Download or read book Prevention of the Formation of N nitrosodimethylamine NDMA During Wastewater Chlorination written by William Armistead Mitch and published by . This book was released on 2003 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book N nitrosodimethylamine Formation During Chlorination of Diuron with Influence Analysis of the Sacramento San Joaquin Delta Water Quality for Urban Uses written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Diuron is a widely used phenylurea herbicide for control of broad leaf and annual grassy weeds for both agricultural and nonagricultural uses. With the combination of the heavy usage and its persistence in typical environmental conditions due to its physical and chemical properties, diuron has been observed frequently in California's water sources. In this study diuron is of concern due to the potential formation of N-nitrosodimethylamine (NDMA), a potent carcinogen that has been identified as an emerging disinfection byproduct (DBP) in drinking water. The first results identified that diuron is a specific NDMA formation precursor that arises from non-point sources, and highlighted the difficulties associated with determining the environmental safety of chemicals and their associated potential byproducts. The influence of additional nitrogen sources on the NDMA formation mechanism during chlorination of diuron was also studied with consideration that the dominant nitrogen-containing specie may vary between surface water and groundwater. The risks posed by representative concentrations of diuron and other reagents with respect to NDMA formation during chlorine-based disinfection may be limited even in the presence of multiple nitrogen species. A broader picture exploring the current and long-term effects of water quality on public health risks from DBP formation and drinking water treatment costs was investigated by considering the Sacramento-San Joaquin Delta system, one of the most important drinking water sources in California. The present DBPs with Delta supplies are manageable within the current treatment regulations. However, the management of Delta water as a drinking water supply would become more difficult and expensive due to a possible sea level rise in the future and western island failures, with residual health risks remaining from residual and unregulated DBPs after treatment. It is likely that water drawn directly from the Delta will pose a higher risk to public health and be more difficult to treat by conventional treatment technologies, indicating that modification of existing treatment operations or addition of new technologies may be required, with higher treatment costs.
Download or read book Strategies for Minimizing Nitrosamine Formation During Disinfection written by Frank Sacher and published by International Water Assn. This book was released on 2008 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the project were to identify str
Download or read book Effect of Preformed Chloramines and Chlorine to Ammonia Ratio on the Formation of N nitrosodimethylamine NDMA in TRWD East Texas Raw Water Delivery System written by Khidir Hamad and published by . This book was released on 2015 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tarrant Regional Water District (TRWD) pumps untreated raw water from Richland Chambers and Cedar Creek reservoirs in East Texas to provide water to several customer cities including Arlington and Fort Worth. TRWD adds chloramines to the pipeline to combat biofilm growth, that reduces pipeline capacity and increases pumping costs, and to control zebra mussels, that clog intake structure screens and the pump wet wells. However, addition of chloramines leads to the formation of Nnitrosodimethylamine (NDMA), a potent carcinogen, by reaction of chloramines with nitrogenous organic precursors possibly present in the raw water. NDMA formation presents a challenge to TRWD because potential regulation of NDMA and other nitrosamines will force TRWD and other utilities alike to seek treatment options. Because post treatment removal of NDMA is ineffective and expensive, the best strategy is to optimize conditions to minimize NDMA formation and to eliminate nitrogenous NDMA precursors in the system. This research examines the effect of preformed chloramines and chlorine to ammonia mass ratio on NDMA formation in the District's current and future pipelines.
Download or read book Evaluation of N Nitrosodimethylamine NDMA Formation at Varied PH and Conditions in Treated Wastewater written by Chetna Vasudeva and published by . This book was released on 2018 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: N-nitrosodimethylamine is a carcinogenic disinfection byproduct which can be reformed after wastewater treatment if appropriate conditions are present. In this study various NDMA formation precursors over a range of conditions have been studied to attempt to quantify this NDMA reformation potential. Efforts were made in this study to demonstrate the effect of time, pH, and multiple different precursor chemicals on the reformation process. Dimethylamine (DMA) has been demonstrated to be a precursor chemical, and was chosen as a standard for initial experiments. The concentration of this precursor was kept constant at 100 ppt (parts per trillion) and solutions at three different pH’s were tested over a 24-hour time period to see if any significant NDMA formation occurred. The impacts of various treated wastewater constituent chemicals including H2O2, monochloramine, dimethylhydrazine, etc. were also performed in this study. Significant difficulties occurred for the analysis of these samples, with large background interferences occurring in the method of analysis. Based on the data obtained, it appears that the formation potential of NDMA with DMA as a precursor was found to be the most efficient compound at basic pH (pH 9) and very basic (pH 13). This is consistent with the last step in wastewater remediation, where quicklime is added to the water to regulate the pH and for protection of distribution system. In addition, preliminary experiments were conducted using Ranitidine as a NDMA reformation precursor.
Download or read book Strategies for Minimizing Nitrosamine Formation During Disinfection written by Frank Sacher and published by American Water Works Association. This book was released on 2008-01-01 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrosamines are among the most toxic and carcinogenic chemical compounds known. Recently, N-nitrosodimethylamine (NDMA) has been identified as a possible water disinfection by-product and has been detected in water treatment plants in the US and Canada that use chloramines as a disinfectant. This report describes a research project on strategies for minimizing nitrosamine levels in drinking water. The research project focuses on the most prominent nitrosamine, NDMA, but also covers other aliphatic nitrosamines. Conclusions from the literature search and laboratory-scale experiments were the verified by full-scale tests in water utilities in the US, Australia, and Germany. The report lacks a subject index. Sacher is affiliated with DVGW-Technologiezentrum Wasser, Germany.
Download or read book Nitrogenous Disinfection Byproducts written by Daniel Logan McCurry and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Disinfection of potable water is one of the great public health victories of the twentieth century, responsible for the avoidance of millions of deaths due to waterborne illness. However, application of disinfectants, typically chemical oxidants, leads to formation of hundreds of trace contaminants, often carcinogens, and consumption of chlorinated water has been epidemiologically linked to bladder cancer and certain birth defects. Eleven of these compounds are federally regulated in drinking water, but certain non-regulated disinfection byproducts (DBPs) are orders of magnitude more toxic than currently regulated compounds. Two specific DBPs, chloropicrin and N-nitrosodimethylamine (NDMA), are especially genotoxic, and are associated with nitrogen input into drinking water supplies. Wastewater-impacted drinking water and recycled wastewater are enriched in the precursors of these compounds, and their formation during potable water treatment is likely to grow, as wastewater increasingly contributes to the water supply. This thesis focuses on applying the tools of environmental organic chemistry to identify the chemical precursors and formation mechanisms of these compounds, leading to strategies for their control during water treatment. In particular, ozonation of primary and secondary amine compounds, leading to formation of nitro compound intermediates, was found be responsible for chloropicrin formation during water treatment. Secondary N-methylamines and primary amines geminal to facile leaving groups were particularly potent precursors, forming chloropicrin at up to 50% yield when exposed to ozone followed by chlorine. Based on this predominant formation pathway, chloropicrin precursors may be oxidized upstream of ozone addition to prevent chloropicrin formation. Strategies for controlling NDMA formation, a major concern during wastewater recycling, were developed based on an understanding of the chemical composition of NDMA precursors, and chloramines, the primary disinfectant applied during wastewater reuse. Minor modifications to wastewater recycling operations, in particular switching from low-pressure to medium-pressure mercury lamps for ultraviolet light treatment, and minor adjustments in the application of chloramines, were shown to dramatically reduce NDMA concentrations in final effluent. Finally, the effluent from a new, all-anaerobic wastewater treatment system was demonstrated to more efficiently remove trace contaminants and DBP precursors than conventional aerobic treatment, suggesting that this energy-saving technology may also be more suitable for water reuse than conventional treatment. These findings facilitate reducing the chronic health risk associated with consumption of (intentionally or unintentionally) recycled wastewater.
Download or read book Formation Studies on N nitrosodimethylamine NDMA in Natural Waters written by Xianghua Luo and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: N-nitrosodimethylamine (NDMA) is a chloramines disinfection by-product and probable carcinogen to human. The California state established a 10 ng/L action level for NDMA in drinking water. Analytical method of NDMA in waters at the trace level was developed using gas chromatography/mass spectrum with chemical ionization in the mode of selected ion storage coupled with solid phase extraction. It was found that 4 utilities in Missouri using monochloramine as disinfectant had NDMA higher than 10 ng/L in drinking water. Natural organic matter (NOM), especially the hydrophilic fraction of the NOM, was found to be a predominant NDMA precursors. Basic conditions and bromide ions favor NDMA formation in natural waters. The findings reported in this dissertation provide data on NDMA occurrences in drinking water and natural waters in Missouri. The results provide valuable information about NDMA precursors in natural waters and this information could be used in the further study of mitigating NDMA formation or removing NDMA precursors in drinking water utilities. The results on factors affecting on NDMA formation provide more information for water utilities to determine operation conditions to reduce and control NDMA formation.
Download or read book The Llobregat written by Sergi Sabater and published by Springer. This book was released on 2012-06-02 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Llobregat belongs to the most thoroughly studied rivers in Europe and is a paradigm of the confluence of human and natural disturbances in a single basin. Because of its location in a very densely populated region and its Mediterranean character, the Llobregat supports a mixture of irregular flow, water abstraction, excess nutrients, mining debris, and a wide array of pollutants. The aquatic organisms strive to survive in a dramatically changing river that passes through a succession of dams, weirs and channels. The long-term river monitoring as well as the research that has been carried out in the river for a long time have provided an extensive knowledge of these disturbances and their effects on the biological communities. This book highlights the available information, with emphasis on the hydrological, chemical and biological elements interspersed in the river. Experts in the field discuss the main nutrient patterns and pollutant occurrence and the responses of the biological quality elements as well as the river ecosystem to the overall natural and man-made influences.
Download or read book Formation of N nitrosodimethylamine During Water Disinfection with Chloramine written by Stephanie Spahr and published by . This book was released on 2016 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'autrice: water disinfection ; chloramination ; disinfection by-products ; N-nitrosodimethylamine (NDMA) ; compound-specific isotope analysis (CSIA) ; stable isotope fractionation.
Download or read book Water Reuse written by National Research Council and published by National Academies Press. This book was released on 2012-07-17 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expanding water reuse-the use of treated wastewater for beneficial purposes including irrigation, industrial uses, and drinking water augmentation-could significantly increase the nation's total available water resources. Water Reuse presents a portfolio of treatment options available to mitigate water quality issues in reclaimed water along with new analysis suggesting that the risk of exposure to certain microbial and chemical contaminants from drinking reclaimed water does not appear to be any higher than the risk experienced in at least some current drinking water treatment systems, and may be orders of magnitude lower. This report recommends adjustments to the federal regulatory framework that could enhance public health protection for both planned and unplanned (or de facto) reuse and increase public confidence in water reuse.
Download or read book Toxicological Profile for N nitrosodimethylamine written by and published by . This book was released on 1989 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NDMA Formation During Chlorination and Chloramination of Aqueous Diuron Solutions written by Thomas M. Young and published by . This book was released on 2008 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations of NDMA Formation by Chlorination of Model Compounds written by Cooperative Research Centre for Water Quality and Treatment (Australia) and published by . This book was released on 2008 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: "There is the potential for the formation of NDMA [N-nitrosodimethylamine] from the chlorination or chloramination of various nitrogenous biological molecules. ... Research into the development of a suitable analytical method for NDMA in disinfected drinking waters has culminated with a sensitive validated method utilising solid phase extraction combined with ammonia positive chemical ionization gas chromatography-mass spectrometry." - - p. 4.
Download or read book Cation Impact on N Nitrosodimethylamine NDMA Formation from Ranitidine in Different Water Matrices written by Yiwen Lin and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry of Ozone in Water and Wastewater Treatment written by Clemens von Sonntag and published by IWA Publishing. This book was released on 2012-08-31 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Even though ozone has been applied for a long time for disinfection and oxidation in water treatment, there is lack of critical information related to transformation of organic compounds. This has become more important in recent years, because there is considerable concern about the formation of potentially harmful degradation products as well as oxidation products from the reaction with the matrix components. In recent years, a wealth of information on the products that are formed has accumulated, and substantial progress in understanding mechanistic details of ozone reactions in aqueous solution has been made. Based on the latter, this may allow us to predict the products of as yet not studied systems and assist in evaluating toxic potentials in case certain classes are known to show such effects. Keeping this in mind, Chemistry of Ozone in Water and Wastewater Treatment: From Basic Principles to Applications discusses mechanistic details of ozone reactions as much as they are known to date and applies them to the large body of studies on micropollutant degradation (such as pharmaceuticals and endocrine disruptors) that is already available. Extensively quoting the literature and updating the available compilation of ozone rate constants gives the reader a text at hand on which his research can be based. Moreover, those that are responsible for planning or operation of ozonation steps in drinking water and wastewater treatment plants will find salient information in a compact form that otherwise is quite disperse. A critical compilation of rate constants for the various classes of compounds is given in each chapter, including all the recent publications. This is a very useful source of information for researchers and practitioners who need kinetic information on emerging contaminants. Furthermore, each chapter contains a large selection of examples of reaction mechanisms for the transformation of micropollutants such as pharmaceuticals, pesticides, fuel additives, solvents, taste and odor compounds, cyanotoxins. Authors: Prof. Dr. Clemens von Sonntag, Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der Ruhr, and Instrumentelle Analytische Chemie, Universität Duisburg-Essen, Essen, Germany and Prof. Dr. Urs von Gunten, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, and Ecole Polytechnique Federal de Lausanne, Lausanne, Switzerland.
Download or read book Isotope Effects In Chemistry and Biology written by Amnon Kohen and published by CRC Press. This book was released on 2005-11-01 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of isotope effects has expanded exponentially in the last decade, and researchers are finding isotopes increasingly useful in their studies. Bringing literature on the subject up to date, Isotope Effects in Chemistry and Biology covers current principles, methods, and a broad range of applications of isotope effects in the physical, biolo
