Download or read book Investigation of N nitrosodimethylamine NDMA Fate and Transport written by and published by . This book was released on 2006 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Assessment of Mechanisms Impacting N nitrosodimethylamine Fate Within the North Boundary Containment System Rocky Mountain Arsenal written by and published by . This book was released on 1997 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemicals as Intentional and Accidental Global Environmental Threats written by Elisabeta Chirila and published by Springer Science & Business Media. This book was released on 2007-01-15 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multidisciplinary book presents a critical assessment of our knowledge of chemical threats to environmental security, with special reference to prevention of chemical releases, rapid detection, risk assessment and effective management of emergency situations and long-term consequences of chemical releases. The technologies evaluated concern mainly prevention and management of both intentional and accident releases of chemicals into the environment. The book features contributors from a range of relevant scientific fields.
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:
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 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 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:
Download or read book N Nitrosodimethylamine written by R. Liteplo and published by . This book was released on 2002 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: N-Nitrosodimethylamine (NDMA) is the simplest dialkylnitrosamine, with a molecular formula of C2H6N2O and a relative molecular mass of 74.08. It is no longer used industrially or commercially in Canada or the USA but continues to be released as a by-product and contaminant from various industries and from municipal wastewater treatment plants. In this volume are assessed the risks to human health and the environment of this chemical. Based upon laboratory studies in which tumours have been induced in all species examined at relatively low doses, NDMA is clearly carcinogenic. It is concluded that NDMA is a genotoxic carcinogen, and exposure should be reduced to the extent possible.
Download or read book Transformation Products of Emerging Contaminants in the Environment written by Dimitra A. Lambropoulou and published by John Wiley & Sons. This book was released on 2014-02-05 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last 15 years, the focus of chemical pollution has shifted from conventional pollutants to so-called “emerging” or “new” unregulated contaminants. These include pharmaceuticals and personal care products, hormones, UV filters, perfluorinated compounds, poylybrominated flame retardants (BFRs), pesticides, plasticizers, artificial sweeteners, illicit drugs, and endocrine disruptor compounds (EDCs). Despite the increasing number of published studies covering emerging contaminants, we know almost nothing about the effects of their transformation products and/or metabolites. This two-volume set provides a unique collection of research on transformation products, their occurrence, fate and risks in the environment. It contains 32 chapters, organised into 7 parts, each with a distinct focus: • General Considerations • Transformation Processes and Treatment Strategies • Analytical Strategies • Occurrence, Fate and Effects in the Environment • Global Speciality and Environmental Status • Risk Assessment, Management and Regulatory Framework • Outlook Transformation Products of Emerging Contaminants in the Environment is a valuable resource for researchers and industry professionals in environmental chemistry, analytical chemistry, ecotoxicology, environmental sciences, and hydrology, as well as environmental consultants and regulatory bodies.
Download or read book N nitrosodimethylamine NDMA in Purified Recycled Water written by and published by . This book was released on 2010 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two projects were established and independently funded, to research N-Dimethylnitrosamine (NDMA) a “B2" carcinogen, produced as a by-product in water treatment, but as they were managed and executed in close collaboration; Dr Farré being the leader of both projects, it was agreed among project partners and funding institutions to publish this joint, comprehensive report covering the entire set of results.
Download or read book Applied and Environmental Microbiology written by and published by . This book was released on 2007 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Mechanistic Studies of N nitrosodimethylamine NDMA in Model Drinking Waters written by Junghoon Choi and published by . This book was released on 2002 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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
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:
