Download or read book The Impacts of UV Direct Photolysis and UV hydrogen Peroxide Advanced Oxidation Processes on the Formation of Nitrosamines and Organic Chloramines from Subsequent Chlor am ination written by Monica Harvey and published by . This book was released on 2009 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultraviolet direct photolysis (UV) and the advanced oxidation process UV/H2O2 are new technologies in the water treatment industry. Both treatments can cause the transformation of organic compounds. Nitrosamines and organic chloramines are disinfection by-products (DBPs) formed from the reaction of organic nitrogen compounds during chlorination or chloramination (chlor(am)ination) disinfection. It is therefore possible for UV and UV/H 2O2 to affect the organic compound precursors for nitrosamines and organic chloramines and thus their formation from subsequent chlor(am)ination. The precursor compounds, UV and H2O2 doses used for UV or UV/H2O2, and alkalinity were found to have an effect on the formation of nitrosamines and organic chloramines during bench-scale experiments. Full scale studies found UV and UV/H2O2 had different effects on the formation of different nitrosamine species and organic chloramine concentrations, and that a potential correlation existed between the formation of organic chloramines from chlorination and the formation of N-nitrosodimethylamine from chloramination.
Download or read book The Impacts of UV Direct Photolysis and UV H2O2 Advanced Oxidation Processes on the Formation of Nitrosamines and Organic Chloramines from Subsequent Chlor am ination written by Monica Harvey and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Application of the UV Chlorine Advanced Oxidation Process for Drinking Water Treatment written by Ding Wang 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 Modifications to Dissolved Organic Matter and Disinfection Byproduct Formation During Solar Chlorine Photolysis and Related Oxidative Treatment as Applied to Drinking Water Treatment written by Tessora Young and published by . This book was released on 2019 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorine is a common disinfectant used for water treatment worldwide, however not all pathogens can be inactivated using chlorine alone. Solar irradiation of chlorinated waters enhances inactivation of chlorine-resistant pathogens, through in situ formation of ozone and hydroxyl radical during photolysis of free available chlorine (FAC) at UVA/UVB wavelengths of sunlight (290 - 400nm). Organic and inorganic water constituents (e.g., natural organic matter (NOM), bromide, and carbonate) are also reactive with these photooxidants and can be linked to the formation of regulated drinking water disinfection byproducts (DBP). To evaluate the feasibility of this process as a novel water treatment, a variety of relevant surface water matrixes need to be treated via solar chlorine photolysis while monitoring consequent DBP. A suite of relevant chlorinated and brominated disinfection/oxidation byproducts (some regulated by the U.S. EPA) were monitored including oxyhalides, four trihalomethanes (THMs), and nine haloacetic acids (HAA9). Changes to NOM were characterized by monitoring spectral and redox properties, and molecular weight distributions during solar chlorine photolysis and compared to changes associated with conventional drinking water treatment (e.g., chlorination, ozonation, and advanced oxidation processes (AOP)). The results from this study show formation of DBPs vary significantly with water composition. Chlorate concentrations increased during solar photolysis of FAC (8mg/L as Cl2) at pH 8, and bromate formation followed similar trends (1.8x increase at pH 8 vs. pH 6) with 200 [micro]g/L bromide. Addition of NOM (Suwannee River) adds a competitor for radical and ozone species, and completely disrupted chlorate and bromate formation mechanisms; less reactive, natural waters limited oxyhalide formation to a lesser degree. Natural organic matter contributes to THM and HAA formation during chlorination and organic DBP yields increased further following solar chlorine photolysis (solar fluences > 4 J/cm2). Control experiments showed that increased organic DBP levels were not due to direct SRNOM photolysis and subsequent dark reactions with HOCl, but to co-exposure of SRNOM to HOCl and reactive species (e.g., O3, HO ̇, Cl ̇, ClO ̇) generated by FAC photolysis. [ABTS ̇+]− was utilized to quantify changes in the electron donating capacity (EDC) of natural organic matter (NOM) isolates and two model compounds: phenol a model for reactive aromatic moieties, and benzoic acid a model for less reactive aromatic moieties. Low exposures of FAC (CT[subscript]FAC = [integral][FAC]dt) significantly decreased the measurable EDC of NOM and phenol, potentially due to rapid halogenation or oxidation of reactive aromatic groups. Once these fast-reacting sites were depleted, the EDC decreased slowly with increasing chlorine exposure. Chlorination resulted in moderate decreases in UV absorbance of the bulk NOM and negligible changes in fluorescence EEM intensity (CT[subscript]FAC [less than or equal to] 400 (mg/L as Cl2)x min). Reactive oxygen species such as ozone and hydroxyl radical (independently or in combination with FAC during solar chlorine photolysis) yielded loss of UV absorbance in the bulk NOM. Pre-treatment of DOM with low exposures of hydroxyl radical (UV/H2O2, X-ray radiolysis, or O2−/O3) led to increased EDC for NOM and benzoic acid, and increased THM and HAA formation after dark chlorination for NOM, benzoic acid, and phenol, likely due to hydroxylation of aromatics during pretreatment. Radical scavengers (50mM tert-butanol) suppressed EDC formation and hindered THM and HAA formation. Exposure to O3 itself (with radical scavengers added) actually appears to lead primarily to oxidation and/or ring cleavage, rather than hydroxylation which appears to occur due to HO ̇ generated via O3 decay. X-ray irradiation of hypochlorite at pH 10 (favoring ClO ̇ from reaction between HO ̇ and OCl−) decreased EDC and spectral properties while increasing DBP yields, similar to sunlight-driven chlorine photolysis. Based on these findings, exposure of NOM to ozone, reactive oxygen and halogen species (e.g., HO ̇, Cl ̇, ClO ̇), and FAC during sunlight-driven chlorine photolysis involves hydroxylation of slow reacting aromatic moieties as a key pathway contributing to (a) increased electron donating capacity in aromatic components of the bulk NOM, and (b) increased reactivities toward FAC (and potentially other halogenating agents) to form halogenated organic DBPs. These findings provide an improved understanding of the processes leading to increased formation of DBP precursors during low to moderate exposures of ozone and reactive oxygen or halogen species, and could help identify strategies to minimize organic DBP formation during solar chlorine photolysis or other combinations of chlorine and ROS (such as UVC chlorine photolysis or sequential AOP/FAC treatment) likely to be applied during water and wastewater treatment.
Download or read book Oxidant Production and Disinfection By product Formation During Chlorine Photolysis written by Devon Marie Manley Bulman and published by . This book was released on 2020 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorine photolysis is an advanced oxidation process used to degrade organic contaminants in water. Ultraviolet photolysis of free chlorine (i.e., the mixture of hypochlorous acid and hypochlorite) results in the formation of a suite of reactive oxidants including hydroxyl radical, chlorine radical, and ozone. The photochemistry of hypochlorous acid and hypochlorite impacts the distribution of reactive oxidants formed under different treatment conditions. Observed chlorine loss rate constants increase with pH during irradiation with long wavelengths due to the higher molar absorptivity of hypochlorite. The steady-state concentration of the two primary oxidants, hydroxyl radical and chlorine radical, is highest at low pH and wavelength. Ozone generation is observed under all conditions, despite the assumption in previous studies that ozone does not form during photolysis at 254 nm. A comprehensive kinetic model is compared against experimental data and generally predicts the trends in chlorine loss and oxidant concentrations. However, a comparison of previously published kinetic models demonstrates the challenges of modeling this complex system. Light, free chlorine, and reactive oxidants can react with naturally occurring dissolved organic matter to form potentially harmful disinfection by-products. Chlorine loss rate constants increase in the presence of dissolved organic matter due to the formation of carbon-centered radicals. Oxidant steady-state concentrations decrease in natural waters due to radical scavenging by organic and inorganic carbon. High-resolution mass spectrometry shows that chlorine photolysis produces dissolved organic matter that is more aliphatic in nature and contains novel high molecular weight chlorinated disinfection by-products. The high molecular weight chlorinated disinfection by-products form via direct halogenation by reactive chlorine species and from dissolved organic matter transformation, primarily due to direct photolysis, that produces dissolved organic matter that is more reactive with chlorine. Quenching experiments demonstrate that reactive chlorine species are partially responsible for the formation of halogenated DOM, haloacetic acids, and haloacetonitriles. Trihalomethane concentrations decrease relative to dark chlorination due to decreased chlorine contact time. The presence of bromide in this system could result in the formation of brominated disinfection by-products, which are more toxic than their chlorinated analogues. Therefore, research is proposed for the investigation of the impact of bromide on disinfection by-product formation during chlorine photolysis. Probe measurements of reactive oxidants, measurement of small aliphatic and inorganic disinfection by-products, and bulk and molecular measurements of dissolved organic matter will be used to determine the impact of bromide on oxidant and disinfection by-product formation during chlorine photolysis.
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 Impact of UV and UV H2O2 AOP on EDC Activity in Water written by K. Linden and published by International Water Assn. This book was released on 2009-08 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research was to assess, through u
Download or read book Aquatic Redox Chemistry written by Paul Tratnyek and published by OUP USA. This book was released on 2012-06-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a comprehensive overview of aquatic redox chemistry through chapters contributed by many of the leading investigators in the field.
Download or read book Comparing UV Chlorine Advanced Oxidation Efficiency to UV H2O2 when Using Monochromatic UV Light written by Te Fang and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis compares the efficiency of the UV/chlorine and UV/H2O2 advanced oxidation processes for contaminant removal using monochromatic UV light. Previous work reported that UV/chlorine is more efficient than UV/H2O2 for trichloroethylene removal in pure water at approximately pH 5 and below using medium pressure (MP) lamps (Wang et al., 2012), and that it may even be more competitive in the presence of elevated total inorganic carbon (TIC) and total organic carbon (TOC). In this work, a LP kinetics model was adapted from the MP model developed by Wang et al. (2012). The modelled results of sucralose decay were then validated by bench-scale experiments with a collimated beam apparatus. The adapted LP models successfully predicted sucralose decay under most of the experimental conditions, but not at pH 10 for the UV/chlorine process. The reason for the inaccuracy of the UV/chlorine model at pH 10 is not clear, and requires more work.
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.
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 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 Chemical Oxidation Applications for Industrial Wastewaters written by Olcay Tunay and published by IWA Publishing. This book was released on 2010-10-12 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most recent scientific and technological developments (state-of-the-art) in the field of chemical oxidation processes applicable for the efficient treatment of biologically-difficult-to-degrade, toxic and/or recalcitrant effluents originating from different manufacturing processes. It is a comprehensive review of process and pollution profiles as well as conventional, advanced and emerging treatment processes & technologies developed for the most relevant and pollution (wet processing)-intensive industrial sectors. It addresses chemical/photochemical oxidative treatment processes, case-specific treatability problems of major industrial sectors, emerging (novel) as well as pilot/full-scale applications, process integration, treatment system design & sizing criteria (figure-of-merits), cost evaluation and success stories in the application of chemical oxidative treatment processes. Chemical Oxidation Applications for Industrial Wastewaters is an essential reference for lecturers, researchers, industrial and environmental engineers and practitioners working in the field of environmental science and engineering. Visit the IWA WaterWiki to read and share material related to this title: http://www.iwawaterwiki.org/xwiki/bin/view/Articles/CHEMICALOXIDATIONAPPLICATIONSFORINDUSTRIALWASTEWATERS Authors: Professor Olcay Tünay, Professor Isik Kabdasli, Associate Professor Idil Arslan-Alaton and Assistant Professor Tugba Ölmez-Hanci, Environmental Engineering Department, Istanbul Technical University, Turkey.
Download or read book Organic Pollutants in the Water Cycle written by Thorsten Reemtsma and published by John Wiley & Sons. This book was released on 2006-12-13 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first in-depth and comprehensive reference on the most pertinent polar contaminant classes and their behavior in the whole water cycle includes, among others, industrial chemicals, consumer products, polar herbicides and pharmaceuticals. All chapters are uniformly structured, covering properties, pollution sources, occurrence in wastewater, surface water, and groundwater as well as water treatment aspects, while ecotoxicological and assessment aspects are also covered. Among the authors are leading experts in their relevant fields, many of whom provide here groundbreaking research results. The result is an up-to-date information source for researchers and professionals working in water quality monitoring, water supply, or wastewater treatment, as well as environmental and water chemists, geochemists, ecologists, chemists and engineers.
Download or read book Formation of Nitrosamines During Chloramination written by I. Marie Schreiber and published by . This book was released on 2007 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
