public water supplies were associated with increased risk of renal cancer. Our results also suggest that nitrite from processed meat is a renal cancer risk factor.

  19. Ultraviolet (UV) Disinfection for Drinking Water Systems

    Science.gov (United States)

    UV disinfection is an effective process for inactivating many microbial pathogens in water with potential to serve as stand-alone treatment or in combination with other disinfectants. USEPA provided guidance on the validation of UV reactors nearly a decade ago. Since then, lesson...

  20. Environmental and personal determinants of the uptake of disinfection by-products during swimming.

    Science.gov (United States)

    Font-Ribera, Laia; Kogevinas, Manolis; Schmalz, Christina; Zwiener, Christian; Marco, Esther; Grimalt, Joan O; Liu, Jiaqi; Zhang, Xiangru; Mitch, William; Critelli, Rossana; Naccarati, Alessio; Heederik, Dick; Spithoven, Jack; Arjona, Lourdes; de Bont, Jeroen; Gracia-Lavedan, Esther; Villanueva, Cristina M

    2016-08-01

    Trihalomethanes (THMs) in exhaled breath and trichloroacetic acid (TCAA) in urine are internal dose biomarkers of exposure to disinfection by-products (DBPs) in swimming pools. We assessed how these biomarkers reflect the levels of a battery of DBPs in pool water and trichloramine in air, and evaluated personal determinants. A total of 116 adults swam during 40min in a chlorinated indoor pool. We measured chloroform, bromodichloromethane, dibromochloromethane and bromoform in exhaled breath and TCAA in urine before and after swimming, trichloramine in air and several DBPs in water. Personal determinants included sex, age, body mass index (BMI), distance swum, energy expenditure, heart rate and 12 polymorphisms in GSTT1, GSTZ1 and CYP2E1 genes. Median level of exhaled total THMs and creatinine adjusted urine TCAA increased from 0.5 to 14.4µg/m(3) and from 2.5 to 5.8µmol/mol after swimming, respectively. The increase in exhaled brominated THMs was correlated with brominated THMs, haloacetic acids, haloacetonitriles, haloketones, chloramines, total organic carbon and total organic halogen in water and trichloramine in air. Such correlations were not detected for exhaled chloroform, total THMs or urine TCAA. Exhaled THM increased more in men, urine TCAA increased more in women, and both were affected by exercise intensity. Genetic variants were associated with differential increases in exposure biomarkers. Our findings suggest that, although affected by sex, physical activity and polymorphisms in key metabolizing enzymes, brominated THMs in exhaled breath could be used as a non-invasive DBP exposure biomarker in swimming pools with bromide-containing source waters. This warrants confirmation with new studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Enhancement of ultraviolet water disinfection process

    African Journals Online (AJOL)

    grabi-1

    2013-05-15

    May 15, 2013 ... disinfected water distribution systems, including. Legionella .... soft agar, mixed, incubated at room temperature for 2 min and poured onto the ... The determination of a log increase methodology was employed to quantify the ...

  2. Degradation kinetics of organic chloramines and formation of disinfection by-products during chlorination of creatinine.

    Science.gov (United States)

    Zhang, Tianyang; Xu, Bin; Wang, Anqi; Cui, Changzheng

    2018-03-01

    Organic chloramines can interfere with the measurement of effective combined chlorine in chlorinated water and are potential intermediate products of highly toxic disinfection by-products (DBPs). In order to know more about the degradation and transformation of organic chloramines, a typical organic chloramine precursor creatinine was selected for investigation and a corresponding individual organic chloramine chlorocreatinine was prepared in this study. The preparation condition of chlorocreatinine by chlorination was established as chlorine/creatinine = 1 M/M, reaction time = 2 h and pH = 7.0. Then the degradation kinetics of chlorocreatinine during further chlorination was studied, and a second-order rate constant of 1.16 (±0.14) M -1 s -1 was obtained at pH 7.0. Solution pH significantly influenced the degradation rate, and the elementary rate constants of chlorocreatinine with HOCl+H + , HOCl, OCl - and chlorocreatinine - with OCl - were calculated as 2.43 (±1.55) × 10 4  M -2  s -1 , 1.05 (±0.09) M -1 s -1 , 2.86 (±0.30) M -1 s -1 and 3.09 (±0.24) M -1 s -1 , respectively. Besides, it was found that chlorocreatinine could be further converted into several C-DBPs (chloroform and trichloroacetone) and N-DBPs (dichloroacetonitrile (DCAN) and trichloronitromethane (TCNM)) during chlorination. The total yield of DBPs increased obviously with increasing pH, especially for TCNM. In addition, the presence of humic acid in creatinine solution could increase the formation of DCAN obviously during chlorination. Based on the UPLC-Q-TOF-MS analysis, the conversion pathways of chlorocreatinine were proposed. Several kinds of intermediate products were also identified as organic chloramines and some of them could even exist stably during the further chlorination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Drinking water contamination and it's disinfection

    International Nuclear Information System (INIS)

    Shah, P.M.J.

    2005-01-01

    High quality water is necessary for the survival of human life. In this paper, an effort has been made to highlight the various causes of water contamination. Some of the most common impurities present in water are pathogenic microorganisms along with organize and in organize pollutants. Different treatment methods are adopted to ensure the potability of water. They include physical, chemical and ultra viable treatment along with solar disinfection etc. The adoption of a particular disinfection strategy depends on the level of treatment required and the resources available to carry out such a treatment. (author)

  4. Intracellular mechanisms of solar water disinfection

    Science.gov (United States)

    Castro-Alférez, María; Polo-López, María Inmaculada; Fernández-Ibáñez, Pilar

    2016-12-01

    Solar water disinfection (SODIS) is a zero-cost intervention measure to disinfect drinking water in areas of poor access to improved water sources, used by more than 6 million people in the world. The bactericidal action of solar radiation in water has been widely proven, nevertheless the causes for this remain still unclear. Scientific literature points out that generation of reactive oxygen species (ROS) inside microorganisms promoted by solar light absorption is the main reason. For the first time, this work reports on the experimental measurement of accumulated intracellular ROS in E. coli during solar irradiation. For this experimental achievement, a modified protocol based on the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA), widely used for oxidative stress in eukaryotic cells, has been tested and validated for E. coli. Our results demonstrate that ROS and their accumulated oxidative damages at intracellular level are key in solar water disinfection.

  5. Basic Information about Chloramines and Drinking Water Disinfection

    Science.gov (United States)

    Chloramines are disinfectants used to treat drinking water. Chloramines are most commonly formed when ammonia is added to chlorine to treat drinking water. Chloramines provide longer-lasting disinfection as the water moves through pipes to consumers.

  6. Ingested nitrate and nitrite, disinfection by-products, and pancreatic cancer risk in postmenopausal women.

    Science.gov (United States)

    Quist, Arbor J L; Inoue-Choi, Maki; Weyer, Peter J; Anderson, Kristin E; Cantor, Kenneth P; Krasner, Stuart; Freeman, Laura E Beane; Ward, Mary H; Jones, Rena R

    2018-01-15

    Nitrate and nitrite are precursors of N-nitroso compounds (NOC), probable human carcinogens that cause pancreatic tumors in animals. Disinfection by-products (DBP) exposures have also been linked with digestive system cancers, but few studies have evaluated relationships with pancreatic cancer. We investigated the association of pancreatic cancer with these drinking water contaminants and dietary nitrate/nitrite in a cohort of postmenopausal women in Iowa (1986-2011). We used historical monitoring and treatment data to estimate levels of long-term average nitrate and total trihalomethanes (TTHM; the sum of the most prevalent DBP class) and the duration exceeding one-half the maximum contaminant level (>½ MCL; 5 mg/L nitrate-nitrogen, 40 µg/L TTHM) among participants on public water supplies (PWS) >10 years. We estimated dietary nitrate and nitrite intakes using a food frequency questionnaire. We computed hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression and evaluated nitrate interactions with smoking and vitamin C intake. We identified 313 cases among 34,242 women, including 152 with >10 years PWS use (N = 15,710). Multivariable models of average nitrate showed no association with pancreatic cancer (HR p95 vs . Q1  = 1.16, 95% CI: 0.51-2.64). Associations with average TTHM levels were also null (HR Q4 vs . Q1  = 0.70, 95% CI:0.42-1.18). We observed no trend with increasing years of exposure to either contaminant at levels >½ MCL. Positive associations were suggested in the highest dietary nitrite intake from processed meat (HR p95 vs . Q1  = 1.66, 95% CI 1.00-2.75;p trend  = 0.05). We found no interactions of nitrate with known modifiers of endogenous NOC formation. Our results suggest that nitrite intake from processed meat may be a risk factor for pancreatic cancer. 2017 UICC.

  7. Effects of Extensive Beetle-Induced Forest Mortality on Aromatic Organic Carbon Loading and Disinfection Byproduct Formation Potential

    Science.gov (United States)

    Brouillard, B.; Mikkelson, K. M.; Dickenson, E.; Sharp, J.

    2015-12-01

    Recent drought and warmer temperatures associated with climate change have caused increased pest-induced forest mortality with impacts on biogeochemical and hydrologic processes. To better understand the seasonal impacts of bark beetle infestation on water quality, samples were collected regularly over two overlapping snow free seasons at surface water intakes of six water treatment facilities in the Rocky Mountain region of Colorado displaying varying levels of bark beetle infestation (high >40%, moderate 20-40%, and low <20%). Organic carbon concentrations were typically 3 to 6 times higher in waters sourced from high beetle-impacted watersheds compared to moderate and low impact watersheds, revealing elevated specific ultraviolet absorbance, fluorescence, and humic-like intensity indicative of elevated aromatic carbon signatures. Accordingly, an increase in disinfection byproduct (DBP) formation potential of 400 to 600% was quantified when contrasted with watersheds containing less tree mortality. Beetle impact exasperated seasonal increases in carbon loading and DBP formation potential following both runoff and precipitation events indicating windows when enhanced water treatment may be utilized by water providers in highly infested regions. Additionally, elevated carbon concentrations throughout the summer and fall along with peaks following precipitation events provide evidence of shifting hydrologic flow paths in areas experiencing high forest mortality from decreased tree water uptake and interception. Collectively, these results demonstrate the need for continued watershed protection and monitoring with a changing climate as the resultant perturbations can have adverse effects on biogeochemistry and water quality in heavily impacted areas.

  8. Alternative disinfection technology for water purification systems; Josui shori ni okeru enso daitai shodoku gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Aizawa, T. [The Institute of Public Health, Tokyo (Japan)

    1998-09-10

    This paper describes chlorination substituting disinfection technologies used in water purification systems. Chloramine treatment is regarded as effective in reducing trihalomethane (THM). Chlorine is injected in the initial stage in the form of free chlorine to disinfect pathogenic microorganisms in a short time, which is then added with ammonia to convert it into chloramine for further utilization. Chlorine dioxide has not been used in Japan, but introduced in Europe and America to treat THM. Ozone has the strongest oxidizing power, and is used for disinfection, virus inactivation, decomposition of THM precursors, and removal of fungus odor. The ozone treatment will produce aldehyde if an organic matter is present, but aldehyde can be removed by treatment using organismic activated carbon. Ultraviolet ray treatment has an advantage of being difficult of producing byproducts. This system was experimentally compared with free chlorine treatment on disinfection effect, mutagenicity, suppression of producing THM byproducts, and odor removal. In order to assure reliability of microorganismic and chemical safety in tap water supply systems, assurance by considering the entire system is important, not only by operating the disinfection units, but also combining such physical water purifying technologies as coagulation, sedimentation, filtration, and membrane treatment. The use of chlorine substituting disinfectants is also a part of the conception. 6 refs., 8 figs., 5 tabs.

  9. A study of the formation of minority chlorination disinfection by-products; Estudio de la formacion de subproductos minoritarios de la desinfeccion con cloro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Vidal, F. J.; Ibeas Reoyo, M. v.; Perez Serrano, A.; Orozco Barrenetxea, C.; Gonzalez Delgado, N. [Universidad de Burgos (Spain)

    2001-07-01

    Chlorine has been the traditional choice of chemical for the disinfection in drinking water treatment; however, chlorination of water can lead to the formation of disinfection by-products (DBPs). Tri halomethanes are the most abundant and studied volatile DBPs, but in recent years the study of the minority DBPs is becoming more and more important due to the possible health effects of these compounds and therefore, the need to establish maximum contaminant levels for their presence in public water supplies. In the present work, some of these minority DBPs are evaluated, di chloroacetonitrile (DCAN), chloropicrin or trichloronitromethane (CP) and 1.1,1-tetrachloroethane (TCAC), studying the main parameters influencing their formation: type and concentration of the precursor organic matter, presence of bromide ion, pH and influence of the previous ozonization treatment. (Author) 33 refs.

  10. The Impact of Commercially Treated Oil and Gas Produced Water Discharges on Bromide Concentrations and Modeled Brominated Trihalomethane Disinfection Byproducts at two Downstream Municipal Drinking Water Plants in the Upper Allegheny River, Pennsylvania, USA

    Science.gov (United States)

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species were observed in finished water at several Western Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in br...

  11. Selective Photocatalytic Disinfection by Coupling StrepMiniSog to the Antibody Catalyzed Water Oxidation Pathway.

    Science.gov (United States)

    Wurtzler, Elizabeth M; Wendell, David

    2016-01-01

    For several decades reactive oxygen species have been applied to water quality engineering and efficient disinfection strategies; however, these methods are limited by disinfection byproduct and catalyst-derived toxicity concerns which could be improved by selectively targeting contaminants of interest. Here we present a targeted photocatalytic system based on the fusion protein StrepMiniSOG that uses light within the visible spectrum to produce reactive oxygen species at a greater efficiency than current photosensitizers, allowing for shorter irradiation times from a fully biodegradable photocatalyst. The StrepMiniSOG photodisinfection system is unable to cross cell membranes and like other consumed proteins, can be degraded by endogenous digestive enzymes in the human gut, thereby reducing the consumption risks typically associated with other disinfection agents. We demonstrate specific, multi-log removal of Listeria monocytogenes from a mixed population of bacteria, establishing the StrepMiniSOG disinfection system as a valuable tool for targeted pathogen removal, while maintaining existing microbial biodiversity.

  12. Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-).

    Science.gov (United States)

    Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

    2017-05-01

    Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO 2 ) as well as two by-products of their use: hydrogen peroxide (H 2 O 2 ) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC 50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO 2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Life Cycle Environmental Impacts of Disinfection Technologies Used in Small Drinking Water Systems.

    Science.gov (United States)

    Jones, Christopher H; Shilling, Elizabeth G; Linden, Karl G; Cook, Sherri M

    2018-03-06

    Small drinking water systems serve a fifth of the U.S. population and rely heavily on disinfection. While chlorine disinfection is common, there is interest in minimizing chemical addition, especially due to carcinogenic disinfection byproducts and chlorine-resistant pathogens, by using ultraviolet technologies; however, the relative, broader environmental impacts of these technologies are not well established, especially in the context of small (environmental trade-offs between chlorine and ultraviolet disinfection via comparative life cycle assessment. The functional unit was the production of 1 m 3 of drinking water to U.S. Treatment included cartridge filtration followed by either chlorine disinfection or ultraviolet disinfection with chlorine residual addition. Environmental performance was evaluated for various chlorine contact zone materials (plastic, concrete, steel), ultraviolet validation factors (1.2 to 4.4), and electricity sources (renewable; U.S. average, high, and low impact grids). Performance was also evaluated when filtration and chlorine residual were not required. From a life cycle assessment perspective, replacing chlorine with UV was preferred only in a limited number of cases (i.e., high pumping pressure but filtration is not required). In all others, chlorine was environmentally preferred, although some contact zone materials and energy sources had an impact on the comparison. Utilities can use these data to inform their disinfection technology selection and operation to minimize environmental and human health impacts.

  14. Carbon nanoparticles for solar disinfection of water.

    Science.gov (United States)

    Maddigpu, Pratap Reddy; Sawant, Bhairavi; Wanjari, Snehal; Goel, M D; Vione, Davide; Dhodapkar, Rita S; Rayalu, S

    2018-02-05

    The present manuscript deals with the application of carbon nano particles (CNP) and chitosan (CHIT) in the form of CHIT-CNP composite for the disinfection of water. The CHIT-CNP composite was prepared by the solution casting method and characterized by TEM, XRD and elemental analysis. In the present investigation we study the disinfection efficiency towards E. coli bacteria of both CNP and CHIT-CNP, under sunlight (SODIS) in identical experimental conditions. Both CNP and CHIT-CNP enhanced disinfection as compared to SODIS alone, and comparable performance was achieved when the same dose of CNP in the two materials was applied. However, the CHIT-CNP composite is in the form of a fabric and it is easier to use and handle as compared to the CNP powder, especially in rural and resource-constrained areas. Moreover the SODIS-CHIT-CNP setup, when used in a compound parabolic collector (CPC) reactor showed high bactericidal efficiency compared to SODIS alone, which is promising for practical applications. The disinfection potential of the CNP powder was compared with that of the well-known material TiO 2 Degussa P25 (DP 25 ): DP 25 gave 6-log kill of bacteria in 180min, whereas CNP produced 6-log kill in 150min. Copyright © 2017. Published by Elsevier B.V.

  15. Combined UV treatment and ozonation for the removal of by-product precursors in swimming pool water

    DEFF Research Database (Denmark)

    Cheema, Waqas Akram; Kaarsholm, Kamilla Marie Speht; Andersen, Henrik Rasmus

    2017-01-01

    Both UV treatment and ozonation are used to reduce different types of disinfection by-products (DBPs) in swimming pools. UV treatment is the most common approach, as it is particularly efficient at removing combined chlorine. However, the UV treatment of pool water increases chlorine reactivity...

  16. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  17. Disinfection By-Product Exposures and the Risk of Specific Cardiac Birth Defects

    Science.gov (United States)

    Wright, J. Michael; Evans, Amanda; Kaufman, John A.; Rivera-Núñez, Zorimar; Narotsky, Michael G.

    2016-01-01

    Background: Epidemiological studies suggest that women exposed to disinfection by-products (DBPs) have an increased risk of delivering babies with cardiovascular defects (CVDs). Objective: We examined nine CVDs in relation to categorical DBP exposures including bromoform, chloroform, dibromochloromethane (DBCM), bromodichloromethane (BDCM), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and summary DBP measures (HAA5, THMBr, THM4, and DBP9). Methods: We calculated adjusted odds ratios (aORs) in a case–control study of birth defects in Massachusetts with complete quarterly 1999–2004 trihalomethane (THM) and haloacetic acid (HAA) data. We randomly matched 10 controls each to 904 CVD cases based on week of conception. Weight-averaged aggregate first-trimester DBP exposures were assigned to individuals based on residence at birth. Results: We detected associations for tetralogy of Fallot and the upper exposure categories for TCAA, DCAA, and HAA5 (aOR range, 3.34–6.51) including positive exposure–response relationships for DCAA and HAA5. aORs consistent in magnitude were detected between atrial septal defects and bromoform (aOR = 1.56; 95% CI: 1.01, 2.43), as well as DBCM, chloroform, and THM4 (aOR range, 1.26–1.67). Ventricular septal defects (VSDs) were associated with the highest bromoform (aOR = 1.85; 95% CI: 1.20, 2.83), MBAA (aOR = 1.81; 95% CI: 0.85, 3.84), and DBCM (aOR = 1.54; 95% CI: 1.00, 2.37) exposure categories. Conclusions: To our knowledge, this is the first birth defect study to develop multi-DBP adjusted regression models as well as the first CVD study to evaluate HAA exposures and the second to evaluate bromoform exposures. Our findings, therefore, inform exposure specificity for the consistent associations previously reported between THM4 and CVDs including VSDs. Citation: Wright JM, Evans A, Kaufman JA, Rivera-Núñez Z, Narotsky MG. 2017. Disinfection by-product exposures and the risk of specific

  18. Transformation among Aromatic Iodinated Disinfection Byproducts in the Presence of Monochloramine: From Monoiodophenol to Triiodophenol and Diiodonitrophenol.

    Science.gov (United States)

    Gong, Tingting; Tao, Yuxian; Zhang, Xiangru; Hu, Shaoyang; Yin, Jinbao; Xian, Qiming; Ma, Jian; Xu, Bin

    2017-09-19

    Aromatic iodinated disinfection byproducts (DBPs) are a newly identified category of highly toxic DBPs. Among the identified aromatic iodinated DBPs, 2,4,6-triiodophenol and 2,6-diiodo-4-nitrophenol have shown relatively widespread occurrence and high toxicity. In this study, we found that 4-iodophenol underwent transformation to form 2,4,6-triiodophenol and 2,6-diiodo-4-nitrophenol in the presence of monochloramine. The transformation pathways were investigated, the decomposition kinetics of 4-iodophenol and the formation of 2,4,6-triiodophenol and 2,6-diiodo-4-nitrophenol were studied, the factors affecting the transformation were examined, the toxicity change during the transformation was evaluated, and the occurrence of the proposed transformation pathways during chloramination of source water was verified. The results revealed that 2,4,6-triiodophenol and 2,6-diiodo-4-nitrophenol, which could account for 71.0% of iodine in the transformed 4-iodophenol, were important iodinated transformation products of 4-iodophenol in the presence of monochloramine. The transformation pathways of 4-iodophenol in the presence of monochloramine were proposed and verified. The decomposition of 4-iodophenol in the presence of monochloramine followed a pseudo-second-order decay. Various factors including monochloramine dose, pH, temperature, nitrite concentration, and free chlorine contact time (before chloramination) affected the transformation. The cytotoxicity of the chloraminated 4-iodophenol samples increased continuously with contact time. The proposed transformation pathways occurred during chloramination of source water.

  19. Disinfection of drinking water by ultraviolet light

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    It is no longer mandatory that a given residue of chlorine is present in drinking water and this has led to interest in the use of ultraviolet radiation for disinfection of water in large public waterworks. After a brief discussion of the effect of ultraviolet radiation related to wavelength, the most usual type of irradiation equipment is briefly described. Practioal considerations regarding the installation, such as attenuation of the radiation due to water quality and deposits are presented. The requirements as to dose and residence time are also discussed and finally it is pointed out that hydraulic imperfections can reduce the effectiveness drastically. (JIW)Ψ

  20. Case control study of the geographic variability of exposure to disinfectant byproducts and risk for rectal cancer

    Directory of Open Access Journals (Sweden)

    Rogerson Peter A

    2007-05-01

    Full Text Available Abstract Background Levels of byproducts that result from the disinfection of drinking water vary within a water distribution system. This prompted us to question whether the risk for rectal cancer also varies, depending upon one's long term geographic location within the system. Such a geographic distribution in rectal cancer risk would follow naturally from an association between level of byproduct and rectal cancer risk. We assess the effects of estimated geographic variability in exposure to some of the components of the trihalomethane group of disinfectant byproducts (DBPs on the odds ratios and probabilities for rectal cancer in white males in a case control study of 128 cases and 253 controls, conducted in Monroe County, Western New York State, U.S.A. The study was designed around health data initially collected at the University at Buffalo (Department of Social and Preventative Medicine as part of the Upstate New York Diet Study, and trihalomethane (THM data collected from a separate independent study of THMs conducted by Monroe County Department of Health. Case participants were chosen from hospital pathology records. The controls are disease-free white males between 35–90 years old, living in Monroe County, and chosen from control groups for studies from cancer of five other (unrelated sites. Using a combination of case control methodology and spatial analysis, the spatial patterns of THMs and individual measures of tap water consumption provide estimates of the effects of ingestion of specific amounts of some DBPs on rectal cancer risk. Trihalomethane (THM data were used to spatially interpolate levels at the taps of cases and controls, and odds ratios were estimated using logistic regression to assess the effects of estimated THM exposure dose on cancer risk, adjusting for alcohol, dietary beta carotene intake, tap water intake, and total caloric intake. Results Trihalomethane levels varied spatially within the county; although

  1. The effect of chlorine and combined chlorine/UV treatment on coliphages in drinking water disinfection.

    Science.gov (United States)

    Zyara, Alyaa M; Torvinen, Eila; Veijalainen, Anna-Maria; Heinonen-Tanski, Helvi

    2016-08-01

    Chlorine disinfection is a globally used method to ensure the safety of drinking water. However, it has not always been successful against viruses and, therefore, it is important to find new methods to disinfect water. Seventeen different coliphages were isolated from the treated municipal wastewater. These coliphages and MS2 were treated with different dosages of chlorine in drinking water, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method.

  2. Electrogeneration of disinfection byproducts at a boron-doped diamond anode with resorcinol as a model substance

    International Nuclear Information System (INIS)

    Li Hongna; Ni Jinren

    2012-01-01

    Highlights: ► DBPs formation was studied in BDD cell with several organics. ► Accumulated chloroform was wholly mineralized in the electrolysis. ► Chlorate produced was oxidized to perchlorate as electrolysis continued. ► Inorganic byproducts should be carefully watched in electrolysis with BDD. ► Resorcinol had the greatest reactivity for DBPs production in the studied precursors. - Abstract: Electrochemical disinfection in chloride electrolyte with a boron-doped diamond (BDD) electrode has unique advantages due to the high oxidizing ability of active chlorine and reactive oxygen species produced under certain conditions in the electrolysis. However, the electrogeneration of disinfection byproducts (DBPs) in the presence of organics in the system has rarely been reported. In this study, the discontinuous formation of DBPs (chloroform, chlorate and perchlorate) was investigated in model water containing chloride electrolyte (10 mM) with a BDD anode in the presence of resorcinol (0.5 mM) at a current density of 20 mA cm −2 . We found that the formation of chloroform and chlorate increased with the free available chlorine production at the beginning and reached peaks at 2 h (0.01 mM), 4 h (1.67 mM), respectively. When the free available chlorine started to decrease, chloroform was gradually mineralized and chlorate was oxidized to perchlorate due to the strong and non-selective oxidizing ability of the BDD. After electrolysis for 25 h, only perchlorate was left (3.84 mM). So inorganic DBPs should be carefully watched in the BDD system. The chloride concentration in the electrolyte affected the production of all three DBPs, due to its influence on the active chlorine production. Organic was not involved in the chlorate and perchlorate formation, and thus the resorcinol concentration had little impact on inorganic DBPs. DBPs formation at acidic pH was lower than that in the basic condition, mainly due to the different forms of resorcinol and chlorine

  3. Spiral-shaped reactor for water disinfection

    KAUST Repository

    Soukane, Sofiane

    2016-04-20

    Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria. The hydrodynamic behavior of contact tanks of different shapes, each with an approximate total volume of 50,000 m3, was analyzed by solving turbulent momentum transport equations with a computational fluid dynamics code, namely ANSYS fluent. Numerical experiments of a tracer pulse were performed for each design to generate flow through curves and investigate species residence time distribution for different inlet flow rates, ranging from 3 to 12 m3 s−1. A new nature-inspired Conch tank design whose shape follows an Archimedean spiral was then developed. The spiral design is shown to strongly outperform the other tanks’ designs for all the selected plug flow criteria with an enhancement in efficiency, less short circuiting, and an order of magnitude improvement in mixing and dispersion. Moreover, following the intensification philosophy, after 50% reduction in its size, the new design retains its properties and still gives far better results than the classical shapes.

  4. Associations Between Disinfection By-Product Exposures and Craniofacial Birth Defects.

    Science.gov (United States)

    Kaufman, John A; Wright, J Michael; Evans, Amanda; Rivera-Núñez, Zorimar; Meyer, Amy; Narotsky, Michael G

    2018-02-01

    The aim of this study was to examine associations between craniofacial birth defects (CFDs) and disinfection by-product (DBP) exposures, including the sum of four trihalomethanes (THM4) and five haloacetic acids (HAA5) (ie, DBP9). We calculated first trimester adjusted odds ratios (aORs) for different DBPs in a matched case-control study of 366 CFD cases in Massachusetts towns with complete 1999 to 2004 THM and HAA data. We detected elevated aORs for cleft palate with DBP9 (highest quintile aOR = 3.52; 95% CI: 1.07, 11.60), HAA5, trichloroacetic acid (TCAA), and dichloroacetic acid. We detected elevated aORs for eye defects with TCAA and chloroform. This is the first epidemiological study of DBPs to examine eye and ear defects, as well as HAAs and CFDs. The associations for cleft palate and eye defects highlight the importance of examining specific defects and DBPs beyond THM4.

  5. Formation of N-nitrosodimethylamine (NDMA) from reaction of monochloramine: a new disinfection by-product.

    Science.gov (United States)

    Choi, Junghoon; Valentine, Richard L

    2002-02-01

    Studies have been conducted specifically to investigate the hypothesis that N-nitrosodimethylamine (NDMA) can be produced by reactions involving monochloramine. Experiments were conducted using dimethylamine (DMA) as a model precursor. NDMA was formed from the reaction between DMA and monochloramine indicating that it should be considered a potential disinfection by-product. The formation of NDMA increased with increased monochloramine concentration and showed maximum in yield when DMA was varied at fixed monochloramine concentrations. The mass spectra of the NDMA formed from DMA and 15N isotope labeled monochloramine (15NH2Cl) showed that the source of one of the nitrogen atoms in the nitroso group in NDMA was from monochloramine. Addition of 0.05 and 0.5 mM of preformed monochloramine to a secondarily treated wastewater at pH 7.2 also resulted in the formation of 3.6 and 111 ng/L of NDMA, respectively, showing that this is indeed an environmentally relevant NDMA formation pathway. The proposed NDMA formation mechanism consists of (i) the formation of 1,1-dimethylhydrazine (UDMH) intermediate from the reaction of DMA with monochloramine followed by, (ii) the oxidation of UDMH by monochloramine to NDMA, and (iii) the reversible chlorine transfer reaction between monochloramine and DMA which is parallel to (i). We conclude that reactions involving monochloramine in addition to classical nitrosation reactions are potentially important pathways for NDMA formation.

  6. Development of the electrical discharge method for water disinfection

    International Nuclear Information System (INIS)

    Vojtenko, L.M.; Kononov, O.V.; Starchik, P.D.; Samojlenko, L.S.; Stavs'ka, S.S.

    1995-01-01

    Studies of processes of bacterially polluted water disinfection by the method of pulse electrical discharge in water are presented. The studies was performed to improve the disinfection technology. Main attention was concentrated to clear up effect of discharge instability on the disinfection. An influence of the shape and sizes of electrodes on repeatability of discharges was also investigated. It was found that salts solved in water greatly influence ultraviolet radiation absorption coefficients

  7. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baiyang, E-mail: poplar_chen@hotmail.com [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Zhang, Tian [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Bond, Tom [Department of Civil and Environmental Engineering, Imperial College, London SW7 2AZ (United Kingdom); Gan, Yiqun [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China)

    2015-12-15

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  8. Genotoxicity analysis of two halonitromethanes, a novel group of disinfection by-products (DBPs), in human cells treated in vitro

    International Nuclear Information System (INIS)

    Liviac, Danae; Creus, Amadeu; Marcos, Ricard

    2009-01-01

    Halonitromethanes (HNMs) constitute an emerging class of disinfection by-products (DBPs) produced when chlorine and/or ozone are used for water treatment. The HNMs are structurally similar to halomethanes, but have a nitro-group in place of hydrogen bonded to the central carbon atom. Since little information exists on the genotoxic potential of HNMs, a study has been carried out with two HNM compounds, namely trichloronitromethane (TCNM) and bromonitromethane (BNM) by using human cells. Primary damage induction has been measured with the Comet assay, which is used to determine both the repair kinetics of the induced damage and the proportion of induced oxidative damage. In addition, the fixed DNA damage has been evaluated by using the micronucleus (MN) assay. The results obtained indicate that both compounds are genotoxic, inducing high levels of DNA breaks in the Comet assay, and that this DNA damage repairs well over time. In addition, oxidized bases constitute a high proportion of DNA-induced damage (50-75%). Contrarily, no positive effects were observed in the frequency of micronucleus, which measures both clastogenic and aneugenic effects, neither using TK6 cells nor peripheral blood lymphocytes. This lack of fixed genetic damage would minimize the potential mutagenic risk associated with HNMs exposure

  9. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    International Nuclear Information System (INIS)

    Chen, Baiyang; Zhang, Tian; Bond, Tom; Gan, Yiqun

    2015-01-01

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  10. Precursors of nitrogenous disinfection by-products in drinking water––A critical review and analysis

    International Nuclear Information System (INIS)

    Bond, Tom; Templeton, Michael R.; Graham, Nigel

    2012-01-01

    Highlights: ► The proportion of N-DBP formation attributable to specific precursors was calculated. ► Precursor concentrations are typically insufficient to account for observed N-DBP formation, except CNX and NDMA. ► Amino acid precursors are easier to remove during water treatment than suggested by laboratory studies. - Abstract: In recent years research into the formation of nitrogenous disinfection by-products (N-DBPs) in drinking water – including N-nitrosodimethylamine (NDMA), the haloacetonitriles (HANs), haloacetamides (HAcAms), cyanogen halides (CNX) and halonitromethanes (HNMs) – has proliferated. This is partly due to their high reported toxicity of N-DBPs. In this review paper information about the formation yields of N-DBPs from model precursors, and about environmental precursor occurrence, has been employed to assess the amount of N-DBP formation that is attributable to known precursors. It was calculated that for HANs and HAcAms, the concentrations of known precursors – mainly free amino acids are insufficient to account for the observed concentrations of these N-DBP groups. However, at least in some waters, a significant proportion of CNX and NDMA formation can be explained by known precursors. Identified N-DBP precursors tend to be of low molecular weight and low electrostatic charge relative to bulk natural organic matter (NOM). This makes them recalcitrant to removal by water treatment processes, notably coagulation, as confirmed by a number of bench-scale studies. However, amino acids have been found to be easier to remove during water treatment than would be suggested by the known molecular properties of the individual free amino acids.

  11. Disinfection of contaminated water by using solar irradiation.

    Science.gov (United States)

    Caslake, Laurie F; Connolly, Daniel J; Menon, Vilas; Duncanson, Catriona M; Rojas, Ricardo; Tavakoli, Javad

    2004-02-01

    Contaminated water causes an estimated 6 to 60 billion cases of gastrointestinal illness annually. The majority of these cases occur in rural areas of developing nations where the water supply remains polluted and adequate sanitation is unavailable. A portable, low-cost, and low-maintenance solar unit to disinfect unpotable water has been designed and tested. The solar disinfection unit was tested with both river water and partially processed water from two wastewater treatment plants. In less than 30 min in midday sunlight, the unit eradicated more than 4 log10 U (99.99%) of bacteria contained in highly contaminated water samples. The solar disinfection unit has been field tested by Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente in Lima, Peru. At moderate light intensity, the solar disinfection unit was capable of reducing the bacterial load in a controlled contaminated water sample by 4 log10 U and disinfected approximately 1 liter of water in 30 min.

  12. Reductive dehalogenation of disinfection byproducts by an activated carbon-based electrode system.

    Science.gov (United States)

    Li, Yuanqing; Kemper, Jerome M; Datuin, Gwen; Akey, Ann; Mitch, William A; Luthy, Richard G

    2016-07-01

    Low molecular weight, uncharged, halogenated disinfection byproducts (DBPs) are poorly removed by the reverse osmosis and advanced oxidation process treatment units often applied for further treatment of municipal wastewater for potable reuse. Granular activated carbon (GAC) treatment effectively sorbed 22 halogenated DBPs. Conversion of the GAC to a cathode within an electrolysis cell resulted in significant degradation of the 22 halogenated DBPs by reductive electrolysis at -1 V vs. Standard Hydrogen Electrode (SHE). The lowest removal efficiency over 6 h electrolysis was for trichloromethane (chloroform; 47%) but removal efficiencies were >90% for 13 of the 22 DBPs. In all cases, DBP degradation was higher than in electrolysis-free controls, and degradation was verified by the production of halides as reduction products. Activated carbons and charcoal were more effective than graphite for electrolysis, with graphite featuring poor sorption for the DBPs. A subset of halogenated DBPs (e.g., haloacetonitriles, chloropicrin) were degraded upon sorption to the GAC, even without electrolysis. Using chloropicrin as a model, experiments indicated that this loss was attributable to the partial reduction of sorbed chloropicrin from reducing equivalents in the GAC. Reducing equivalents depleted by these reactions could be restored when the GAC was treated by reductive electrolysis. GAC treatment of an advanced treatment train effluent for potable reuse effectively reduced the concentrations of chloroform, bromodichloromethane and dichloroacetonitrile measured in the column influent to below the method detection limits. Treatment of the GAC by reductive electrolysis at -1 V vs. SHE over 12 h resulted in significant degradation of the chloroform (63%), bromodichloromethane (96%) and dichloroacetonitrile (99%) accumulated on the GAC. The results suggest that DBPs in advanced treatment train effluents could be captured and degraded continuously by reductive electrolysis

  13. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  14. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment.

    Science.gov (United States)

    Postigo, Cristina; Richardson, Susan D

    2014-08-30

    Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Drinking Water Supply without Use of a Disinfectant

    Science.gov (United States)

    Rajnochova, Marketa; Tuhovcak, Ladislav; Rucka, Jan

    2018-02-01

    The paper focuses on the issue of drinking water supply without use of any disinfectants. Before the public water supply network operator begins to consider switching to operation without use of chemical disinfection, initial assessment should be made, whether or not the water supply system in question is suitable for this type of operation. The assessment is performed by applying the decision algorithm. The initial assessment is followed by another decision algorithm which serves for managing and controlling the process of switching to drinking water supply without use of a disinfectant. The paper also summarizes previous experience and knowledge of this way operated public water supply systems in the Czech Republic.

  16. Impact of disinfection on drinking water biofilm bacterial community.

    Science.gov (United States)

    Mi, Zilong; Dai, Yu; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-11-01

    Disinfectants are commonly applied to control the growth of microorganisms in drinking water distribution systems. However, the effect of disinfection on drinking water microbial community remains poorly understood. The present study investigated the impacts of different disinfectants (chlorine and chloramine) and dosages on biofilm bacterial community in bench-scale pipe section reactors. Illumina MiSeq sequencing illustrated that disinfection strategy could affect both bacterial diversity and community structure of drinking water biofilm. Proteobacteria tended to predominate in chloraminated drinking water biofilms, while Firmicutes in chlorinated and unchlorinated biofilms. The major proteobacterial groups were influenced by both disinfectant type and dosage. In addition, chloramination had a more profound impact on bacterial community than chlorination. Copyright © 2015. Published by Elsevier B.V.

  17. Disinfection by-product formation during chlor(am)ination of algal organic matters (AOM) extracted from Microcystis aeruginosa: effect of growth phases, AOM and bromide concentration.

    Science.gov (United States)

    Chen, Juxiang; Gao, Naiyun; Li, Lei; Zhu, Mingqiu; Yang, Jing; Lu, Xian; Zhang, Yansen

    2017-03-01

    Algae organic matter (AOM), including extracellular organic matter (EOM) and intracellular organic matter (IOM), has caused a series of problems to the water quality, among which formation of disinfection by-products (DBPs) during subsequent chlor(am)ination process was especially serious and concerned. This study characterized physicochemical properties of the EOM and IOM solution extracted from different growth phases of Microcystis aeruginosa and investigated the corresponding formation potential of DBPs during chlor(am)ination process. Besides, the effects of initial concentration of xEOM, IOM, and Br - on the yields of disinfection by-product formation potential were studied. The results indicated that the specific UV absorbance (SUVA 254 ) values of IOM and EOM (1.09 and 2.66 L/mg m) were considerably lower than that of natural organic matter (NOM) (4.79 L/mg m). Fluorescence dates showed the soluble microbial by-product was dominant in both EOM and IOM, and the tryptophan was the main component of AOM. From the excitation-emission matrix figure of EOM and IOM, we found that the content of the high molecular weight protein substance in IOM was higher than EOM. During chlorination of EOM and IOM, the yields of four kinds of DBPs followed the order trichloroethene (TCM) > 1,1-DCP > dichloride acetonitrile (DCAN) > trichloronitromethane (TCNM), while the order was TCM > DCAN > TCNM > 1,1-DCP during chloramination process. The bromine substitution factor (BSF) value increased with the increasing of the concentration of Br - . When the concentration of Br - was 500 μg/L, the BSF values of chlorination EOM and IOM were 51.1 and 68.4%, respectively. As the concentration of Br - increased, the formation of Cl-DBPs was inhibited and the formation of Br-DBPs was promoted. Graphical abstract ᅟ.

  18. A pilot solar water disinfecting system: performance analysis and testing

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, T.S.; El-Ghetany, H.H. [Tohoku University, Sendai (Japan). Dept. of Aeronautics and Space Engineering

    2002-07-01

    In most countries, contaminated water is the major cause of most water-borne diseases. Disinfection of water may be accomplished by a number of different physical-chemical treatments including direct application of thermal energy, chemical and filtration techniques. Solar energy also can be used effectively in this field because inactivation of microorganisms is done either by heating water to a disinfecting temperature or by exposing it to ultraviolet solar radiation. A pilot solar system for disinfecting contaminated water is designed, constructed and tested. Investigations are carried out to evaluate the performance of a wooden hot box solar facility as a solar disinfectant. Experimental data show that solar energy is viable for the disinfection process. A solar radiation model is presented and compared with the experimental data. A mathematical model of the solar disinfectant is also presented. The governing equations are solved numerically via the fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed, solar radiation, etc.) on the performance of the solar disinfectant are examined. Results showed that the system is affected by ambient temperature, wind speed, ultraviolet solar radiation intensity, the turbidity of the water, the quantity of water exposed, the contact area between the transparent water container in the solar disinfectant and the absorber plate as well as the geometrical parameters of the system. It is pointed out that for partially cloudy conditions with a low ambient temperature and high wind speeds, the thermal efficiency of the solar disinfectant is at a minimum. The use of solar energy for the disinfection process will increase the productivity of the system while completely eliminating the coliform group bacteria at the same time. (author)

  19. Sewage disinfection towards protection of drinking water resources.

    Science.gov (United States)

    Kolch, A

    2000-01-01

    Wastewater applied in agriculture for irrigation could replace the use of natural drinking-water resources. With respect to high concentrations of human pathogens wastewater has to be disinfected prior to use. This paper introduces disinfection methods with emphasis on UV irradiation.

  20. Chlorination disinfection by-products in drinking water and congenital anomalies: review and meta-analyses Subprodutos da desinfecção com cloro em água potável e anomalias congênitas: revisão e meta-análise

    Directory of Open Access Journals (Sweden)

    Mark J. Nieuwenhuijsen

    2010-10-01

    Full Text Available This study aims to review epidemiologic evidence of the association between exposure to chlorination disinfection by-products (DBPs and congenital anomalies. All epidemiologic studies that evaluated a relationship between an index of DBP exposure and risk of congenital anomalies were analyzed. For all congenital anomalies combined, the meta-analysis gave a statistically significant excess risk for high versus low exposure to water chlorination or TTHM (17%; 95% CI, 3-34 based on a small number of studies. The meta-analysis also suggested a statistically significant excess risk for ventricular septal defects (58%; 95% CI, 21-107, but based on only three studies, and there was little evidence of an exposure-response relationship. It was observed no statistically significant relationships in the other meta-analyses and little evidence for publication bias, except for urinary tract defects and cleft lip and palate. Although some individual studies have suggested an association between chlorination disinfection by-products and congenital anomalies, meta-analyses of all currently available studies demonstrate little evidence of such association.O objetivo deste estudo é revisar evidências epidemiológicas da associação entre a exposição a subprodutos da desinfecção com cloro (DBPs e anomalias congênitas. Todos os estudos epidemiológicos que avaliaram a relação entre o índice de exposição a DBPs e o risco de anomalias congênitas foram analisados. Para todas as anomalias congênitas combinadas, a meta-análise resultou em um risco de excesso estatisticamente significante para alta versus baixa exposição à cloração da água ou ao TTHM (17%; 95% CI, 3-34 baseado em um pequeno número de estudos. A meta-análise também sugere um excesso de risco estatisticamente significante para defeitos septais ventriculares (58%; 95% CI, 21-107, porém com base em apenas três estudos, nos quais se encontrou pouca evidência na relação exposi

  1. [Water disinfection by the combined exposure to super-high frequency energy and available chlorine produced during water electrolysis].

    Science.gov (United States)

    Klimarev, S I; Siniak, Iu E

    2014-01-01

    The article reports the results of studying the effects on polluted water of SHF-energy together with the residual free (active) chlorine as a by-product of electrolysis action on dissolved chlorine-containing salts. Purpose of the studies was to evaluate input of these elements to the water disinfection effect. The synergy was found to kill microorganisms without impacts on the physicochemical properties of processed water or nutrient medium; therefore, it can be used for water treatment, and cultivation of microorganisms in microbiology.

  2. Potassium permanganate in drinking water treatment: reduction of organic matter and disinfection by-products; Permanganato potasico en potabilizacion de aguas : Reduccion de materias organicas y subproductos de desinfeccion

    Energy Technology Data Exchange (ETDEWEB)

    Marin Galvin, R. [Universidad de Cordoba (Spain)

    1997-09-01

    This paper deals on the results obtained with the use of potassium permanganate (KMnO{sub 4}) in drinking water treatment. Thus, permanganization of water before chlorination implied the reduction of 50% in odors. Moreover, oxidation with KMnO{sub 4} reduced UV absorbency of water (UV-254nm) by a 17% more as compared with that obtained by chlorine. Finally as far as the production of organo-chlorinated compounds, the treatment with (potassium permanganate+chlorine) allowed an important reduction vs the conventional chlorination: only a 65% of total THMs were generated (between 58% and 80% of specific THM) and between 30 % and 68% of tri-and tetra-phenolchlorinated, as compared with only chlorination. (Author)

  3. Evaluation of thirteen haloacetic acids and ten trihalomethanes formation by peracetic acid and chlorine drinking water disinfection.

    Science.gov (United States)

    Xue, Runmiao; Shi, Honglan; Ma, Yinfa; Yang, John; Hua, Bin; Inniss, Enos C; Adams, Craig D; Eichholz, Todd

    2017-12-01

    Free chlorine is a commonly used disinfectant in drinking water treatment. However, disinfection by-products (DBPs) are formed during water disinfection. Haloacetic acids (HAAs) and trihalomethanes (THMs) are two major groups of DBPs. Iodo-HAAs and iodo-THMs (I-HAAs and I-THMs) are formed during the disinfection of the water containing high levels of iodide and are much more toxic than their chlorinated and brominated analogs. Peracetic acid (PAA) is a strong antimicrobial disinfectant that is expected to reduce the formation of HAAs and THMs during disinfection. In this study, the formations of thirteen HAAs and ten THMs, including the iodinated forms, have been investigated during PAA disinfection and chlorination as the comparison. The DBP formations under different iodide concentrations, pHs, and contact times were systematically investigated. Two types of commercial PAAs containing different concentrations of PAA and hydrogen peroxide (H 2 O 2 ) were studied. A solid-phase microextraction gas chromatography-mass spectrometry method was upgraded for THM analysis including I-THMs. HAAs were analyzed by following a recently developed high performance ion chromatography-tandem mass spectrometry method. Results show that the ratio of PAA and H 2 O 2 concentration significantly affect the formation of I-THMs and I-HAAs. During PAA disinfection with lower PAA than H 2 O 2 , no detectable levels of THMs and HAAs were observed. During PAA disinfection with higher PAA than H 2 O 2 , low levels of monoiodoacetic acid, diiodoacetic acid, and iodoform were formed, and these levels were enhanced with the increase of iodide concentration. No significant quantities of chloro- or bromo-THMs and HAAs were formed during PAA disinfection treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Formation of secondary products in water purification. ; Charactarization of chlorination by-products. Josui shori ni okeru fukuseiseibutsu. ; Enso shori ni yoru shodoku fukuseiseibutsu no seisei tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Aizawa, T [The Inst. of Public Health, Tokyo (Japan)

    1993-12-10

    Chlorination of drinking water is an inevitable process for the purification of drinking water. It has been made clear that injected free chlorine reacts with organic matter in water to produce chlorinated by-products. Many of those compounds are toxic, and studies have been made on the international water quality standard. Water quality standard has been revised also in Japan. The sources of organic matter which is the cause for production of chlorinated by-products vary according to the kinds and conditions of the water source for drinking water. Removal of precursors in the original water, removal of by-products, and change in the disinfection system with alternate disinfectant for chlorine are among the measures for decreasing chlorinated by-products at water purification plants, but the first one is employed as the basis method. It is expected that more severe regulation may be imposed on the quality of the water source for drinking water, and more strict oxidation and disinfection systems is inevitable for water management based on the new water quality standard. 10 refs., 5 figs., 2 tabs.

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - REMOVAL OF PRECURSORS TO DISINFECTION BY-PRODUCTS IN DRINKING WATER, PCI MEMBRANE SYSTEMS FYNE PROCESS MODEL ROP 1434 WITH AFC-30 NANOFILTRATON AT BARROW, AK - NSF 00/19/EPADW395

    Science.gov (United States)

    Equipment testing and verification of PCI Membrane Systems Inc. Fyne Process nanofiltraton systems Model ROP 1434 equipped with a C10 module containing AFC-30 tubular membranes was conducted from 3/16-5/11/2000 in Barrow, AS. The source water was a moderate alkalinity, moderately...

  6. Drinking water disinfection by means of ultraviolet radiation

    International Nuclear Information System (INIS)

    Gelzhaeuser, P.; Bewig, F.; Holm, K.; Kryschi, R.; Reich, G.; Steuer, W.

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice. (orig./PW) [de

  7. Waterline ATS B. globigii spore water disinfection data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Disinfection of B. globigii spores (a non-pathogenic surrogate for B. anthracis) in clean and dirty water using the ATS-Waterline system, which uses ultraviolet...

  8. development of an automated batch-process solar water disinfection

    African Journals Online (AJOL)

    user

    This work presents the development of an automated batch-process water disinfection system ... Locally sourced materials in addition to an Arduinomicro processor were used to control ..... As already mentioned in section 3.1.1, a statistical.

  9. Selection Criteria for Water Disinfection Techniques in Agricultural Practices

    OpenAIRE

    Haute, Sam van; Sampers, Imca; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2013-01-01

    This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology fo...

  10. Inactivation model for disinfection of biofilms in drinking water

    International Nuclear Information System (INIS)

    Karlicki, A.; O'Leary, K.C.; Gagnon, G.A.

    2002-01-01

    The purpose of the project was to investigate experimentally the effects of free chlorine, monochloramine and chlorine dioxide on the removal of biofilm growth in water as it applies to drinking water in distribution systems. In particular, biofilm kill for a particular dosage of disinfectant was measured as a function of time for each disinfectant over a range of disinfectant concentrations. These results were used to formulate concentration-time (Ct) inactivation values for each disinfectant to compare the efficacy of the three disinfectants for biofilm control. The biofilm reactor system consisted of a 125 mL columns, each containing tightly packed 3 mm glass beads on which heterotrophic bacterial biofilm is established. Following an initial biofilm inoculation period, the glass beads were removed from the columns and placed into glass jars for disinfection with free chlorine, monochloramine and chlorine dioxide. Cell counts were determined on a time series basis with the goal of achieving a Ct inactivation model that is similar to models presently used for inactivation of suspended cells. Ultimately this research could be used to develop a rationale method for setting regulatory values for secondary disinfection in drinking water distribution systems, which presently in only a few states and provinces. (author)

  11. Application of neutral electrolyzed water to disinfection of alginate impression.

    Science.gov (United States)

    Nagamatsu, Yuki; Chen, Ker-Kong; Nagamatsu, Hiroshi; Kozono, Yoshio; Shimizu, Hiroshi

    2016-01-01

    Neutral electrolyzed water was developed with new concepts of long-term good durability and minimum corrosiveness to metal in addition to its excellent bactericidal activities similar to acid type of electrolyzed waters. The present study examined the bactericidal effects of the neutral electrolyzed water on disinfection of the alginate impression of a dental arch model contaminated by bacteria. Only 1-min immersion in neutral electrolyzed water could sufficiently disinfect the alginate impression including the metallic tray under ultrasonic with no significant differences from acid electrolyzed waters. No bactericidal effects were found in any electrolyzed water when used as mixing water. Considering the advantages and disadvantages of each electrolyzed water in a comprehensive way, it was suggested that neutral electrolyzed water may be the most appropriate for the disinfection of alginate impression.

  12. Dynamics of dissolved organic matter during four storm events in two forest streams: source, export, and implications for harmful disinfection byproduct formation.

    Science.gov (United States)

    Yang, Liyang; Hur, Jin; Lee, Sonmin; Chang, Soon-Woong; Shin, Hyun-Sang

    2015-06-01

    Dynamics of river dissolved organic matter (DOM) during storm events have profound influences on the downstream aquatic ecosystem and drinking water safety. This study investigated temporal variations in DOM during four storm events in two forest headwater streams (the EH and JH brooks, South Korea) and the impacts on the disinfection byproducts (DBPs) formation potential. The within-event variations of most DOM quantity parameters were similar to the flow rate in the EH but not in the larger JH brook. The dissolved organic carbon (DOC) showed clockwise and counterclockwise hysteresis with the flow rate in the EH and JH brooks, respectively, indicating the importance of both flow path and DOM source pool size in determining the effects of storm events. The stream DOM became less aromatic/humified from the first to the last event in both brooks, probably due to the increasing fresh plant pool and the decreasing leaf litter pool during the course of rainy season. The DOC export during each event increased 1.3-2.7- and 1.1-7.0-fold by stormflows in the EH and JH brooks, respectively. The leaf litter and soil together was the major DOM source, particularly during early events. The enhanced DOM export probably increases the risks of DBPs formation in disinfection, as indicated by a strong correlation observed between DOC and trihalomethanes formation potential (THMFP). High correlations between two humic-like fluorescent components and THMFP further suggested the potential of assessing THMFP with in situ fluorescence sensors during storms.

  13. Effect of ultrasonic pretreatment on purified water disinfection

    International Nuclear Information System (INIS)

    Simon Andreu, P.; Lardin Mifsut, C.; Vergara Romero, L.; Polo Canas, P. M.; Perez Sanchez, P.; Rancano Perez, A.

    2009-01-01

    Due to the importance of a suitable water disinfection in order to insure a pollutant effect minimization against environment, this work has been carried out to determine how can affect an ultrasonic pre-treatment upon disinfection step. It has been confirmed the ultrasonic disintegration of bacterial cells in treated water and disinfectant power of treatment by itself, which is not enough to be used as a single method in water disinfection. It has also been proved that from a technical and economical point of view the combination of UV and ultrasound improves the UV treatment performance. Finally, it has been detected that an ultrasonic pre-treatment increases chlorination effectiveness, however the high cost in this combination makes it unfeasible of industrial scale. (Author) 6 refs

  14. Evaluation of bactericidal efficacy of silver ions on Escherichia coli for drinking water disinfection.

    Science.gov (United States)

    Pathak, Satya P; Gopal, K

    2012-07-01

    The purpose of this study is the development of a suitable process for the disinfection of drinking water by evaluating bactericidal efficacy of silver ions from silver electrodes. A prototype of a silver ioniser with silver electrodes and control unit has been fabricated. Silver ions from silver electrodes in water samples were estimated with an atomic absorption spectrophotometer. A fresh culture of Escherichia coli (1.75 × 10(3) c.f.u./ml) was exposed to 1, 2, 5, 10 and 20 ppb of silver ions in 100 ml of autoclaved tap water for 60 min. The effect of different pH and temperatures on bactericidal efficacy was observed at constant silver ion concentration (5 ppb) and contact time of 30 min. The maximum bactericidal activity (100%) was observed at 20 ppb of silver ion concentration indicating total disinfection after 20 min while minimum bactericidal activity (25%) was observed after 10 min at 01 ppb of silver ions. Likewise, 100% bactericidal activity was noticed with 2, 5 and 10 ppb of silver ions after 60, 50 and 40 min, respectively. Bactericidal activity at pH 5, 6, 7, 8 and 9 was observed at 79.9%, 79.8%, 80.5%, 100% and 100%, respectively, whereas it was 80.4%, 88.3%, 100%, 100% and 100% at 10°C, 20°C, 30°C, 40°C and 50°C, respectively. The findings of this study revealed that very low concentrations of silver ions at pH 8-9 and temperature >20°C have bactericidal efficacy for total disinfection of drinking water. Silver ionisation is suitable for water disinfection and an appropriate alternative to chlorination which forms carcinogenic disinfection by-products.

  15. Ultraviolet (UV) disinfection of grey water: particle size effects.

    Science.gov (United States)

    Winward, G P; Avery, L M; Stephenson, T; Jefferson, B

    2008-02-01

    The impact of water quality on the ultraviolet (UV) disinfection of grey water was investigated with reference to urban water reuse. Direct UV disinfection of grey water did not meet the stringent California State Title 22 criteria for unrestricted urban water reuse due to the presence of particulate material ranging from or = 2000 microm in size. Grey water was manipulated by settling to produce fractions of varying particle size distributions and blending was employed post-disinfection to extract particle-associated coliforms (PACs). The efficacy of UV disinfection was found to be linked to the particle size of the grey water fractions. The larger particle size fractions with a mean particle size of 262 microm and above were observed to shield more coliforms from UV light than did the smaller particles with a mean particle size below 119 microm. Up to 70% of total coliforms in the larger particle size fractions were particle-associated following a UV dose (fluence) of 260 mJ.cm(-2) and would remain undetected by standard coliform enumeration techniques. Implications for urban water reuse are discussed and recommendations made for grey water treatment to ensure removal of particle-associated indicator bacteria and pathogens prior to UV disinfection.

  16. Safety and durability of low-density polyethylene bags in solar water disinfection applications.

    Science.gov (United States)

    Danwittayakul, Supamas; Songngam, Supachai; Fhulua, Tipawan; Muangkasem, Panida; Sukkasi, Sittha

    2017-08-01

    Solar water disinfection (SODIS) is a simple point-of-use process that uses sunlight to disinfect water for drinking. Polyethylene terephthalate (PET) bottles are typically used as water containers for SODIS, but a new SODIS container design has recently been developed with low-density polyethylene (LDPE) bags and can overcome the drawbacks of PET bottles. Two nesting layers of LDPE bags are used in the new design: the inner layer containing the water to be disinfected and the outer one creating air insulation to minimize heat loss from the water to the surroundings. This work investigated the degradation of LDPE bags used in the new design in actual SODIS conditions over a period of 12 weeks. The degradation of the LDPE bags was investigated weekly using a scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometer, and tensile strength tester. It was found that the LDPE bags gradually degraded under the sunlight due to photo-oxidation reactions, especially in the outer bags, which were directly exposed to the sun and surroundings, leading to the reduction of light transmittance (by 11% at 300 nm) and tensile strength (by 33%). In addition, possible leaching of organic compounds into the water contained in the inner bags was examined using gas chromatography-mass spectrometer. 2,4-Di-tert-butylphenol was found in some SODIS water samples as well as the as-received water samples, in the concentration range of 1-4 μg/L, which passes the Environmental Protection Agency Drinking Water Guidance on Disinfection By-Products.

  17. A review on wastewater disinfection

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2013-01-01

    Full Text Available Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent disinfection. Understanding the differences in inactivation mechanisms is critical to identify rate-limiting steps involved in the inactivation process as well as to develop more effective disinfection strategies. Disinfection byproducts discharged from wastewater treatment plants may impair aquatic ecosystems and downstream drinking-water quality. Numerous inorganic and organic micropollutants can undergo reactions with disinfectants. Therefore, to mitigate the adverse effects and also to enhance that efficiency, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. This review gives a summary of the traditional, innovative, and combined disinfection alternatives and also disinfection byproducts for effluent of municipal wastewater treatment plants.

  18. Selective Photocatalytic Disinfection by Coupling StrepMiniSog to the Antibody Catalyzed Water Oxidation Pathway.

    Directory of Open Access Journals (Sweden)

    Elizabeth M Wurtzler

    Full Text Available For several decades reactive oxygen species have been applied to water quality engineering and efficient disinfection strategies; however, these methods are limited by disinfection byproduct and catalyst-derived toxicity concerns which could be improved by selectively targeting contaminants of interest. Here we present a targeted photocatalytic system based on the fusion protein StrepMiniSOG that uses light within the visible spectrum to produce reactive oxygen species at a greater efficiency than current photosensitizers, allowing for shorter irradiation times from a fully biodegradable photocatalyst. The StrepMiniSOG photodisinfection system is unable to cross cell membranes and like other consumed proteins, can be degraded by endogenous digestive enzymes in the human gut, thereby reducing the consumption risks typically associated with other disinfection agents. We demonstrate specific, multi-log removal of Listeria monocytogenes from a mixed population of bacteria, establishing the StrepMiniSOG disinfection system as a valuable tool for targeted pathogen removal, while maintaining existing microbial biodiversity.

  19. Applications of Photocatalytic Disinfection

    Directory of Open Access Journals (Sweden)

    Joanne Gamage

    2010-01-01

    Full Text Available Due to the superior ability of photocatalysis to inactivate a wide range of harmful microorganisms, it is being examined as a viable alternative to traditional disinfection methods such as chlorination, which can produce harmful byproducts. Photocatalysis is a versatile and effective process that can be adapted for use in many applications for disinfection in both air and water matrices. Additionally, photocatalytic surfaces are being developed and tested for use in the context of “self-disinfecting” materials. Studies on the photocatalytic technique for disinfection demonstrate this process to have potential for widespread applications in indoor air and environmental health, biological, and medical applications, laboratory and hospital applications, pharmaceutical and food industry, plant protection applications, wastewater and effluents treatment, and drinking water disinfection. Studies on photocatalytic disinfection using a variety of techniques and test organisms are reviewed, with an emphasis on the end-use application of developed technologies and methods.

  20. Fresh water disinfection by pulsed low electric field

    International Nuclear Information System (INIS)

    Zheng, C; Xu, Y; Liu, Z; Yan, K

    2013-01-01

    In this paper, we describe a pulsed low electric field process for water disinfection. Electric intensity of 0.6–1.7 kV cm −1 is applied. Experiments are performed with a 1.2 L axis-cylinder reactor. A bipolar pulsed power source with pulsed width of 25 μs and frequency of 100–3000 Hz is used. Water conductivity of 3–200 μs cm −1 is investigated, which can significantly affect pulsed voltage-current waveforms and injected energy. Energy per pulse rises with increased water conductivity. The initial E. Coli density and water conductivity are two major factors influencing the disinfection. No disinfection effect is performed with deionized water of 3 μs cm −1 . When water conductivity is 25 μs cm −1 and bacteria density is 10 4 –10 6 cfu ml −1 , significant disinfection effect is observed. More than 99% of the cells can be disinfected with an energy density of less than 70 J ml −1 , while water temperature is below 30 °C.

  1. Reductions of dissolved organic matter and disinfection by-product precursors in full-scale wastewater treatment plants in winter.

    Science.gov (United States)

    Xue, Shuang; Jin, Wujisiguleng; Zhang, Zhaohong; Liu, Hong

    2017-07-01

    The reductions of dissolved organic matter (DOM) and disinfection byproduct precursors in four full-scale wastewater treatment plants (WWTPs) (Liaoning Province, China) where different biological treatment processes were employed in winter were investigated. The total removal efficiencies of dissolved organic carbon (DOC), ultraviolet light at 254 nm (UV-254), trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) were in the range of 70.3-76.0%, 49.6-57.3%, 54.4-65.0%, and 53.7-63.8% in the four WWTPs, respectively. The biological treatment was the predominant process responsible for the removal of DOC, THMFP, and HAAFP in WWTPs. Differences in the reduction of UV-254 were not significant (p > 0.05) among biochemical reaction pool, secondary sedimentation tank, and disinfection tank. Biological aerated filter and suspended carrier activated sludge processes achieved higher DOM removal than the conventional active sludge and anaerobic-anoxic-oxic processes. Hydrophobic neutral and hydrophilic fraction were removed to a higher degree through biological treatment than the other three DOM fractions. HAAFP removal was more efficient than THMFP reduction during biological treatment. During primary treatment, fluorescent materials in secondary sedimentation tanks were preferentially removed, as compared to the bulk DOM. Humic-like fluorescent compounds were not readily eliminated during biological treatment. The fluorescent materials were more susceptible to chlorine than nonfluorescent compounds. Copyright © 2017. Published by Elsevier Ltd.

  2. A Review of Heterogeneous Photocatalysis for Water and Surface Disinfection

    Directory of Open Access Journals (Sweden)

    John Anthony Byrne

    2015-03-01

    Full Text Available Photo-excitation of certain semiconductors can lead to the production of reactive oxygen species that can inactivate microorganisms. The mechanisms involved are reviewed, along with two important applications. The first is the use of photocatalysis to enhance the solar disinfection of water. It is estimated that 750 million people do not have accessed to an improved source for drinking and many more rely on sources that are not safe. If one can utilize photocatalysis to enhance the solar disinfection of water and provide an inexpensive, simple method of water disinfection, then it could help reduce the risk of waterborne disease. The second application is the use of photocatalytic coatings to combat healthcare associated infections. Two challenges are considered, i.e., the use of photocatalytic coatings to give “self-disinfecting” surfaces to reduce the risk of transmission of infection via environmental surfaces, and the use of photocatalytic coatings for the decontamination and disinfection of medical devices. In the final section, the development of novel photocatalytic materials for use in disinfection applications is reviewed, taking account of materials, developed for other photocatalytic applications, but which may be transferable for disinfection purposes.

  3. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    International Nuclear Information System (INIS)

    Postigo, Cristina; Richardson, Susan D.

    2014-01-01

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H 2 O 2 . • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment

  4. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Postigo, Cristina [Institute for Environmental Assessment and Water Research (IDAEA)—Spanish National Research Council (CID-CSIC), Barcelona (Spain); Richardson, Susan D., E-mail: richardson.susan@sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC (United States)

    2014-08-30

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H{sub 2}O{sub 2}. • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment.

  5. Solar water disinfecting system using compound parabolic concentrating collector

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghetany, H.H.; Saitoh, T.S. [Tohoku Univ., Sendai (Japan)

    2000-05-31

    Solar water disinfection is an alternative technology using solar radiation and thermal treatment to inactivate and destroy pathogenic microorganisms present in water. The Compound Parabolic Concentrating, (CPC) collector can be used as an efficient key component for solar disinfectanting system. Two types of the CPC collectors are studied, namely the transparent-tube and the Copper-tube CPC collector. It is found that after 30 minutes of exposing the water sample to solar radiation or heating it up to 65 degree C for a few minuets all the coliform bacterial present in the contaminated water sample were completely eliminated. In this article, the effect of water temperature on the disinfecting process was presented. Thermal and micro-biological measurements were also made to evaluate the system performance. (author)

  6. Biological efficacy and toxic effect of emergency water disinfection process based on advanced oxidation technology.

    Science.gov (United States)

    Tian, Yiping; Yuan, Xiaoli; Xu, Shujing; Li, Rihong; Zhou, Xinying; Zhang, Zhitao

    2015-12-01

    An innovative and removable water treatment system consisted of strong electric field discharge and hydrodynamic cavitation based on advanced oxidation technologies was developed for reactive free radicals producing and waterborne pathogens eliminating in the present study. The biological efficacy and toxic effects of this advanced oxidation system were evaluated during water disinfection treatments. Bench tests were carried out with synthetic microbial-contaminated water, as well as source water in rainy season from a reservoir of Dalian city (Liaoning Province, China). Results showed that high inactivation efficiency of Escherichia coli (>5 log) could be obtained for synthetic contaminated water at a low concentration (0.5-0.7 mg L(-1)) of total oxidants in 3-10 s. The numbers of wild total bacteria (108 × 10(3) CFU mL(-1)) and total coliforms (260 × 10(2) MPN 100 mL(-1)) in source water greatly reduced to 50 and 0 CFU mL(-1) respectively after treated by the advanced oxidation system, which meet the microbiological standards of drinking water, and especially that the inactivation efficiency of total coliforms could reach 100%. Meanwhile, source water qualities were greatly improved during the disinfection processes. The values of UV254 in particular were significantly reduced (60-80%) by reactive free radicals. Moreover, the concentrations of possible disinfection by-products (formaldehyde and bromide) in treated water were lower than detection limits, indicating that there was no harmful effect on water after the treatments. These investigations are helpful for the ecotoxicological studies of advanced oxidation system in the treatments of chemical polluted water or waste water. The findings of this work suggest that the developed water treatment system is ideal in the acute phases of emergencies, which also could offer additional advantages over a wide range of applications in water pollution control.

  7. TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water.

    Science.gov (United States)

    Plewa, Michael J; Wagner, Elizabeth D; Richardson, Susan D

    2017-08-01

    The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products (DBPs). Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the environment. Only a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes (THMs) and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water. Copyright © 2017. Published by Elsevier B.V.

  8. Selection criteria for water disinfection techniques in agricultural practices.

    Science.gov (United States)

    Haute, Sam van; Sampers, Imca; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2015-01-01

    This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology for pre- or postharvest applications. Introduced criteria were divided into three principal components: (i) criteria related to the technology and which relate to the disinfection efficiency, (ii) attention points for the management and proper operation, and (iii) necessities in order to sustain the operation with respect to the environment. The selection criteria may help the end user of the water disinfection technology to obtain a systematic insight into all relevant aspects to be considered for preliminary decision making on which technologies should be put to feasibility testing for water disinfection in pre- and postharvest practices of the fresh produce chain.

  9. Organic Carbon and Disinfection Byproduct Precursor Loads from a Constructed, Non-Tidal Wetland in California's Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Jacob A. Fleck

    2007-05-01

    Full Text Available Wetland restoration on peat islands in the Sacramento-San Joaquin Delta will change the quality of island drainage waters entering the Delta, a primary source of drinking water in California. Peat island drainage waters contain high concentrations of dissolved and particulate organic carbon (DOC and POC and organic precursors to drinking water disinfection byproducts, such as trihalomethanes (THMs. We quantified the net loads of DOC, POC, and THM-precursors from a constructed subsidence mitigation wetland on Twitchell Island in the Delta to determine the change in drainage water quality that may be caused by conversion of agricultural land on peat islands to permanently flooded, non-tidal wetlands. Creation of permanently flooded wetlands halts oxidative loss of the peat soils and thereby may mitigate the extensive land-surface subsidence of the islands that threatens levee stability in the Delta. Net loads from the wetland were dominated by DOC flushed from the oxidized shallow peat soil layer by seepage flow out of the wetland. The permanently flooded conditions in the overlying wetland resulted in a gradual evolution to anaerobic conditions in the shallow soil layer and a concomitant decrease in the flow could be minimized by reducing the hydraulic gradient between the wetland and the adjacent drainage ditch. Estimates of net loads from the wetland assuming efflux of surface water only were comparable in magnitude to net loads from nearby agricultural fields, but the wetland and agricultural net loads had opposite seasonal variations. Wetland surface water net loads of DOC, POC, and THM-precursors were lower during the winter months when the greatest amounts of water are available for diversion from the Delta to drinking water reservoirs.

  10. Drinking water and biofilm disinfection by Fenton-like reaction.

    Science.gov (United States)

    Gosselin, F; Madeira, L M; Juhna, T; Block, J C

    2013-10-01

    A Fenton-like disinfection process was conducted with Fenton's reagent (H2O2) at pH 3 or 5 on autochthonous drinking water biofilms grown on corroded or non-corroded pipe material. The biofilm disinfection by Fenton-like oxidation was limited by the low content of iron and copper in the biomass grown on non-corroded plumbing. It was slightly improved by spiking the distribution system with some additional iron source (soluble iron II or ferrihydrite particles appeared as interesting candidates). However successful in situ disinfection of biofilms was only achieved in fully corroded cast iron pipes using H2O2 and adjusting the pH to 5. These new results provide additional support for the use of Fenton's processes for cleaning drinking water distribution systems contaminated with biological agents or organics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru; Le Roux, Julien; Zhang, Tao; Croue, Jean-Philippe

    2014-01-01

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

  12. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru

    2014-12-16

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

  13. Organic chloramines in chlorine-based disinfected water systems: A critical review.

    Science.gov (United States)

    How, Zuo Tong; Kristiana, Ina; Busetti, Francesco; Linge, Kathryn L; Joll, Cynthia A

    2017-08-01

    This paper is a critical review of current knowledge of organic chloramines in water systems, including their formation, stability, toxicity, analytical methods for detection, and their impact on drinking water treatment and quality. The term organic chloramines may refer to any halogenated organic compounds measured as part of combined chlorine (the difference between the measured free and total chlorine concentrations), and may include N-chloramines, N-chloramino acids, N-chloraldimines and N-chloramides. Organic chloramines can form when dissolved organic nitrogen or dissolved organic carbon react with either free chlorine or inorganic chloramines. They are potentially harmful to humans and may exist as an intermediate for other disinfection by-products. However, little information is available on the formation or occurrence of organic chloramines in water due to a number of challenges. One of the biggest challenges for the identification and quantification of organic chloramines in water systems is the lack of appropriate analytical methods. In addition, many of the organic chloramines that form during disinfection are unstable, which results in difficulties in sampling and detection. To date research has focussed on the study of organic monochloramines. However, given that breakpoint chlorination is commonly undertaken in water treatment systems, the formation of organic dichloramines should also be considered. Organic chloramines can be formed from many different precursors and pathways. Therefore, studying the occurrence of their precursors in water systems would enable better prediction and management of their formation. Copyright © 2017. Published by Elsevier B.V.

  14. Acute toxicity of dichloroacetonitrile (DCAN), a typical nitrogenous disinfection by-product (N-DBP), on zebrafish (Danio rerio).

    Science.gov (United States)

    Lin, Tao; Zhou, Dongju; Dong, Jian; Jiang, Fuchun; Chen, Wei

    2016-11-01

    Dichloroacetonitrile (DCAN) is a typical nitrogenous disinfection by-product (N-DBP) and its toxicity on aquatic animals is investigated for the first time. The present study was designed to investigate the potential adverse effects of DCAN on zebrafish. DCAN could induce developmental toxicity to zebrafish embryos. A significant decrease in hatchability and an increase in malformation and mortality occurred when DCAN concentration was above 100µg/L. Heart function alteration and neuronal function disturbance occurred at concentration higher than 500 and 100µg/L, respectively. Further, DCAN was easily accumulated in adult zebrafish. The rank order of declining bioconcentration factor (BCF) was liver (1240-1670)> gill (1210-1430)> muscle (644-877). DCAN caused acute metabolism damage to adult zebrafish especially at 8 days exposure, at which time the "Integrated Biomarker Response" (IBR) index value reached 798 at 1mg/L DCAN dose. Acute DNA damage was induced to adult zebrafish by DCAN even at 10µg/L dose. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Use of ozone-biofiltration for bulk organic removal and disinfection byproduct mitigation in potable reuse applications.

    Science.gov (United States)

    Arnold, Mayara; Batista, Jacimaria; Dickenson, Eric; Gerrity, Daniel

    2018-07-01

    The purpose of this research was to investigate the impacts of ozone dose and empty bed contact time (EBCT) in ozone-biofiltration systems on disinfection byproduct (DBP) formation potential. The data were used to evaluate the possibility of using DBP formation potential as an alternative guideline for total organic carbon (TOC) removal in potable reuse applications. A pilot-scale ozone-biofiltration system was operated with O 3 /TOC ratios ranging from 0.1 to 2.25 and EBCTs ranging from 2 to 20 min. The biofiltration columns contained anthracite or biological activated carbon (BAC). Bench-scale chlorination was performed using the uniform formation conditions (UFC) approach, and quenched samples were analyzed for total trihalomethanes (TTHMs) and regulated haloacetic acids (HAA5s). The data demonstrated that ozone-biofiltration achieved TOC removals ranging from ∼10 to 30%, depending on operational conditions, but biofiltration without ozone generally achieved <10% TOC removal. UFC testing demonstrated that ozone alone was efficient in transforming bulk organic matter and reducing DBP formation potential by 10-30%. The synergistic combination of ozone and biofiltration achieved average overall reductions in TTHM and HAA5 formation potential of 26% and 51%, respectively. Finally, a maximum TOC concentration of 2.0 mg/L was identified as a recommended treatment target for reliable compliance with TTHM and HAA5 regulations for potable reuse systems in the United States. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Probing Coagulation Behavior of Individual Aluminum Species for Removing Corresponding Disinfection Byproduct Precursors: The Role of Specific Ultraviolet Absorbance.

    Directory of Open Access Journals (Sweden)

    He Zhao

    Full Text Available Coagulation behavior of aluminum chloride and polyaluminum chloride (PACl for removing corresponding disinfection byproduct (DBP precursors was discussed in this paper. CHCl3, bromine trihalomethanes (THM-Br, dichloroacetic acid (DCAA and trichloroacetic acid (TCAA formation potential yields were correlated with specific ultraviolet absorbance (SUVA values in different molecular weight (MW fractions of humic substances (HS, respectively. Correlation analyses and principal component analysis were performed to examine the relationships between SUVA and different DBP precursors. To acquire more structural characters of DBP precursors and aluminum speciation, freeze-dried precipitates were analyzed by fourier transform infrared (FTIR and C 1s, Al 2p X-ray photoelectron spectroscopy (XPS. The results indicated that TCAA precursors (no MW limits, DCAA and CHCl3 precursors in low MW fractions (MW30 kDa were preferentially removed by PACl coagulation with preformed Al13 species at pH 5.0. Additionally, for DCAA precursors in high MW fractions (MW>30 kDa with relatively low aromatic content and more carboxylic structures, the greatest removal occurred at pH 6.0 through PACl coagulation with aggregated Al13 species.

  17. Bromination of Marine Dissolved Organic Matter following Full Scale Electrochemical Ballast Water Disinfection.

    Science.gov (United States)

    Gonsior, Michael; Mitchelmore, Carys; Heyes, Andrew; Harir, Mourad; Richardson, Susan D; Petty, William Tyler; Wright, David A; Schmitt-Kopplin, Philippe

    2015-08-04

    An extensively diverse array of brominated disinfection byproducts (DBPs) were generated following electrochemical disinfection of natural coastal/estuarine water, which is one of the main treatment methods currently under consideration for ballast water treatment. Ultra-high-resolution mass spectrometry revealed 462 distinct brominated DBPs at a relative abundance in the mass spectra of more than 1%. A brominated DBP with a relative abundance of almost 22% was identified as 2,2,4-tribromo-5-hydroxy-4-cyclopentene-1,3-dione, which is an analogue to several previously described 2,2,4-trihalo-5-hydroxy-4-cyclopentene-1,3-diones in drinking water. Several other brominated molecular formulas matched those of other known brominated DBPs, such as dibromomethane, which could be generated by decarboxylation of dibromoacetic acid during ionization, dibromophenol, dibromopropanoic acid, dibromobutanoic acid, bromohydroxybenzoic acid, bromophenylacetic acid, bromooxopentenoic acid, and dibromopentenedioic acid. Via comparison to previously described chlorine-containing analogues, bromophenylacetic acid, dibromooxopentenoic acid, and dibromopentenedioic acid were also identified. A novel compound at a 4% relative abundance was identified as tribromoethenesulfonate. This compound has not been previously described as a DBP, and its core structure of tribromoethene has been demonstrated to show toxicological implications. Here we show that electrochemical disinfection, suggested as a candidate for successful ballast water treatment, caused considerable production of some previously characterized DBPs in addition to novel brominated DBPs, although several hundred compounds remain structurally uncharacterized. Our results clearly demonstrate that electrochemical and potentially direct chlorination of ballast water in estuarine and marine systems should be approached with caution and the concentrations, fate, and toxicity of DBP need to be further characterized.

  18. Integrated Disinfection Byproducts (DBPs) Mixtures Research: DBP Concentration via Reverse Osmosis Membrane Techniques

    Science.gov (United States)

    With the completion of the 4-lab project, the NOM concentration aspect of 4-lab is being continued with renewed focus on creating drinking water relevant freeze-dried NOM isolates that can be used for many drinking water research efforts from DBP investigations to water reuse inv...

  19. 40 CFR 141.135 - Treatment technique for control of disinfection byproduct (DBP) precursors.

    Science.gov (United States)

    2010-07-01

    ...), is less than 4.0 mg/L, calculated quarterly as a running annual average; the source water alkalinity... treated water alkalinity to less than 60 mg/L (as CaCO3), measured monthly according to § 141.131(d)(1... Step 1 TOC reductions in the far-right column (Source water alkalinity >120 mg/L) for the specified...

  20. Infectious Disinfection: "Exploring Global Water Quality"

    Science.gov (United States)

    Mahaya, Evans; Tippins, Deborah J.; Mueller, Michael P.; Thomson, Norman

    2009-01-01

    Learning about the water situation in other regions of the world and the devastating effects of floods on drinking water helps students study science while learning about global water quality. This article provides science activities focused on developing cultural awareness and understanding how local water resources are integrally linked to the…

  1. 77 FR 8865 - Public Water System Supervision Program Approval for the State of Illinois; Tentative Approval

    Science.gov (United States)

    2012-02-15

    ... Enhanced Surface Water Treatment Rule. Illinois is also applying its Stage 2 Disinfectants and Disinfection... for Long-Term 2 Enhanced Surface Water Treatment and Stage 2 Disinfectants and Disinfection By-product..., Ground Water and Drinking Water Branch (WG-15J), 77 West Jackson Boulevard, Chicago, Illinois 60604. FOR...

  2. Conventional and Alternative Disinfection Methods of Legionella in Water Distribution Systems – Review

    Directory of Open Access Journals (Sweden)

    Pūle Daina

    2016-12-01

    Full Text Available Prevalence of Legionella in drinking water distribution systems is a widespread problem. Outbreaks of Legionella caused diseases occur despite various disinfectants are used in order to control Legionella. Conventional methods like thermal disinfection, silver/copper ionization, ultraviolet irradiation or chlorine-based disinfection have not been effective in the long term for control of biofilm bacteria. Therefore, research to develop more effective disinfection methods is still necessary.

  3. Solar disinfection of drinking water and oral rehydration solutions

    Energy Technology Data Exchange (ETDEWEB)

    Acra, A; Raffoul, Z; Karahagopian, Y

    1984-01-01

    This document provides concise information on oral rehydration therapy for the control of diarrheal diseases in developing countries; however, the main emphasis has been placed on the disinfection of oral rehydration solutions, or the water used in their preparation, as achieved by exposure to sunlight in transparent containers. The fundamental principles of solar energy are presented as well as studies which demonstrate the efficacy of the method. 2 figures, 6 tables.

  4. Formation of secondary products in water purification. ; Toxicological evaluation of mutagenic chlorination by-products during drinking water treatment. Josui shori ni okeru fukuseiseibutsu. ; Josui shori ni okeru hen'i genseibusshitsu no dokusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Nakamuro, K [Setsunan Univ., Osaka (Japan). Faculty of Pharmaceutical Sciences; Sayato, Y [Setsunan Univ., Osaka (Japan)

    1993-12-10

    The biological effects of acute toxicity, chronic toxicity, carcinogenicity, etc. of chlorination by-products detected in drinking water in Japan are discussed. The biological effects of representative chlorination by-products such as trihalomethane, haloacetic acid, haloaldehyde, haloacetonitrile, chlorophenol, chloropicrin, etc. as well as the evaluation of mutagenicity in drinking water purification process, for which Ames Salmonella/microsome assay is used for safety evaluation of drinking water, are discussed. The extent of the contribution of mutagenicity of chlorination disinfection by-products to the mutagenicity of drinking water is investigated. It must be admitted that biological evaluation of the safety of water quality is impossible currently by using only the known chemical substances contained in drinking water. The effects of chlorination and ozone treatment which are often applied to drinking water treatment are different each other. 58 refs., 1 fig., 4 tabs.

  5. Prediction of N-nitrosodimethylamine (NDMA) formation as a disinfection by-product.

    Science.gov (United States)

    Kim, Jongo; Clevenger, Thomas E

    2007-06-25

    This study investigated the possibility of a statistical model application for the prediction of N-nitrosodimethylamine (NDMA) formation. The NDMA formation was studied as a function of monochloramine concentration (0.001-5mM) at fixed dimethylamine (DMA) concentrations of 0.01mM or 0.05mM. Excellent linear correlations were observed between the molar ratio of monochloramine to DMA and the NDMA formation on a log scale at pH 7 and 8. When a developed prediction equation was applied to a previously reported study, a good result was obtained. The statistical model appears to predict adequately NDMA concentrations if other NDMA precursors are excluded. Using the predictive tool, a simple and approximate calculation of NDMA formation can be obtained in drinking water systems.

  6. The efficiency of water treatment and disinfection by means of ultraviolet radiation

    International Nuclear Information System (INIS)

    Sobotka, J.

    1993-01-01

    Advantages and disadvantages of various water disinfection methods are discussed. The report examines the effectiveness of combined chlorine treatment and UV irradiation method of water disinfection and describes methods of determining UV radiation intensity, α absorption coefficient and radiation dose by means of measuring equipment constructed by the author. The α absorption coefficient dependence on the colour and turbidity of water exposed to radiation is defined. Enchytraeus albidus was applied as bioindicator in UV radiation intensity and disinfection effects measurements. The influence of UV radiation on microbiological, physical, chemical, and toxicological properties of water was determined. Prototype devices for water disinfection with UV radiation were made. (author)

  7. The efficiency of water treatment and disinfection by means of ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sobotka, J [Medical Academy, Warsaw (Poland). Inst. of Social Medicine

    1993-01-01

    Advantages and disadvantages of various water disinfection methods are discussed. The report examines the effectiveness of combined chlorine treatment and UV irradiation method of water disinfection and describes methods of determining UV radiation intensity, [alpha] absorption coefficient and radiation dose by means of measuring equipment constructed by the author. The [alpha] absorption coefficient dependence on the colour and turbidity of water exposed to radiation is defined. Enchytraeus albidus was applied as bioindicator in UV radiation intensity and disinfection effects measurements. The influence of UV radiation on microbiological, physical, chemical, and toxicological properties of water was determined. Prototype devices for water disinfection with UV radiation were made. (author).

  8. 17β-estradiol as precursors of Cl/Br-DBPs in the disinfection process of different water samples.

    Science.gov (United States)

    Shao, Yanan; Pan, Zihan; Rong, Chuan; Wang, Yinghui; Zhu, Hongxiang; Zhang, Yuanyuan; Yu, Kefu

    2018-05-21

    During chlorine disinfection process, reactions between the disinfectant and 17β-estradiol (E2) lead to the formation of halogenated disinfection byproducts (DBPs) which can be a risk to both ecosystem and human health. The degradation and transformation products of E2 in sodium hypochlorite (NaClO) disinfection processes of different water samples were investigated. The reaction kinetics research showed that the degradation rates of E2 were considerably dependent on the initial pH value and the types of water samples. In fresh water, synthetic marine aquaculture water and seawater, the reaction rate constant was 0.133 min -1 , 2.067 min -1 and 2.592 min -1 , respectively. The reasons for the above phenomena may be due to the different concentrations of bromide ions (Br - ) in these three water samples which could promote the reaction between NaClO and E2. Furthermore, Br - could also cause the formation of brominated DBPs (Br-DBPs). The main DBPs, reaction centers and conceivable reaction pathways were explored. Seven halogenated DBPs have been observed including three chlorinated DBPs (Cl-DBPs) and four Br-DBPs. The active sites of E2 were found to be the pentabasic cyclic ring and the ortho position of the phenol moiety as well as C9-C10 position. The identified Cl/Br-DBPs were also confirmed in actual marine aquaculture water from a shrimp pond. The comparison of bio-concentration factors (BCF) values based on calculation of EPI-suite showed that the toxicities of the Br-DBPs were stronger than that of their chloride analogues. The absorbable organic halogens (AOX) analysis also suggested that the DBPs produced in the marine aquaculture water were more toxic than that in the fresh water system. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Ozone Disinfection of Vibrio vulnificus in Shrimp Pond Water

    Science.gov (United States)

    Dyah Pita Rengga, Wara; Cahya Julyta Putri, Echa; Wulansarie, Ria; Suryanto, Agus

    2018-03-01

    One variety of shrimp, L.Vanamei, often uses brackish water during the operation in the shrimp pond. Chlorination and ultraviolet are usually used for disinfection of brackish water. However, it is ineffective and forms sediment in the water distribution. It can be a negative impact on the water quality cause a contamination on the shrimp, so the farmers might have loss of profit because Vibrio vulnificus causes infection and dead on the shrimp. It affects the safety of consumers and should be minimized. The purpose of this study is to reduce the number of V. vulnificus bacteria in the pond water. The water was put in the storage tanks then pumped to filter out the impurities of the water. Furthermore, the water set the flow rate in 1 LPM, 2 LPM, and 3 LPM. After that, the ozone was injected to the water flow to sterilize the V. vulnificus bacteria. Finally, the water was returned to the original tank. The water from the tank was taken through a valve and analyzed in 0, 3, 7, 12, 18, 24, 30 minutes. The sample was analyzed immediately using a Total Plate Count method to determine the number of V. vulnificus bacteria in the shrimp pond water. The flow rate shows that the longer time of ozone made a lower amount of Vibrio v. bacteria. In 2 LPM water, it shows the optimum results of V. vulnificus. bacteria reduction for 88.1% compared to the flow rate of 1 LPM and 3 LPM with the bacteria reduction of 68,8% and 70.6%. This study shows that the ozone with a flow rate of 2 LPM circulation is the most effective method to help reducing the number of V. vulnificus in brackish water distribution system in the shrimp environment and potentially as a disinfectant.

  10. Phthalocyanines as sensitizers for photodynamic water disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, N.; Slivka, L.; Kaliya, O.; Lukyanets, E.; Negrimovsky, V.; Vorozhtsov, G. [Organic Intermediates and Dyes Inst., Moscow (Russian Federation); Nedachin, E.; Artemova, T.; Ivanova, L.; Lavrova, D. [A.N. Sysin Research Inst. of Human Ecology and Environmental Health of Russian Academy of Medical Sciences, Moscow (Russian Federation)

    2003-07-01

    New octapyridiniomethyl-substituted phthalocyanines of Al and Zn have been synthesized. These octacationic complexes are readily soluble in water, show monomeric behavior and sensitize formation of singlet oxygen efficiently. They are of high photodynamic potential in killing both Gram-negative and Gram-positive bacteria in contrast to negatively charged sulfonated derivatives, which are substantially less effective, particularly towards coliform bacteria in natural or sewage water. The present study confirms that cationic phthalocyanines represent a class of photosensitizing agents with an efficient antibacterial activity. (orig.)

  11. Prevalence of Ocular, Respiratory and Cutaneous Symptoms in Indoor Swimming Pool Workers and Exposure to Disinfection By-Products (DBPs

    Directory of Open Access Journals (Sweden)

    Guglielmina Fantuzzi

    2010-03-01

    Full Text Available The objective of this cross-sectional study was to investigate the prevalence of self-reported respiratory, ocular and cutaneous symptoms in subjects working at indoor swimming pools and to assess the relationship between frequency of declared symptoms and occupational exposure to disinfection by-products (DBPs. Twenty indoor swimming pools in the Emilia Romagna region of Italy were included in the study. Information about the health status of 133 employees was collected using a self-administered questionnaire. Subjects working at swimming pools claimed to frequently experience the following symptoms: cold (65.4%, sneezing (52.6%, red eyes (48.9% and itchy eyes (44.4%. Only 7.5% claimed to suffer from asthma. Red eyes, runny nose, voice loss and cold symptoms were declared more frequently by pool attendants (lifeguards and trainers when compared with employees working in other areas of the facility (office, cafe, etc.. Pool attendants experienced generally more verrucas, mycosis, eczema and rash than others workers; however, only the difference in the frequency of self-declared mycosis was statistically significant (p = 0.010. Exposure to DBPs was evaluated using both environmental and biological monitoring. Trihalomethanes (THMs, the main DBPs, were evaluated in alveolar air samples collected from subjects. Swimming pool workers experienced different THM exposure levels: lifeguards and trainers showed the highest mean values of THMs in alveolar air samples (28.5 ± 20.2 µg/m3, while subjects working in cafe areas (17.6 ± 12.1 µg/m3, offices (14.4 ± 12.0 µg/m3 and engine rooms (13.6 ± 4.4 µg/m3 showed lower exposure levels. Employees with THM alveolar air values higher than 21 µg/m3 (median value experienced higher risks for red eyes (OR 6.2; 95% CI 2.6–14.9, itchy eyes (OR 3.5; 95% CI 1.5–8.0, dyspnea/asthma (OR 5.1; 95% CI 1.0–27.2 and blocked nose (OR 2.2; 95% CI 1.0–4.7 than subjects with less exposure. This study confirms

  12. Decontamination of B. globigii spores from drinking water infrastructure using disinfectants

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination of Bacillus spores adhered to common drinking water infrastructure surfaces was evaluated using a variety of disinfectants. Corroded iron and...

  13. Assessment of water quality in distribution networks through the lens ...

    African Journals Online (AJOL)

    Disinfection with chlorine is a common practice to ensure secured drinking water, but results in potentially harmful disinfection by-products (DBPs), when excess chlorination is done. The US Environmental Protection Agency (US EPA) has established Stage 1 and Stage 2 disinfection by-product Rules (DBP rules) to control ...

  14. An overview of water disinfection in developing countries and the potential for solar thermal water pasteurization

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Thomas, K.E.

    1998-01-01

    This study originated within the Solar Buildings Program at the U.S. Department of Energy. Its goal is to assess the potential for solar thermal water disinfection in developing countries. In order to assess solar thermal potential, the alternatives must be clearly understood and compared. The objectives of the study are to: (a) characterize the developing world disinfection needs and market; (b) identify competing technologies, both traditional and emerging; (c) analyze and characterize solar thermal pasteurization; (d) compare technologies on cost-effectiveness and appropriateness; and (e) identify research opportunities. Natural consequences of the study beyond these objectives include a broad knowledge of water disinfection problems and technologies, introduction of solar thermal pasteurization technologies to a broad audience, and general identification of disinfection opportunities for renewable technologies.

  15. Chlorine disinfection of grey water for reuse: effect of organics and particles.

    Science.gov (United States)

    Winward, Gideon P; Avery, Lisa M; Stephenson, Tom; Jefferson, Bruce

    2008-01-01

    Adequate disinfection of grey water prior to reuse is important to prevent the potential transmission of disease-causing microorganisms. Chlorine is a widely utilised disinfectant and as such is a leading contender for disinfection of grey water intended for reuse. This study examined the impact of organics and particles on chlorine disinfection of grey water, measured by total coliform inactivation. The efficacy of disinfection was most closely linked with particle size. Larger particles shielded total coliforms from inactivation and disinfection efficacy decreased with increasing particle size. Blending to extract particle-associated coliforms (PACs) following chlorine disinfection revealed that up to 91% of total coliforms in chlorinated grey water were particle associated. The organic concentration of grey water affected chlorine demand but did not influence the disinfection resistance of total coliforms when a free chlorine residual was maintained. Implications for urban water reuse are discussed and it is recommended that grey water treatment systems target suspended solids removal to ensure removal of PACs prior to disinfection.

  16. Ultraviolet light-emitting diodes in water disinfection.

    Science.gov (United States)

    Vilhunen, Sari; Särkkä, Heikki; Sillanpää, Mika

    2009-06-01

    The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps, like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of two emitted wavelengths and different test mediums to Escherichia coli destruction. Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and water with humic acids. Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also, the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases. When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage. UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but the test medium did not have much impact. This study found UV LEDs to be an optimal method for bacterial

  17. Titanium Dioxide-Based Antibacterial Surfaces for Water Treatment

    Science.gov (United States)

    The field of water disinfection is gaining much interest since waterborne diseases caused by pathogenic microorganisms directly endanger human health. Antibacterial surfaces offer a new, ecofriendly technique to reduce the harmful disinfection byproducts that form in medical and ...

  18. Disinfection for small water supplies: a technical guide

    CSIR Research Space (South Africa)

    Solsona, F

    1990-01-01

    Full Text Available This guide will present some disinfection systems, which will be useful in supporting disinfection programmes. The description of the different systems will provide a guideline for the selection of equipment base on balancing the simplicity...

  19. Practical considerations in the use of UV light for drinking water disinfection

    International Nuclear Information System (INIS)

    Jeyanayagam, S.; Cotton, C.

    2002-01-01

    Ultraviolet (UV) light was discovered approximately 150 years ago. The first commercial UV lamp was made in the early 1900s soon followed by the manufacture of the quartz sleeve. These technological advances allowed the first application of UV light for water disinfection in 1907 in France. In the mid 1980s, UV disinfection was named as a Best available technology (BAT) for wastewater disinfection in the United States. Fueled by the recent findings that UV disinfection can inactivate key pathogens at cost effective UV doses, the drinking water industry in North America is closely investigating its application in large installations. (author)

  20. Innovative Approach to Validation of Ultraviolet (UV) Reactors for Disinfection in Drinking Water Systems - presentation

    Science.gov (United States)

    UV disinfection is an effective process for inactivating many microbial pathogens found in source waters with the potential as stand-alone treatment or in combination with other disinfectants. For surface and groundwater sourced drinking water applications, the U.S. Environmental...

  1. Peracetic acid in the disinfection of a hospital water system contaminated with Legionella species.

    Science.gov (United States)

    Ditommaso, Savina; Biasin, Cinzia; Giacomuzzi, Monica; Zotti, Carla Maria; Cavanna, Alberto; Ruggenini Moiraghi, Angela

    2005-05-01

    To assess the efficacy of an alternative disinfection method for hospital water distribution systems contaminated with Legionella. Disinfection with peracetic acid was performed in a small hospital contaminated with L. pneumophila serotype 1. The disinfectant was used at concentrations of 50 ppm (first three surveillance phases) and 1,000 ppm (fourth surveillance phase) for 30 minutes. Environmental monitoring revealed that disinfection was maintained 1 week after treatment; however, levels of recontamination surpassing baseline values were detected after approximately 1 month. Comparison of water temperatures measured at the distal outlets showed a statistically significant association between temperature and bacterial load. The circulating water temperature was found to be lower in the two wards farthest away from the hot water production plant than in other wards. It was thought that the lower water temperature in the two wards promoted the bacterial growth even after disinfection. Peracetic acid may be useful in emergency situations, but does not provide definitive protection even if used monthly.

  2. Comparison of electrochemical method with ozonation, chlorination and monochloramination in drinking water disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongna, E-mail: lihongna@gmail.com [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Zhu Xiuping [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Ni Jinren, E-mail: nijinren@iee.pku.edu.cn [Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)

    2011-11-30

    Highlights: > Electrochemical, O{sub 3}, NaClO and NH{sub 2}Cl were compared at respective optimal condition. > Disinfection efficacy was similar for different bacteria in electrolysis. > Harsh Bacillus was inactivated more difficult in O{sub 3}, NaClO and NH{sub 2}Cl system. > Efficient disinfection of electrolysis was attributed to nonselectivity of {center_dot}OH. > Cell surface damage was more obvious in electrochemical process than the others. - Abstract: Electrochemical process in chloride-free electrolytes was proved to be powerful in disinfection due to the strong oxidants produced in the electrolysis and no formation of disinfection byproducts (DBPs). In this study, disinfection experiments were conducted by electrochemical treatment compared with ordinary and advanced methods (ozonation, chlorination and monochloramination), with Escherichia coli (E. coli) K-12, Staphylococcus aureus (S. aureus) A106, Bacillus subtilis (BST) and an isolated Bacillus as the representative microorganisms. Firstly, factor tests were performed on E. coli to obtain the optimal conditions of the four disinfection procedures. At their respective optimal condition, CT (concentration of disinfectant x contact time) value of a 4-log E. coli inactivation was 33.5, 1440, 1575, 1674 mg min L{sup -1} for electrochemical process, ozonation, chlorination and monochloramination, respectively. It was demonstrated that the disinfection availability was in the following order: electrochemical process > ozonation > chlorination > monochloramination, which could be attributed to the hydroxyl radical generated in the electrolysis, with strong oxidizing ability and non-selectivity compared with the other three disinfectants. Moreover, the disinfection efficacy of the four disinfection procedures was compared for four different bacteria. It was found that the disinfection efficacy was similar for the selected four bacteria in electrochemical process, while in the other three treatments

  3. Comparison of electrochemical method with ozonation, chlorination and monochloramination in drinking water disinfection

    International Nuclear Information System (INIS)

    Li Hongna; Zhu Xiuping; Ni Jinren

    2011-01-01

    Highlights: → Electrochemical, O 3 , NaClO and NH 2 Cl were compared at respective optimal condition. → Disinfection efficacy was similar for different bacteria in electrolysis. → Harsh Bacillus was inactivated more difficult in O 3 , NaClO and NH 2 Cl system. → Efficient disinfection of electrolysis was attributed to nonselectivity of ·OH. → Cell surface damage was more obvious in electrochemical process than the others. - Abstract: Electrochemical process in chloride-free electrolytes was proved to be powerful in disinfection due to the strong oxidants produced in the electrolysis and no formation of disinfection byproducts (DBPs). In this study, disinfection experiments were conducted by electrochemical treatment compared with ordinary and advanced methods (ozonation, chlorination and monochloramination), with Escherichia coli (E. coli) K-12, Staphylococcus aureus (S. aureus) A106, Bacillus subtilis (BST) and an isolated Bacillus as the representative microorganisms. Firstly, factor tests were performed on E. coli to obtain the optimal conditions of the four disinfection procedures. At their respective optimal condition, CT (concentration of disinfectant x contact time) value of a 4-log E. coli inactivation was 33.5, 1440, 1575, 1674 mg min L -1 for electrochemical process, ozonation, chlorination and monochloramination, respectively. It was demonstrated that the disinfection availability was in the following order: electrochemical process > ozonation > chlorination > monochloramination, which could be attributed to the hydroxyl radical generated in the electrolysis, with strong oxidizing ability and non-selectivity compared with the other three disinfectants. Moreover, the disinfection efficacy of the four disinfection procedures was compared for four different bacteria. It was found that the disinfection efficacy was similar for the selected four bacteria in electrochemical process, while in the other three treatments inactivation of the two

  4. A new silver based composite material for SPA water disinfection.

    Science.gov (United States)

    Tartanson, M A; Soussan, L; Rivallin, M; Chis, C; Penaranda, D; Lapergue, R; Calmels, P; Faur, C

    2014-10-15

    A new composite material based on alumina (Al2O3) modified by two surface nanocoatings - titanium dioxide (TiO2) and silver (Ag) - was studied for spa water disinfection. Regarding the most common microorganisms in bathing waters, two non-pathogenic bacteria Escherichia coli (Gram-negative) and Staphylococcus epidermidis (Gram positive) were selected as surrogates for bacterial contamination. The bactericidal properties of the Al2O3-TiO2-Ag material were demonstrated under various operating conditions encountered in spa water (temperature: 22-37 °C, presence of salt: CaCO3 or CaCl2, high oxygen content, etc.). Total removal of 10(8) CFU mL(-1) of bacteria was obtained in less than 10 min with 16 g L(-1) of material. Best results were observed for both conditions: a temperature of 37 °C and under aerobic condition; this latest favouring Reactive Oxygen Species (ROS) generation. The CaCO3 salt had no impact on the bactericidal activity of the composite material and CaCl2 considerably stabilized the silver desorption from the material surface thanks to the formation of AgCl precipitate. Preliminary tests of the Al2O3-TiO2-Ag bactericidal behaviour in a continuous water flow confirmed that 2 g L(-1) of material eliminated more than 90% of a 2.0 × 10(8) CFU mL(-1) bacterial mixture after one water treatment recycle and reached the disinfection standard recommended by EPA (coliform removal = 6 log) within 22 h. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Ultraviolet light in the use of water disinfection

    International Nuclear Information System (INIS)

    Dabbagh, R.

    1999-01-01

    Ultraviolet light is an effective method in the use of water disinfection for swimming pools, potable water and industry required water. For many reasons Ultraviolet light and Ultraviolet compounded with chlorine (Ultraviolet/chlorine) has been brought to attention ed in resent years. In this research, a swimming pool water disinfection was carried out by means of a system with the use of a reactor which was made of stainless steel (SS-304) and with many another standards required. Operation of system was carried out at first in the pilot plant and then installation in essential water treatment integrated. Inactivation of pollution index, E. Coli or Total coliform and Pseudomonas aeroginosa studies with 6000,16000 and 30000 μW.s/cm 2 Ultraviolet dose and then in presence of 0.3,0.6,0.9 and 1.2 mg/1 free chlorine (Ultraviolet/chlorine). In swimming pools minimum free chlorine residual usually is 1.5 mg/1. Optimum Ultraviolet dose was 16000 μW.s/cm 2 attention to 50 percent Ultraviolet absorption ca sued to TSS,TDS and turbidity. In the Ultraviolet/chlorine system suitable rate was 16000μW.s/cm 2 Ultraviolet dose/0.6 mg/1 chlorine in the 2.4 * 10 5 CFU/100 ml for Total coliform and 3600 CFU/100 ml for Pseudomonas aeroginosa. Most probable number (MPN) estimated multiple tube fermentation technique. In this way the flow rate for system indicated about 240 cm 3 /s or 0.9 m 3 /h. The samples polluted for secondary pollution with 54000 CFU/100 ml for E. Coli and 1800 CFU/100ml Pseudomonas aeroginosa. The number of microbes decreased to zero duration after 45 minutes contact time in presence of free chlorine residual in samples. In practical conditions which that disinfectant system was installed in essential water treatment circuit under 1.4 atm hydraulic pressure no growth was seen for pollution index in disinfected water with Ultraviolet in microbial density about 840 CFU/100 ml for Total coliform and 12 CFU/100 ml for pseudomonas aeroginosa. Attention to lower

  6. Ultraviolet light in the use of water disinfection

    International Nuclear Information System (INIS)

    Dabbagh, R.

    1999-01-01

    Ultraviolet light is an effective method in the use of water disinfection for swimming pools, potable water and industry required water. For many reasons UV light and UV compounded with chlorine (UV/chlorine) has been brought to attention in resent years. In this research, a swimming pool water disinfection was carried out by means of a system with the use of a reactor which was made of stainless steel (SS-304) and with many another standards required. Operation of system was carried out at first in the pilot plant and then installation in essential water treatment integrated. Inactivation of pollution index, E. Coli or Total coliform and Pseudomonas aeroginosa studied with 6000,16000 and 30000 μW.s/cm 2 UV dose and then in presence of 0.3,0.6,0.9 and 1.2 mg/1 free chlorine (UV/chlorine). In swimming pools minimum free chlorine residual usually is 1.5 mg/1. Optimum UV dose was 16000 μW.s/cm 2 attention to 50 percent UV absorption caused to TSS,TDS and turbidity. In the UV/chlorine system suitable rate was 16000μW.s/cm 2 UV dose /0.6 mg/1 chlorine in the 2.4 * 10 5 CFU/100 ml for Total coliform and 3600CFU/100 ml for Pseudomonas aeroginosa. Most probable number(MPN) estimated multiple tube fermentation technique. In this way the flow rate for system indicated about 240 cm 3 /s or 0.9 m 3 /h. The samples polluted for secondary pollution with 54000 CFU/100 ml for E.Coli and 1800 CFU/100ml Pseudomonas aeroginosa. The number of microbes decreased to zero duration after 45 minutes contact time in presence of free chlorine residual in samples. In practical conditions which that disinfectant system was installed in essential water treatment circuit under 1.4 atm hydraulic pressure no growth was seen for pollution index in disinfected water with UV in microbial density about 840 CFU/100 ml for Total coliform and 12CFU/100 ml for Pseudomonas aeroginosa. Attention to lower turbidity, TSS and TDS in tap water, higher flow rate about 560 cm 3 /s or 2 m 3 /h acessesed

  7. Photoreactivation Study of Wastewater Treatment Effluent Disinfected by UV-disinfection for Water Reuse

    International Nuclear Information System (INIS)

    Yoon, C.G.; Jung, K.W.; Ham, J.H.; Jeon, J.H.

    2003-01-01

    Photoreactivation of microorganism following UV-disinfection is one of the research topics of interest in assessing the UV-disinfection performance. Apparent photoreactivation was examined under fluorescent lamp and solar radiation as well as in darkness. Total coliform, fecal coliform, and Escherichia coli were used as indicator microorganisms, and their concentration of 10~30 MPN/100mL increased to the level of 100 MPN/100mL after 24 hours, which implied that part of damaged microorganisms by UV-disinfection might be repairable with time

  8. Why Do People Stop Treating Contaminated Drinking Water with Solar Water Disinfection (SODIS)?

    Science.gov (United States)

    Tamas, Andrea; Mosler, Hans-Joachim

    2011-01-01

    Solar Water Disinfection (SODIS) is a simple method designed to treat microbiologically contaminated drinking water at household level. This article characterizes relapse behavior in comparison with continued SODIS use after a 7-month nonpromotion period. In addition, different subtypes among relapsers and continuers were assumed to diverge mainly…

  9. Alternative disinfectant in drinking water systems. The peracetic acid; Disinfettanti alternativi in potabilizzazione. L`acido peracetico

    Energy Technology Data Exchange (ETDEWEB)

    Ragazzo, Patrizia; Navazio, Giancarlo [Padua, Univ. (Italy). Fac. di Ingegneria. Dipt. dei Processi Chimici dell`Ingegneria; Cavadore, Alberto [Solvay Interox, Rosignano (Italy); Babato, Ferdinando [Consorzio per l`Acquedotto del Basso Piave, S. Dona` di Piave (Italy)

    1997-03-01

    The need to use oxidation techniques in mains water systems, especially when treating surface water, has brought about a greater awareness as to the health risks associated to the presence of residual chemical compounds or disinfection by-products (DBP), which are commonly found in water supplies treated by means of traditional disinfectants (i.e. Cl{sub 2}, ClO{sub 2}, NH{sub 2}Cl, O{sub 3}, etc.). As a consequence, legislative standards have had to define greater restrictions regarding their use. In the light of this situation, the authors have set out to examine the feasibility of employing peracetic acid (PAA), which features low production of DBPs, as an alternative disinfectant. Preliminary experimental tests have been carried out on water samples taken from several process points within a water treatment plant at the Basso Piave mains water system, located in Jesolo, near Venice in Italy. These samples were treated with batch PAA doses ranging from 1 to 5 ppm for a variety of different exposition periods, also with varying temperature, pH and water properties. These experiments made it possible to asses the decay kinetics of PAA as well as reduction of characteristic microbiological parameters in raw and treated incoming and outgoing water throughout the various stages of the treatment process. The results achieved during these tests appear to provide ample evidence regarding the possibilities of use for PAA (with medium dosage of 1.5 to 2 ppm, contact times from 30` to 60` and abatement up to 95 %), after having assessed its compatibility, especially in order to the increase of the assimilable organic carbon, with the characteristics of the plant and distribution network, by continuous reactors and pilot plants.

  10. [Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

    Science.gov (United States)

    Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

    Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

  11. New Water Disinfection Technology for Earth and Space Applications as Part of the NPP Fellowship Research

    Science.gov (United States)

    SilvestryRodriquez, Nadia

    2010-01-01

    There is the need for a safe, low energy consuming and compact water disinfection technology to maintain water quality for human consumption. The design of the reactor should present no overheating and a constant temperature, with good electrical and optical performance for a UV water treatment system. The study assessed the use of UVA-LEDs to disinfectant water for MS2 Bacteriophage. The log reduction was sufficient to meet US EPA standards as a secondary disinfectant for maintaining water quality control. The study also explored possible inactivation of Pseudomonas aeruginosa and E. coli.

  12. Thermal disinfection of hotels, hospitals, and athletic venues hot water distribution systems contaminated by Legionella species.

    Science.gov (United States)

    Mouchtouri, Varvara; Velonakis, Emmanuel; Hadjichristodoulou, Christos

    2007-11-01

    Legionella spp. (> or = 500 cfu liter(-1)) were detected in 92 of 497 water distribution systems (WDS) examined. Thermal disinfection was applied at 33 WDS. After the first and second application of the disinfection procedure, 15 (45.4%) and 3 (9%) positive for remedial actions WDS were found, respectively. Legionella pneumophila was more resistant to thermal disinfection than Legionella non-pneumophila spp. (relative risk [RR]=5.4, 95% confidence intervals [CI]=1-35). WDS of hotels with oil heater were more easily disinfected than those with electrical or solar heater (RR=0.4 95% CI=0.2-0.8). Thermal disinfection seems not to be efficient enough to eliminate legionellae, unless repeatedly applied and in combination with extended heat flushing, and faucets chlorine disinfection.

  13. UV disinfection of injection and drinking water - an accepted method on offshore oil platforms

    International Nuclear Information System (INIS)

    Brunner, H.; Klein, H.P.

    1985-01-01

    Ultraviolet disinfection packages have been developed for the treatment of drinking water and injection water on offshore oil platforms. Large-scale tests with sulphate reducing bacteria out outlined. (Auth.)

  14. Disinfection of bore well water with chlorine dioxide/sodium hypochlorite and hydrodynamic cavitation.

    Science.gov (United States)

    Wang, Yifei; Jia, Aiyin; Wu, Yue; Wu, Chunde; Chen, Lijun

    2015-01-01

    The effect of hydrodynamic cavitation (HC) on potable water disinfection of chemicals was investigated. The bore well water was introduced into HC set-up to examine the effect of HC alone and combination of HC and chemicals such as chlorine dioxide and sodium hypochlorite. The effect of inlet pressure and geometrical parameters on disinfection was studied using HC alone and the results showed that increasing inlet pressure and using more and bigger holes of orifice plates can result in a higher disinfection rates. When HC was combined with chemicals, HC can reduce the doses of the chemicals and shorten the time of disinfection. It was also found that the decrease in bacteria concentration followed a first-order kinetic model. As for the experiment of combination of HC and sodium hypochlorite for disinfection, HC not only improves the disinfection rate but also degrades natural organic matter and chloroform. Compared with only sodium hypochlorite disinfection, combined processes get higher disinfection rate and lower production of chloroform, particularly the pretreatment with HC enhances the disinfection rate by 32% and there is a simultaneous reduction in production of chloroform by 39%.

  15. SHORTER MENSTRUAL CYCLES ASSOCIATED WITH CHLORINATION BY-PRODUCTS IN DRINKING WATER

    Science.gov (United States)

    Shorter Menstrual Cycles Associated with Chlorination by-Products in Drinking Water. Gayle Windham, Kirsten Waller, Meredith Anderson, Laura Fenster, Pauline Mendola, Shanna Swan. California Department of Health Services.In previous studies of tap water consumption we...

  16. Disinfection of bacteriophage MS2 by copper in water.

    Science.gov (United States)

    Armstrong, Andrew M; Sobsey, Mark D; Casanova, Lisa M

    2017-09-01

    Households that lack piped water supply are often forced to meet water needs by storing in the home, leaving water vulnerable to contamination by viruses. Storage in copper containers can potentially prevent this type of contamination, but the inactivation kinetics of viruses by copper need to be described to make appropriate storage recommendations. This work characterized inactivation kinetics of bacteriophage MS2 as a surrogate for enteric viruses by dissolved ionic copper in water. Reduction of MS2 increased with increasing doses of copper. At 0.3 mg/L, there was a 1.8-log 10 reduction of MS2 within 6 h. At 1 and 3 mg/L, 2-2.5 log 10 inactivation could be achieved between 6 and 24 h. Parameters for the Chick-Watson, Hom, and One Hit-Two Population models of inactivation were calculated and evaluated, all of which demonstrated strong goodness-of-fit and predictability at various contact times. Copper inactivates MS2 under controlled conditions at doses between 0.3 and 3 mg/L. Although requiring longer contact times than conventional disinfectants, it is a candidate for improving the safety of stored drinking water.

  17. Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley).

    Science.gov (United States)

    Trujillo, J; Barrios, J A; Jimenez, B

    2008-01-01

    Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1-1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 microg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 microg/L. The recommended scheme is nanofiltration + chlorination.

  18. Nutrients, Dissolved Organic Carbon, Color, and Disinfection Byproducts in Base Flow and Stormflow in Streams of the Croton Watershed, Westchester and Putnam Counties, New York, 2000-02

    Science.gov (United States)

    Heisig, Paul M.

    2009-01-01

    The Croton Watershed is unique among New York City's water-supply watersheds because it has the highest percentages of suburban development (52 percent) and wetland area (6 percent). As the City moves toward filtration of this water supply, there is a need to document water-quality contributions from both human and natural sources within the watershed that can inform watershed-management decisions. Streamwater samples from 24 small (0.1 to 1.5 mi2) subbasins and three wastewater-treatment plants (2000-02) were used to document the seasonal concentrations, values, and formation potentials of selected nutrients, dissolved organic carbon (DOC), color, and disinfection byproducts (DBPs) during stormflow and base-flow conditions. The subbasins were categorized by three types of drainage efficiency and a range of land uses and housing densities. Analyte concentrations in subbasin streams differed in response to the subbasin charateristics. Nutrient concentrations were lowest in undeveloped, forested subbasins that were well drained and increased with all types of development, which included residential, urban commercial/industrial, golf-course, and horse-farm land uses. These concentrations were further modified by subbasin drainage efficiency. DOC, in contrast, was highly dependent on drainage efficiency. Color intensity and DBP formation potentials were, in turn, associated with DOC and thus showed a similar response to drainage efficiency. Every constituent exhibited seasonal changes in concentration. Nutrients. Total (unfiltered) phosphorus (TP), soluble reactive phosphorus (SRP), and nitrate were associated primarily with residential development, urban, golf-course, and horse-farm land uses. Base-flow and stormflow concentrations of the TP, SRP, and nitrate generally increased with increasing housing density. TP and SRP concentrations were nearly an order of magnitude higher in stormflow than in base flow, whereas nitrate concentrations showed little difference

  19. Efficacy of detergent and water versus bleach for disinfection of direct contact ophthalmic lenses.

    Science.gov (United States)

    Abbey, Ashkan M; Gregori, Ninel Z; Surapaneni, Krishna; Miller, Darlene

    2014-06-01

    Although manufacturers recommend cleaning ophthalmic lenses with detergent and water and then with a specific disinfectant, disinfectants are rarely used in ophthalmic practices. The aim of this pilot study was to evaluate the efficacy of detergent and water versus that of bleach, a recommended disinfectant, to eliminate common ocular bacteria and viruses from ophthalmic lenses. Three bacterial strains (Staphylococcus epidermidis, Corynebacterium straitum, and methicillin-resistant Staphylococcus aureus and 2 viral strains (adenovirus and herpes simplex virus [HSV] type-1) were individually inoculated onto 20 gonioscopy and laser lenses. The lenses were washed with detergent and water and then disinfected with 10% bleach. All the lenses were cultured after inoculation, after washing with detergent and water, and after disinfecting with the bleach. Bacterial cultures in thioglycollate broth were observed for 3 weeks, and viral cultures were observed for 2 weeks. The presence of viruses was also detected by multiplex polymerase chain reaction (PCR). All 20 lenses inoculated with S. epidermidis, C. straitum, adenovirus, and HSV-1 showed growth after inoculation but no growth after washing with detergent/water and after disinfecting with the bleach. All lenses showed positive HSV and adenovirus PCR results after inoculation and negative PCR results after washing with detergent/water and after disinfecting with bleach. All methicillin-resistant S. aureus-contaminated lenses showed growth after inoculation and no growth after washing with detergent and water. However, 1 lens showed positive growth after disinfecting with bleach. Cleaning with detergent and water seemed to effectively eliminate bacteria and viruses from the surface of contaminated ophthalmic lenses. Further studies are warranted to design practical disinfection protocols that minimize lens damage.

  20. Pulsed-Plasma Disinfection of Water Containing Escherichia coli

    Science.gov (United States)

    Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

    2007-03-01

    The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

  1. Drinking water disinfection by means of ultraviolet radiation. Desinfektion von Trinkwasser durch UV-Bestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Gelzhaeuser, P; Bewig, F; Holm, K; Kryschi, R; Reich, G; Steuer, W

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice.

  2. Genotoxicity of drinking water treated with different disinfectants and effects of disinfection conditions detected by umu-test.

    Science.gov (United States)

    Nie, Xuebiao; Liu, Wenjun; Zhang, Liping; Liu, Qing

    2017-06-01

    The genotoxicity of drinking water treated with 6 disinfection methods and the effects of disinfection conditions were investigated using the umu-test. The pretreatment procedure of samples for the umu-test was optimized for drinking water analysis. The results of the umu-test were in good correlation with those of the Ames-test. The genotoxicity and production of haloacetic acids (HAAs) were the highest for chlorinated samples. UV+chloramination is the safest disinfection method from the aspects of genotoxicity, HAA production and inactivation effects. For chloramination, the effects of the mass ratio of Cl 2 to N of chloramine on genotoxicity were also studied. The changes of genotoxicity were different from those of HAA production, which implied that HAA production cannot represent the genotoxic potential of water. The genotoxicity per chlorine decay of chlorination and chloramination had similar trends, indicating that the reaction of organic matters and chlorine made a great contribution to the genotoxicity. The results of this study are of engineering significance for optimizing the operation of waterworks. Copyright © 2016. Published by Elsevier B.V.

  3. Halogenating reaction activity of aromatic organic compounds during disinfection of drinking water

    International Nuclear Information System (INIS)

    Guo Gaimei; Chen Xiaodong

    2009-01-01

    The halogenating reactions of five aromatic organic compounds (AOCs) with aqueous chlorine (HOCl/OCl - ) and aqueous bromine (HOBr/OBr - ) were studied with an aim to compare the formation properties of haloacetic acids (HAAs) for the corresponding chlorination or bromination reactions of AOCs, respectively. The experiment results indicated that the HAAs substitution efficiency for the bromination reactions of AOCs was greater than that for the chlorination reactions, and the formation of HAAs had a strong dependence on the chemical structure of AOCs. The chlorination or bromination reaction activities for the AOCs with electron donating functional groups were higher than that for them with electron withdrawing functional groups. The kinetic experiments indicated that the reactions of aqueous bromine with phenol were faster than those of aqueous chlorine with phenol and the halogen consumption exhibited rapid initial and slower consumption stages for the reactions of phenol with aqueous chlorine and bromine, respectively. In addition, the HAAs production for the chlorination reaction of phenol decreased with the increase of pH. These conclusions could provide the valuable information for the effective control of the disinfection by-products during drinking water treatment operation

  4. Numerical and experimental investigation of UV disinfection for water treatment

    International Nuclear Information System (INIS)

    Li, H.Y.; Osman, H.; Kang, C.W.; Ba, T.

    2017-01-01

    Highlights: • UV irradiation for water treatment is numerically and experimentally investigated. • Fluence rate E increases exponentially with the increase of UVT. • UV dose distribution moves to a high range with increase of UVT and lamp power. • A linear relationship is observed between fluence rate E and average UV dose D_a_v_e. • D_a_v_e decreases with the increase of UVT and fluid flow rate. - Abstract: Disinfection by ultraviolet (UV) for water treatment in a UV reactor is numerically and experimentally investigated in this paper. The flow of water, UV radiation transportation as well as microorganism particle trajectories in the UV reactor is simulated. The effects of different parameters including UV transmittance (UVT), lamp power and water flow rate on the UV dose distribution and average UV dose are studied. The UV reactor performance in terms of average UV dose under these parameters is analysed. Comparisons are made between experiments and simulations on the average UV dose and reasonable agreement is achieved. The results show that the fluence rate increases exponentially with the increase of UVT. The UV dose distribution profiles moves to a high range of UV dose with the increase of UVT and lamp power. The increase of water flow rate reduces the average exposure time of microorganism particles to the UV light, resulting in the shifting of UV dose distribution to a low range of UV dose. A linear relationship is observed between fluence rate and the average UV dose. The average UV dose increases with the increase of lamp power while it decreases with the increase of UVT and water flow rate.

  5. Biochars made from agro-industrial by-products remove chlorine from water and wastewater

    Science.gov (United States)

    Tzachristas, Andreas; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

    2017-04-01

    Chlorination is the most common disinfection process for water and wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination kinetics of the different raw and biochar materials as well as those of commercial activated carbons. The removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0.5 mg/g. For the two commercial activated carbons, removal efficiencies were 11.4 ± 0.2 mg/g. The first-order constant k1 ranged between 0.001 and 0.014 (min-1) for the biosorbents and the biochars and it was equal to 0.017 (min-1) for the commercial

  6. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  7. Electrochemically activated water as an alternative to chlorine for decentralized disinfection

    KAUST Repository

    Ghebremichael, Kebreab A.; Muchelemba, E.; Petruševski, Branislav; Amy, Gary L.

    2011-01-01

    Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive

  8. Risk of viral acute gastrointestinal illness from non-disinfected drinking water distribution systems

    Science.gov (United States)

    Acute gastrointestinal illness (AGI) resulting from pathogens directly entering the piping of drinking water distribution systems is insufficiently understood. Here, we estimate AGI incidence attributable to virus intrusions into non-disinfecting municipal distribution systems. Viruses were enumerat...

  9. Continuous-flow solar UVB disinfection reactor for drinking water.

    Science.gov (United States)

    Mbonimpa, Eric Gentil; Vadheim, Bryan; Blatchley, Ernest R

    2012-05-01

    Access to safe, reliable sources of drinking water is a long-standing problem among people in developing countries. Sustainable solutions to these problems often involve point-of-use or community-scale water treatment systems that rely on locally-available resources and expertise. This philosophy was used in the development of a continuous-flow, solar UVB disinfection system. Numerical modeling of solar UVB spectral irradiance was used to define temporal variations in spectral irradiance at several geographically-distinct locations. The results of these simulations indicated that a solar UVB system would benefit from incorporation of a device to amplify ambient UVB fluence rate. A compound parabolic collector (CPC) was selected for this purpose. Design of the CPC was based on numerical simulations that accounted for the shape of the collector and reflectance. Based on these simulations, a prototype CPC was constructed using materials that would be available and inexpensive in many developing countries. A UVB-transparent pipe was positioned in the focal area of the CPC; water was pumped through the pipe to allow exposure of waterborne microbes to germicidal solar UVB radiation. The system was demonstrated to be effective for inactivation of Escherichia coli, and DNA-weighted UV dose was shown to govern reactor performance. The design of the reactor is expected to scale linearly, and improvements in process performance (relative to results from the prototype) can be expected by use of larger CPC geometry, inclusion of better reflective materials, and application in areas with greater ambient solar UV spectral irradiance than the location of the prototype tests. The system is expected to have application for water treatment among communities in (developing) countries in near-equatorial and tropical locations. It may also have application for disaster relief or military field operations, as well as in water treatment in areas of developed countries that receive

  10. Microbial quality of swimming pool water with treatment without disinfection, with ultrafiltration, with UV-based treatment and with chlorination

    NARCIS (Netherlands)

    Keuten, M.G.A.; Peters, M.C.F.M.; van Dijk, J.C.; van Loosdrecht, Mark C.M.; Rietveld, L.C.

    2017-01-01

    Swimming pools are traditionally disinfected with a residual disinfectant such as sodium hypochlorite. Nowadays, swimming water without a residual disinfectant is increasingly popular, as can be seen by the growing number of (natural) swimming ponds (Weilandt 2015), but health risks for bathers do

  11. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    Science.gov (United States)

    Banach, Jennifer L.; Sampers, Imca; Van Haute, Sam; van der Fels-Klerx, H.J. (Ine)

    2015-01-01

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant’s reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer’s efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer. PMID:26213953

  12. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    Directory of Open Access Journals (Sweden)

    Jennifer L. Banach

    2015-07-01

    Full Text Available The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant’s reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer’s efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer.

  13. Biochars made from agro-industrial by-products remove chlorine and lower water toxicity

    Science.gov (United States)

    Tzachristas, Andreas; Xirou, Maria; Manariotis, Ioannis D.; Dailianis, Stefanos; Karapanagioti, Hrissi K.

    2016-04-01

    Chlorination is the most common disinfection process for water and treated wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination efficiency and kinetics of the different raw and biochar materials as well as those of commercial activated carbons. As chlorine concentration increases the removal also increases linearily. After 1 and 24 hours of contact the chlorine relative removal efficiencies for the biochar made from olive seeds are 50 and 77 ± 4%, respectively. It seems that the removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0

  14. Chlorine dioxide as a disinfectant for Ralstonia solanacearum control in water, storage and equipment

    Directory of Open Access Journals (Sweden)

    Popović Tatjana

    2016-01-01

    Full Text Available Brown rot or bacterial wilt caused by bacterium Ralstonia solanacearum is the main limiting factor in potato production. Quarantine measures are necessary to avoid spread of disease to disease-free areas. R. solanacearum has been shown to contaminate watercourses from which crop irrigation is then prohibited causing further potential losses in yield and quality. The bacteria also spread via surfaces that diseased seed potatoes come into contact with. This study showed bactericidal activity of chlorine dioxide (CIO2 on R. solanacearum for disinfection of water, surface and equipment. The results showed that CIO2 solution at concentration of 2 ppm at 30 minutes of exposure time had bactericidal effect for disinfection of water. For surface and equipment disinfection, concentration of 50 ppm showed total efficacy at 30 min and 5 sec exposure time, respectively. Results suggest that use of CIO2 as a disinfectant has a potential for control of brown rot pathogen in water, storage and equipment.

  15. Exopolymeric substances from drinking water biofilms: Dynamics of production and relation with disinfection by products.

    Science.gov (United States)

    Lemus Pérez, M F; Rodríguez Susa, M

    2017-06-01

    Exopolymeric substances (EPS) as an external matrix of biofilm could react with disinfectants in drinking water networks forming disinfection by-products (DBP). Based on an experimental setup using two chlorine conditions-biofilm 1 (2.6 ± 0.8 mgCl/L) and biofilm 2 (0.7 ± 0.2 mg Cl/L)-samples of biofilms were recovered during 9 campaigns and EPS were extracted. Analyses of SUVA, fluorescence and amino acid (AA) content were carried out on the EPS to observe variation over time and correlations with DBP formation potential (DBP fp ) after chlorination. SUVA values were under 2 L/mgC*m showing that both EPS were hydrophilic. Slightly higher SUVA in biofilm 2 with low variation over time was observed. Fluorescence showed that aromatic proteins and fulvic like substances were the principal components and increased in biofilm 1 over time. AA decreased with time, and higher values of alanine, threonine, proline and isoleucine were observed in biofilm 2. Based on general associations, the SUVA of biofilm 2 correlated well with chloroform (CF) (r = 0.80). Generally, in both biofilms, tryptophan-like substances were negatively correlated with DBP while humic acid-like substances correlated positively, but with low indexes (r = 0.3-0.6). Correlations of data from individual sampling increased the indices (r over 0.8), suggesting a temporal influence of other factors on DBP fp such as inorganics, filtered water and the structural composition of EPS. In biofilm 1, Br-haloacetic acids (Br-HAA), dibromoacetonitrile and bromochloro acetonitrile were inversely associated with arginine and valine, as were di and trichloropropanone to arginine. On the contrary, in biofilm 2, the following amino acids correlated positively with DBP: alanine with Br-HAA, alanine with CF, alanine with N-DBP (chloropicrin, di and tri-chloro acetonitrile), and valine with CF. As this is the first report about the relation between temporal variation of EPS and DBP fp of biofilms in two

  16. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

  17. Disinfection of sewage water and sludge using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Musaad, R M.A. [Department of Radiation Chemistry, Atomic Energy Research Coordination Council, Sudan Academy of Sciences, Khartoum (Sudan)

    2008-04-15

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6{sup 0} cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D{sub 10}) and 50% (D {sub 50}) were determined for each species. The D{sub 10} values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D{sub 50} fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  18. Disinfection of sewage water and sludge using gamma radiation

    International Nuclear Information System (INIS)

    Musaad, R.M.A.

    2008-04-01

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6 0 cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D 10 ) and 50% (D 50 ) were determined for each species. The D 10 values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D 50 fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  19. Solar disinfection of water for low income communities; Desinfeccao solar de agua para comunidades de baixa renda

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Lorna Falcao

    2010-03-15

    The use of solar energy for water disinfection, and is accessible to disadvantaged communities because of its low cost, has the advantage of using disposable materials such as bottles of polyethylene terephthalate (PET). We present a study that used two methods of disinfection: the methodology proposed by the project Solar Water Disinfection (SODIS), which consisted of water disinfection by solar radiation and temperature and the methodology which the temperature of the water for disinfection. In both, we seek to eliminate microorganisms that cause serious diseases such as dysentery, typhoid, cholera, etc. Water samples were collected in the community of Bass, where the population has low income and the incidence of waterborne diseases is high. The experiments were divided into two stages. In step 1 we studied the feasibility of disinfection and in step 2 the feasibility of the pilot plant to obtain adequate levels of disinfection temperatures desired. The results showed the efficiency of the disinfection process, reaching an average of 80 to 100% death of microorganisms, but regrowth was observed in some samples. Finally on the good results of stage 1, is designed and built and tested in an experimental pilot plant, which has shown to be feasible to promote water disinfection through the use of solar energy. The water after treatment is in accordance with the limits established by Brazilian legislation for clean water, maintaining a positive performance for the disinfection and acceptable levels of bacterial regrowth. (author)

  20. Prospective Power Calculations for the Four Lab Study of A Multigenerational Reproductive/Developmental Toxicity Rodent Bioassay Using A Complex Mixture of Disinfection By-Products in the Low-Response Region

    Directory of Open Access Journals (Sweden)

    Jane Ellen Simmons

    2011-10-01

    Full Text Available In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA’s Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90% to detect pup weight decreases, while providing the most power to detect increased prenatal loss.

  1. Prospective Power Calculations for the Four Lab Study of A Multigenerational Reproductive/Developmental Toxicity Rodent Bioassay Using A Complex Mixture of Disinfection By-Products in the Low-Response Region

    Science.gov (United States)

    Dingus, Cheryl A.; Teuschler, Linda K.; Rice, Glenn E.; Simmons, Jane Ellen; Narotsky, Michael G.

    2011-01-01

    In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA’s Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss. PMID:22073030

  2. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    NARCIS (Netherlands)

    Banach, J.L.; Sampers, I.; Haute, van S.; Fels, van der H.J.

    2015-01-01

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water

  3. Effect of selection of pH in swimming pool on formation of chlorination by-products

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Willach, Sarah; Mosbæk, Hans

    2011-01-01

    Chlorine is used as disinfection agent in public swimming pools, but also reacts with organic matter in the water forming chlorinat ed disinfection by-products. In order to evaluate the effect of choice of pHsetpoint in the pool we investigated the effect of chlorination of artificial body fluid...

  4. A practical demonstration of water disinfection using TiO2 films and sunlight.

    Science.gov (United States)

    Gelover, Silvia; Gómez, Luis A; Reyes, Karina; Teresa Leal, Ma

    2006-10-01

    The scope of this study is the assessment of the efficiency of solar disinfection by heterogeneous photocatalysis with sol-gel immobilized (titanium dioxide) TiO2 films over glass cylinders. The solar disinfection process known as SODIS was considered as a reference. Spring water naturally polluted with coliform bacteria was exposed to sunlight in plastic bottles with and without TiO2 over simple solar collectors and the disinfection effectiveness was measured. Total and fecal coliforms quantification was performed by means of the chromogenic substrate method in order to obtain the efficiency of each disinfection treatment. The disinfection with TiO2 was more efficient than the SODIS process, inactivating total coliforms as well as fecal coliforms. On a sunny day (more than 1000 W m(-2) irradiance), it took the disinfection with immobilized TiO2 15 min of irradiation to inactivate the fecal coliforms to make them undetectable. For inactivation of total coliforms, 30 min was required, so that in less than half the time it takes SODIS, the treated water complies with the microbial standards for drinking water in Mexico. Another important part of this study has been to determine the bacterial regrowth in water after the disinfection processes were tested. After SODIS, bacterial regrowth of coliforms was observed. In contrast, when using the TiO2 catalyst, coliforms regrowth was not detected, neither for total nor for fecal coliforms. The disinfection process using TiO2 kept treated water free of coliforms at least for seven days after sun irradiation. This demonstration opens the possibility of application of this simple method in rural areas of developing countries.

  5. Efficacy of Detergent and Water Versus Bleach for the Disinfection of Direct Contact Ophthalmic Lenses

    Science.gov (United States)

    Abbey, Ashkan M.; Gregori, Ninel Z.; Surapaneni, Krishna; Miller, Darlene

    2014-01-01

    Purpose While manufacturers recommend cleaning ophthalmic lenses with detergent and water and then a specific disinfectant, disinfectants are rarely used in ophthalmic practices. The aim of this pilot study was to evaluate the efficacy of detergent and water versus bleach, a recommended disinfectant, to eliminate common ocular bacteria and viruses from ophthalmic lenses. Methods Three bacterial strains (Staphylococcus epidermidis, Corynebacterium straitum, and methicillin-resistant Staphylococcus aureus (MRSA) and two viral strains (adenovirus and herpes simplex virus (HSV) type-1) were individually inoculated to 20 gonioscopy and laser lenses. Lenses were washed with detergent and water and then disinfected with 10% bleach. All lenses were cultured after inoculation, after detergent and water, and after the bleach. Bacterial cultures in thioglycollate broth were observed for 3 weeks and viral cultures for 2 weeks. The presence of viruses was also detected by multiplex polymerase chain reaction (PCR). Results All 20 lenses inoculated with Staphylococcus epidermidis, Corynebacterium straitum, adenovirus, and HSV-1 showed growth after inoculation, but no growth after detergent/water and after the bleach. All lenses showed positive HSV and adenovirus PCR after inoculation and negative PCR after detergent/water and after bleach. All MRSA contaminated lenses showed growth after inoculation and no growth after detergent and water. However, one lens showed positive growth after bleach. Conclusions Cleaning with detergent and water appeared to effectively eliminate bacteria and viruses from the surface of contaminated ophthalmic lenses. Further studies are warranted to design practical disinfection protocols that minimize lens damage. PMID:24747806

  6. Solid-Phase Extraction and High-Performance Liquid Chromatography Mass Spectrometry Analysis of Nitrosamines in Treated Drinking Water and Wastewater

    Science.gov (United States)

    N-Nitrosamines, including N-dimethylnitrosamine (NDMA), were identified as chlorination byproducts in drinking water in 1989. Nitrosamines are known rodent carcinogens and probable human carcinogens, so that they have been considered disinfection byproducts (DBPs) of public healt...

  7. Aggregation of Adenovirus 2 in Source Water and Impacts on Disinfection by Chlorine

    Science.gov (United States)

    Cromeans, Theresa L.; Metcalfe, Maureen G.; Humphrey, Charles D.; Hill, Vincent R.

    2016-01-01

    It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water. PMID:26910058

  8. Optimization of fixed titanium dioxide film on PET bottles and visual indicator for water disinfection

    Science.gov (United States)

    Heredia-Munoz, Manuel Antonio

    Water is perhaps the most important resource that sustains human life. According to the World Health Organization (WHO), almost two billion people do not have access to the required water that is needed to satisfy their daily needs and one billion do not have access to clean sources of water for consumption, most of them living in isolated and poor areas around the globe. Poor quality water increases the risk of cholera, typhoid fever and dysentery, and other water-borne illness making this problem a real crisis that humankind is facing. Several water disinfection technologies have been proposed as solutions for this problem. Solar water disinfection using TiO2 coated PET bottles was the alternative that is studied in this work. This technology does not only inactivate bacteria but also disintegrates organic chemicals that can be present in water. The objectives of this work address the optimization of the TiO 2 coated PET bottles technologies. The improvement on the bottle coating process, using two coats of 10% W/V of TiO2 in a solution of vinegar and sodium bicarbonate to form the TiO2 film, the use of a different indigo carmine (1.25 X 10-1mg/pill) concentration in the pill indicator of contamination, the increase of the disinfection rate through shaking the bottles, degradation under intermittent UV radiation and the effect of bottle size on photocatalytic water disinfection were among the most important findings. A new mathematical model that describes better photocatalytic water disinfection in TiO2 coated bottles and simulates water disinfection under different working conditions was another important achievement. These results can now be used to design a strategy for disseminating this technology in areas where it is required and, in that way, generate the greatest positive impact on the people needing safe drinking water.

  9. Effect of Ozonation and Biological Activated Carbon Treatment of Wastewater Effluents on Formation of N-nitrosamines and Halogenated Disinfection Byproducts.

    Science.gov (United States)

    Chuang, Yi-Hsueh; Mitch, William A

    2017-02-21

    Ozonation followed by biological activated carbon (O 3 /BAC) is being considered as a key component of reverse osmosis-free advanced treatment trains for potable wastewater reuse. Using a laboratory-scale O 3 /BAC system treating two nitrified wastewater effluents, this study characterized the effect of different ozone dosages (0-1.0 mg O 3 /mg dissolved organic carbon) and BAC empty bed contact times (EBCT; 15-60 min) on the formation after chlorination or chloramination of 35 regulated and unregulated halogenated disinfection byproducts (DBPs), 8 N-nitrosamines, and bromate. DBP concentrations were remarkably similar between the two wastewaters across O 3 /BAC conditions. Ozonation increased bromate, TCNM, and N-nitrosodimethylamine, but ozonation was less significant for other DBPs. DBP formation generally decreased significantly with BAC treatment at 15 min EBCT, but little further reduction was observed at higher EBCT where low dissolved oxygen concentrations may have limited biological activity. The O 3 /BAC-treated wastewaters met regulatory levels for trihalomethanes (THMs), haloacetic acids (HAAs), and bromate, although N-nitrosodimethylamine exceeded the California Notification Level in one case. Regulated THMs and HAAs dominated by mass. When DBP concentrations were weighted by measures of their toxic potencies, unregulated haloacetonitriles, haloacetaldehydes, and haloacetamides dominated. Assuming toxicity is additive, the calculated DBP-associated toxicity of the O 3 /BAC-treated chloraminated effluents were comparable or slightly higher than those calculated in a recent evaluation of Full Advanced Treatment trains incorporating reverse osmosis.

  10. Formation of Emerging Disinfection By-products by Chlorination/Chloramination of Seawater Impacted by Algal Organic Matter

    KAUST Repository

    Nihemaiti, Maolida

    2015-08-31

    The aim of this work was to study the formation of haloacetamides (HAcAms) and other DBPs during chlorination and chloramination of algal organic matter (AlOM). The HAcAms formation potentials of different precursors (amino acids, simulated algal blooms grown in the Red Sea) were evaluated. Experiments with simulated algal blooms were conducted in the presence of bromide ion (synthetic seawater containing 800 μg/L Br−) to assess the formation of brominated analogues of HAcAms in conditions close to the disinfection of real seawater. Chlorination produced more HAcAms than chloramination from real algae (Synecococcus sp.), thus indicating that the nitrogen of HAcAms comes predominantly from DON through the decarboxylation of amino acids rather than from NH2Cl. Dibrominated species of DBPs (i.e., DBAcAm, DBAA and DBAN) were the dominant species formed by both chlorination and chloramination of algal bloom samples. Chloramination of the amino acid asparagine produced an important amount of DCAcAm as compared to chlorination, indicating the existence of a specific reaction pathway.

  11. Formation of Emerging Disinfection By-products by Chlorination/Chloramination of Seawater Impacted by Algal Organic Matter

    KAUST Repository

    Nihemaiti, Maolida; Le Roux, Julien; Croue, Jean-Philippe

    2015-01-01

    The aim of this work was to study the formation of haloacetamides (HAcAms) and other DBPs during chlorination and chloramination of algal organic matter (AlOM). The HAcAms formation potentials of different precursors (amino acids, simulated algal blooms grown in the Red Sea) were evaluated. Experiments with simulated algal blooms were conducted in the presence of bromide ion (synthetic seawater containing 800 μg/L Br−) to assess the formation of brominated analogues of HAcAms in conditions close to the disinfection of real seawater. Chlorination produced more HAcAms than chloramination from real algae (Synecococcus sp.), thus indicating that the nitrogen of HAcAms comes predominantly from DON through the decarboxylation of amino acids rather than from NH2Cl. Dibrominated species of DBPs (i.e., DBAcAm, DBAA and DBAN) were the dominant species formed by both chlorination and chloramination of algal bloom samples. Chloramination of the amino acid asparagine produced an important amount of DCAcAm as compared to chlorination, indicating the existence of a specific reaction pathway.

  12. Reduced Efficiency of Chlorine Disinfection of Naegleria fowleri in a Drinking Water Distribution Biofilm.

    Science.gov (United States)

    Miller, Haylea C; Wylie, Jason; Dejean, Guillaume; Kaksonen, Anna H; Sutton, David; Braun, Kalan; Puzon, Geoffrey J

    2015-09-15

    Naegleria fowleri associated with biofilm and biological demand water (organic matter suspended in water that consumes disinfectants) sourced from operational drinking water distribution systems (DWDSs) had significantly increased resistance to chlorine disinfection. N. fowleri survived intermittent chlorine dosing of 0.6 mg/L for 7 days in a mixed biofilm from field and laboratory-cultured Escherichia coli strains. However, N. fowleri associated with an attached drinking water distribution biofilm survived more than 30 times (20 mg/L for 3 h) the recommended concentration of chlorine for drinking water. N. fowleri showed considerably more resistance to chlorine when associated with a real field biofilm compared to the mixed laboratory biofilm. This increased resistance is likely due to not only the consumption of disinfectants by the biofilm and the reduced disinfectant penetration into the biofilm but also the composition and microbial community of the biofilm itself. The increased diversity of the field biofilm community likely increased N. fowleri's resistance to chlorine disinfection compared to that of the laboratory-cultured biofilm. Previous research has been conducted in only laboratory scale models of DWDSs and laboratory-cultured biofilms. To the best of our knowledge, this is the first study demonstrating how N. fowleri can persist in a field drinking water distribution biofilm despite chlorination.

  13. Cellular adverse actions of dibromoacetonitrile, a by-product in water bacterial control, at sublethal levels in rat thymocytes.

    Science.gov (United States)

    Kishida, Takumi; Akiyoshi, Kenji; Erdenedalai, Erdenebat; Enhetomuru, Anu; Imai, Shoji; Oyama, Yasuo

    2018-09-01

    The aim of this study was to investigate the effects of dibromoacetonitrile (DBAN), a by-product in water bacterial control, at sublethal concentrations on rat thymocytes, by using a cytometric technique with appropriate fluorescent dyes. By using this method, the possibility that DBAN induces cellular actions related to oxidative stress was assessed. DBAN reduced the content of cellular nonprotein thiols under Zn 2+ -free conditions. It elevated the intracellular level of Zn 2+ , being independent from external Zn 2+ . DBAN increased cell vulnerability to the cytotoxic action of hydrogen peroxide. These actions of DBAN were likely related to oxidative stress. DBAN is formed by the reaction of bromides and chlorinated oxidants during water disinfection. Hydrolysis of 2,2-dibromo-3-nitrilopropionamide, an antimicrobial used in hydraulic fracturing fluids for production of shale gas and oil, produces DBAN. Therefore, the concern regarding the levels of DBAN in industrial water systems is necessary to avoid the environmental risk to humans and wild mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Characterization of a stirred tank electrochemical cell for water disinfection processes

    International Nuclear Information System (INIS)

    Polcaro, A.M.; Vacca, A.; Mascia, M.; Palmas, S.; Pompei, R.; Laconi, S.

    2007-01-01

    Laboratory experiments were performed to characterize the behaviour of an electrochemical cell equipped with boron-doped diamond anodes and to verify its effectiveness in water disinfection. The hydrodynamic regime was determined when the cell worked either in batch or in continuous mode. Galvanostatic electrolyses of aqueous 1 mM Na 2 SO 4 solutions were performed to investigate on the oxidant production in different experimental conditions. The same solutions contaminated by E. coli, enterococci and coliforms were used as test media to verify the effectiveness of the system in the disinfection process. Experimental results indicated that the major inactivation mechanism of bacteria in the electrochemical cell is a disinfection by electrochemically generated oxidants, however a cooperative effect of superficial reaction has to be taken into account. The great capability of BDD anode to produce reactive oxygen species (ROS) and other oxidizing species during the electrolysis allows to establish a chlorine-free disinfection process

  15. Real-time ArcGIS and heterotrophic plate count based chloramine disinfectant control in water distribution system.

    Science.gov (United States)

    Bai, Xiaohui; Zhi, Xinghua; Zhu, Huifeng; Meng, Mingqun; Zhang, Mingde

    2015-01-01

    This study investigates the effect of chloramine residual on bacteria growth and regrowth and the relationship between heterotrophic plate counts (HPCs) and the concentration of chloramine residual in the Shanghai drinking water distribution system (DWDS). In this study, models to control HPCs in the water distribution system and consumer taps are also developed. Real-time ArcGIS was applied to show the distribution and changed results of the chloramine residual concentration in the pipe system by using these models. Residual regression analysis was used to get a reasonable range of the threshold values that allows the chloramine residual to efficiently inhibit bacteria growth in the Shanghai DWDS; the threshold values should be between 0.45 and 0.5 mg/L in pipe water and 0.2 and 0.25 mg/L in tap water. The low residual chloramine value (0.05 mg/L) of the Chinese drinking water quality standard may pose a potential health risk for microorganisms that should be improved. Disinfection by-products (DBPs) were detected, but no health risk was identified.

  16. Assessing microbiological water quality in drinking water distribution systems with disinfectant residual using flow cytometry.

    Science.gov (United States)

    Gillespie, Simon; Lipphaus, Patrick; Green, James; Parsons, Simon; Weir, Paul; Juskowiak, Kes; Jefferson, Bruce; Jarvis, Peter; Nocker, Andreas

    2014-11-15

    Flow cytometry (FCM) as a diagnostic tool for enumeration and characterization of microorganisms is rapidly gaining popularity and is increasingly applied in the water industry. In this study we applied the method to obtain a better understanding of total and intact cell concentrations in three different drinking water distribution systems (one using chlorine and two using chloramines as secondary disinfectants). Chloramine tended to result in lower proportions of intact cells than chlorine over a wider residual range, in agreement with existing knowledge that chloramine suppresses regrowth more efficiently. For chlorinated systems, free chlorine concentrations above 0.5 mg L(-1) were found to be associated with relatively low proportions of intact cells, whereas lower disinfectant levels could result in substantially higher percentages of intact cells. The threshold for chlorinated systems is in good agreement with guidelines from the World Health Organization. The fact that the vast majority of samples failing the regulatory coliform standard also showed elevated proportions of intact cells suggests that this parameter might be useful for evaluating risk of failure. Another interesting parameter for judging the microbiological status of water, the biological regrowth potential, greatly varied among different finished waters providing potential help for investment decisions. For its measurement, a simple method was introduced that can easily be performed by water utilities with FCM capability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Solar water disinfection (SODIS): A review from bench-top to roof-top

    CSIR Research Space (South Africa)

    McGuigan, KG

    2012-10-01

    Full Text Available Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2 L PET beverage bottles) which are then exposed to the sun. Exposure times vary...

  18. Bactericidal efficacy of silver impregnated activated carbon for disinfection of water

    International Nuclear Information System (INIS)

    Sultana, L.; Khan, F.A.; Usmani, T.H.

    2009-01-01

    When highly contaminated water was passed through two types of silver coated activated carbon and their mixtures with sand, the former was found to be far better medium for disinfection of water, with bactericidal efficacy of about 2.5 times that of the latter. (author)

  19. Ultraviolet disinfection of treated municipal wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Vander Laan, H; Cairns, B

    1993-12-31

    A wastewater disinfection system developed by a Canadian company, Trojan Technologies Inc., was discussed. Disinfection for pathogen reduction prior to discharge of treated municipal wastewater back into rivers and lakes has been either ignored or treated by the use of chemicals. In 1979 the first pilot ultraviolet (UV) wastewater disinfection system was established. Since then, over 500 municipal UV installations have been commissioned. The largest installation can process 212 million gallons of water per day. The advantages of UV as a disinfectant are: (1) It is more effective than chlorine. (2) There are no mutagenic/carcinogenic byproducts formed with UV. (3) No toxic chemical residuals are discharged. (4) UV is safe to both the operators and the public. (5) It is cost effective. Europe has not been as active in wastewater disinfection as has North America. One result of the absence of wastewater disinfection in Europe is that the Rhine River, for example, carries 50 million salmonella per second. Disinfection of wastewater effluents is, of course, indispensable in protecting our drinking water supply. 2 figs.

  20. Solar water disinfection (SODIS): A review from bench-top to roof-top

    Energy Technology Data Exchange (ETDEWEB)

    McGuigan, Kevin G., E-mail: kmcguigan@rcsi.ie [Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Conroy, Ronan M. [Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Mosler, Hans-Joachim [EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133: CH-8600 Duebendorf (Switzerland); Preez, Martella du; Ubomba-Jaswa, Eunice [CSIR, Natural Resources and the Environment, Pretoria, Gauteng (South Africa); Fernandez-Ibanez, Pilar [Plataforma Solar de Almeria - CIEMAT, P.O. Box 22, 07200 Tabernas, Almeria (Spain)

    2012-10-15

    Graphical abstract: . Water being treated by solar disinfection outside a primary school classroom in Southern Uganda. Students fill their bottles at home and expose them to the sun while they are at school. Highlights: Black-Right-Pointing-Pointer A thorough review of current state of play of solar water disinfection. Black-Right-Pointing-Pointer An examination of both laboratory and field studies. Black-Right-Pointing-Pointer Description of the economic and behaviour change aspects of this technology. - Abstract: Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2 L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to 48 h depending on the intensity of sunlight and sensitivity of the pathogens. Its germicidal effect is based on the combined effect of thermal heating of solar light and UV radiation. It has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity including cholera. Since 1980 much research has been carried out to investigate the mechanisms of solar radiation induced cell death in water and possible enhancement technologies to make it faster and safer. Since SODIS is simple to use and inexpensive, the method has spread throughout the developing world and is in daily use in more than 50 countries in Asia, Latin America, and Africa. More than 5 million people disinfect their drinking water with the solar disinfection (SODIS) technique. This review attempts to revise all relevant knowledge about solar disinfection from microbiological issues, laboratory research, solar testing, up to and including real application studies, limitations, factors influencing adoption of the technique and health impact.

  1. Solar water disinfection (SODIS): A review from bench-top to roof-top

    International Nuclear Information System (INIS)

    McGuigan, Kevin G.; Conroy, Ronán M.; Mosler, Hans-Joachim; Preez, Martella du; Ubomba-Jaswa, Eunice; Fernandez-Ibañez, Pilar

    2012-01-01

    Graphical abstract: . Water being treated by solar disinfection outside a primary school classroom in Southern Uganda. Students fill their bottles at home and expose them to the sun while they are at school. Highlights: ► A thorough review of current state of play of solar water disinfection. ► An examination of both laboratory and field studies. ► Description of the economic and behaviour change aspects of this technology. - Abstract: Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2 L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to 48 h depending on the intensity of sunlight and sensitivity of the pathogens. Its germicidal effect is based on the combined effect of thermal heating of solar light and UV radiation. It has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity including cholera. Since 1980 much research has been carried out to investigate the mechanisms of solar radiation induced cell death in water and possible enhancement technologies to make it faster and safer. Since SODIS is simple to use and inexpensive, the method has spread throughout the developing world and is in daily use in more than 50 countries in Asia, Latin America, and Africa. More than 5 million people disinfect their drinking water with the solar disinfection (SODIS) technique. This review attempts to revise all relevant knowledge about solar disinfection from microbiological issues, laboratory research, solar testing, up to and including real application studies, limitations, factors influencing adoption of the technique and health impact.

  2. Disinfection of Water and Wastewater Using Gamma Irradiation in Isfahan Water and Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2011-01-01

    Full Text Available To investigate the effect of gamma irradiation on the disinfection of water and wastewater, water samples were collected from raw and filtered water and wastewater samples were taken from the effluent of the secondary sedimentation, polished effluent (1-day retention time, and also from filtered (rapid sand filter effluent. The samples were irradiated with gamma collimated beam in a batch system using a Co-60 therapeutic gamma radiation machine with a radioactive source emission rate of 405.38CGy/min at different doses of 20-160 Gy and 80-240 Gy, respectively. The samples were analyzed before and after irradiation for total and fecal coliforms. It was observed that nearly 100% reduction was achieved in total and fecal coliforms in water samples treated with a dose of 160 Gy. Depending on effluent quality, disinfection efficiencies achieved using 240 Gy gamma irradiation for inactivation of total coliforms in wastewater samples were 83, 64, and 56 percent for filtered, clarified, and secondary effluents, respectively. The same values were nearly 81, 58, and 46 percent, respectively, for inactivation of fecal coliforms. At lower doses of 120-240Gy, the coliform bacteria were successfully inactivated. It was concluded that a linear correlation holds between the dose delivered and the inactivation of microorganisms, so that inactivation increases with increasing irradiation time.

  3. Evaluation of an Innovative Approach to Validation of Ultraviolet (UV) Reactors for Disinfection in Drinking Water Systems

    Science.gov (United States)

    UV disinfection is an effective process for inactivating many microbial pathogens found in source waters with the potential as stand-alone treatment or in combination with other disinfectants. For surface and groundwater sourced drinking water applications, the U.S. Environmental...

  4. Disinfection of drain water of tomato by means of UV radiation and slow sand filtration in real greenhouse circumstances.

    Science.gov (United States)

    De Rocker, E; Goen, K; Van Poucke, K

    2006-01-01

    The efficiency of the disinfection of drain water was tested at 11 greenhouses with tomato cultivation on rockwool substrate in Flanders (Belgium) by means of mycological analysis. In addition the presence of phytopathogenic fungi in the drain water was analysed at 2 supplementary greenhouses with recirculation without disinfection.

  5. Ozonization effects on trihalo methane formation during the disinfection of drinking water with chlorine; Efectos de la ozonizacion sobre la formacion de trihalometanos durante la desinfeccion final del agua potable con cloro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Vidal, F. J.; Perez Serrano, A.; Orozco Barrentxea, C.; Sanllorente Santamaria, M. C.; Ibeas Reoyo, M. V.

    2001-07-01

    One of the main aspects in the control of drinking water treatment is the formation of disinfection by-products (DBP), some of the most important are the trihalomethanes (THM). The use of ozone as primary disinfectant in drinking water treatment plants reduces noticeably the amount of THM generated after the chlorination at the end of the treatment. The aim of this work is to study the main factors influencing the ozone effect in this process: the delay between the time of ozonization and chlorination, the applied ozone dose and the presence of bromide ion ind the raw water. These factors have been studied on natural waters (Uzquiza Reservoir-Burgos) and on synthetic waters (fulvic and humic acids extracted from the mentioned reservoir). (Author) 36 refs.

  6. Impact of Nitrification on the Formation of N-Nitrosamines and Halogenated Disinfection Byproducts within Distribution System Storage Facilities.

    Science.gov (United States)

    Zeng, Teng; Mitch, William A

    2016-03-15

    Distribution system storage facilities are a critical, yet often overlooked, component of the urban water infrastructure. This study showed elevated concentrations of N-nitrosodimethylamine (NDMA), total N-nitrosamines (TONO), regulated trihalomethanes (THMs) and haloacetic acids (HAAs), 1,1-dichloropropanone (1,1-DCP), trichloroacetaldehyde (TCAL), haloacetonitriles (HANs), and haloacetamides (HAMs) in waters with ongoing nitrification as compared to non-nitrifying waters in storage facilities within five different chloraminated drinking water distribution systems. The concentrations of NDMA, TONO, HANs, and HAMs in the nitrifying waters further increased upon application of simulated distribution system chloramination. The addition of a nitrifying biofilm sample collected from a nitrifying facility to its non-nitrifying influent water led to increases in N-nitrosamine and halogenated DBP formation, suggesting the release of precursors from nitrifying biofilms. Periodic treatment of two nitrifying facilities with breakpoint chlorination (BPC) temporarily suppressed nitrification and reduced precursor levels for N-nitrosamines, HANs, and HAMs, as reflected by lower concentrations of these DBPs measured after re-establishment of a chloramine residual within the facilities than prior to the BPC treatment. However, BPC promoted the formation of halogenated DBPs while a free chlorine residual was maintained. Strategies that minimize application of free chlorine while preventing nitrification are needed to control DBP precursor release in storage facilities.

  7. Limnoithona sinensis as refuge for bacteria: protection from UV radiation and chlorine disinfection in drinking water treatment.

    Science.gov (United States)

    Lin, Tao; Cai, Bo; Chen, Wei

    2014-11-01

    In this study, we tested the potential of Limnoithona sinensis to provide its attached bacteria refuge against disinfection. The experimental results indicated that in water devoid of zooplankton, both UV radiation and chlorine disinfection significantly decreased the viability of free-living bacteria. In the presence of L. sinensis, however, the attached bacteria could survive and rapidly recover from disinfection. This demonstrated that L. sinensis provided protection from external damage to various aquatic bacteria that were attached to its body. The surviving bacteria remained on L. sinensis after disinfection exposure, which enabled a rapid increase in the bacterial population followed by their subsequent release into the surrounding water. Compared with UV radiation, chlorine disinfection was more effective in terms of inactivating attached bacteria. Both UV radiation and chlorine disinfection had little effect in terms of preventing the spread of undesirable bacteria, due to the incomplete inactivation of the bacteria associated with L. sinensis.

  8. Iodine Disinfection in the Use of Individual Water Purification Devices

    Science.gov (United States)

    2006-03-01

    Effect of Resin Disinfectants-I3 and –I5 on Giardia muris and Giardia lamblia. Applied and Environmental Microbiology, 46(5), 965-969. 24. AWWA... Giardia or Cryptosporidium). Iodine-using IWPDs meeting these standards are considered effective against disease causing bacteria, viruses, and...CT = 65 mg-min/L) for a 2-log inactivation of E. histolytica cysts (references 9 and 10). Another study using Giardia cysts showed CT’s up to 3

  9. From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectanta and Precursors and Implications for Exposure and Toxicity

    Science.gov (United States)

    Introduction The current study investigated the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, samples across the complete water pathway (untr...

  10. Solar disinfection: an approach for low-cost household water treatment technology in Southwestern Ethiopia.

    Science.gov (United States)

    Dessie, Awrajaw; Alemayehu, Esayas; Mekonen, Seblework; Legesse, Worku; Kloos, Helmut; Ambelu, Argaw

    2014-01-10

    Disinfection of contaminated water using solar radiation (SODIS) is known to inactivate bacteria. Its inactivation efficiency depends on local conditions where the disinfection is made. This study was aiming to test the efficiency of solar disinfection using different water parameters as low-cost household water treatment technology. Inactivation of microbes was tested using fecal coliform as test organism. The SODIS experiment was carried out at turbidity 2NTU, pH 7, and various water temperature (38.1°C, 41.8°C, 45.6°Cand 51.1°C) and solar intensities, using clear and black plastic bottles filled to different depths. The results show that the rate of microbial inactivation in relation to depth of water, turbidity, container type, intensity of light and color of container was statistically significant (p solar disinfection. By adjusting the parameters, complete and irreversible fecal coliform inactivation was achieved within an exposure time of less than four hours in the areas where the solar irradiance is about 3.99 kW/m2 and above. Our results indicate that application of SODIS could play a significant role in the provision of safe water in rural communities of developing countries where there is ample sunshine, specifically in sub-Saharan African countries.

  11. The performance and applicability study of a fixed photovoltaic-solar water disinfection system

    International Nuclear Information System (INIS)

    Jin, Yanchao; Wang, Yiping; Huang, Qunwu; Zhu, Li; Cui, Yong; Cui, Lingyun

    2016-01-01

    Highlights: • A fixed photovoltaic-SODIS (solar water disinfection) system was constructed. • The system could generate electricity and produce clean water simultaneously. • The daily solar generated electricity was much more than the system consumption. • The system can be used for about 90% of whole year in Lhasa and Chennai. • Temperature enhanced the SODIS process for about 60% days of whole year in Chennai. - Abstract: The objective of the study is to construct and evaluate a fixed PV (photovoltaic) cell integrated with SODIS (solar water disinfection) system to treat drinking water and generate electricity under different climate through experimental and simulation methods. The photovoltaic and disinfection performances of the hybrid system were studied by the disinfection of Escherichia coli. The applicability of the system in Lhasa and Chennai was evaluated by analyzing the daily radiation and predicting the daily water temperature and the system electricity output. The results confirm that the temperature would dramatically enhance the SODIS process and shorten the disinfection time, when the water temperature was above 45 °C. The PV cell in the hybrid system could work under low temperature because of the water layer and the generated electricity was much more than the system consumption. The simulation results show that the days with maximum water temperature above 45 °C were more than 60% of whole year in Chennai. The generated electricity of the hybrid system was 49682.3 W h and 45615.9 W h a year in Lhasa and Chennai respectively. It was sufficient to drive the system of whole year. The number of days which realized drinking water treatment was 324 days in Lhasa and 315 days in Chennai a year.

  12. Point-of-use water disinfection using ultraviolet and visible light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lui, Gough Yumu, E-mail: gough@student.unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); School of Photovoltaics and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Roser, David, E-mail: djroser@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Corkish, Richard, E-mail: r.corkish@unsw.edu.au [School of Photovoltaics and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Ashbolt, Nicholas J., E-mail: ashbolt@ualberta.ca [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); School of Public Health, South Academic Building, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada); Stuetz, Richard, E-mail: r.stuetz@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-05-15

    Improvements in point-of-use (POU) drinking water disinfection technologies for remote and regional communities are urgently needed. Conceptually, UV-C light-emitting diodes (LEDs) overcome many drawbacks of low-pressure mercury tube based UV devices, and UV-A or visible light LEDs also show potential. To realistically evaluate the promise of LED disinfection, our study assessed the performance of a model 1.3 L reactor, similar in size to solar disinfection bottles. In all, 12 different commercial or semi-commercial LED arrays (270–740 nm) were compared for their ability to inactivate Escherichia coli K12 ATCC W3110 and Enterococcus faecalis ATCC 19433 over 6 h. Five log{sub 10} and greater reductions were consistently achieved using the 270, 365, 385 and 405 nm arrays. The output of the 310 nm array was insufficient for useful disinfection while 430 and 455 nm performance was marginal (≈ 4.2 and 2.3-log{sub 10}s E. coli and E. faecalis over the 6 h). No significant disinfection was observed with the 525, 590, 623, 660 and 740 nm arrays. Delays in log-phase inactivation of E. coli were observed, particularly with UV-A wavelengths. The radiation doses required for > 3-log{sub 10} reduction of E. coli and E. faecalis differed by 10 fold at 270 nm but only 1.5–2.5 fold at 365–455 nm. Action spectra, consistent with the literature, were observed with both indicators. The design process revealed cost and technical constraints pertaining to LED electrical efficiency, availability and lifetime. We concluded that POU LED disinfection using existing LED technology is already technically possible. UV-C LEDs offer speed and energy demand advantages, while UV-A/violet units are safer. Both approaches still require further costing and engineering development. Our study provides data needed for such work. - Highlights: • Disinfection of E. coli and E. faecalis achieved with 270 and 365–455 nm LEDs • No significant disinfection was found with 310 and > 455 nm LEDs

  13. Point-of-use water disinfection using ultraviolet and visible light-emitting diodes

    International Nuclear Information System (INIS)

    Lui, Gough Yumu; Roser, David; Corkish, Richard; Ashbolt, Nicholas J.; Stuetz, Richard

    2016-01-01

    Improvements in point-of-use (POU) drinking water disinfection technologies for remote and regional communities are urgently needed. Conceptually, UV-C light-emitting diodes (LEDs) overcome many drawbacks of low-pressure mercury tube based UV devices, and UV-A or visible light LEDs also show potential. To realistically evaluate the promise of LED disinfection, our study assessed the performance of a model 1.3 L reactor, similar in size to solar disinfection bottles. In all, 12 different commercial or semi-commercial LED arrays (270–740 nm) were compared for their ability to inactivate Escherichia coli K12 ATCC W3110 and Enterococcus faecalis ATCC 19433 over 6 h. Five log_1_0 and greater reductions were consistently achieved using the 270, 365, 385 and 405 nm arrays. The output of the 310 nm array was insufficient for useful disinfection while 430 and 455 nm performance was marginal (≈ 4.2 and 2.3-log_1_0s E. coli and E. faecalis over the 6 h). No significant disinfection was observed with the 525, 590, 623, 660 and 740 nm arrays. Delays in log-phase inactivation of E. coli were observed, particularly with UV-A wavelengths. The radiation doses required for > 3-log_1_0 reduction of E. coli and E. faecalis differed by 10 fold at 270 nm but only 1.5–2.5 fold at 365–455 nm. Action spectra, consistent with the literature, were observed with both indicators. The design process revealed cost and technical constraints pertaining to LED electrical efficiency, availability and lifetime. We concluded that POU LED disinfection using existing LED technology is already technically possible. UV-C LEDs offer speed and energy demand advantages, while UV-A/violet units are safer. Both approaches still require further costing and engineering development. Our study provides data needed for such work. - Highlights: • Disinfection of E. coli and E. faecalis achieved with 270 and 365–455 nm LEDs • No significant disinfection was found with 310 and > 455 nm LEDs. • UV

  14. 75 FR 75761 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters

    Science.gov (United States)

    2010-12-06

    ... from high levels of nitrates, possible formation of disinfection byproducts in drinking water, and... treat drinking water react with organic carbon (from the algae in source waters). Some disinfection... nitrate limit of 10 mg/L and nitrite limit of 1 mg/L for the protection of human health in drinking water...

  15. Combined effects of coagulation and adsorption on ultrafiltration membrane fouling control and subsequent disinfection in drinking water treatment.

    Science.gov (United States)

    Xing, Jiajian; Liang, Heng; Cheng, Xiaoxiang; Yang, Haiyan; Xu, Daliang; Gan, Zhendong; Luo, Xinsheng; Zhu, Xuewu; Li, Guibai

    2018-06-02

    This study investigated the combined effects of coagulation and powdered activated carbon (PAC) adsorption on ultrafiltration (UF) membrane fouling control and subsequent disinfection efficiency through filtration performance, dissolved organic carbon (DOC) removal, fluorescence excitation-emission matrix (EEM) spectroscopy, and disinfectant curve. The fouling behavior of UF membrane was comprehensively analyzed especially in terms of pollutant removal and fouling reversibility to understand the mechanism of fouling accumulation and disinfectant dose reduction. Pre-coagulation with or without adsorption both achieved remarkable effect of fouling mitigation and disinfection dose reduction. The two pretreatments were effective in total fouling control and pre-coagulation combined with PAC adsorption even decreased hydraulically irreversible fouling notably. Besides, pre-coagulation decreased residual disinfectant decline due to the removal of hydrophobic components of natural organic matters (NOM). Pre-coagulation combined with adsorption had a synergistic effect on further disinfectant decline rate reduction and decreased total disinfectant consumption due to additional removal of hydrophilic NOM by PAC adsorption. The disinfectant demand was further reduced after membrane. These results show that membrane fouling and disinfectant dose can be reduced in UF coupled with pretreatment, which could lead to the avoidance of excessive operation cost disinfectant dose for drinking water supply.

  16. Efficacy of various chemical disinfectants on biofilms formed in spacecraft potable water system components.

    Science.gov (United States)

    Wong, Wing C; Dudinsky, Lynn A; Garcia, Veronica M; Ott, Charlie M; Castro, Victoria A

    2010-07-01

    As the provision of potable water is critical for successful habitation of the International Space Station (ISS), life support systems were installed in December 2008 to recycle both humidity from the atmosphere and urine to conserve available water in the Station. In-flight pre-consumption testing from the dispensing needle at the Potable Water Dispenser (PWD) indicated that bacterial concentrations exceeded the current ISS specifications of 50 colony-forming units (CFU) ml(-1). Subsequent investigations revealed that a corrugated stainless steel flex hose upstream of the dispensing needle in the PWD was filled with nonsterile water and left at room temperature for more than 1 month before launch. To simulate biofilm formation that was suspected in the flight system, sterile flex hoses were seeded with a consortium of bacterial isolates previously recovered from other ISS water systems, including Ralstonia pickettii, Burkholderia multivorans, Caulobacter vibrioides, and Cupriavidus pauculus. After incubation for 5 days, the hoses were challenged with various chemical disinfectants including hydrogen peroxide (H2O2), colloidal silver, and buffered pH solutions to determine the ability of the disinfectants to decrease and maintain bacterial concentrations below ISS specifications. The disinfection efficacy over time was measured by collecting daily heterotrophic plate counts after exposure to the disinfectants. A single flush with either 6% H2O2 solution or a mixture of 3% H2O2 and 400 ppb colloidal silver effectively reduced the bacterial concentrations to <1 CFU ml(-1) for a period of up to 3 months.

  17. Rapid water disinfection using vertically aligned MoS_2 nanofilms and visible light

    International Nuclear Information System (INIS)

    Liu, Chong; Kong, Desheng; Hsu, Po-Chun; Yuan, Hongtao; Lee, Hyun-Wook

    2016-01-01

    Here, solar energy is readily available in most climates and can be used for water purification. However, solar disinfection of drinking water (SODIS) mostly relies on ultraviolet light, which represents only 4% of total solar energy, and this leads to slow treatment speed. The development of new materials that can harvest visible light for water disinfection, and speed up solar water purification, is therefore highly desirable. Here, we show that few-layered vertically aligned MoS_2 (FLV-MoS_2) films can be used to harvest the whole spectrum of visible light (~ 50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS_2 was increased from 1.3 eV to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS_2 to generate reactive oxygen species (ROS) for bacterial inactivation in water. The FLV-MoS_2 showed ~15 times better log inactivation efficiency of indicator bacteria compared to bulk MoS_2, and much faster inactivation of bacteria under both visible light and sunlight illumination compared to widely used TiO_2. Moreover, by using a 5 nm copper film on top of the FLV-MoS_2 as a catalyst to facilitate electron-hole pair separation and promote the generation of ROS, the disinfection rate was further increased 6 fold. With our approach, we achieved water disinfection of >99.999% inactivation of bacteria in 20 minutes with a small amount of material (1.6 mg/L) under simulated visible light.

  18. Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light

    International Nuclear Information System (INIS)

    Liu, Chong; Kong, Desheng; Hsu, Po-Chun; Yuan, Hongtao; Lee, Hyun-Wook

    2016-01-01

    In most climates, solar energy is readily available and can be used for water purification. But, solar disinfection of drinking water mostly relies on ultraviolet light, which represents only 4% of the total solar energy, and this leads to a slow treatment speed. Therefore, the development of new materials that can harvest visible light for water disinfection, and so speed up solar water purification, is highly desirable. Here we show that few-layered vertically aligned MoS_2 (FLV-MoS_2) films can be used to harvest the whole spectrum of visible light (~50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS_2 was increased from 1.3 to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS_2 to generate reactive oxygen species (ROS) for bacterial inactivation in the water. The FLV-MoS_2 showed a ~15 times better log inactivation efficiency of the indicator bacteria compared with that of bulk MoS_2, and a much faster inactivation of bacteria under both visible light and sunlight illumination compared with the widely used TiO_2. Moreover, by using a 5 nm copper film on top of the FLV-MoS_2 as a catalyst to facilitate electron–hole pair separation and promote the generation of ROS, the disinfection rate was increased a further sixfold. Here, we achieved water disinfection of >99.999% inactivation of bacteria in 20 min with a small amount of material (1.6 mg l–1) under simulated visible light.

  19. Mine water treatment with yellowcake by-production

    International Nuclear Information System (INIS)

    Csicsak, J.; Csoevari, M.; Eberfalvy, J.; Lendvai, Zs.

    2002-01-01

    Mining and milling of uranium ore in Hungary was terminated at the end of 1997. From that time rehabilitation works have been carrying out, which include manly the relocation of different solid wastes, such as waste rocks, heap leached residues, demolishing of former industrial buildings, clean up contaminated sites. Overall rehabilitation of the tailings ponds has also started. At first step the ground water restoration system is under construction, aiming at protecting the drinking water aquifer situated in the immediate vicinity of the tailings ponds. Former mining activity has been carried out also in the vicinity of the drinking water catchment area, for protection of that is compulsory to maintain appropriate depression in the mine in question. This means that mine water has to be pumped out continuously and because of the elevated uranium concentration in mine water, the water has to be treated. Thus the water quality protection is connected with uranium removal from the mine water. Mine water treatment process developed is based on anion-exchange process and removal of the uranium from the eluates with hydrogen peroxide. (author)

  20. Batch Test Screening of Industrial Product/Byproduct Filter Materials for Agricultural Drainage Water Treatment

    Directory of Open Access Journals (Sweden)

    Barry J. Allred

    2017-10-01

    Full Text Available Filter treatment may be a viable means for removing the nitrate (NO3−, phosphate (PO43−, and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water treatment potential was conducted on 58 industrial product/byproduct filter materials grouped into six categories: (1 high carbon content media; (2 high iron content media; (3 high aluminum content media; (4 surfactant modified clay/zeolite; (5 coal combustion residuals; and (6 spent foundry sands. Based on a percent contaminant removal criteria of 75% or greater, seven industrial products/byproducts were found to meet this standard for NO3− alone, 44 met this standard for PO43−, and 25 met this standard for the chlorinated triazine herbicide, atrazine. Using a 50% or greater contaminant removal criteria, five of the industrial product/byproduct filter materials exhibited potential for removing NO3−, PO43−, and atrazine together; eight showed capability for combined NO3− and PO43− removal; 21 showed capability for combined PO43− and atrazine removal; and nine showed capability for combined NO3− and atrazine removal. The results of this study delineated some potential industrial product/byproduct filter materials for drainage water treatment; however, a complete feasibility evaluation for drainage water treatment of any of these filter materials will require much more extensive testing.

  1. Can water disinfection prevent the transmission of infectious koi herpesvirus to naïve carp? - a case report.

    Science.gov (United States)

    Bergmann, S M; Monro, E S; Kempter, J

    2017-07-01

    Hygienic measures such as disinfection are important tools for the maintenance of fish health in aquaculture. While little information is available on the disinfection of water intended for fish containment, Huwa-San ® , a disinfectant used in food and water industries, was used for daily treatment at concentrations of approximately 60 ppm over a total period of 3 months (experiment 1) with a 3-week treatment-free interval after 2 months (experiment 2). During this period, koi herpesvirus (KHV) was added to the water of two aquaria, one used as a normal contact control, the other one receiving daily water disinfectant treatments that prevented KHV infection of carp. In the second experiment, Huwa-San ® treatment was interrupted and KHV infection was prevalent. However, when naïve fish were introduced to the same aquarium after re-application of disinfectant, KHV could not be detected in those naïve fish. Whilst KHV could not be detected in samples where disinfectant had been applied, it was present in samples of naïve fish cohabiting with infection contact control animals which had undergone no disinfectant treatment over experiments 1 and 2. The results presented here show that water treatment with a disinfectant may prevent transmission of infectious KHV to naïve carp cohabited with infected carp. © 2016 John Wiley & Sons Ltd.

  2. Disinfection and physical and chemical changes in waste waters, sludge and agricultural wastes

    International Nuclear Information System (INIS)

    Groneman, A.F.; Oosterheert, W.F.

    1980-01-01

    It is of interest for agriculture to consider recycling scenarios that use undigested sludges as they contain higher concentrations of nitrogen, phosphorus and organic matter than digested sludges. Also from the point of view of waste water management, this approach is of interest because it reduces the time and number of treatments of sludges, thus resulting in technological and economic advantages. However, the utilization of this type of sludge in agriculture is restricted by the presence of human pathogens. Therefore studies concerning the disinfection efficiency of gamma irradiation in undigested sludge at pilot plant level were performed and results compared with the disinfection efficiency of this radiation treatment in digested sludge. (Auth.)

  3. Suitability of electrolyzed oxidizing water for the disinfection of hard surfaces and equipment in radiology.

    Science.gov (United States)

    Pintaric, Robert; Matela, Joze; Pintaric, Stefan

    2015-01-01

    Hospitals are faced with increasingly resistant strains of micro-organisms. When it comes to disinfection, individual parts of electronic equipment of angiology diagnostics such as patient couches of computer tomography (CT) and magnetic resonance imaging (MRI) scanners prove to be very hard to disinfect. Disinfectants of choice are therefore expected to possess properties such as rapid, residue-free action without any damaging effect on the sensitive electronic equipment. This paper discusses the use of the neutral electrolyzed oxidizing water (EOW) as a biocide for the disinfection of diagnostic rooms and equipment. The CT and MRI rooms were aerosolized with EOW using aerosolization device. The presence of micro-organisms before and after the aerosolization was recorded with the help of sedimentation and cyclone air sampling. Total body count (TBC) was evaluated in absolute and log values. The number of micro-organisms in hospital rooms was low as expected. Nevertheless, a possible TBC reduction between 78.99-92.50% or 50.50-70.60% in log values was recorded. The research has shown that the use of EOW for the air and hard surface disinfection can considerably reduce the presence of micro-organisms and consequently the possibility of hospital infections. It has also demonstrated that the sedimentation procedure is insufficient for the TBC determination. The use of Biocide aerosolization proved to be efficient and safe in all applied ways. Also, no eventual damage to exposed devices or staff was recorded.

  4. Utilization of ultraviolet radiation of cold hollow cathode discharge plasma for water disinfection

    International Nuclear Information System (INIS)

    Soloshenko, I.O.; Bazhenov, V.Yu.; Khomych, V.O.; Tsiolko, V.V.; Potapchenko, N.G.; Goncharuk, V.V.

    2006-01-01

    We study the possibility to use the ultraviolet radiation of a hollow cathode discharge plasma for water disinfection. We have performed the comparative experiments on the influence of ultraviolet radiation of the mentioned discharge plasma, as well as that of a standard low pressure mercury lamp

  5. Non-PRASA Drinking Water Research on UV Disinfection in Puerto Rico

    Science.gov (United States)

    The U.S. EPA and InterAmerican University of San German worked with water treatment operators from Patillas, Puerto Rico on the installation, training and testing of pretreatment/UV disinfection systems in the communities of La Sofia and Apeadero. This presentation provides path...

  6. Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

    Science.gov (United States)

    Rodriquez, Branelle; Anderson, Molly; Adams, Niklas; Vega, Leticia; Botkin, Douglas

    2013-01-01

    Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant for the International Space Station (ISS) is iodine; however, with the end of the Space Shuttle Program, there is a need to develop redundant biocide systems that do not require regular up-mass dependencies. Throughout the course of a year, four different electrochemical systems were investigated as a possible biocide for potable water on the ISS. Research has indicated that a wide variability exists with regards to efficacy in both concentration and exposure time of these disinfectants; therefore, baseline efficacy values were established. This paper describes a series of tests performed to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria. Results of the testing determined whether these electrochemical disinfection systems are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on the ISS.

  7. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, NorEddine; Ait-Djoudi, Fariza; Naceur, Wahib Mohamed; Soukane, Sofiane

    2015-01-01

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body

  8. Evaluation of Filtration and UV Disinfection for Inactivation of Viruses in Non-Community Water Systems in Minnesota

    Science.gov (United States)

    This study evaluated filtration and disinfection processes for removal and inactivation of pathogens in non-community water systems (NCWS) in two surface water supplies. Pretreatment systems included 1) pressure sand filtration, and 2) granular activated carbon adsorption, and 3...

  9. The Use of Genetic Algorithms in UV Disinfection of Drinking Water

    OpenAIRE

    Hugo Zaldaña; Emerson Castañeda

    2015-01-01

    In order to have drinking water, some countries have to use chlorine. It is use cause is effective and it’s cheap. An alternative to this process is the UV disinfection of drinking water. Most of the devices in the market use UV bulbs or mercury lamps. The UV LED, which is cheaper and smaller, allows creating new smaller devices. The main contribution of this paper is the use of Genetic Algorithms to help design a drinking water device with UV LEDs.

  10. Efficacy of Various Chemical Disinfectants on Biofilms Formed in Spacecraft Potable Water System Component

    Science.gov (United States)

    Wong, Willy; Garcia, Veronica; Castro, Victoria; Ott, Mark; Duane

    2009-01-01

    As the provision of potable water is critical for successful habitation of the International Space Station (ISS), life support systems were installed in December 2008 to recycle both humidity from the atmosphere and urine to conserve available water in the vehicle. Pre-consumption testing from the dispensing needle at the Potable Water Dispenser (PWD) indicated that bacterial concentrations exceeded the current ISS specifications of 50 colony forming units (CFU) per ml. Subsequent investigations revealed that a corrugated stainless steel flex hose upstream of the dispensing needle in the PWD was filled with non-sterile water and left at room temperature for over one month before launch. To simulate biofilm formation that was suspected in the flight system, sterile flex hoses were seeded with a consortium of bacterial isolates previously recovered from other ISS water systems, which included Ralstonia pickettii, Burkholderia multivorans, Caulobacter vibrioides., and Cupriavidus pauculus. After 5 days of incubation, these hoses were challenged with various chemical disinfectants including hydrogen peroxide, colloidal silver, and buffered pH solutions to determine the ability of the disinfectants to decrease and maintain bacterial concentrations below ISS specifications. Disinfection efficacy over time was measured by collecting daily heterotrophic plate counts following exposure to the disinfectants. A single flush with either 6% hydrogen peroxide solution or a mixture of 3% hydrogen peroxide and 400 ppb colloidal silver effectively reduced the bacterial concentrations to less than 1 CFU/ml for a period of up to 2 months. Testing results indicated that hydrogen peroxide and mixtures of hydrogen peroxide and colloidal silver have tremendous potential as alternative disinfectants for ISS water systems.

  11. Water extracts from winery by-products as tobacco defense inducers.

    Science.gov (United States)

    Benouaret, Razik; Goujon, Eric; Trivella, Aurélien; Richard, Claire; Ledoigt, Gérard; Joubert, Jean-Marie; Mery-Bernardon, Aude; Goupil, Pascale

    2014-10-01

    Water extracts from winery by-products exhibited significant plant defense inducer properties. Experiments were conducted on three marc extracts containing various amounts of polyphenols and anthocyanins. Infiltration of red, white and seed grape marc extracts into tobacco leaves induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining. The infiltration zones and the surrounding areas revealed accumulation of autofluorescent compounds under UV light. Leaf infiltration of the three winery by-product extracts induced defense gene expression. The antimicrobial PR1, β-1,3-glucanase PR2, and chitinase PR3 target genes were upregulated locally in tobacco plants following grape marc extract treatments. The osmotin PR5 transcripts accumulated as well in red marc extract treated-tobacco leaves. Overall, the winery by-product extracts elicited an array of plant defense responses making the grape residues a potential use of high value compounds.

  12. The reactivity of natural organic matter to disinfection by-products formation and its relation to specific ultraviolet absorbance.

    Science.gov (United States)

    Kitis, M; Karanfil, T; Kilduff, J E; Wigton, A

    2001-01-01

    Five natural waters with a broad range of DOC concentrations were fractionated using various coal- and wood-based granular activated carbons (GAC) and alum coagulation. Adsorption and alum coagulation fractionated NOM solutions by preferentially removing components having high specific ultraviolet absorbance (SUVA). UV absorbing fractions of NOM were found to be the major contributors to DBP formation. SUVA appears to be an accurate predictor of reactivity with chlorine in terms of DBP yield; however, it was also found that low-SUVA components of NOM have higher bromine incorporation. SUVA has promise as a parameter for on-line monitoring and control of DBP formation in practical applications; however, the effects of bromide concentration may also need to be considered. Understanding how reactivity is correlated to SUVA may allow utilities to optimize the degree of treatment required to comply with DBP regulations. The reactive components that require removal, and the degree of treatment necessary to accomplish this removal, may be directly obtained from the relationship between SUVA removal and the degree of treatment (e.g., alum dose).

  13. Performance analysis of a solar photovoltaic hybrid system for electricity generation and simultaneous water disinfection of wild bacteria strains

    International Nuclear Information System (INIS)

    Pichel, N.; Vivar, M.; Fuentes, M.

    2016-01-01

    Highlights: • A new hybrid solar water disinfection and energy generation system was designed and tested. • SOLWAT comprises a water disinfection reactor and a PV module fully integrated into a single unit. • Natural water with wild strains of E. coli, Enterococcus spp. and C. perfringens were studied. • The water disinfection reactor located above the PV module did not affect the final energy output. • The SOLWAT disinfection results were always higher than conventional PET bottles. - Abstract: A hybrid solar water disinfection and energy generation system for meeting the needs of safe drinking water and electricity was designed and tested in Alcalá de Henares (Spain) under summer climatic conditions to demonstrate the feasibility of the concept. Natural water sources with wild strains of Escherichia coli, total coliforms, Enterococcus spp. and Clostridium perfringens (including spores) were studied. Results showed that SOLWAT disinfection efficiency was higher than conventional PET bottles and that the water disinfection reactor located above the PV module did not affect the total energy output produced by the hybrid system in comparison to the single PV module, achieving the same power losses over the 6 h of sun exposure in relation to their power at standard test conditions (STC).

  14. Impact of chlorinated disinfection on copper corrosion in hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Montes, J. Castillo [Centre Scientifique et Technique du Bâtiment Nantes, 11 rue Henri Picherit, BP 82341, 44323 Nantes Cedex 03 (France); Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Hamdani, F. [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Creus, J., E-mail: jcreus@univ-lr.fr [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Touzain, S. [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Correc, O. [Centre Scientifique et Technique du Bâtiment Nantes, 11 rue Henri Picherit, BP 82341, 44323 Nantes Cedex 03 (France)

    2014-09-30

    Highlights: • Impact of disinfectant treatment on the durability of copper pipes. • Synergy between disinfectant concentration and temperature. • Pitting corrosion of copper associated to the corrosion products formation on copper. - Abstract: In France, hot water quality control inside buildings is occasionally ensured by disinfection treatments using temperature increases or addition of sodium hypochlorite (between 0.5 ppm and 1 ppm residual free chlorine). This disinfectant is a strong oxidiser and it could interact with metallic pipes usually used in hot water systems. This work deals with the study of the impact of these treatments on the durability of copper pipes. The objective of this work was to investigate the influence of sodium hypochlorite concentration and temperature on the copper corrosion mechanism. Copper samples were tested under dynamic and static conditions of ageing with sodium hypochlorite solutions ranging from 0 to 100 ppm with temperature at 50 °C and 70 °C. The efficiency of a corrosion inhibitor was investigated in dynamic conditions. Visual observations and analytical analyses of the internal surface of samples was studied at different ageing duration. Corrosion products were characterised by X-ray diffraction and Raman spectroscopy. Temperature and disinfectant were found to considerably affect the copper corrosion mechanism. Surprisingly, the corrosiveness of the solution was higher at lower temperatures. The temperature influences the nature of corrosion products. The protection efficiency is then strongly depend on the nature of the corrosion products formed at the surface of copper samples exposed to the aggressive solutions containing different concentration of disinfectant.

  15. Isolation of Bacillus subtilis as indicator in the disinfection of residual water by means of gamma radiation

    International Nuclear Information System (INIS)

    Mata J, M.; Colin C, A.; Lopez V, H.; Brena V, M.; Carrasco A, H.; Pavon R, S.

    2002-01-01

    In the attempt to get more alternatives of disinfection of residual water, the Bacillus subtilis was isolated by means of gamma radiation as a bio indicator of disinfection since it turned out to be resistant to the 5 KGy dose, comparing this one with other usual microorganisms as biondicators like E. coli and S typhimurium which turn out more sensitive to such dose. (Author)

  16. Nutrient and dissolved organic carbon removal from water using mining and metallurgical by-products.

    Science.gov (United States)

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2012-05-15

    Excess nutrient input to water bodies frequently results in algal blooms and development of oxygen deficient conditions. Mining or metallurgical by-products can potentially be utilised as filtration media within water treatment systems such as constructed wetlands, permeable reactive barriers, or drain liners. These materials may offer a cost-effective solution for the removal of nutrients and dissolved organic carbon (DOC) from natural waters. This study investigated steel-making, alumina refining (red mud and red sand) and heavy mineral processing by-products, as well as the low-cost mineral-based material calcined magnesia, in laboratory column trials. Influent water and column effluents were analysed for pH and flow rate, alkalinity, nutrient species and DOC, and a range of major cations and anions. In general, by-products with high Ca or Mg, and to a lesser extent those with high Fe content, were well-suited to nutrient and DOC removal from water. Of the individual materials examined, the heavy mineral processing residue neutralised used acid (NUA) exhibited the highest sorption capacity for P, and removed the greatest proportions of all N species and DOC from influent water. In general, NUA and mixtures containing NUA, particularly those with calcined magnesia or red mud/red sand were the most effective in removing nutrients and DOC from influent water. Post-treatment effluents from columns containing NUA and NUA/steel-making by-product, NUA/red sand and NUA/calcined magnesia mixtures exhibited large reductions in DOC, P and N concentrations and exhibited a shift in nutrient ratios away from potential N- and Si-limitation and towards potential P-limitation. If employed as part of a large-scale water treatment scheme, use of these mining and metallurgical by-products for nutrient removal could result in reduced algal biomass and improved water quality. Identification and effective implementation of mining by-products or blends thereof in constructed wetlands

  17. Ionizing radiation in the disinfection of water contaminated with potentially pathogenic mycobacteria

    International Nuclear Information System (INIS)

    Kubin, M.; Sedlackova, J.; Vacek, K.

    1982-01-01

    Sterile drinking water samples were artificially colonized with M. kansasii, M. gardonae and M. fortuitum suspensions (the numbers of viable units in 1 ml were 1.2x10 3 , 48.5 and 3.2x10 3 , respectively) prepared from mycobacterial strains replicated in Tween 80-free liquid Dubos medium STO. The contaminated water samples were irradiated from a rotary cobalt 60 source (gamma radiation, E=1.17 and 1.33 MeV, dose rate 1 kJ/kg.h at room temperature) with doses 0.7, 1.5, 2.2, 3, 9, 16 and 27 kJ/kg. The disinfecting effectiveness was assessed by direct cultivation tests (0.5 ml volumes of water inoculated on egg medium) and by cultivation on membrane filtres after filtering the whole amount of the water examined (about 500 ml). Total disinfection was recorded for M. kansasii and M. fortuitum irradiated with 9 kJ/kg and for M. gordonae after irradiation with 1.5 kJ/kg. The calculated value of D 10 =0.4 kJ/kg (i.e., the radiation dose that reduces the number of viable mycobacteria by an order of magnitude) is suggestive of a strong disinfecting effect of ionizing radiation on the tested strains of potentially pathogenic mycobacteria. The results indicate that ionizing radiation could be applxcable in disinfecting supply and potable water contaminated with mycobacteria difficult to remove by other methods which, as a rule, cannot ensure permanent disinfection. (author)

  18. Ionizing radiation in the disinfection of water contaminated with potentially pathogenic mycobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kubin, M [Institut Hygieny a Epidemiologie, Prague (Czechoslovakia); Sedlackova, J; Vacek, K [Ustav Jaderneho Vyzkumu CSKAE, Rez (Czechoslovakia)

    1982-01-01

    Sterile drinking water samples were artificially colonized with M. kansasii, M. gardonae and M. fortuitum suspensions (the numbers of viable units in 1 ml were 1.2x10/sup 3/, 48.5 and 3.2x10/sup 3/, respectively) prepared from mycobacterial strains replicated in Tween 80-free liquid Dubos medium STO. The contaminated water samples were irradiated from a rotary cobalt 60 source (gamma radiation, E=1.17 and 1.33 MeV, dose rate 1 kJ/kg.h at room temperature) with doses 0.7, 1.5, 2.2, 3, 9, 16 and 27 kJ/kg. The disinfecting effectiveness was assessed by direct cultivation tests (0.5 ml volumes of water inoculated on egg medium) and by cultivation on membrane filtres after filtering the whole amount of the water examined (about 500 ml). Total disinfection was recorded for M. kansasii and M. fortuitum irradiated with 9 kJ/kg and for M. gordonae after irradiation with 1.5 kJ/kg. The calculated value of D/sub 10/=0.4 kJ/kg (i.e., the radiation dose that reduces the number of viable mycobacteria by an order of magnitude) is suggestive of a strong disinfecting effect of ionizing radiation on the tested strains of potentially pathogenic mycobacteria. The results indicate that ionizing radiation could be applicable in disinfecting supply and potable water contaminated with mycobacteria difficult to remove by other methods which, as a rule, cannot ensure permanent disinfection.

  19. Changes in Biofilm Community Structure Associated with Monochloramine-treated Drinking Water Biofilms

    Science.gov (United States)

    Monochloramine is increasingly used as a drinking water disinfectant because it forms lower levels of traditional disinfectant by-products compared to free-chlorine disinfection treatment. The use of monochloramine has been shown to increase ammonia-oxidizing bacteria and the pr...

  20. High-performance, low-cost solar collectors for disinfection of contaminated water.

    Science.gov (United States)

    Vidal, A; Diaz, A I

    2000-01-01

    Although the germicidal action of sunlight has long been recognized, its potential for practical applications has to be researched more thoroughly. This paper summarizes the progress made toward a commercially practical collector for solar disinfection applications. Nontracking compound parabolic collectors (CPCs), developed originally for capturing solar photons for thermal energy applications, were examined as potential solar photoreactors. A field demonstration of solar disinfection treatment using commercially manufactured solar reactors was conducted. Field tests showed successful destruction of Escherichia coli and Enterococcus faecalis and have provided data for full-scale design of water treatment systems. From above observations, a throughput value of 50 L/m2 h for the low-cost CPC reactor tested was estimated. For a 190 m3/d (0.05 MGD) facility, the estimated total costs for disinfection using UV-A is U.S. $0.19/m3 ($0.70/1000 gal). The use of near-UV sunlight to disinfect water supplies seems promising in rural communities of developing countries where treated water is unavailable.

  1. UV disinfection of water. 1. Effect on microorganisms/virus conditions which can limit the use of UV radiation as a means of disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Skipperud, E; Johansen,; Myhrstad, J A [Statens Inst. for Folkehelse, Oslo (Norway)

    1978-01-01

    UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW).

  2. Validation of the analytical method for sodium dichloroisocyanurate aimed at drinking water disinfection

    International Nuclear Information System (INIS)

    Martinez Alvarez, Luis Octavio; Alejo Cisneros, Pedro; Garcia Pereira, Reynaldo; Campos Valdez, Doraily

    2014-01-01

    Cuba has developed the first effervescent 3.5 mg sodium dichloroisocyanurate tablets as a non-therapeutic active principle. This ingredient releases certain amount of chlorine when dissolved into a litre of water and it can cause adequate disinfection of drinking water ready to be taken after 30 min. Developing and validating an analytical iodometric method applicable to the quality control of effervescent 3.5 mg sodium dichloroisocyanurate tablets

  3. Disinfection of municipal water using solar radiation: an economical approach for rural dwellers in the coastal region of Karachi

    International Nuclear Information System (INIS)

    Ahmed, M.F.; Saleem, M.

    2010-01-01

    At present acquiring safe drinking water in rural or remote areas of Pakistan is a challenging task for dwellers. Coast line of Karachi is a sporadic habitat of villages not having access to safe drinking water. Many incidents of waterborne diseases have been reported in that area and attributed to contaminated municipal water supply. Solution of the problem is disinfection however, general methods of water disinfection such as boiling, UV-lamp, ozonation and chemical additive are costly or require skilled manpower. Present study investigates the solar disinfection method to treat municipal water supply at Karachi Institute of Power Engineering (KINPOE) located at the coastal belt of Karachi. Effect of exposure time, bottle material and turbidity of water on the process performance was evaluated. Model indicator bacteria total coliform (TC) was used to evaluate the solar disinfection process. Study revealed that in order to disinfect the municipal water, samples should be filled in PET transparent bottles, having turbidity below 23 NTU, and expose to solar radiation in the study area at least for one hour. Study shows that solar disinfection may provide safe drinking water meeting national and international water quality standards at minimum cost and effort in sunshine rich areas and not having access to other water purification systems. (author)

  4. Formation of by-products at radiation - chemical treatment of water solutions of chloroform

    International Nuclear Information System (INIS)

    Ahmedov, S.A.; Abdullayev, E.T.; Gurbanov, M.A.; Gurbanov, A.H.; Ibadov, N.A.

    2006-01-01

    Full text: Radiation-chemical treatment is considered as a perspective method of water purification from chloroform. It provides the high level of purification (98 percent) of water solutions from chloroform and other chlorine-containing compounds. Meanwhile, other chlorine-containing products can be formed during the process of chloroform degradation and as a result of it the quality of water can change. This work studies the formation of by-products of γ-radiolysis of water solutions at various initial contents of chloroform. Dichlormethane and tetrachlorethane are identified as by-products. It is shown that at high contents of chloroform after certain adsorbed dose the forming products are reducing till their full disappearing. At small contents of chloroform in the studied interval of doses di-chlor-methane is forming. Differences of dose dependences of by-products at various contents of chloroform can be connected with the transition from radical mechanism to chain reaction at high concentrations of chloroform in solutions saturated by oxygen. pH-solutions also reduces during the radiation till pH=1, although this reduction also depends on initial concentration of chloroform. Essential change of pH occurs only at the radiolysis of water solutions containing chloroform ≥0,2 percent. And at radiating of 0,03 percent solution pH reduces only till 4 - 4,5

  5. Breakthrough analysis for water disinfection using silver nanoparticles coated resin beads in fixed-bed column

    International Nuclear Information System (INIS)

    Mthombeni, Nomcebo H.; Mpenyana-Monyatsi, Lizzy; Onyango, Maurice S.; Momba, Maggie N.B.

    2012-01-01

    Highlights: ► Performance of silver nanoparticles coated resin in water disinfection is presented. ► Sigmoidal models are used to describe breakthrough curves. ► The performance of the media in water disinfection is affected by process variables. ► Test with environmental water shows the media is effective in water disinfection. - Abstract: This study demonstrates the use of silver nanoparticles coated resin beads in deactivating microbes in drinking water in a column filtration system. The coated resin beads are characterized using X-ray diffraction (XRD), Fourier transform infra-red (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) to confirm the functional groups, morphology and the presence of silver nanoparticles on the surface of the resin. The performance of the coated resin is evaluated as a function of bed mass, initial bacterial concentration and flow rate using Escherichia coli as model microbial contaminant in water. The survival curves of E. coli are expressed as breakthrough curves (BTCs), which are modeled using sigmoidal regression equations to obtain relevant rate parameters. The number of bed volumes processed at breakthrough point and capacity of the bed are used as performance indicators. Results show that performance increases with a decrease in initial bacterial concentration, an increase in flow rate and an increase in bed mass.

  6. Disinfection of deionised water inoculated with enterobacter using ultra violet light

    International Nuclear Information System (INIS)

    Mathrani, M.

    2001-01-01

    For the first time the enterobacter, not the escherichia coli,was used as a model bacteria to asses the disinfection of microorganisms in water by UV (Ultra Violet) irradiation. The cell density of the liquid culture was followed by optical density of 1.837 at 600 nm on spectrometer. For the disinfection purpose, a laboratory scale batch reactor (10 cm wide, 20 cm long, and 10 cm height), containing 250 ml sterilised deionized water inoculated with enterobacter,was run under supra-band gap light (wavelength < 400 nm, peaking between 340 and 365 nm with a maximum of 350 nm). After carrying out seven batch experiments it is concluded that the complete inactivation of Enterobacter ( approx. equal to x 10/sup 6/ CFU/ml) in the water can be achieved by UV irradiation for 2 hours. (author)

  7. Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

    Science.gov (United States)

    Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

    2011-01-01

    Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in UV-A LEDs and semi

  8. Peracetic acid as an alternative disinfection technology for wet weather flows.

    Science.gov (United States)

    Coyle, Elizabeth E; Ormsbee, Lindell E; Brion, Gail M

    2014-08-01

    Rain-induced wet weather flows (WWFs) consist of combined sewer overflows, sanitary sewer overflows, and stormwater, all of which introduce pathogens to surface waters when discharged. When people come into contact with the contaminated surface water, these pathogens can be transmitted resulting in severe health problems. As such, WWFs should be disinfected. Traditional disinfection technologies are typically cost-prohibitive, can yield toxic byproducts, and space for facilities is often limited, if available. More cost-effective alternative technologies, requiring less space and producing less harmful byproducts are currently being explored. Peracetic acid (PAA) was investigated as one such alternative and this research has confirmed the feasibility and applicability of using PAA as a disinfectant for WWFs. Peracetic acid doses ranging from 5 mg/L to 15 mg/L over contact times of 2 to 10 minutes were shown to be effective and directly applicable to WWF disinfection.

  9. Efficient Disinfection of Tap and Surface Water with Single High Power 285 nm LED and Square Quartz Tube

    Directory of Open Access Journals (Sweden)

    Martin Hessling

    2016-01-01

    Full Text Available A small water disinfection system based on the combination of a strong single 25 mW LED with a wavelength of 285 nm and a short quartz tube with an outer rectangular cross section is presented. For the disinfection tests clear tap water and slightly turbid and yellow pond water are contaminated with high concentrations of Escherichia coli bacteria. These water samples are exposed to the germicidal 285 nm LED radiation while they flow through the quartz tube. The portion of surviving germs is determined by membrane filtration for different water qualities and flow rates. For clear tap water the bacteria concentration can be reduced by at least three orders of magnitude up to flow rates of about 20 L/h. In pond water the maximum flow rate for such a reduction is less than 3 L/h. These high disinfection capabilities and the small size of this system, allow its integration in medical systems for point of use disinfection or even its application in the Third World for decentralized water disinfection powered by small solar cells, because this disinfection capacity should be sufficient for small groups or families.

  10. Kinetic model of water disinfection using peracetic acid including synergistic effects.

    Science.gov (United States)

    Flores, Marina J; Brandi, Rodolfo J; Cassano, Alberto E; Labas, Marisol D

    2016-01-01

    The disinfection efficiencies of a commercial mixture of peracetic acid against Escherichia coli were studied in laboratory scale experiments. The joint and separate action of two disinfectant agents, hydrogen peroxide and peracetic acid, were evaluated in order to observe synergistic effects. A kinetic model for each component of the mixture and for the commercial mixture was proposed. Through simple mathematical equations, the model describes different stages of attack by disinfectants during the inactivation process. Based on the experiments and the kinetic parameters obtained, it could be established that the efficiency of hydrogen peroxide was much lower than that of peracetic acid alone. However, the contribution of hydrogen peroxide was very important in the commercial mixture. It should be noted that this improvement occurred only after peracetic acid had initiated the attack on the cell. This synergistic effect was successfully explained by the proposed scheme and was verified by experimental results. Besides providing a clearer mechanistic understanding of water disinfection, such models may improve our ability to design reactors.

  11. Electrochemically activated water as an alternative to chlorine for decentralized disinfection

    KAUST Repository

    Ghebremichael, Kebreab A.

    2011-06-01

    Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive oxygen species such as ozone and hydroxyl radicals in addition to chlorine. This study compares sodium hypochlorite (NaOCl) and ECA in terms of disinfection efficacy, trihalomethanes (THMs) formation, stability and composition. The studies were carried out under different process conditions (pH 5,7 and 9, disinfectant concentrations of 2-5 mg/L and dissolved organic carbon (DOC) concentration of 2-4 mg/L). The results indicated that in the presence of low DOC (<2 mg/L) ECA showed better disinfection efficacy for Escherichia coli inactivation, formed lower THM and had better stability compared with NaOCl at both pH 5 and 7. Stability studies of stock solutions showed that over a period of 30 days, ECA decayed by only 5% while NaOCl decayed by 37.5% at temperatures of 4 °C. In a fresh ECA of 200 mg/L chlorine, about 5.3 mg/L ozone and 36.9 mg/L ClO2 were detected. The study demonstrates that ECA could be a suitable alternative to NaOCl where decentralized production and use are required. © IWA Publishing 2011.

  12. Simultaneous determination of polycyclic aromatic hydrocarbons and their chlorination by-products in drinking water and the coatings of water pipes by automated solid-phase microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Tillner, Jocelyn; Hollard, Caroline; Bach, Cristina; Rosin, Christophe; Munoz, Jean-François; Dauchy, Xavier

    2013-11-08

    In this study, an automated method for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their chlorination by-products in drinking water was developed based on online solid-phase microextraction-gas chromatography-mass spectrometry. The main focus was the optimisation of the solid-phase microextraction step. The influence of the agitation rate, type of fibre, desorption time, extraction time, extraction temperature, desorption temperature, and solvent addition was examined. The method was developed and validated using a mixture of 17 PAHs, 11 potential chlorination by-products (chlorinated and oxidised PAHs) and 6 deuterated standards. The limit of quantification was 10 ng/L for all target compounds. The validated method was used to analyse drinking water samples from three different drinking water distribution networks and the presumably coal tar-based pipe coatings of two pipe sections. A number of PAHs were detected in all three networks although individual compositions varied. Several PAH chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also found, their presence correlating closely with that of their respective parent compounds. Their concentrations were always below 100 ng/L. In the coatings, all PAHs targeted were detected although concentrations varied between the two coatings (76-12,635 mg/kg and 12-6295 mg/kg, respectively). A number of chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also detected (from 40 to 985 mg/kg), suggesting that the reaction of PAHs with disinfectant agents takes place in the coatings and not in the water phase after migration. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. 77 FR 12581 - Public Water System Supervision Program Revision for the State of Montana

    Science.gov (United States)

    2012-03-01

    ... accordance with the provisions of section 1413 of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300g-2, and... Water Treatment Rule, Stage 2 Disinfectants and Disinfection Byproducts Rule and Ground Water Rule that correspond to the National Primary Drinking Water Regulations (NPDWR) in 40 CFR part 141 and 142. The EPA has...

  14. 78 FR 42945 - Public Water Supply Supervision Program; Program Revision for the State of Oregon

    Science.gov (United States)

    2013-07-18

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9834-9] Public Water Supply Supervision Program; Program... Water Supply Supervision Primacy Program. Oregon has adopted regulations analogous to EPA's Stage 2 Disinfectants and Disinfection Byproducts Rule; Long Term 2 Enhanced Surface Water Treatment Rule; Ground Water...

  15. Water and sewage sludge disinfection by irradiation. Pt. 4 and 5

    International Nuclear Information System (INIS)

    Alexandre, D.

    1978-01-01

    Estimation of cost shows that water disinfection by irradiation is too expensive. Liquid wastes can be treated by low and medium energy accelerators but they are competitive with thermal process only for large installations. Dry sludges can be treated by radioelements, energy saving is important with gamma ray sources, this process is cheaper especially for small installations, results with high energy accelerators are encouraging for dry sludges and large installations [fr

  16. Use of solar energy for disinfection of polluted water

    OpenAIRE

    Y. Jamil; M.R. Ahmad; K. Ali; A. Habeeb; M. Hassan

    2009-01-01

    Polluted water is causing serious health problems especially in the rural areas of Pakistan. People have limited access to safe water supply and many diseases like diarrhea and gastrointestinal diseases are transmitted by consumption of polluted water. We have investigated the potential of using solar energy to pasteurize water. Low cost indigenously available materials have been utilized to design and fabricate a solar box type pasteurizer having a capacity of three liters. The p...

  17. Effect of ultrasonic pretreatment on purified water disinfection; Efecto del pretratamiento con ultrasonidos sobre la desinfeccion de agua depurada

    Energy Technology Data Exchange (ETDEWEB)

    Simon Andreu, P.; Lardin Mifsut, C.; Vergara Romero, L.; Polo Canas, P. M.; Perez Sanchez, P.; Rancano Perez, A.

    2009-07-01

    Due to the importance of a suitable water disinfection in order to insure a pollutant effect minimization against environment, this work has been carried out to determine how can affect an ultrasonic pre-treatment upon disinfection step. It has been confirmed the ultrasonic disintegration of bacterial cells in treated water and disinfectant power of treatment by itself, which is not enough to be used as a single method in water disinfection. It has also been proved that from a technical and economical point of view the combination of UV and ultrasound improves the UV treatment performance. Finally, it has been detected that an ultrasonic pre-treatment increases chlorination effectiveness, however the high cost in this combination makes it unfeasible of industrial scale. (Author) 6 refs.

  18. Characterizing natural organic matter in drinking water treatment processes and trains

    NARCIS (Netherlands)

    Baghoth, S.A.

    2012-01-01

    Natural organic matter (NOM) generally influences water treatment processes such as coagulation, oxidation, adsorption, and membrane filtration. NOM contributes colour, taste and odour in drinking water, fouls membranes, serves as a precursor for disinfection by-products, increases the exhaustion

  19. Reducing the chlorine dioxide demand in final disinfection of drinking water treatment plants using activated carbon.

    Science.gov (United States)

    Sorlini, Sabrina; Biasibetti, Michela; Collivignarelli, Maria Cristina; Crotti, Barbara Marianna

    2015-01-01

    Chlorine dioxide is one of the most widely employed chemicals in the disinfection process of a drinking water treatment plant (DWTP). The aim of this work was to evaluate the influence of the adsorption process with granular activated carbon (GAC) on the chlorine dioxide consumption in final oxidation/disinfection. A first series of tests was performed at the laboratory scale employing water samples collected at the outlet of the DWTP sand filter of Cremona (Italy). The adsorption process in batch conditions with seven different types of GAC was studied. A second series of tests was performed on water samples collected at the outlet of four GAC columns installed at the outlet of the DWTP sand filter. The results showed that the best chlorine dioxide demand (ClO2-D) reduction yields are equal to 60-80% and are achieved in the first 30 min after ClO2 addition, during the first 16 days of the column operation using a mineral, coal-based, mesoporous GAC. Therefore, this carbon removes organic compounds that are more rapidly reactive with ClO2. Moreover, a good correlation was found between the ClO2-D and UV absorbance at wavelength 254 nm using mineral carbons; therefore, the use of a mineral mesoporous GAC is an effective solution to control the high ClO2-D in the disinfection stage of a DWTP.

  20. Water Purification and Disinfection by using Solar Energy: Towards Green Energy Challenge

    Directory of Open Access Journals (Sweden)

    Md Z.H. Khan

    2015-12-01

    Full Text Available The aim of this work was to design a solar water treatment plant for household purpose. Water purification is the process of eradicating detrimental chemicals, biological poisons, suspended solids and gases from contaminated water. In this work we have reported an investigation of compact filter which is cost effective for developing countries and ease of maintenance. We have arranged a solar water disinfection system that improves the microbiological quality of drinking water at household level. We get 14 L pure water and 16 ml water vapour within 240 min by using filtration method. From our work we get hot water up to 49°C. The efficiency of the system at sunny days and cloudy days are 18.23% and 18.13% respectively. This simple solar hybrid system helps to remove turbidity as well as chemical and pathogenic contaminants from water sources in the most affordable, and expedient manner possibly.

  1. Zeolites modified with silver for the development of a water disinfection system

    International Nuclear Information System (INIS)

    Aparicio V, S.

    2013-01-01

    In spite of great strides that have been taken in sanitation technologies, there still exist health problems due to microbiological contamination by water. The waterborne diseases have not been completely eradicated and are a big problem of economic interest and health. Moreover, the microbicidal properties of silver have been used for a long time. The use of silver as a disinfectant has many advantages; for example it inhibits a wide spectrum of microorganisms, it has oligo dynamic properties and owing its mechanisms of cell inactivation, it also does not allow the emergence of new resistant strains. In the present research, the kinetics of water disinfection with silver has been investigated, to develop small system for water disinfection, based in silver modified Mexican clinoptilolite. The chemical species of silver play a significant role in the disinfection processes. For this reason, in this work, were both the Ag + and nanoparticles of Ag ο considered. The synthesis of nanoparticles of Ag ο woes performed by thermal and chemical reduction. It was found that the chemical reduction of Ag + to Ag ο was more efficient because it presented more defined nano structures and better distribution than those of thermal reduction. Clinoptilolite of Taxco (Guerrero) was chosen to exchange the native ions from the clinoptilolite by Ag + from the aqueous medium, or to deposit the nanoparticles of Ag ο on this surface. These silver modified zeolitic materials were characterized by scanning electron microscopy (Sem), elemental analyses (EDS), X-ray diffraction (XRD) and neutron activation analysis (NAA). The results showed that the crystallographic structure of the clinoptilolite did not change during thermal and chemical reduction treatments of Ag + to obtain the nanoparticles of Ag ο . The bactericide activity of the silver modified zeolitic materials (with Ag + or nanoparticles of Ag ο ) was evaluated on Escherichia coli Atcc 8739, in both distilled water and well

  2. The Use of Genetic Algorithms in UV Disinfection of Drinking Water

    Directory of Open Access Journals (Sweden)

    Hugo Zaldaña

    2015-06-01

    Full Text Available In order to have drinking water, some countries have to use chlorine. It is use cause is effective and it’s cheap. An alternative to this process is the UV disinfection of drinking water. Most of the devices in the market use UV bulbs or mercury lamps. The UV LED, which is cheaper and smaller, allows creating new smaller devices. The main contribution of this paper is the use of Genetic Algorithms to help design a drinking water device with UV LEDs.

  3. Electrochemical disinfection of bacteria-laden water using antimony-doped tin-tungsten-oxide electrodes.

    Science.gov (United States)

    Ghasemian, Saloumeh; Asadishad, Bahareh; Omanovic, Sasha; Tufenkji, Nathalie

    2017-12-01

    Electrochemical disinfection has been shown to be an efficient method with a shortrequired contact time for treatment of drinking water supplies, industrial raw water supplies, liquid foodstuffs, and wastewater effluents. In the present work, the electrochemical disinfection of saline water contaminated with bacteria was investigated in chloride-containing solutions using Sb-doped Sn 80% -W 20% -oxide anodes. The influence of current density, bacterial load, initial chloride concentration, solution pH, and the type of bacteria (E. coli D21, E. coli O157:H7, and E. faecalis) on disinfection efficacy was systematically examined. The impact of natural organic matter and a radical scavenger on the disinfection process was also examined. The electrochemical system was highly effective in bacterial inactivation for a 0.1 M NaCl solution contaminated with ∼10 7  CFU/mL bacteria by applying a current density ≥1 mA/cm 2 through the cell.100% inactivation of E. coli D21 was achieved with a contact time of less than 60 s and power consumption of 48 Wh/m 3 , by applying a current density of 6 mA/cm 2 in a 0.1 M NaCl solution contaminated with ∼10 7 CFU/mL. Reactive chlorine species as well as reactive oxygen species (e.g. hydroxyl radicals) generated in situ during the electrochemical process were determined to be responsible for inactivation of bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Detection of mutagens in water-distribution systems after disinfection.

    Science.gov (United States)

    Guzzella, Licia; Di Caterino, Filomena; Monarca, Silvano; Zani, Claudia; Feretti, Donatella; Zerbini, Ilaria; Nardi, Giuseppe; Buschini, Annamaria; Poli, Paola; Rossi, Carlo

    2006-09-19

    This research examined the quality of water-before and after distribution-of four drinking-water production plants located in Northern Italy, two of which collected water from local aquifers and two from the River Po. A battery of genotoxicity assays for monitoring drinking-water was performed to assess the quality of the water produced by the treatment plants under study. Three different sampling stations were selected at each plant, one right at the outlet of the treatment plant and two along with the distribution pipelines. Raw river water was also sampled and analysed as a control. The water samples (500 l) were concentrated on silica C18 cartridges and the extracts were tested in in vitro mutagenicity assays (Salmonella/microsome assay with strains TA 98 and TA 100; SOS Chromotest with Escherichia coli strain PQ37); gene conversion, point mutation and mitochondrial DNA mutability assays with the diploid Saccharomyces cerevisiae strain D7 and a toxicity test using the bioluminescent bacterium Vibrio fischeri (Microtox). The Microtox test and the mitochondrial DNA mutability assay showed the greatest sensitivity towards toxic or mutagenic substances in the water extracts considered. The results show that this battery of short-term tests is applicable in the routine monitoring of drinking-water quality before and after distribution.

  5. Disinfection Pilot Trial for Little Miami WWTP | Science ...

    Science.gov (United States)

    There is a serious interest growing nationally towards the use of PAA at various stages of public waste water treatment facilities; one of such use is secondary waste water treatment. MSDGC is currently interested in improving efficiency and economic aspects of waste water treatment. MSDGC requested for ORD’s support to evaluate alternative cost-effective disinfectants. This report herein is based on the data generated from the field pilot test conducted at the Little Miami Wastewater Treatment Plant. Chlorine assisted disinfection of wastewaters created the concern regarding the formation of high levels of toxic halogenated disinfection byproducts (DBPs) detrimental to aquatic life and public health. Peracetic acid is emerging as a green alternative to chlorine and claimed to have economic and social benefits. In addition, it is a relatively simple retrofit to the existing chlorine treated wastewater treatment facilities. PAA is appealed to possess a much lower aquatic toxicity profile than chlorine and decays rapidly in the environment, even if overdosed. As a result, PAA generally does not need a quenching step, such as dechlorination, reducing process complexity, sodium pollution and cost. PAA treatment does not result in the formation of chlorinated disinfection by-products such as trihalomethanes (THMs), haloacetic acids and other byproducts such as cyanide and n-Nitrosodimethylamine (NDMA).

  6. Survey of disinfection efficiency of small drinking water treatment ...

    African Journals Online (AJOL)

    A survey involving 181 water treatment plants across 7 provinces of South Africa: Mpumalanga, Limpopo, North West, Free State, KwaZulu-Natal, Eastern Cape and Western Cape was undertaken to identify the challenges facing small water treatment plants (SWTPs) in South Africa . Information gathered included ...

  7. Frequency of use controls chemical leaching from drinking-water containers subject to disinfection.

    Science.gov (United States)

    Andra, Syam S; Makris, Konstantinos C; Shine, James P

    2011-12-15

    Microbial-, and chemical-based burden of disease associated with lack of access to safe water continues to primarily impact developing countries. Cost-effective health risk-mitigating measures, such as of solar disinfection applied to microbial-contaminated water stored in plastic bottles have been increasingly tested in developing countries adversely impacted by epidemic water-borne diseases. Public health concerns associated with chemical leaching from water packaging materials led us to investigate the magnitude and variability of antimony (Sb) and bromine (Br) leaching from reused plastic containers (polyethylene terephthalate, PET; and polycarbonate, PC) subject to UV and/or temperature-driven disinfection. The overall objective of this study was to determine the main and interactive effects of temperature, UV exposure duration, and frequency of bottle reuse on the extent of leaching of Sb and Br from plastic bottles into water. Regardless of UV exposure duration, frequency of reuse (up to 27 times) was the major factor that linearly increased Sb leaching from PET bottles at all temperatures tested (13-47 °C). Leached Sb concentrations (∼360 ng L(-1)) from the highly reused (27 times) PET bottles (minimal Sb leaching from PC bottles, water at much lower concentrations. Additional research on potential leaching of organic chemicals from water packaging materials is deemed necessary under relevant environmental conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. A Comparison of Different Disinfectants on the Microbiological Quality of Water from the Dental Unit Waterlines of a Military Hospital

    International Nuclear Information System (INIS)

    Ma, M.S.; Zalini Yunus; Ahmad Razi Mohamed Yunus; Zukri Ahmad; Farizah Abdul Fatah

    2015-01-01

    Water from the dental unit waterlines (DUWLs) is known to contaminate with microbial from the biofilm that formed in the tubing system. The water quality from DUWLs is important to patients and dental health care professionals as they could be infected either directly from the contaminated water or aerosol that is generated during dental procedures. Suppliers claimed that dental units supplied to the hospital can only use a specific disinfectant which is uneconomic compared with the others. The aims of this study were to evaluate and compare the efficacy of different disinfectant on the water quality of DUWLs. Four disinfectants (Calbenium, A-dec ICX tablet, Dentel 5, Metassys) and distil water were evaluated. 350 mL water sample was collected separately, from the outlet of high-speed hand piece, scaler, 3-ways syringe and cup filler into a sterile thiosulfate bag on the 1st, 2nd, 4th, 8th, 12th and 24th weeks of the study. The samples were tested on the following day for total viable count (TVC). There is significant difference in the efficacies of the different disinfectants. Only one disinfectant consistently produces water quality within the recommended level of American Dental Association (ADA). Within the limitation of this study, it was found that there is alternative disinfectant that can reduce the TVC to the level recommended by ADA. However, the water qualities produced with these disinfectants were not consistent although they did not cause any technical problem to the dental units during the period of study. (author)

  9. Anodic oxidation as a new practical procedure for water disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Kirmaier, N; Schoeberl, M

    1980-05-01

    The anodic oxidation could be developed for practical purposes by extensive scientific investigations and engineering optimization. Its safe bactericide, virucide, fungicide and bacteriostatic effect combined with engineering advantages makes it an essential component for water processing.

  10. Assesment of disinfectant by product in chlorinated drinking water

    International Nuclear Information System (INIS)

    Khattak, M.I.

    2010-01-01

    The present study was design to establish the report of spatial pattern and variations of Trihalomethanes (THMs) in drinking water sample collected from the area of Karachi. This is the first attempt of its nature to assess mainly the THMs level in drinking water samples of this region. THMs occurrence in water samples as investigated based on a program for preliminary monitoring of water quality throughout the distribution system. The most important species CHCl/sub 3/ of THMs were measured in the samples and were found at average level. The results of present investigation demonstrated that there are more than 95.06% of total Trihalomethanes spatial variations. Specially the CHCl/sub 3/ is considerable in all the utilities in question. (author)

  11. The Dependence of Chlorine Decay and DBP Formation Kinetics On Pipe Flow Properties in Drinking Water Distribution

    Science.gov (United States)

    Simultaneous chlorine decay and disinfection byproduct (DBP) formation has long been discussed because of its regulatory and operational significance. This study further examines the water quality changes under hydrodynamic settings during drinking water distribution. Comparative...

  12. Use of solar energy for disinfection of polluted water

    Directory of Open Access Journals (Sweden)

    Y. Jamil

    2009-05-01

    Full Text Available Polluted water is causing serious health problems especially in the rural areas of Pakistan. People have limited access to safe water supply and many diseases like diarrhea and gastrointestinal diseases are transmitted by consumption of polluted water. We have investigated the potential of using solar energy to pasteurize water. Low cost indigenously available materials have been utilized to design and fabricate a solar box type pasteurizer having a capacity of three liters. The performance study of the pasteurizer was performed during the month of May 2008. The designed pasteurizer maintained water temperature in the range of60 oC to 70 oC continuously for more than an hour which is enough for deactivation of coliform bacteria. The maximum water temperature on a clear sunny day was found to be 67 oC, corresponding to an ambient temperature of40 oC. With the pasteurizer facing south, a very little repositioning was required. The low cost and operational simplicity of the pasteurizer make it affordable and usable. It is more useful in rural areas where other sources of energy like electricity and gas are not easily available

  13. Effect of chlorination by-products on the quantitation of microcystins in finished drinking water.

    Science.gov (United States)

    Rosenblum, Laura; Zaffiro, Alan; Adams, William A; Wendelken, Steven C

    2017-11-01

    Microcystins are toxic peptides that can be produced by cyanobacteria in harmful algal blooms (HABs). Various analytical techniques have been developed to quantify microcystins in drinking water, including liquid chromatography tandem mass spectrometry (LC/MS/MS), enzyme linked immunosorbent assay (ELISA), and oxidative cleavage to produce 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) with detection by LC/MS/MS, the "MMPB method". Both the ELISA and MMPB methods quantify microcystins by detecting a portion of the molecule common to most microcystins. However, there is little research evaluating the effect of microcystin chlorination by-products potentially produced during drinking water treatment on analytical results. To evaluate this potential, chlorinated drinking water samples were fortified with various microcystin congeners in bench-scale studies. The samples were allowed to react, followed by a comparison of microcystin concentrations measured using the three methods. The congener-specific LC/MS/MS method selectively quantified microcystins and was not affected by the presence of chlorination by-products. The ELISA results were similar to those obtained by LC/MS/MS for most microcystin congeners, but results deviated for a particular microcystin containing a variable amino acid susceptible to oxidation. The concentrations measured by the MMPB method were at least five-fold higher than the concentrations of microcystin measured by the other methods and demonstrate that detection of MMPB does not necessarily correlate to intact microcystin toxins in finished drinking water. Published by Elsevier Ltd.

  14. 76 FR 5157 - Public Water Supply Supervision Program; Program Revision for the State of Alaska

    Science.gov (United States)

    2011-01-28

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9259-6] Public Water Supply Supervision Program; Program... Water Supply Supervision Primacy Program. Alaska has adopted regulations analogous to EPA's Stage 2 Disinfectants and Disinfection Byproducts Rule; Long Term 2 Enhanced Surface Water Treatment Rule; and Lead and...

  15. Water and sewage sludge disinfection by irradiation. Pt. 3

    International Nuclear Information System (INIS)

    Alexandre, D.

    1978-01-01

    In view of disinfestation of water and sludges qualitative aspects of irradiation are given. Effects of different parameters: pH, dose rate, hydratation, synergism of oxygen, heat and chlorine are examined. No toxic products are created by radiations. Filtrability and decantability of sludges are improved [fr

  16. Effects of Disinfectants in Water on Mir- and Earth-Grown Wheat

    Science.gov (United States)

    Campbell, William .F.; Bubenheim, D. L.; Bugbee, B.; Salisbury, F. B.; Bingham, G. E.; Levinskikh, M.; Sytchev, V. N.; Ivanova, I.; Chernova, L.; Podolsky, I.

    2002-01-01

    Iodine and silver fluoride are used to purify water onboard U. S. Shuttles and the Russian Space Station, Mir, respectively. In 1995, iodine-treated water, which ranged from 1.0-4.0 mg x kg(exp -1) with a mean of 2.9 mg x kg(exp -1), was applied to Super Dwarf wheat (Triticum aestivum L.) plants when Mir water (grey or tech grade) became scarce. The potential phytotoxicity of iodine on Super Dwarf wheat is an unknown. Since use of iodine-treated water was not part of the experiment, we sought to determine whether it accounted for the subsequent poor wheat seedling growth and floral development onboard the Mir. Super Dwarf wheat seeds were imbibed in iodine or silver fluoride concentrations of 0.0, 1.0, 2.0, 4.0, 8.0 or 16.0 mg x kg(exp -1) for 96 h at 4 C. Five seeds were then planted per 13.3 cm x 13.3 cm pots containing a granular clinoptilolite (Cp) zeolite (1 -2 mm dia.) and placed in Percival(TM) growth chambers programmed for 20/15 C and 18/6 h d/n regime. Plants were irrigated with distilled water, and Iodine- or silver fluoride-treated distilled water. In separate experiments, seeds were treated as above and germination and early seedling growth were determined by examining seedling responses to disinfectants in rolled paper towels. Silver fluoride had very little effect on wheat seed germination. By contrast, iodine reduced germination at all treatment levels. Seedlings exposed to 1.0, 2.0, and 4.0 mg x kg(exp -1) of iodine or silver fluoride levels exhibited a slight stimulation in shoot and root growth. Both disinfectants at 8 and 16 mg x kg(exp -1) showed significantly (p is less than or equal to 0.01) reduced seedling shoot and root lengths and fresh biomasses compared to the control and lower disinfectant levels. The number of spikelets per spike, florets per spikelet, seeds per spike and seed weight were also significantly reduced at the 8 and 16 mg x kg(exp -1) compared to the control and lower levels of disinfectant. Based on these ground

  17. 40 CFR 141.72 - Disinfection.

    Science.gov (United States)

    2010-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.72 Disinfection. A public water... the direct influence of surface water and provides filtration treatment must provide disinfection...) Disinfection requirements for public water systems which provide filtration. Each public water system that...

  18. Cyto- and genotoxic profile of groundwater used as drinking water supply before and after disinfection.

    Science.gov (United States)

    Pellacani, C; Cassoni, F; Bocchi, C; Martino, A; Pinto, G; Fontana, F; Furlini, M; Buschini, A

    2016-12-01

    The assessment of the toxicological properties of raw groundwater may be useful to predict the type and quality of tap water. Contaminants in groundwater are known to be able to affect the disinfection process, resulting in the formation of substances that are cytotoxic and/or genotoxic. Though the European directive (98/83/EC, which establishes maximum levels for contaminants in raw water (RW)) provides threshold levels for acute exposure to toxic compounds, the law does not take into account chronic exposure at low doses of pollutants present in complex mixture. The purpose of this study was to evaluate the cyto- and genotoxic load in the groundwater of two water treatment plants in Northern Italy. Water samples induced cytotoxic effects, mainly observed when human cells were treated with RW. Moreover, results indicated that the disinfection process reduced cell toxicity, independent of the biocidal used. The induction of genotoxic effects was found, in particular, when the micronucleus assay was carried out on raw groundwater. These results suggest that it is important to include bio-toxicological assays as additional parameters in water quality monitoring programs, as their use would allow the evaluation of the potential risk of groundwater for humans.

  19. Remediation of Ni(2+)-contaminated water using iron powder and steel manufacturing byproducts.

    Science.gov (United States)

    Jin, Jian; Zhao, Wei-Rong; Xu, Xin-Hua; Hao, Zhi-Wei; Liu, Yong; He, Ping; Zhou, Mi

    2006-01-01

    Steel manufacturing byproducts and commercial iron powders were tested in the treatment of Ni(2+)-contaminated water. Ni2+ is a priority pollutant of some soils and groundwater. The use of zero-valent iron, which can reduce Ni2+ to its neural form appears to be an alternative approach for the remediation of Ni(2+)-contaminated sites. Our experimental data show that the removal efficiencies of Ni2+ were 95.15% and 94.68% at a metal to solution ratio of 20 g/L for commercial iron powders and the steel manufacturing byproducts in 60 min at room temperature, respectively. The removal efficiency reached 98.20% when the metal to solution ratio was 40 g/L for commercial iron powders. Furthermore, we found that the removal efficiency was also largely affected by other factors such as the pHs of the treated water, the length of time for the metal to be in contact with the Ni(2+)-contaminated water, initial concentrations of metal solutions, particle sizes and the amount of iron powders. Surprisingly, the reaction temperature appeared to have little effect on the removal efficiency. Our study opens the way to further optimize the reaction conditions of in situ remediation of Ni2+ or other heavy metals on contaminated sites.

  20. On the factors influencing the performance of solar reactors for water disinfection with photosensitized singlet oxygen.

    Science.gov (United States)

    Manjón, Francisco; Villén, Laura; García-Fresnadillo, David; Orellana, Guillermo

    2008-01-01

    Two solar reactors based on compound parabolic collectors (CPCs) were optimized for water disinfection by photosensitized singlet oxygen (1O2) production in the heterogeneous phase. Sensitizing materials containing Ru(II) complexes immobilized on porous silicone were produced, photochemically characterized, and successfully tested for the inactivation of up to 10(4) CFU mL(-1) of waterborne Escherichia coli (gram-negative) or Enterococcus faecalis (gram-positive) bacteria. The main factors determining the performance of the solar reactors are the type of photosensitizing material, the sensitizer loading, the CPC collector geometry (fin- vs coaxial-type), the fluid rheology, and the balance between concurrent photothermal--photolytic and 1O2 effects on the microorganisms' inactivation. In this way, at the 40 degrees N latitude of Spain, water can be disinfected on a sunny day (0.6-0.8 MJ m(-2) L(-1) accumulated solar radiation dose in the 360-700 nm range, typically 5-6 h of sunlight) with a fin-type reactor containing 0.6 m2 of photosensitizing material saturated with tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) (ca. 2.0 g m(-2)). The optimum rheological conditions require laminar-to-transitional water flow in both prototypes. The fin-type system showed better inactivation efficiency than the coaxial reactor due to a more important photolytic contribution. The durability of the sensitizing materials was tested and the operational lifetime of the photocatalyst is at least three months without any reduction in the bacteria inactivation efficiency. Solar water disinfection with 1O2-generating films is demonstrated to be an effective technique for use in isolated regions of developing countries with high yearly average sunshine.

  1. Compliance Determination for Inactivation Requirements of the National Primary Drinking Water Regulations when a Public Water Systems Uses Dichlor and Trichlor for Primary Disinfection

    Science.gov (United States)

    This memorandum has been developed to assist SDWA primacy agencies (EPA Regions, states and territories) when considering inactivation/disinfection compliance requirements for those water systems that choose to use Dichlor or Trichlor.

  2. Nutrient and dissolved organic carbon removal from natural waters using industrial by-products.

    Science.gov (United States)

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2013-01-01

    Attenuation of excess nutrients in wastewater and stormwater is required to safeguard aquatic ecosystems. The use of low-cost, mineral-based industrial by-products with high Ca, Mg, Fe or Al content as a solid phase in constructed wetlands potentially offers a cost-effective wastewater treatment option in areas without centralised water treatment facilities. Our objective was to investigate use of water treatment residuals (WTRs), coal fly ash (CFA), and granular activated carbon (GAC) from biomass combustion in in-situ water treatment schemes to manage dissolved organic carbon (DOC) and nutrients. Both CaO- and CaCO(3)-based WTRs effectively attenuated inorganic N species but exhibited little capacity for organic N removal. The CaO-based WTR demonstrated effective attenuation of DOC and P in column trials, and a high capacity for P sorption in batch experiments. Granular activated carbon proved effective for DOC and dissolved organic nitrogen (DON) removal in column trials, but was ineffective for P attenuation. Only CFA demonstrated effective removal of a broad suite of inorganic and organic nutrients and DOC; however, Se concentrations in column effluents exceeded Australian and New Zealand water quality guideline values. Water treated by filtering through the CaO-based WTR exhibited nutrient ratios characteristic of potential P-limitation with no potential N- or Si-limitation respective to growth of aquatic biota, indicating that treatment of nutrient-rich water using the CaO-based WTR may result in conditions less favourable for cyanobacterial growth and more favourable for growth of diatoms. Results show that selected industrial by-products may mitigate eutrophication through targeted use in nutrient intervention schemes. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  3. [Improvement of effectivity of photo disinfection of water from bacterial contaminants in the presence of heterogeneous sensitizers based on phthalocyanines grafted to aminopropyl silicagel].

    Science.gov (United States)

    Maksimkina, T N; Artemova, T Z; Kuznetsova, N A; Sinitsyna, O O; Gipp, E K; Zagaĭnova, A V; Butorina, N N; Iuzhakova, O A; Krasniak, A V

    2012-01-01

    The possibility of using 12 heterogeneous sensitizers (HS) based on phthalocyanines covalently grafted to aminopropyl silicagel for disinfection of water from bacteria has been studied. For reliable water quality control the technique of performing bacteriological analysis in the presence of HS beads in the sample has been elaborated. The conditions increasing the efficiency of photo disinfection in the presence of HS were studied. Algorithm for estimation of photo disinfectant effect of HS against bacteria was substantiated. Obtained data confirm the perspective of further studies on the substantiation of the possibility of the application of HS for water disinfection.

  4. Study for effective use of fishery byproducts as alternative earth materials focusing on their water retention

    International Nuclear Information System (INIS)

    Kobayashi, Kaoru; Nakafusa, Satoru; Nishimura, Tomoyoshi; Morii, Toshihiro

    2011-01-01

    Capillary barriers have been known and widely used in geoenvironmental engineering applications as soil cover for typical rainfall infiltration control systems. The capillary barrier is consisting of a fine-grained soil layer placed over a coarse-grained soil layer. The applications of capillary barriers are significantly useful to preventing infiltration into waste materials. Natural gravel or coarse-grained soil material had a exhaustion problems in practices. On the contrary, shells a kind of fishery byproduct, are classified as industrial waste in laws concerning waste disposal. The majority of shells are piled and left near the fishing port without controlling system. Therefore, it is proposed that the crushed shells are available to layer material instead of natural coarse-grained soil. This solution is considered to great contribute developing of recycle for fisher byproduct shells and is related to environment conservation. Water retention for crushed shells, however, never been fully investigate. This study focuses on the ability of crushed shells to capillary barrier applications. The soil-water characteristic curve for crushed shells with three different grain size distributions was determined using the modified SWCC testing apparatus. Also, it is observed using a conventional model equipment that the getting of fine sand into crushed shell layer is prevented. (author)

  5. THM reduction on water distribution network with chlorine dioxide as disinfectant

    International Nuclear Information System (INIS)

    Ventura, G.; Gorriz, D.; Pascual, E.; Romero, M.

    2009-01-01

    A disinfectant change on water distribution network, by chlorine dioxide in that case, avoids THM formation. In the other hand it creates big doubts about utilization and analytical determination of another oxidant different to chlorine. Just a need to comply the current legislation points us to make a change as the one mentioned above and carried out in DWTP Rio Verde, being managed by Acosol, where the THM formation is been reduced to 80%, according to the new limit of 100μg/l, along the 200 km of the supply network. (Author) 13 refs.

  6. Chlorine dioxide oxidation of Escherichia coli in water - A study of the disinfection kinetics and mechanism.

    Science.gov (United States)

    Ofori, Isaac; Maddila, Suresh; Lin, Johnson; Jonnalagadda, Sreekantha B

    2017-06-07

    This study investigated the kinetics and mechanism of chlorine dioxide (ClO 2 ) inactivation of a Gram-negative bacteria Escherichia coli (ATCC 35218) in oxidant demand free (ODF) water in detail as a function of disinfectant concentration (0.5-5.0 mg/L), water pH (6.5-8.5), temperature variations (4-37°C) and bacterial density (10 5 -10 7 cfu/mL). The effects of ClO 2 on bacterial cell morphology, outer membrane permeability, cytoplasmic membrane disruption and intracellular enzymatic activity were also studied to elucidate the mechanism of action on the cells. Increasing temperature and disinfectant concentration were proportional to the rate of cell killing, but efficacy was found to be significantly subdued at 0.5 mg/L and less dependent on the bacterial density. The bactericidal efficiency was higher at alkaline pH of 8 or above as compared to neutral and slightly acidic pH of 7 and 6.5 respectively. The disinfection kinetic curves followed a biphasic pattern of rapid inactivation within the initial 2 min which were followed by a tailing even in the presence of residual biocide. The curves were adequately described by the C avg Hom model. Transmission Electron Microscopy images of the bacteria cells exposed to lethal concentrations of ClO 2 indicated very little observable morphological damage to the outer membranes of the cells. ClO 2 however was found to increase the permeability of the outer and cytoplasmic membranes leading to the leakage of membrane components such as 260 nm absorbing materials and inhibiting the activity of the intracellular enzyme β-D-galactosidase. It is suggested that the disruption of the cytoplasmic membrane and subsequent efflux of intracellular components result in the inactivation of the Gram-negative bacteria.

  7. Monitoring nitrosamines in large water distribution systems and their removal using cyclodextrin polyurethanes

    OpenAIRE

    2010-01-01

    M.Sc. The disinfection of drinking water is an important step in the water treatment process. However, toxic (unwanted) disinfection by-products (DBPs) are often produced during the disinfection of drinking water. One such group of DBPs are the nitrosamines such as N-Nitrosodimethylamine (NDMA). Nitrosamines, particularly NDMA, are highly carcinogenic, mutagenic and teratogenic. The US Environmental Protection Agency (USEPA) placed these compounds into the group B2, which indicates compoun...

  8. Balancing the risks and benefits of drinking water disinfection: disability adjusted life-years on the scale.

    OpenAIRE

    Havelaar, A H; De Hollander, A E; Teunis, P F; Evers, E G; Van Kranen, H J; Versteegh, J F; Van Koten, J E; Slob, W

    2000-01-01

    To evaluate the applicability of disability adjusted life-years (DALYs) as a measure to compare positive and negative health effects of drinking water disinfection, we conducted a case study involving a hypothetical drinking water supply from surface water. This drinking water supply is typical in The Netherlands. We compared the reduction of the risk of infection with Cryptosporidium parvum by ozonation of water to the concomitant increase in risk of renal cell cancer arising from the produc...

  9. Comprehensive Assessment of a Chlorinated Drinking Water Concentrate in a Rat Multigenerational Reproductive Toxicity Study##

    Science.gov (United States)

    Some epidemiological studies report associations between drinking water disinfection by-products (DBPs) and adverse reproductive and developmental effects, e.g., low birth weight, spontaneous abortion, stillbirth, and birth defects. To address concerns raised by these studies, w...

  10. Comprehensive assessment of a chlorinated drinking water concentrate in a rat multigenerational reproductive toxicity study

    Science.gov (United States)

    Some epidemiological studies report associations between drinking water disinfection by-products (DBPs) and adverse reproductive and developmental effects, e.g., low birth weight, spontaneous abortion, stillbirth, and birth defects. To address concerns raised by these studies, w...

  11. 77 FR 58132 - Public Water System Supervision Program Revision for the State of Utah

    Science.gov (United States)

    2012-09-19

    ... accordance with the provisions of Section 1413 of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300g-2... 2 Disinfectants and Disinfection Byproducts Rule that correspond to the National Primary Drinking... Administrator, c/o Robert Clement, Drinking Water Unit (8P-W-DW), U.S. EPA, Region 8, 1595 Wynkoop Street...

  12. Quantification of pathogen inactivation efficacy by free chlorine disinfection of drinking water for QMRA.

    Science.gov (United States)

    Petterson, S R; Stenström, T A

    2015-09-01

    To support the implementation of quantitative microbial risk assessment (QMRA) for managing infectious risks associated with drinking water systems, a simple modeling approach for quantifying Log10 reduction across a free chlorine disinfection contactor was developed. The study was undertaken in three stages: firstly, review of the laboratory studies published in the literature; secondly, development of a conceptual approach to apply the laboratory studies to full-scale conditions; and finally implementation of the calculations for a hypothetical case study system. The developed model explicitly accounted for variability in residence time and pathogen specific chlorine sensitivity. Survival functions were constructed for a range of pathogens relying on the upper bound of the reported data transformed to a common metric. The application of the model within a hypothetical case study demonstrated the importance of accounting for variable residence time in QMRA. While the overall Log10 reduction may appear high, small parcels of water with short residence time can compromise the overall performance of the barrier. While theoretically simple, the approach presented is of great value for undertaking an initial assessment of a full-scale disinfection contactor based on limited site-specific information.

  13. Evaluation of Handheld Assays for the Detection of Ricin and Staphylococcal Enterotoxin B in Disinfected Waters

    Directory of Open Access Journals (Sweden)

    Mary Margaret Wade

    2011-01-01

    Full Text Available Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs in detecting ricin and Staphylococcal Enterotoxin B (SEB in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured.

  14. Community challenges when using large plastic bottles for Solar Energy Disinfection of Water (SODIS

    Directory of Open Access Journals (Sweden)

    Preeti Borde

    2016-09-01

    Full Text Available Abstract Background Communities living in developing countries as well as populations affected by natural or man-made disasters can be left at great risk from water related diseases, especially those spread through the faecal-oral route. Conventional water treatments such as boiling and chlorination can be effective but may prove costly for impoverished communities. Solar water disinfection (SODIS has been shown to be a cheap and effective way for communities to treat their water. The exposure to sunlight is typically carried out in small volume plastic beverage bottles (up to 2 l. Given the water requirements of consumption and basic personal hygiene, this may not always meet the needs of communities. Recent work has shown 19-L plastic water dispenser containers to be effective SODIS reactors, comparable in efficacy to PET bottles. In this paper we outline the need for studying SODIS in large volumes and discuss 4 main associated challenges. Discussion Apart from clean water needed for consumption, access to adequate water is essential for sanitation and hygiene. Contamination of treated water through unwashed hands or vessels contributes heavily to the spread of water borne pathogens in communities. Traditional water treatments such as boiling and chlorination can be effective but may prove financially burdensome for low income communities. SODIS in large vessels could be used as a simple method to meet water requirements in low income and disaster affected populations. However, there have been some concerns associated with the conventional SODIS method; we identify the main ones to be: (1 cold or cloudy weather; (2 the fear of leaching in plastic bottles; (3 water turbidity, and; (4 community acceptance. Summary The application of SODIS in large bottles like WDCs has the potential to be an efficient and cost effective method of disinfecting water, either for consumption until more rigorous water treatments can be put in place, or for

  15. Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater.

    Science.gov (United States)

    Jasper, Justin T; Yang, Yang; Hoffmann, Michael R

    2017-06-20

    Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10-30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO 2 /IrO 2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO 2 /IrO 2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine).

  16. New chlorinated amphetamine-type-stimulants disinfection-by-products formed during drinking water treatment.

    Science.gov (United States)

    Huerta-Fontela, Maria; Pineda, Oriol; Ventura, Francesc; Galceran, Maria Teresa

    2012-06-15

    Previous studies have demonstrated high removal rates of amphetamine-type-stimulants (ATSs) through conventional drinking water treatments; however the behaviour of these compounds through disinfection steps and their transformation into disinfection-by-products (DBPs) is still unknown. In this work, for the first time, the reactivity of some ATSs such as amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA) with chlorine has been investigated under simulated and real drinking water treatment conditions in order to evaluate their ability to give rise to transformation products. Two new DBPs from these illicit drugs have been found. A common chlorinated-by-product (3-chlorobenzo)-1,3-dioxole, was identified for both MDA and MDEA while for MDMA, 3-chlorocatechol was found. The presence of these DBPs in water samples collected through drinking water treatment was studied in order to evaluate their formation under real conditions. Both compounds were generated through treatment from raw river water samples containing ATSs at concentration levels ranging from 1 to 15 ng/L for MDA and from 2.3 to 78 ng/L for MDMA. One of them, (3-chlorobenzo)-1,3-dioxole, found after the first chlorination step, was eliminated after ozone and GAC treatment while the MDMA DBP mainly generated after the postchlorination step, showed to be recalcitrant and it was found in final treated waters at concentrations ranging from 0.5 to 5.8 ng/L. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Comparative study of the formation of brominated disinfection byproducts in UV/persulfate and UV/H2O2 oxidation processes in the presence of bromide.

    Science.gov (United States)

    Wang, Lu; Ji, Yuefei; Lu, Junhe; Kong, Deyang; Yin, Xiaoming; Zhou, Quansuo

    2017-10-01

    The objective of this research was to compare the transformation of Br - and formation of brominated byproducts in UV/persulfate (PS) and UV/H 2 O 2 processes. It was revealed that Br - was efficiently transformed to free bromine which reacted with humic acid (HA) or dihydroxybenzoic acid resulting in the formation of brominated byproducts such as bromoacetic acids (BAAs) in UV/PS system. In contrast, no free bromine and brominated byproducts could be detected in UV/H 2 O 2 system, although the oxidization of Br - was evident. We presumed that the oxidation of Br - by hydroxyl radicals led to the formation of bromine radicals. However, the bromine radical species could be immediately reduced back to Br - by H 2 O 2 before coupling to each other to form free bromine, which explains the undetection of free bromine and BAAs in UV/H 2 O 2 . In addition to free bromine, we found that the phenolic functionalities in HA molecules, which served as the principal reactive sites for free chlorine attack, could be in situ generated when HA was exposed to free radicals. This study demonstrates that UV/H 2 O 2 is more suitable than UV/PS for the treatment of environmental matrices containing Br - . Graphical abstract Graphical abstract.

  18. [Disinfection efficiency of peracetic acid, alone and in combination with hypochlorite, against Mycobacterium avium in drinking water].

    Science.gov (United States)

    Schiavano, G F; Sisti, M; De Santi, M; Brandi, G

    2006-01-01

    Peracetic acid (PAA) is a disinfectant with a wide spectrum of antimicrobial activity, but little is known about the feasibility of using it in the field of drinking water treatment. The aim of this study has been assess disinfectant efficacy of PAA, alone or in combination with hypochlorite, against M. avium in drinking water M. avium is a common opportunistic pathogen in immunocompromised subjects that is able to survive and grow in drinking water distribution systems. In this study PAA did not show appreciable activity against the greater number of tested strains (16/21) up to 5 ppm of PAA, a weak activity was seen on 4 strains, while a significant reduction in viable cells (about 50%) was seen only on 1 strain after 48 h of treatment with 5 ppm of PAA. We also evidenced that M. avium was unaffected by chlorine concentration usually present in drinking water distribution system. Finally, the combination of PAA and sodium hypochlorite did not promote enhanced antimicrobial efficacy respect to the single disinfectants. In conclusion, our result would indicate that PAA is an unlikely candidate for the disinfection of drinking water from M. avium and further strategies are required to eliminate M. avium from drinking water system.

  19. Water disinfection with solar radiation; Desinfeccion del agua con radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Alejandra; Cortes, Juana E; Rodriguez, Miriam; Mundo, Alfredo; Vazquez, Sandra [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Estrada, Claudio A [Centro de Investigacion en Energia, Temixco, Morelos (Mexico)

    2000-07-01

    Water disinfection by exposure to solar radiation is a low cost and easy application option to rural communities. The treatment of water can be done using plastic bags or plastic bottles of two litters setting on a reflective material. The efficient of the plastic bottles is lower than the one plastic bags, but the plastic bottles have a much better control of the treated water avoiding its recontamination. In order to increase the efficiency of disinfection using plastic bottles, two solar concentrators, using flat mirrors, were designed and built. Effluent water from a treatment plant of residual waters was used for the testing. Several comparison were carried out taking into account the position of the concentrators, the transparency of the bottles and the bags. The results show that using the concentrator that adjust its position to the sun every hour, a 100% disinfection is obtained in 4 hours of direct exposure to the sun rays in a sunny day. The period of time can be reduced up to 2 hours, if instead using transparent bottles, the bottles are black painted at their bottom half. With these results, the basis to design a cheap concentrator of easy construction to be used in rural communities have been settle. [Spanish] La desinfeccion del agua por exposicion a la luz solar fotodesinfeccion es una opcion de bajo costo y facil aplicacion para las comunidades rurales. El tratamiento puede llevarse a cabo utilizando bolsas o botellas de plastico transparente de dos litros de capacidad colocadas sobre un material reflejante. Las botellas son menos eficientes que las bolsas, pero permiten un mejor control del agua tratada evitando su recontaminacion. Para aumentar la eficiencia de la desinfeccion utilizando las botellas, se disenaron y construyeron dos concentradores solares de espejos planos que permitieron disminuir el tiempo de exposicion requerido cuando se utilizan estas. Para las pruebas de desinfeccion se utilizo agua del efluente de una planta de tratamiento

  20. The study of chloroform levels during water disinfection by chlorination reference to health risk in drinking water of karachi (pakistan)

    International Nuclear Information System (INIS)

    Khawaja, H.A.; Khattak, I.

    2008-01-01

    This study presents the levels of the chloroform formation during water disinfiction treatment by chlorination with the subsequent formation of by-products like trihalomethanes (THMs) are formed. These THMs in drinking water are found in the form of chloroform, bromodichloromethane, Chlorodibromomethane and bromoform. Out of these four compounds chloroform is the major culprit and Contribute 9.0% of the total THMs concentration (I). Therefore the present work was focused on the Estimation of levels of chloroform in the drinking water samples of Karachi city (Pakistan) by using Bootstrapping statistical technique with regards to the average cancer risk in the community. (author)

  1. Bacterial community changes in copper and PEX drinking water pipeline biofilms under extra disinfection and magnetic water treatment.

    Science.gov (United States)

    Inkinen, J; Jayaprakash, B; Ahonen, M; Pitkänen, T; Mäkinen, R; Pursiainen, A; Santo Domingo, J W; Salonen, H; Elk, M; Keinänen-Toivola, M M

    2018-02-01

    To study the stability of biofilms and water quality in pilot scale drinking water copper and PEX pipes in changing conditions (extra disinfection, magnetic water treatment, MWT). Next-generation sequencing (NGS) of 16S ribosomal RNA genes (rDNA) to describe total bacterial community and ribosomal RNA (rRNA) to describe active bacterial members in addition to traditional microbiological methods were applied. Biofilms from control copper and PEX pipes shared same most abundant bacteria (Methylobacterium spp., Sphingomonas spp., Zymomonas spp.) and average species diversities (Shannon 3·8-4·2) in rDNA and rRNA libraries, whereas few of the taxa differed by their abundance such as lower total Mycobacterium spp. occurrence in copper (disinfection (total chlorine increase from c. 0·5 to 1 mg l -1 ) affected total and active population in biofilms seen as decrease in many bacterial species and diversity (Shannon 2·7, P disinfected copper and PEX samples formed separate clusters in unweighted non-metric multidimensional scaling plot (rRNA) similarly to MWT-treated biofilms of copper (but not PEX) pipes that instead showed higher species diversity (Shannon 4·8, P < 0·05 interaction). Minor chlorine dose addition increased selection pressure and many species were sensitive to chlorination. Pipe material seemed to affect mycobacteria occurrence, and bacterial communities with MWT in copper but not in PEX pipes. This study using rRNA showed that chlorination affects especially active fraction of bacterial communities. Copper and PEX differed by the occurrence of some bacterial members despite similar community profiles. © 2017 The Society for Applied Microbiology.

  2. Disinfection of titanium dioxide nanotubes using super-oxidized water decrease bacterial viability without disrupting osteoblast behavior

    Energy Technology Data Exchange (ETDEWEB)

    Beltrán-Partida, Ernesto [Department of Biomaterials, Dental Materials and Tissue Engineering, Faculty of Dentistry Mexicali, Autonomous University of Baja California, Av. Zotoluca and Chinampas St., 21040 Mexicali, Baja California (Mexico); Department of Corrosion and Materials, Engineering Institute, Autonomous University of Baja California, Blvd. Benito Juarez and Normal St., 21280 Mexicali, Baja California (Mexico); Valdez-Salas, Benjamín, E-mail: benval@uabc.edu.mx [Department of Corrosion and Materials, Engineering Institute, Autonomous University of Baja California, Blvd. Benito Juarez and Normal St., 21280 Mexicali, Baja California (Mexico); Escamilla, Alan; Curiel, Mario [Department of Corrosion and Materials, Engineering Institute, Autonomous University of Baja California, Blvd. Benito Juarez and Normal St., 21280 Mexicali, Baja California (Mexico); Valdez-Salas, Ernesto [Ixchel Medical Centre, Av. Bravo y Obregón, 21000 Mexicali, Baja California (Mexico); Nedev, Nicola [Department of Corrosion and Materials, Engineering Institute, Autonomous University of Baja California, Blvd. Benito Juarez and Normal St., 21280 Mexicali, Baja California (Mexico); Bastidas, Jose M. [National Centre for Metallurgical Research, CSIC, Av. Gregorio del Amo 8, 28040 Madrid (Spain)

    2016-03-01

    Amorphous titanium dioxide (TiO{sub 2}) nanotubes (NTs) on Ti6Al4V alloy were synthesized by anodization using a commercially available super-oxidized water (SOW). The NT surfaces were sterilized by ultraviolet (UV) irradiation and disinfected using SOW. The adhesion and cellular morphology of pig periosteal osteoblast (PPO) cells and the behavior of Staphylococcus aureus (S. aureus) cultured on the sterilized and disinfected surfaces were investigated. A non-anodized Ti6Al4V disc sterilized by UV irradiation (without SOW) was used as control. The results of this study reveal that the adhesion, morphology and filopodia development of PPO cells in NTs are dramatically improved, suggesting that SOW cleaning may not disrupt the benefits obtained by NTs. Significantly decreased bacterial viability in NTs after cleaning with SOW and comparing with non-cleaned NTs was seen. The results suggest that UV and SOW could be a recommendable method for implant sterilization and disinfection without altering osteoblast behavior while decreasing bacterial viability. - Highlights: • The effect of super-oxidized water cleaning was studied on Ti6Al4V nanotubes. • Super oxidized-water cleaning caused a decline in S. aureus viability. • Osteoblast behavior was not disrupted after super-oxidized water disinfection. • Super-oxidized water is suggested as a cleaning protocol for TiO{sub 2} nanotubes.

  3. Disinfection of titanium dioxide nanotubes using super-oxidized water decrease bacterial viability without disrupting osteoblast behavior

    International Nuclear Information System (INIS)

    Beltrán-Partida, Ernesto; Valdez-Salas, Benjamín; Escamilla, Alan; Curiel, Mario; Valdez-Salas, Ernesto; Nedev, Nicola; Bastidas, Jose M.

    2016-01-01

    Amorphous titanium dioxide (TiO_2) nanotubes (NTs) on Ti6Al4V alloy were synthesized by anodization using a commercially available super-oxidized water (SOW). The NT surfaces were sterilized by ultraviolet (UV) irradiation and disinfected using SOW. The adhesion and cellular morphology of pig periosteal osteoblast (PPO) cells and the behavior of Staphylococcus aureus (S. aureus) cultured on the sterilized and disinfected surfaces were investigated. A non-anodized Ti6Al4V disc sterilized by UV irradiation (without SOW) was used as control. The results of this study reveal that the adhesion, morphology and filopodia development of PPO cells in NTs are dramatically improved, suggesting that SOW cleaning may not disrupt the benefits obtained by NTs. Significantly decreased bacterial viability in NTs after cleaning with SOW and comparing with non-cleaned NTs was seen. The results suggest that UV and SOW could be a recommendable method for implant sterilization and disinfection without altering osteoblast behavior while decreasing bacterial viability. - Highlights: • The effect of super-oxidized water cleaning was studied on Ti6Al4V nanotubes. • Super oxidized-water cleaning caused a decline in S. aureus viability. • Osteoblast behavior was not disrupted after super-oxidized water disinfection. • Super-oxidized water is suggested as a cleaning protocol for TiO_2 nanotubes.

  4. Virus Disinfection in Water by Biogenic Silver Immobilized in Polyvinylidene Fluoride Membranes

    Energy Technology Data Exchange (ETDEWEB)

    B De Gusseme; T Hennebel; E Christiaens; H Saveyn; K Verbeken; J Fitts; N Boon; W Vertraete

    2011-12-31

    The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sup 0}{sub powder} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {mu}g L{sub -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {mu}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale.

  5. Electrochemical disinfection of simulated ballast water on PbO2/graphite felt electrode

    International Nuclear Information System (INIS)

    Chen, Shuiping; Hu, Weidong; Hong, Jianxun; Sandoe, Steve

    2016-01-01

    A novel PbO 2 /graphite felt electrode was constructed by electrochemical deposition of PbO 2 on graphite felt and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) analysis. The prepared electrode is a viable technology for inactivation of Escherichia coli, Enterococcus faecalis, and Artemia salina as indicator organisms in simulated ballast water treatment, which meets the International Maritime Organization (IMO) Regulation D-2. The effects of contact time and current density on inactivation were investigated. An increase in current density generally had a beneficial effect on the inactivation of the three species. E.faecalis and A.salina were more resistant to electrochemical disinfection than E. coli. The complete disinfection of E.coli was achieved in <8 min at an applied current density of 253 A/m 2 . Complete inactivation of E. faecalis and A.salina was achieved at the same current density after 60 and 40 min of contact time, respectively. A. salina inactivation follows first-order kinetics. - Highlights: •A novel PbO 2 /graphite felt anode was developed for the electrochemical treatment of the simulated ballast water. •The technology meets the IMO D‐2 regulation and provides a high degree of removal of the microorganisms of ballast water without any additional chemical substances. •E.faecalis, E.coli, and A.salina cells in simulated ballast water were completely inactivated after 60, 8 and 40 min of contact time at 253 A/m 2 of current density, respectively.

  6. Sequential use of ultraviolet light and chlorine for reclaimed water disinfection

    Institute of Scientific and Technical Information of China (English)

    Xiujuan Wang; Xuexiang Hu; Chun Hu; Dongbin Wei

    2011-01-01

    Several disinfection processes of ultraviolet (UV),chlorine or UV followed by chlorine were investigated in municipal wastewater according to the inactivation of Escherichia coli,Shigella dysenteriae and toxicity formation.The UV inactivation of the tested pathogenic bacteria was not affected by the quality of water.It was found that the inactivated bacteria were obviously reactivated after one day in dark.Fluorescent light irradiation increased the bacteria repair.The increase of UV dosage could cause more damage to bacteria to inhibit bacteria self-repair.No photoreactivation was detected when the UV dose was up to 80 mJ/cm2 for E.coli DH5α,and 23 mJ/cm2 for S.dysenteriae.Nevertheless,sequential use of 8 mJ/cm2 of UV and low concentration of chlorine (1.5mg/L) could effectively inhibit the photoreactivation and inactivate E.coli below the detection limits within seven days.Compared to chlorination alone,the sequential disinfection decreased the genotoxicity of treated wastewater,especially for the sample with high NH3-N concentration.

  7. Electrochemical disinfection of simulated ballast water on PbO2/graphite felt electrode.

    Science.gov (United States)

    Chen, Shuiping; Hu, Weidong; Hong, Jianxun; Sandoe, Steve

    2016-04-15

    A novel PbO2/graphite felt electrode was constructed by electrochemical deposition of PbO2 on graphite felt and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) analysis. The prepared electrode is a viable technology for inactivation of Escherichia coli, Enterococcus faecalis, and Artemia salina as indicator organisms in simulated ballast water treatment, which meets the International Maritime Organization (IMO) Regulation D-2. The effects of contact time and current density on inactivation were investigated. An increase in current density generally had a beneficial effect on the inactivation of the three species. E.faecalis and A.salina were more resistant to electrochemical disinfection than E. coli. The complete disinfection of E.coli was achieved in <8min at an applied current density of 253A/m(2). Complete inactivation of E. faecalis and A.salina was achieved at the same current density after 60 and 40min of contact time, respectively. A. salina inactivation follows first-order kinetics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. MODULATION OF THE CYTOTOXICITY AND GENOTOXICITY OF THE DRINKING WATER DBP IODOACETIC ACID BY SUPPRESSORS OF OXIDATIVE STRESS

    Science.gov (United States)

    Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose a hazard to the public health. Previously we demonstrated that iodoacetic acid was the most cytotoxic and genotoxic DBP analyzed in a mammalian cell system. Little is k...

  9. Drugs, diagnostic agents and disinfectants in wastewater and water--a review.

    Science.gov (United States)

    Kümmerer, K

    2000-01-01

    After administration pharmaceuticals are excreted by the patients into the aquatic environment via wastewater. Unused medications are sometimes disposed of in drains. The drugs may enter the aquatic environment and eventually reach drinking water, if they are not biodegraded or eliminated during sewage treatment. Additionally, antibiotics and disinfectants are assumed to disturb the wastewater treatment process and the microbial ecology in surface waters. Furthermore, resistant bacteria may be selected in the aeration tanks of sewage treatment plants by the antibiotic substances present. Since the 1980s, data on the occurrence of pharmaceuticals in natural surface waters and the effluents of sewage treatment plants have been reported. More recently, pharmaceuticals have been detected in ground and drinking water. However, only little is known about the risk imposed on humans by pharmaceuticals and their metabolites in surface and drinking water. An overview of input, occurrence, elimination (e.g. biodegradability) and possible effects of different pharmaceutical groups such as anti-tumour drugs, antibiotics and contrast media as well as AOX resulting from hospitals effluent input into sewage water and surface water is presented.

  10. Experimental and simulation validation of ABHE for disinfection of Legionella in hot water systems

    International Nuclear Information System (INIS)

    Altorkmany, Lobna; Kharseh, Mohamad; Ljung, Anna-Lena; Staffan Lundström, T.

    2017-01-01

    Highlights: • ABHE system can supply a continues thermal treatment of water with saving energy. • Mathematical and experimental validation of ABHE performance are presented. • EES-based model is developed to simulate ABHE system. • Energy saving by ABHE is proved for different initial working parameters. - Abstract: The work refers to an innovative system inspired by nature that mimics the thermoregulation system that exists in animals. This method, which is called Anti Bacteria Heat Exchanger (ABHE), is proposed to achieve continuous thermal disinfection of bacteria in hot water systems with high energy efficiency. In particular, this study aims to demonstrate the opportunity to gain energy by means of recovering heat over a plate heat exchanger. Firstly, the thermodynamics of the ABHE is clarified to define the ABHE specification. Secondly, a first prototype of an ABHE is built with a specific configuration based on simplicity regarding design and construction. Thirdly, an experimental test is carried out. Finally, a computer model is built to simulate the ABHE system and the experimental data is used to validate the model. The experimental results indicate that the performance of the ABHE system is strongly dependent on the flow rate, while the supplied temperature has less effect. Experimental and simulation data show a large potential for saving energy of this thermal disinfection method by recovering heat. To exemplify, when supplying water at a flow rate of 5 kg/min and at a temperature of 50 °C, the heat recovery is about 1.5 kW while the required pumping power is 1 W. This means that the pressure drop is very small compared to the energy recovered and consequently high saving in total cost is promising.

  11. Wastewater disinfection by peracetic acid: assessment of models for tracking residual measurements and inactivation.

    Science.gov (United States)

    Santoro, Domenico; Gehr, Ronald; Bartrand, Timothy A; Liberti, Lorenzo; Notarnicola, Michele; Dell'Erba, Adele; Falsanisi, Dario; Haas, Charles N

    2007-07-01

    With its potential for low (if any) disinfection byproduct formation and easy retrofit for chlorine contactors, peracetic acid (PAA) or use of PAA in combination with other disinfectant technologies may be an attractive alternative to chlorine-based disinfection. Examples of systems that might benefit from use of PAA are water reuse schemes or plants discharging to sensitive receiving water bodies. Though PAA is in use in numerous wastewater treatment plants in Europe, its chemical kinetics, microbial inactivation rates, and mode of action against microorganisms are not thoroughly understood. This paper presents results from experimental studies of PAA demand, PAA decay, and microbial inactivation, with a complementary modeling analysis. Model results are used to evaluate techniques for measurement of PAA concentration and to develop hypotheses regarding the mode of action of PAA in bacterial inactivation. Kinetic and microbial inactivation rate data were collected for typical wastewaters and may be useful for engineers in evaluating whether to convert from chlorine to PAA disinfection.

  12. Improved concrete properties to resist the saline water using environmental by-product

    Directory of Open Access Journals (Sweden)

    Mohamed Anwar

    2013-10-01

    Full Text Available This paper investigates the influence of using environmental by-product materials (silica fume and fly ash in concrete on the chloride ion permeability of concrete. Nine concrete mixtures were designed to have the same degree of workability and air content with water/cementitious material ratio of 0.4. The studied parameters include the main fresh and hardened concrete properties such as slump, air content, unit weight, compressive strength, tensile strength, flexural strength, static Young's modulus, and dynamic elastic modulus. Concrete samples were kept in water for 28 days, then immersed in artificial sea water for 5 months. The total and soluble chloride contents were measured through the concrete using the potentiometric titration analysis. The obtained test results indicated that the use of ternary systems in concrete improved the different characteristics of the product concrete and showed a significant resistance to chloride penetration. The weights of chloride in mix 9 (10% silica fume and 25% fly ash at depths from the concrete surface to 30 mm were less than the weights of control mix 1 (100% ordinary Portland cement by about 60%. Further, the ternary systems can be used in concrete industry with considerable proportions.

  13. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    Science.gov (United States)

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-02

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Hepatitis A Virus Disinfection in Water by Solar Photo-Fenton Systems.

    Science.gov (United States)

    Polo, David; García-Fernández, Irene; Fernández-Ibañez, Pilar; Romalde, Jesús L

    2018-06-01

    This study evaluates and compares the effectiveness of solar photo-Fenton systems for the inactivation of hepatitis A virus (HAV) in water. The effect of solar irradiance, dark- Fenton reaction and three different reactant concentrations (2.5/5, 5/10 and 10/20 mg/L of Fe 2+ /H 2 O 2 ) on the photo-Fenton process were tested in glass bottle reactors (200 mL) during 6 h under natural sunlight. Disinfection kinetics were determined both by RT-qPCR and infectivity assays. Mean water temperatures ranged from 25 to 27.3 °C, with a maximum local noon UV irradiances of 22.36 W/m 2 . Photo-Fenton systems yielded increased viral reduction rates in comparison with the isolated effect under the Fenton reaction in darkness (negligible viral reduction) or the solar radiation (0.25 Log of RNA reduction). With the highest concentration employed (10-20 mg/L Fe 2+ -H 2 O 2 ), an average RNA reduction rate of ~ 1.8 Log (initial concentration of 10 5 pfu/mL) and a reduction of 80% in the infectivity capacity were reached. Results showed a strong synergistic effect between Fe 2+ /H 2 O 2 and sunlight, demonstrating that significant disinfection rates of HAV under photo-Fenton systems may occur with relatively higher efficiency at middle environmental temperatures and without the need for an energy-intensive light source.

  15. Suitability of electrolyzed oxidizing water for the disinfection of hard surfaces and equipment in radiology

    OpenAIRE

    Pintaric, Robert; Matela, Joze; Pintaric, Stefan

    2015-01-01

    Background Hospitals are faced with increasingly resistant strains of micro-organisms. When it comes to disinfection, individual parts of electronic equipment of angiology diagnostics such as patient couches of computer tomography (CT) and magnetic resonance imaging (MRI) scanners prove to be very hard to disinfect. Disinfectants of choice are therefore expected to possess properties such as rapid, residue-free action without any damaging effect on the sensitive electronic equipment. This pap...

  16. Disinfection of tertiary wastewater effluent prior to river discharge using peracetic acid; treatment efficiency and results on by-products formed in full scale tests.

    Science.gov (United States)

    Pedersen, Per Overgaard; Brodersen, Erling; Cecil, David

    2013-01-01

    This is an investigation of chemical disinfection, with peracetic acid (PAA), in a tertiary sand filter at a full scale activated sludge plant with nitrification/denitrification and P-removal. The reduction efficiency of Escherichia coli and intestinal enterococci in the sand filter is reported. E. coli log reductions of between 0.4 and 2.2 were found with contact times from 6 to 37 min and with dosing from 0 to 4.8 mg L(-1). The average log reduction was 1.3. The decomposition products, bromophenols, chlorophenols and formaldehyde and residual H2O2 were measured before and after the sand filter. The residual H2O2 concentration in the effluent was critical at short contact times and high dosages of PAA due to the discharge limit of 25 μg L(-1). The other three products could not be detected at 0.1 μg L(-1) levels. The chemical cost of PAA dosing is estimated to be 0.039 US$ m(-3) treated wastewater.

  17. Ozone reactions with indoor materials during building disinfection

    DEFF Research Database (Denmark)

    Poppendieck, D.; Hubbard, H.; Ward, M.

    2007-01-01

    , and particularly after several hours of disinfection, surface reaction resistance dominated the overall resistance to ozone deposition for nearly all materials. Total building disinfection by-products (all carbonyls) were quantified per unit area of each material for the experimental period. Paper, office...... partition, and medium density fiberboard each released greater than 38 mg m(-2) of by-products....

  18. Virus disinfection in water by biogenic silver immobilized in polyvinylidene fluoride membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gusseme, B.D.; Fitts, J.; Hennebel, T.; Christiaens, E.; Saveyn, H.; Verbeken, K.; Boon, N.; Verstraete, W.

    2011-03-01

    The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sub powder}{sup 0} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {micro}g L{sup -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {micro}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale. In biogenic silver, silver nanoparticles are attached to a bacterial carrier matrix. Bio-Ag{sup 0} was successfully immobilized in PVDF membranes using immersion-precipitation. The antiviral activity of this material was demonstrated in a plate membrane reactor. The antimicrobial mechanism was most probably related to the slow release of Ag{sup +} ions. The membranes can be applied for treatment of limited volumes of contaminated water.

  19. 78 FR 47697 - Public Water System Supervision Program Revision for the State of Louisiana

    Science.gov (United States)

    2013-08-06

    ...: 1) Long Term 2 Enhanced Surface Water Treatment Rule (LT2), 2) the Stage 2 Disinfectants and Disinfection Byproducts Rule (DBP2), and 3) the Lead and Copper Rule Short-Term Revisions and Clarifications...: Louisiana Department of Health and Hospitals, Office of Public Health, Bienville Building, 628 4th Street...

  20. Establishment and Early Succession of Bacterial Communities in Monochloramine-Treated Drinking Water Biofilms

    Science.gov (United States)

    Monochloramine is increasingly used as a drinking water disinfectant because it forms lower levels of regulated disinfection by-products. While its use has been shown to increase nitrifying bacteria, little is known about the bacterial succession within biofilms in monochloramin...

  1. Use of reflectors to enhance the synergistic effects of solar heating and solar wavelengths to disinfect drinking water sources

    Energy Technology Data Exchange (ETDEWEB)

    Rijal, G.K. [Metropolitan Water Reclamation District of Greater Chicago, Cicero, Illinois (United States); Fujioka, R.S. [University of Hawaii, Honolulu (United States). Water Resources Research Center

    2004-07-01

    Aluminum reflectors were added to solar units designed to inactivate faecal microorganisms (faecal coliform, E. coli, enterococci, FRNA coliphage, C. perfringens) in stream water and diluted sewage by the two mechanisms (solar heat, solar UV) known to inactivate microorganisms. During sunny conditions, solar units with and without reflectors inactivated E. coli to <1 CFU/100 ml to meet drinking water standards. Solar units with reflectors disinfected to the water sooner by increasing the water temperature by 8-10{sup o}C to 64-75{sup o}C. However, FRNA coliphages were still detected in these samples, indicating that this treatment may not inactivate pathogenic human enteric viruses. During cloudy conditions, reflectors only increased the water temperature by 3-4{sup o}C to a maximum of 43-49{sup o}C and E. coli was not completely inactivated. Under sunny and cloudy conditions, the UV wavelengths of sunlight worked synergistically with increasing water temperatures and were able to disinfect microorganisms at temperatures (45-56{sup o}C), which were not effective in inactivating microorganisms. Relative resistance to the solar disinfecting effects were C perfringens > FRNA coliphages > enterococci >E. coli > faecal coliform. (author)

  2. Use of reflectors to enhance the synergistic effects of solar heating and solar wavelengths to disinfect drinking water sources.

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2003-01-01

    Aluminum reflectors were added to solar units designed to inactivate faecal microorganisms (faecal coliform, E. coli, enterococci, FRNA coliphage, C. perfringens) in stream water and diluted sewage by the two mechanisms (solar heat, solar UV) known to inactivate microorganisms. During sunny conditions, solar units with and without reflectors inactivated E. coli to water standards. Solar units with reflectors disinfected the water sooner by increasing the water temperature by 8-10 degrees C to 64-75 degrees C. However, FRNA coliphages were still detected in these samples, indicating that this treatment may not inactivate pathogenic human enteric viruses. During cloudy conditions, reflectors only increased the water temperature by 3-4 degrees C to a maximum of 43-49 degrees C and E. coli was not completely inactivated. Under sunny and cloudy conditions, the UV wavelengths of sunlight worked synergistically with increasing water temperatures and were able to disinfect microorganisms at temperatures (45-56 degrees C), which were not effective in inactivating microorganisms. Relative resistance to the solar disinfecting effects were C. perfringens > FRNA coliphages > enterococci > E. coli > faecal coliform.

  3. Strontium isotope study of coal utilization by-products interacting with environmental waters.

    Science.gov (United States)

    Spivak-Birndorf, Lev J; Stewart, Brian W; Capo, Rosemary C; Chapman, Elizabeth C; Schroeder, Karl T; Brubaker, Tonya M

    2012-01-01

    Sequential leaching experiments on coal utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements-including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc-during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ((87)Sr/(86)Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-(87)Sr/(86)Sr) component. A changing Sr isotope ratio of CUB-interacting waters in a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB-water interaction. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Determinants of disinfectant pretreatment efficacy for nitrosamine control in chloraminated drinking water.

    Science.gov (United States)

    McCurry, Daniel L; Krasner, Stuart W; von Gunten, Urs; Mitch, William A

    2015-11-01

    Utilities using chloramines need strategies to mitigate nitrosamine formation to meet potential future nitrosamine regulations. The ability to reduce NDMA formation under typical post-chloramination conditions of pretreatment with ultraviolet light from a low pressure mercury lamp (LPUV), free chlorine (HOCl), ozone (O3), and UV light from a medium pressure mercury lamp (MPUV) were compared at exposures relevant to drinking water treatment. The order of efficacy after application to waters impacted by upstream wastewater discharges was O3 > HOCl ≈ MPUV > LPUV. NDMA precursor abatement generally did not correlate well between oxidants, and waters exhibited different behaviors with respect to pH and temperature, suggesting a variety of source-dependent NDMA precursors. For wastewater-impacted waters, the observed pH dependence for precursor abatement suggested the important role of secondary or tertiary amine precursors. Although hydroxyl radicals did not appear to be important for NDMA precursor abatement during O3 or MPUV pretreatment, the efficacy of MPUV correlated strongly with dissolved organic carbon concentration (p = 0.01), suggesting alternative indirect photochemical pathways. The temperature dependences during pre- and post-disinfection indicated that NDMA formation is likely to increase during warm seasons for O3 pretreatment, decrease for HOCl pretreatment, and remain unchanged for MPUV treatment, although seasonal changes in source water quality may counteract the temperature effects. For two waters impacted by relatively high polyDADMAC coagulant doses, pretreatment with HOCl, O3, and MPUV increased NDMA formation during post-chloramination. For O3 pretreatment, hydroxyl radicals likely led to precursor formation from the polymer in the latter tests. MPUV treatment of polymer-impacted water increased subsequent NDMA formation through an indirect photochemical process. Many factors may mitigate the importance of this increased NDMA formation

  5. Investigation of coal combustion by-product utilization for oyster reef development in Texas bay waters

    International Nuclear Information System (INIS)

    Baker, W.B. Jr.; Ray, S.M.; Landry, A.M. Jr.

    1991-01-01

    Houston Lighting and Power Company (HL and P), Texas A and M University at Galveston and JTM Industries, Inc. initiated research in May 1988 and coordinated it with state and federal resource protection agencies to investigate the use of certain HL and P coal combustion by-products (CCBP) for enhancing and creating oyster reefs. Initial research involved determining and optimum mix design based on compressive strength, leaching potential, biofouling success, and cost. CCBP material was found to exceed compressive strength criterion (300 psi for at sign 14 days) and was not a significant leaching source. Candidate mix designs and oyster shell controls were exposed to hatchery-reared oyster larvae to determine spat setability and biofouling success. Larvae setting on CCBP substrate developed into spat and grew at a rate comparable to that for larvae on controls. Since all candidate mix designs exhibited excellent biofouling, an optimum design was chosen based on strength and material cost factors. Chemical analyses conducted to determine materials did not significantly contribute to the trace element load in oysters. Development of oyster cultch material was initiated with input from commercial 2.5 to 7.6 cm (1 to 3 inch) diameter pellets which are irregularly shaped and rough textured. These pellets greatly enhance water circulation, provide maximum setting potential for oyster larvae, and maximize the surface area to volume potential of the CCBP material

  6. Disinfection by-products/precursor control using an innovative treatment process -- high energy electron beam irradiation

    International Nuclear Information System (INIS)

    Sawal, K.; Millington, B.; Slifker, R.A.; Cooper, W.J.; Nickelsen, M.G.; Kurucz, C.N.; Waite, T.D.

    1993-01-01

    When waters containing naturally occurring humic substances, precursors, are chlorinated, reaction (disinfection) by-products (DBPs) that may compromise the chemical water quality of the drinking water are formed. Two options exist for the treatment of THMs and other DBPs, removal of precursor material prior to chlorination, or destruction of the by-products once they are formed. The authors have initiated a study using an innovative process, high energy electron beam irradiation, as an alternative treatment for the destruction of toxic organic compounds. Preliminary studies indicated that the process would also be effective in the removal of precursors. An added advantage of this process is that is would serve as a primary disinfectant, destroying any toxic compounds in the source water and may assist in the removal of algae and cyanobacteria toxins. This paper discusses studies in precursor removal and control of THMs

  7. UV disinfection and flocculation-chlorination sachets to reduce hepatitis E virus in drinking water.

    Science.gov (United States)

    Guerrero-Latorre, Laura; Gonzales-Gustavson, Eloy; Hundesa, Ayalkibet; Sommer, Regina; Rosina, Girones

    2016-07-01

    Hepatitis E Virus (HEV) is a major cause of waterborne outbreaks in areas with poor sanitation. As safe water supplies are the keystone for preventing HEV outbreaks, data on the efficacy of disinfection treatments are urgently needed. Here, we evaluated the ability of UV radiation and flocculation-chlorination sachets (FCSs) to reduce HEV in water matrices. The HEV-p6-kernow strain was replicated in the HepG2/C3A cell line, and we quantified genome number using qRT-PCR and infectivity using an immunofluorescence assay (IFA). UV irradiation tests using low-pressure radiation showed inactivation kinetics for HEV of 99.99% with a UV fluence of 232J/m(2) (IC 95%, 195,02-269,18). Moreover, the FCSs preparations significantly reduced viral concentrations in both water matrices, although the inactivation results were under the baseline of reduction (4.5 LRV) proposed by WHO guidelines. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Development of silver and zinc oxide decorated nanoclay containing polymeric composites for water disinfection applications

    International Nuclear Information System (INIS)

    Motshekga, Sarah C.; Ray, Suprakas Sinha; Onyango, Maurice S.; Momba, Maggie N. B.

    2015-01-01

    Contaminated drinking water has serious implications to the human health that could lead to death. The rapid growth of bacterial contamination in drinking water is alarming, and yet a robust and cost effective method with less limitation has not been developed. The current study is aimed at evaluating the performance of nanoclay composites dispersed in chitosan biopolymer as an antibacterial material. The performances of the composites were evaluated using the batch kinetic studies. Three composites of Ag-CtsB, ZnO-CtsB and Ag/ZnO-CtsB were prepared and evaluated against gram negative Escherichia coli and gram positive Enterococcus faecalis bacteria. The composites were characterized by powder X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and BET surface area measurements. Antibacterial activity results showed that