Download or read book Formation and Decay of Disinfection By products in the Distribution System written by and published by American Water Works Association. This book was released on 2006 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project was to understand the formation and decay of selected DBPs in full-scale distribution systems focusing on the four THMs and the nine HAAs, as well as individual THM and HAA species. Because of its critical nature, NDMA was also included. The project objectives were: evaluate the critical factors that affect THM and HAA behavior in distribution systems; determine the fate and behavior of NDMA in distribution systems; evaluate the effect of pipe material and diameter on the fate of DBPs in distribution systems; examine the effect of storage reservoirs / tanks and booster chlorination stations on THM, HAA and NDMA concentrations; evaluate the changes in DBP concentrations and speciation when a system seasonally switches from chloramines to free chlorine to limit potential nitrification episodes....

Download or read book Disinfection By product Formation in the Water Distribution System of Morehead Kentucky written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of the distribution system on water quality seems complex. Water demands and average residence times change continually, and chlorine residuals depend on these changing residence times as well as changes in temperature, pH, and organic matter characteristics caused by distribution system hydraulic dynamics. Furthermore, these changing physical/chemical conditions inherently affect the formation of regulated disinfection by-products (DBPs). The research focuses on a water distribution system in eastern Kentucky, which is fed by a 5 MGD conventional treatment plant. The field study was conducted in two phases. A 24-hour hydraulic field sampling event was performed to provide basic data for characterizing the system hydraulics and for understanding the kinetics of chlorine decay and DBP formation. A 48-hour water quality sampling event was conducted using the utility's four regulatory sampling locations, augmented by 15 locations designed to sample representative water from storage tanks, dead-ends, and different pipe materials and ages.

Download or read book Analysis and Management of Disinfection by Product Formation in Distribution Systems written by Sandhya Rao Poleneni and published by . This book was released on 2013 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: The newly promulgated Stage-2 Disinfectant and Disinfection By-Product (D/DBP) regulations force water utilities of all sizes to be more concerned with their finished and distributed water quality. Compliance for many small-scale utilities requires changes to their current operational strategy. However, these changes affect the formation of DBPs over time. This study is performed in an effort to examine and quantify the extent of change in DBP formation and chlorine decay kinetics under different operational conditions and pipe materials found at many small-scale water utilities. As a part of this study a physical model (Pipe Loop) of a distribution system was used to evaluate the change in water quality as a function of time under different operational conditions such as having a high chlorine dosage entering the distribution system, using a chlorine booster system in the distribution system, and operation of clearwells/storage tanks. It is determined that High Chlorine run is least optimal option with approximately 64% and 30% higher production of TTHMs when compared to Normal and Chlorine Booster run, respectively. It is also determined that High Chlorine conditions minimize the wall effects and the location of Boosters should always be after the storage systems to avoid extra contact time that can produce approximately 23-78% higher concentrations of TTHMs. In case of storage systems, it is statistically proven that storage time before entering the tank, mixing conditions and fillings cycles play an important role in maintaining water quality in the tanks.

Download or read book Stage 2 Disinfectants and Disinfection Byproducts Rule written by and published by DIANE Publishing. This book was released on 2003 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Disinfection By products in Drinking Water written by K. Clive Thompson and published by Royal Society of Chemistry. This book was released on 2016 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the latest developments in themes related to water disinfection by-products, this book brings the academic and industry researchers right up to date.

Download or read book Disinfection Byproducts in Drinking Water written by Yuefeng Xie and published by CRC Press. This book was released on 2003-08-27 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The EPA has established regulations which classify four types of disinfection byproducts - TTHMs, haloacetic acids, bromate, and chlorite - and requires public water systems limit these byproducts to specific levels. Most of the information required to comply with these standards is either scattered throughout the literature or derived from confere

Download or read book Disinfection By Products in Drinking Water written by M Fielding and published by Elsevier. This book was released on 1999-01-01 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together contributors from water regulators, and water suppliers in Europe and North America to discuss the main issues associated with reaching a cost-effective balance between microbial and chemical risks. Overviews of research are presented alongside illuminating case studies of the practical approaches taken by water companies and regulators on both sides of the Atlantic.

Download or read book Disinfection By products in Drinking Water written by M.N.V. Prasad and published by Butterworth-Heinemann. This book was released on 2020-02-18 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disinfection Byproducts in Drinking Water: Detection and Treatment presents cutting-edge research on how to understand the procedures, processes and considerations for detecting and treating disinfection by-products from drinking water, swimming pool water, and wastewater. The book begins with an overview of the different groups of Disinfection Byproducts (DBPs), such as: Trihalomethanes (THM), Halo acetic acids, and Haloacetonitrile (HAN). This coverage is quickly followed by a clear and rigorous exposition of the latest methods and technologies for the characterization, occurrence, formation, transformation and removal of DBPs in drinking water. Other chapters focus on ultraviolet-visible spectroscopy, electron spin resonance, and gas chromatography-mass spectrometry. Researchers will find a valuable resource to a breath of topics for DBP detection and treatment, including various recent techniques, such as microfiltration, nanofiltration membrane and nanotechnology. Explains the latest research in detection, treatment processes and remediation technologies Includes sampling, analytical and characterization methods and approaches Covers cutting-edge research, including membrane based technologies, nanotechnology treatment technologies and bioremediation treatment technologies Provides background information regarding contamination sources

Download or read book Influence of Biofilm on Disinfection Byproducts Formation and Decay in a Simulated Water Distribution System written by Zhikang Wang and published by . This book was released on 2013 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since biofilm has been implicated in the deterioration water quality and the increase of public health risks, various efforts have been made to minimize biofilm regrowth in drinking water distribution systems. Although traditional water treatment processes can greatly remove a large fraction of disinfection by-products (DBPs) precursors, a small portion of natural organic matter (NOM) may still enter water distribution systems. Untreated NOM can serve as nutrients for biofilm growth while also consuming maintained disinfection residuals, which can result in microbial contamination in drinking water. To suppress biofilm formation, water utilities maintain disinfectant residuals for the distribution system. However, upon disinfectant addition, toxic DBPs are inevitably produced. Biofilm and its secreted extracellular polymeric substances (EPS) produce toxic DBPs, due to the very similar chemical composition compared to traditional investigated DBP precursors. This research investigated the role of biofilm on DBP formation and decay in simulated drinking water distribution systems with four objectives. The first objective was to investigate the influence of chemical composition and quantity of bacterial EPS on the biosorption of NOM in drinking water. Results indicated that both protein and polysaccharide based EPS adsorbed existing NOM. Biosorption capacity was mainly determined by divalent ion (Ca2+ and Mg2+) concentrations. Mechanistically, the presence of a diffuse electrical double layer inhibited NOM biosorption by potential energy barriers, however, presence of divalent ions in the aquatic environment enhanced biosorption processes, permitting functional group interactions between EPS and NOM. In addition, hydrophobic interactions, EPS characteristics and quantity can also be used to explain biosorption results. Bridging between hydrophilic carboxyl groups on alginate EPS and NOM appeared to be the dominant form of biosorption, while hydrophobic interactions enhanced biosorption for protein-based EPS. The second and third objectives of this study were to investigate the role of biofilm EPS on the formation of both carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs). DBP yield (formation potential) tests of both bacterial culture and extracted EPS indicated that the chemical composition and quality of EPS played a critical role for DBP formation. In general, protein based EPS possessed higher DBP yields compared to polysaccharide based EPS, especially for N-DBPs. To further determine the relative contribution of each biomolecule in EPS to DBP formation and speciation, detailed chemical compositions of biomolecules in EPS (amino acids, polysaccharide monomers, and fatty acids) from both pure culture and mixed species biofilm isolated from a water utility were analyzed. DBP yield results from both extracted EPS and EPS surrogates (amino acids and polysaccharide monomers) indicated that proteins in EPS have a greater impact on DBP formation, where amino acids containing unsaturated organic carbon or conjugated bonds in R-group produced higher amount of DBPs. However, DBP yields of polysaccharide monomers were lower than those of tested amino acids groups and the DBP yields were not significantly influenced by their chemical structures. The last objective of this study was to understand the influence of biofilm on DBP formation and decay in a simulated water distribution system using lab scale annular reactors. For Cl2 disinfection at 0.5 mg L-1 Cl2 residual concentration, no obvious DBP formation was observed. This was mainly due to the combination of low DBP formation, DBP volatilization, and biodegradation. However, when high Cl2 residuals were maintained, the formations of both C-DBPs and N-DBPs increased dramatically beyond the DBP formation potential of the feed solution. This suggests higher Cl2 residual not only reacted with humic acid (HA) in feed solution but also reacted with biofilm and produced extra DBPs, especially the high formation of N-DBPs (haloacetonitriles). For NH2Cl disinfection, the DBP levels were much lower than those of Cl2 disinfection and differences in DBP formation were not significant under different NH2Cl residual concentrations. Combined results suggested that biofilm can impact both C-DBP and N-DBP formation and decay in water distribution systems, where biomolecules in EPS affect DBP speciation.

Download or read book Disinfection By Products and Human Health written by Steve E. Hrudey and published by IWA Publishing. This book was released on 2012-04-30 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disinfection By-Products and Human Health is based on contributions from speakers who participated in May 2011 workshops on Disinfection By-Products (DBPs) and Human Health at Ozwater 11 in Adelaide, Australia or at an AWA sponsored workshop at the Curtin Water Quality Research Centre, Perth, Australia. The contributions are prepared to facilitate communication with practitioners, rather than researchers, making use of overview illustrations rather than dense text or data tables. Each chapter concludes with up to 5 key findings that are take-home messages for practitioners. Disinfection By-Products and Human Health is aimed specifically at drinking water professionals (engineers, chemists and public health professionals) working on the front lines of drinking water issues where they must encounter actual day-to-day issues of risk management concerning DBPs in relation to all the other regulatory and water quality issues they must manage. Although a topic this complex is certainly not amenable to simplistic explanations, this book aims to provide drinking water professionals with a pragmatic assessment of the current evidence and emerging issues concerning DBPs and public health. Disinfection By-Products and Human Health is an essential, practical and accessible guide for drinking water professionals, engineers, chemists and public health professionals. Editors: Steve E. Hrudey, Professor Emeritus, Analytical & Environmental Toxicology, University of Alberta, Canada, Jeffrey W.A. Charrois, Director and Associate Professor, Curtin Water Quality Research Centre, Curtin University of Technology, Australia, Steve Hrudey is professor emeritus in analytical and environmental toxicology in the University of Alberta's Faculty of Medicine & Dentistry. He spent 13 years as a cabinet-appointed member of the Alberta Environmental Appeals Board, the last four as chair, and was the first non-lawyer to hold this position. During this period, he served on 36 public hearing panels, 19 as chair of the panel. In addition he has testified before senate committees in Canada and the Legislative Council in Western Australia. Hrudey has served on a number of high-profile expert panels, including the Research Advisory Panel to the Walkerton Inquiry (2000-2002), the Expert Panel on Safe Drinking Water for First Nations (2006), the Technical Advisory Committee to the B.C. Minister of Health on turbidity and microbial risk in drinking water (2007-2008, as chair), the Expert Advisory Panel on Water Quality for Washington, D.C., to the U.S. Army Corps of Engineers (2009-2011) and chair of the Royal Society of Canada Expert Panel on Environmental and Health Impacts of Canada's Oil Sands Industry (2009-2010). He has also co-authored or edited nine books, including the widely acclaimed book inspired by the Walkerton tragedy: Safe Drinking Water - Lessons from Recent Outbreaks in Affluent Nations (IWA Publishing, 2004). He has written 26 book chapters, 19 expert panel reports, 163 refereed journal articles, 15 science discussions, six media op-eds and 73 conference proceeding papers. Hrudey is the 2012 winner of the American Water Works Association A.P. Black Research Award for contributions to water science and water supply. This book is sponsored by Australian Water Association (AWA)

Download or read book Controlling Disinfection By products and Microbial Contaminants in Drinking Water written by Robert M. Clark and published by DIANE Publishing. This book was released on 2001 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Disinfection By products written by and published by . This book was released on 1989 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Extracellular Polymeric Substances written by Jost Wingender and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial extracellular polymeric substances (EPS) are the key components for the aggregation of microorganisms in biofilms, flocs and sludge. They are composed of polysaccharides, proteins, nucleic acids, lipids and other biological macromolecules. EPS provide a highly hydrated gel matrix in which microbial cells can establish stable synergistic consortia. Cohesion and adhesion as well as morphology, structure, biological function and other properties such as mechanical stability, diffusion, sorption and optical properties of microbial aggregates are determined by the EPS matrix. Also, the protection of biofilm organisms against biocides is attributed to the EPS. Their matrix allows phase separation in biofiltration and is also important for the degradation of particulate material which is of great importance for the self purification processes in surface waters and for waste water treatment.

Download or read book Impact of Water Heating on Disinfection Byproducts Concentration written by Boning Liu and published by . This book was released on 2014 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drinking water disinfection byproducts (DBP) are a group of inorganic and organic compounds formed during water disinfection. Epidemiologic studies suggest an association between rectal, and colon cancer and exposure to DBPs in chlorinated surface water. Therefore, DBPs are a growing public health concern; one that has been mitigated by multiple regulations of US Environmental Protection Agency (EPA) including the Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR). Tremendous efforts and cost have been spent on controlling DBPs in drinking water; however, human exposure has been poorly characterized. In addition to ingestion exposure, inhalation and dermal absorption during showering for example could also be significant exposure pathways. This dissertation focuses on investigating DBP formation and degradation in heated water (~50oC) in both lab simulated tests and field studies. The first objective of this dissertation was to investigate the temporal variability of regulated DBPs and non-regulated DBPs in cold and hot tap water at a residential home, in a water plant and in a simulated distribution system test. The results showed that the residence time of water in hot water tanks plays an important role on the formation and degradation of DBPs in the hot water plumbing. There was no obvious difference between the concentrations of TCAA (trichloroacetic acid) in long-heated hot tap water and cold tap water. The terminal DBPs for cold and hot tap water were measured and compared to the instantaneous DBP formation in cold and hot tap water. The heating of tap water in the water tank was found to increase the extent of THM formation. The second objective of this dissertation was to investigate the impact of heating scenarios on the formation and degradation of DBPs. A field study involving homes equipped with either tankless heaters or tank heaters was conducted. The concentrations of DBPs were measured for cold and hot tap water of each home. A lab-controlled heating test was later on set up to investigate the formation and degradation of DBPs in short term and long term heating to understand the difference in DBP concentrations in the hot tap water out of different types of water heaters. The results from the field study revealed that the differences in DBP levels in the hot tap water out of the two types of heaters were statistically significant for chlorine residual, total trihalomethanes (TTHMs), dichloroacetic acids (DCAA), dichloroacetonitrile (DCAN), trichloroproprane (TCP) and chloropicrin (CP). Bench scale heating tests showed that long term heating changed the concentrations of DBPs significantly. The third objective of this dissertation was to investigate the thermal formation and degradation in various conditions. Especially, the impact of water age on DBP formation and degradation in cold and heated water was investigated. The results of this study demonstrate that DBP concentration profiles in heated water were quite different from the DBP concentrations in the cold tap water. Chloroform concentrations in the heated water remained constant or even decreased slightly with increasing distribution system water age, despite the fact that its levels always increased with water age in the cold water. The final objective of this dissertation was to propose a method to model chlorine decay, not only in the distribution system, but also applicable to home heating scenarios. A robust two-site chlorine decay model of combined effects of pH, temperature in water distribution system and heating condition was proposed. A single set of readily interpretable parameters were estimated by stochastic search using differential evolution.

Download or read book Investigation of Disinfection By Product Formation Potential Test Methodologies in Drinking Water Systems written by Julie DiCicco and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drinking Water Distribution Systems written by National Research Council and published by National Academies Press. This book was released on 2007-01-22 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protecting and maintaining water distributions systems is crucial to ensuring high quality drinking water. Distribution systems-consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances-carry drinking water from a centralized treatment plant or well supplies to consumers' taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management challenge from both an operational and public health standpoint. Recent data on waterborne disease outbreaks suggest that distribution systems remain a source of contamination that has yet to be fully addressed. This report evaluates approaches for risk characterization and recent data, and it identifies a variety of strategies that could be considered to reduce the risks posed by water-quality deteriorating events in distribution systems. Particular attention is given to backflow events via cross connections, the potential for contamination of the distribution system during construction and repair activities, maintenance of storage facilities, and the role of premise plumbing in public health risk. The report also identifies advances in detection, monitoring and modeling, analytical methods, and research and development opportunities that will enable the water supply industry to further reduce risks associated with drinking water distribution systems.

Download or read book Development of a Chlorine Decay and Trihalomethane Formation Modeling Protocol Using Initial Distribution System Evaluation Data written by James P. Cooper and published by . This book was released on 2009 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently many water distribution systems (WDS) developed and calibrated extended period simulation model to assist in the Initial Distribution System Evaluation (IDSE). The IDSE is the first phase of the Stage 2 Disinfectants and Disinfection Byproducts (D/DBP) Rule promulgated by the United States Environmental Protection Agency (USEPA). The purpose of the IDSE was to identify locations within the WDS for Stage 2 D/DBP compliance monitoring. This research aided two northern Ohio distribution systems in completion of the IDSE requirements and further develops the models to predict chlorine residuals and trihalomethane (THM) concentrations.Existing models were utilized as a base and updated with data collected during extensive field studies. A Form 4: Modeling Study Plan, which provides justification that the models meet minimum calibration requirements was submitted and approved by the USEPA. The updated models were utilized to select Stage 2 D/DBP future monitoring locations. Drafts of Form 5: IDSE Report for a Modeling SSS were completed for each system.First-order reaction expressions were developed to estimate the effects of bulk reactions and reactions occurring along the surface of the distribution system pipes (wall) for free chlorine decay and THM formation. Most reaction expressions that utilize a global wall reaction rate coefficient in units of inverse time do not accurately represent the proportion of reactions occurring along the wall. As a chemical travels through a pipe, wall reactions within larger diameter pipes will have less of an effect on the overall reaction than when flowing through a smaller diameter pipe. This is because the ratio of the pipe surface to a unit volume of water is not constant throughout the distribution system. This is, however, constant given a specific flow path from the point of entry into the distribution system to any fixed point, such as a sampling location. In order to account for this wall reaction variability, a series of flow path diameter fractions are employed within the chlorine decay and THM formation expressions. A probabilistic approach using Bayesian statistics is then utilized to estimate the bulk and wall reaction coefficients. The flow path specific expressions better predicted actual data.