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Author : Xiaoyan Qin
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (999 download)
Download or read book Stability, Formation Potential and Removal of N-nitrosodimethylamine (NDMA) in Drinking Water written by Xiaoyan Qin and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Xianghua Luo
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (162 download)
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.
Author :
Publisher :
ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.X/5 (3 download)
Download or read book A Study of the Effect of Polymers on Potential N-Nitrosodimethylamine (NDMA) Formation at Water and Wastewater Treatment Plants written by and published by . This book was released on 2007 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Frank Sacher
Publisher : International Water Assn
ISBN 13 : 9781843392132
Total Pages : 196 pages
Book Rating : 4.3/5 (921 download)
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
Author : Piti Piyachaturawat
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (74 download)
Download or read book Potential N-Nitrosodimethylamine (NDMA) Formation from Water Treatment Polymers written by Piti Piyachaturawat and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: N-Nitrosodimethylamine (commonly known as NDMA) is a probable human carcinogen that has been recognized as an emerging drinking water contaminant in recent years. Previous studies have shown that certain N-containing organic compounds may form NDMA in reaction with chlorine or monochloramine and the NDMA yield is affected by the structure of the organic-N compounds, water conditions and treatment parameters. Many amine-based water treatment polymers contain organic-N functional groups and thus have been suspected as potential NDMA precursors in water treatment systems. The purpose of this research was to systematically assess the potential NDMA formation from different structural types of water treatment polymers in reactions with various oxidants and probe the possible factors that influence the NDMA formation. Robust analytical methods for detection of NDMA and the well-known NDMA precursor dimethylamine (DMA) in the reaction samples were established. The cationic polyacrylamide (cationic PAMS), aminomethylated polyacrylamide (Mannich), poly-diallyldimethylammonium chloride (polyDADMAC) and polyamine polymers were evaluated in reactions with nitrite, free chlorine, monochloramine or chlorine dioxide in aqueous solutions at circumneutral pH and room temperature conditions. This study employed high dosages of polymer and oxidant and long reaction time in order to assess the maximum potential to form NDMA. A range of operational parameters that may affect the above reactions were also evaluated.
Author : Corinne Elizabeth Bertoia
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)
Download or read book Removal of N-nitrosodimethylamine (NDMA) Precursors During Drinking Water Treatment written by Corinne Elizabeth Bertoia and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : William Armistead Mitch
Publisher :
ISBN 13 :
Total Pages : 294 pages
Book Rating : 4.:/5 (34 download)
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:
Author : Habibullah Uzan
Publisher :
ISBN 13 : 9781605732572
Total Pages : 231 pages
Book Rating : 4.7/5 (325 download)
Download or read book Seasonal Changes of NDMA Formation Potential and Its Removal During Water Treatment written by Habibullah Uzan and published by . This book was released on 2016 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 136 pages
Book Rating : 4.3/5 (91 download)
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:
Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 0309224624
Total Pages : 276 pages
Book Rating : 4.3/5 (92 download)
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.
Author :
Publisher :
ISBN 13 :
Total Pages : 96 pages
Book Rating : 4.:/5 (18 download)
Download or read book A Study on the Effect of Polymers on Potential N-nitrosodimethylamine (NDMA) Formation at Water and Wastewater Treatment Plants written by and published by . This book was released on 2007 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Jinwei Zhang
Publisher :
ISBN 13 :
Total Pages : 135 pages
Book Rating : 4.:/5 (96 download)
Download or read book Investigations Into the Occurrence, Formation and Fate of N-nitrosodimethylamine (NDMA) in Air and Water written by Jinwei Zhang and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: N-nitrosodimethylamine (NDMA), a probable human carcinogen, has been found in clouds and fogs at concentration up to 500 ng/L and in drinking water as a disinfection by-product. NDMA exposure to the general public is not well understood because of knowledge gaps in terms of occurrence, formation and fate - both in air and water. The goal of this dissertation was to contribute to closing these knowledge gaps on potential human NDMA exposure through contributions to atmospheric measurements and fate as well as aqueous formation processes. Novel, sensitive methods of measuring NDMA in air were developed based on Solid Phase Extraction (SPE) and Solid Phase Microextraction (SPME) coupled to Gas Chromatography-Mass Spectrometry (GC-MS). The two measuring techniques were evaluated in laboratory experiments. SPE-GC-MS was applicable in ambient air sampling and NDMA in ambient air was found in the 0.1-13.0 ng/m3 range. NDMA photolysis, the main degradation atmospheric pathway, was studied in the atmospheric aqueous phase. Water soluble organic carbon (WSOC) was found to have more impact than inorganic species on NDMA photolysis by competing with NDMA for photons and therefore could substantially increase the NDMA lifetime in the atmosphere. The optical properties of atmospheric WSOC were investigated in aerosol, fog and cloud samples and showed WSOC from atmospheric aerosols has a higher mass absorption efficiency (MAE) than organic matter in fog and cloud water, resulting from a different composition, especially in regards to volatile species, that are not very absorbing but abundant in fogs and clouds. NDMA formation kinetics during chloramination were studied in aqueous samples including wastewater, surface water and ground water, at two monochloramine concentrations. A simple second order NDMA formation model was developed using measured NDMA and monochloramine concentrations at select reaction times. The model fitted the NDMA formation well (R2 >0.88) in all water matrices. The proposed model was then optimized and applied to fit the data of NDMA formation from natural organic matter (NOM) and model precursors in previously studies. By determining the rate constants, the model was able to describe the effect of water conditions such as DOC and pH on NDMA formation.
Author : Chetna Vasudeva
Publisher :
ISBN 13 : 9780438752139
Total Pages : 43 pages
Book Rating : 4.7/5 (521 download)
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.
Author : Huong Thu Pham
Publisher :
ISBN 13 :
Total Pages : 74 pages
Book Rating : 4.:/5 (15 download)
Download or read book Understanding N-nitrosodimethylamine Formation in Water written by Huong Thu Pham and published by . This book was released on 2017 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from dichloramine decay, in the absence of hydroxylamine. In this study, a series of batch kinetic experiments were conducted to investigate the decomposition of chloramine species at pH 8.0 to 10.0 and the concomitant formation of NDMA. Chloramine species were quantified using UV/Vis spectroscopy (Direct UV) and colorimetric methods (Hach) and compared to simulations from the unified chloramine model. NDMA was quantified using GC-MS following liquid-liquid extraction. The model captured the decay of monochloramine and dichloramine adequately, with the exception of monochloramine at pH 10.0, possibly due to an interference from a previously reported unidentified chloramine decomposition compound (UC1). NDMA formation was pH dependent with the maximum yields at pH 9.0 and the fastest kinetics at pH 10.0. A second unidentified compound (UC2), with a mass spectrum identified as UDMH, was detected only at pH 9.0 and 10.0 in batch reactors with DMA and dichloramine. Importantly, NDMA formation appeared to be insensitive to the presence or absence of UC2, suggesting UC2 was not involved in NDMA formation. Hydroxylamine accelerates the decomposition of monochloramine. The reaction between DMA and hydroxylamine formed a third unidentified compound (UC3), preliminarily identified as acetoxime, which was not observed in the presence of monochloramine. Upon addition of hydroxylamine, NDMA yields decreased by more than half in batch reactors with DMA and monochloramine. On balance, the findings suggest the existence of a NDMA formation pathway that may not involve UDMH, and points to the need for studies with scavengers and donors of short-lived species from chloramine decay.
Author : Yang Zhao
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (13 download)
Download or read book Quantification of the Reactivity of Nitrosamine Precursors written by Yang Zhao and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : David Hanigan
Publisher :
ISBN 13 :
Total Pages : 254 pages
Book Rating : 4.:/5 (932 download)
Download or read book Identification of N-Nitrosodimethylamine Precursors to Improve Their Control written by David Hanigan and published by . This book was released on 2015 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: N-nitrosodimethylamine (NDMA) is a probable human carcinogen and drinking water disinfection by-product. NDMA forms as the product of reactions between chloramines and precursor compounds in water. This dissertation aims to provide insight into the removal of NDMA precursors, their nature, and a method to aid in their identification. Watershed-derived precursors accounted for more of and greater variability to NDMA formation upon chloramination than polymer-derived precursors in environmental samples. Coagulation polymers are quaternary amines, which have low NDMA yield but high use rates. Watershed-derived precursors were removed up to 90% by sorption to activated carbon, but activated carbon exhibited much less (10%) sorption of polymer-derived precursors. Combined with literature NDMA molar yields of model anthropogenic compounds, where anthropogenic chemicals in some cases have NDMA yields 90% and biological compounds always have yields
Author : Mihaela I. Stefan
Publisher : IWA Publishing
ISBN 13 : 1780407181
Total Pages : 712 pages
Book Rating : 4.7/5 (84 download)
Download or read book Advanced Oxidation Processes for Water Treatment written by Mihaela I. Stefan and published by IWA Publishing. This book was released on 2017-09-15 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Oxidation Processes (AOPs) rely on the efficient generation of reactive radical species and are increasingly attractive options for water remediation from a wide variety of organic micropollutants of human health and/or environmental concern. Advanced Oxidation Processes for Water Treatment covers the key advanced oxidation processes developed for chemical contaminant destruction in polluted water sources, some of which have been implemented successfully at water treatment plants around the world. The book is structured in two sections; the first part is dedicated to the most relevant AOPs, whereas the topics covered in the second section include the photochemistry of chemical contaminants in the aquatic environment, advanced water treatment for water reuse, implementation of advanced treatment processes for drinking water production at a state-of-the art water treatment plant in Europe, advanced treatment of municipal and industrial wastewater, and green technologies for water remediation. The advanced oxidation processes discussed in the book cover the following aspects: - Process principles including the most recent scientific findings and interpretation. - Classes of compounds suitable to AOP treatment and examples of reaction mechanisms. - Chemical and photochemical degradation kinetics and modelling. - Water quality impact on process performance and practical considerations on process parameter selection criteria. - Process limitations and byproduct formation and strategies to mitigate any potential adverse effects on the treated water quality. - AOP equipment design and economics considerations. - Research studies and outcomes. - Case studies relevant to process implementation to water treatment. - Commercial applications. - Future research needs. Advanced Oxidation Processes for Water Treatment presents the most recent scientific and technological achievements in process understanding and implementation, and addresses to anyone interested in water remediation, including water industry professionals, consulting engineers, regulators, academics, students. Editor: Mihaela I. Stefan - Trojan Technologies - Canada
