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An Exploratory Study Of N Nitrosodimethylamine Ndma Formation In Chloraminated Natural Waters
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Book Synopsis An Exploratory Study of N-nitrosodimethylamine (NDMA) Formation in Chloraminated Natural Waters by : Jason Michael Assouline
Download or read book An Exploratory Study of N-nitrosodimethylamine (NDMA) Formation in Chloraminated Natural Waters written by Jason Michael Assouline and published by . This book was released on 2004 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Formation Studies on N-nitrosodimethylamine (NDMA) in Natural Waters by : Xianghua Luo
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.
Book Synopsis Factors Affecting the Formation of NDMA in Water and Occurrence by : Richard Louis Valentine
Download or read book Factors Affecting the Formation of NDMA in Water and Occurrence written by Richard Louis Valentine and published by Amer Water Works Assn. This book was released on 2005-01 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The USEPA has classified NDMA (N-nitrosodimethylamine) as a probable human carcinogen. It is suspected that chlorination and chloramination may be contributing factors in NDMA formation. This study surveys the levels of NDMA in selected drinking water, recycled water, and wastewater, and describes how various treatment processes impact NDMA formation.
Book Synopsis A Study of Riverbank Filtration and the Formation of N-nitrosodimethylamine (NDMA ) in Natural Waters by : Ashley Elisabeth Mordasky
Download or read book A Study of Riverbank Filtration and the Formation of N-nitrosodimethylamine (NDMA ) in Natural Waters written by Ashley Elisabeth Mordasky and published by . This book was released on 2005 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Prevention of the Formation of N-nitrosodimethylamine (NDMA) During Wastewater Chlorination by : William Armistead Mitch
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:
Book Synopsis A Study of the Effect of Polymers on Potential N-Nitrosodimethylamine (NDMA) Formation at Water and Wastewater Treatment Plants by :
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:
Book Synopsis The Formation of N-nitrosodimethylamine (NDMA) from Reaction of Monochloramine with Natural Organic Matter by : Zhuo Chen
Download or read book The Formation of N-nitrosodimethylamine (NDMA) from Reaction of Monochloramine with Natural Organic Matter written by Zhuo Chen and published by . This book was released on 2006 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigations Into the Occurrence, Formation and Fate of N-nitrosodimethylamine (NDMA) in Air and Water by : Jinwei Zhang
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.
Book Synopsis Cation Impact on N-Nitrosodimethylamine (NDMA) Formation from Ranitidine in Different Water Matrices by : Yiwen Lin
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:
Book Synopsis N-nitrosodimethylamine Formation During Chlorination of Diuron with Influence Analysis of the Sacramento-San Joaquin Delta Water Quality for Urban Uses by :
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.
Book Synopsis Understanding N-nitrosodimethylamine Formation in Water by : Huong Thu Pham
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.
Book Synopsis A Study on the Effect of Polymers on Potential N-nitrosodimethylamine (NDMA) Formation at Water and Wastewater Treatment Plants by :
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 :Cooperative Research Centre for Water Quality and Treatment (Australia) Publisher : ISBN 13 : Total Pages :30 pages Book Rating :4.:/5 (69 download)
Book Synopsis Investigations of NDMA Formation by Chlorination of Model Compounds by : Cooperative Research Centre for Water Quality and Treatment (Australia)
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.
Book Synopsis Toxicological Profile for N-nitrosodimethylamine by :
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:
Book Synopsis Advanced Oxidation Processes for Water and Wastewater Treatment by : Simon Parsons
Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.
Book Synopsis Long-Term Effects of Disinfection Changes on Water Quality by : John E. Dyksen
Download or read book Long-Term Effects of Disinfection Changes on Water Quality written by John E. Dyksen and published by American Water Works Association. This book was released on 2007 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to many U.S. water utilities that are considering changing disinfectants from chlorine to alternative disinfectants, this research has been undertaken to gain knowledge of long-term effects.
Book Synopsis Prospects for Managed Underground Storage of Recoverable Water by : National Research Council
Download or read book Prospects for Managed Underground Storage of Recoverable Water written by National Research Council and published by National Academies Press. This book was released on 2008-01-07 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growing demands for water in many parts of the nation are fueling the search for new approaches to sustainable water management, including how best to store water. Society has historically relied on dams and reservoirs, but problems such as high evaporation rates and a lack of suitable land for dam construction are driving interest in the prospect of storing water underground. Managed underground storage should be considered a valuable tool in a water manager's portfolio, although it poses its own unique challenges that need to be addressed through research and regulatory measures.
