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Exploring Relationships Between Catchment Dissolved Organic Matter Characteristics And The Formation Of Disinfection Byproducts
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Book Synopsis Exploring Relationships Between Catchment Dissolved Organic Matter Characteristics and the Formation of Disinfection Byproducts by : Matthew Hopes
Download or read book Exploring Relationships Between Catchment Dissolved Organic Matter Characteristics and the Formation of Disinfection Byproducts written by Matthew Hopes and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems by : Reid Milstead
Download or read book The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems written by Reid Milstead and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a complex heterogeneous mixture of organic compounds that is found in all water systems. DOM is derived from both terrestrial and microbial sources. The composition of DOM can vary greatly depending on a number of variables, including time of year, surrounding groundcover type, and water column depth. The characterization of DOM composition is increasingly performed using high-resolution mass spectrometry, although different instrumentation and techniques may yield different results. Importantly, DOM plays a key role in a number of chemical processes in both natural and engineered systems, such as the generation of carbon dioxide (CO2) from surface waters, the degradation of aquatic contaminants, and the formation of disinfection byproducts (DBPs) during drinking water treatment. The composition of DOM determines its reactivity in all of these processes. Using both bulk and high-resolution analytical techniques, the photooxidation of DOM can be explored. DOM compounds that are more oxidized and aromatic tend to be associated with the consumption of oxygen and the production of CO2. Bulk scale measurements show that DOM becomes less aromatic and lower in molecular weight as a result of partial photooxidation. High-resolution mass spectrometry also provides evidence of oxygen addition and the loss of CO2 from DOM during irradiation experiments. However, the chemical formulas that are most photolabile vary depending on the initial composition of DOM. Using light exposure experiments the kinetics of degradation of four contaminants were quantified for a large set of diverse waters. Using this information, we evaluated the relationships between indirect photolysis rate constants and the formation of photochemically produced reactive intermediates (PPRI) using linear regression analysis. Additionally, quencher experiments were performed to identify the PPRI associated with the degradation of each contaminant in all waters. Triplet state DOM (3DOM) and singlet oxygen (1O2) were identified as critical for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (•OH) is important for benzotriazole. Our results suggest that quenching experiments should be used with caution due to the non-targeted nature of quenching compounds and the interconnection of PPRI. All of these factors result in probe compounds possibly overstating the importance of PPRI in the indirect photolysis of common contaminants. The characterization of DOM in drinking waters reveals a high degree of variability in DOM composition and reactivity with chlorine, particularly in groundwater samples. Despite the variability in DOM composition, novel DBPs with up to three halogen substituents are compositionally similar among all waters. These novel DBPs are positively correlated with trihalomethane and, to a lesser extent, the formation of haloacetonitriles. This suggests that some low molecular weight DBPs and novel DBPs detected via high-resolution mass spectrometry share similar aromatic precursors, providing evidence that low molecular weight DBPs are useful proxies for the formation of unknown, unidentified high molecular weight DBPs. Compared to Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS), Orbitrap MS yields significantly fewer formula matches and appears to have a bias towards sulfur-containing formulas and against nitrogen-containing formulas. Additionally, the choice of calibration method is particularly important for the less powerful Orbitrap MS. The matched formulas yielded from Orbitrap MS tend to be more oxidized and less highly saturated than those yielded by FT-ICR MS. Despite these differences, the formulas produced by both instruments tend to yield similar relative differences between samples, suggesting that Orbitrap MS is an acceptable replacement for FT-ICR MS in some cases.
Book Synopsis Characteristics of Dissolved Organic Matter in Water and Formation of Chlorinated Disinfection By-products by : Raphael Kwaku Klake
Download or read book Characteristics of Dissolved Organic Matter in Water and Formation of Chlorinated Disinfection By-products written by Raphael Kwaku Klake and published by . This book was released on 2008 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis and Formation of Disinfection Byproducts in Drinking Water by :
Download or read book Analysis and Formation of Disinfection Byproducts in Drinking Water written by and published by Elsevier. This book was released on 2021-04-01 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drinking water disinfection has markedly reduced diseases causes by waterborne pathogenic microorganisms. However, an unintended consequence of disinfection and/or oxidation processes is the generation of disinfection byproducts (DBPs) which are formed from the reactions of disinfectants/oxidants with water matrix components. This volume of the Comprehensive Analytical Chemistry Handbook presents recent advances about the formation, identification, and quantification of inorganic and organic DBPs during oxidative processes. The book begins with a first chapter reviewing the most recent non-targeted screening approaches and workflows to characterize DBPs using low-, high-, and ultra-high-resolution mass spectrometry. The second chapter discusses the analysis of inorganic chloramines in waters using on-site and/or in-lab analytical methods. The third chapter provides an overview of the current knowledge about the mechanisms of chlorine dioxide reactions and byproducts formation. The fourth chapter presents some fundamental and practical aspects about ozonation processes in water treatment and provides an overview about ozone reaction mechanisms and byproducts formation. The fifth chapter focuses on the reactivity of halide ions, particularly bromide and iodide, with common oxidants and the role they play in determining the speciation of DBPs in treated waters. The chapter also presents strategies to mitigate the formation of DBPs during oxidation processes. Finally, the last chapter tackles the topic of DBPs formation during potable water reuse. It discusses the formation of DBPs of major concern in both memebrane-based and non-membrane-based potable water reuse treatment schemes. Researchers, water treatment specialists, and regulators will find in this book a valuable and compact resource on several key topics regarding the formation, identification, quantification, and mitigation of DBPs. Identification and quantification of known and unknown DBPs Formation of DBPs during different disinfection/oxidation processes DBPs of concern in new technologies and/or new applications of existing technologies in water treatment
Book Synopsis The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems by : Reid Milstead
Download or read book The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems written by Reid Milstead and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a complex heterogeneous mixture of organic compounds that is found in all water systems. DOM is derived from both terrestrial and microbial sources. The composition of DOM can vary greatly depending on a number of variables, including time of year, surrounding groundcover type, and water column depth. The characterization of DOM composition is increasingly performed using high-resolution mass spectrometry, although different instrumentation and techniques may yield different results. Importantly, DOM plays a key role in a number of chemical processes in both natural and engineered systems, such as the generation of carbon dioxide (CO2) from surface waters, the degradation of aquatic contaminants, and the formation of disinfection byproducts (DBPs) during drinking water treatment. The composition of DOM determines its reactivity in all of these processes. Using both bulk and high-resolution analytical techniques, the photooxidation of DOM can be explored. DOM compounds that are more oxidized and aromatic tend to be associated with the consumption of oxygen and the production of CO2. Bulk scale measurements show that DOM becomes less aromatic and lower in molecular weight as a result of partial photooxidation. High-resolution mass spectrometry also provides evidence of oxygen addition and the loss of CO2 from DOM during irradiation experiments. However, the chemical formulas that are most photolabile vary depending on the initial composition of DOM. Using light exposure experiments the kinetics of degradation of four contaminants were quantified for a large set of diverse waters. Using this information, we evaluated the relationships between indirect photolysis rate constants and the formation of photochemically produced reactive intermediates (PPRI) using linear regression analysis. Additionally, quencher experiments were performed to identify the PPRI associated with the degradation of each contaminant in all waters. Triplet state DOM (3DOM) and singlet oxygen (1O2) were identified as critical for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (•OH) is important for benzotriazole. Our results suggest that quenching experiments should be used with caution due to the non-targeted nature of quenching compounds and the interconnection of PPRI. All of these factors result in probe compounds possibly overstating the importance of PPRI in the indirect photolysis of common contaminants. The characterization of DOM in drinking waters reveals a high degree of variability in DOM composition and reactivity with chlorine, particularly in groundwater samples. Despite the variability in DOM composition, novel DBPs with up to three halogen substituents are compositionally similar among all waters. These novel DBPs are positively correlated with trihalomethane and, to a lesser extent, the formation of haloacetonitriles. This suggests that some low molecular weight DBPs and novel DBPs detected via high-resolution mass spectrometry share similar aromatic precursors, providing evidence that low molecular weight DBPs are useful proxies for the formation of unknown, unidentified high molecular weight DBPs. Compared to Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS), Orbitrap MS yields significantly fewer formula matches and appears to have a bias towards sulfur-containing formulas and against nitrogen-containing formulas. Additionally, the choice of calibration method is particularly important for the less powerful Orbitrap MS. The matched formulas yielded from Orbitrap MS tend to be more oxidized and less highly saturated than those yielded by FT-ICR MS. Despite these differences, the formulas produced by both instruments tend to yield similar relative differences between samples, suggesting that Orbitrap MS is an acceptable replacement for FT-ICR MS in some cases.
Book Synopsis Disinfection Byproducts in Drinking Water by : Yuefeng Xie
Download or read book Disinfection Byproducts in Drinking Water written by Yuefeng Xie and published by CRC Press. This book was released on 2003-08-27 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The EPA has established regulations which classify four types of disinfection byproducts - TTHMs, haloacetic acids, bromate, and chlorite - and requires public water systems limit these byproducts to specific levels. Most of the information required to comply with these standards is either scattered throughout the literature or derived from confere
Book Synopsis Disinfection By-product Formation Potential and the Structural Characteristics of Dissolved Organic Carbon in Springfield Water and Sewer Commission's Cobble Mountain Reservoir Watershed by : Thomas J. Naughton
Download or read book Disinfection By-product Formation Potential and the Structural Characteristics of Dissolved Organic Carbon in Springfield Water and Sewer Commission's Cobble Mountain Reservoir Watershed written by Thomas J. Naughton and published by . This book was released on 2011 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: USEPA regulations of Disinfection By-Products (DBPs) require water suppliers to be in compliance with maximum contaminant levels set by the agency's Stage 2 DBP Rule. Controlling watershed sources of byproduct precursors are of interest to water suppliers. By-product formation potential and DOC (dissolved organic carbon) character were evaluated at eight sites on four dates (n=32). All sites are within Springfield Water and Sewer Commission's Cobble Mountain Reservoir watershed (Blandford and Granville, Ma). The goal was to investigate how DBPFP (DBP formation potential) changes in relation to landscape driven changes in DOC chemical characteristics. Analysis was performed on raw water samples using UV-Visible Spectroscopy. 1H Nuclear Magnetic Resonance Spectroscopy (NMR), and Fourier Transform Infrared Spectroscopy (FT-IR) were performed on solid phase extractable (SPE-C18) hydrophobic DOC. Changes in DBPFP are related to landscape changes in hydrophobic DOC characteristics. On three of the four sample dates (n=24) DBPFP was positively correlated to the E2:E3 ratio (R2=.37), SUVA (R2=.72), percent aromatic resonance (R2=.60), and percent carbohydrate resonance (R2=.44). DBPFP on three sample dates (n=24) was negatively correlated to percent aliphatic resonance (R2=.48). DOC aromaticity, SUVA and specific formation potential were lowest in headwater streams and increased with distance downstream. Substantial reductions in DOC concentration are seen upon reservoir export. For most parameters headwater in-stream variability was greater than inter-stream variability. Differences among headwater streams of different forest type are not distinguishable in our small sample size (n=12). Only slight differences in specific formation potential were observed among two different depth samples in Cobble Mountain Reservoir. Our results have implications for watershed management practices in the drinking water supply industry of New England.
Book Synopsis The Effects of Dissolved Organic Matter on Pollutant Removal and Formation in Aquatic Environment by : Meng-Horng Hsu
Download or read book The Effects of Dissolved Organic Matter on Pollutant Removal and Formation in Aquatic Environment written by Meng-Horng Hsu and published by . This book was released on 2012 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrophobic organic pollutants (HOPs), such as polyaromatic hydrocarbons primarily from automobile exhausts and dissolved organic matter (DOM) are ubiquitous in the aquatic environment. The association between DOM and HOPs as a bound interaction of DOM-HOPs minimizes the bioavailability of free HOPs and their potential health effects. In addition, DOM is also the precursor of disinfection by-products involving the disinfection treatment processes. It is very important to understand the relationship between free and bound HOPs, disinfection by-products, and DOM in drinking water treatment, stormwater runoff and dry weather flow of aquatic environment. This thesis will explore the binding phenomenon between HOPs and DOM in raw and treated water from water treatment plants, after powdered activated carbon treatment, and in stormwater runoff and dry weather flow. This thesis also introduced the analytical methodologies for characterizing DOM and the hazardous potential of HOPs and thus understanding their relationship. DOM characteristics were measured for: 1) total concentration of organic carbon by dissolved organic carbon (DOC), 2) aromaticity by UV absorbance and specific UV absorbance (SUVA), and 3) size distribution by ultrafiltration (UF), 4) polarity by polarity rapid assessment method (PRAM), 5) UV and fluorescent chemical components by UV spectrometer and fluorescence excitation-emission matrix (EEM) and fluorescence regional integration (FRI). Hazardous potential of HOPs was measured by fluorescence quenching determined partition coefficient KDOM. Studies have been completed and showed that monitoring both the free and bound forms of HOPs as well as disinfection by-products (such as, trihalomethanes) and their relationship to DOM during drinking water treatment processes is necessary to better understand drinking water quality and give more effective suggestions to optimize treatment processes. In addition, this work showed the relationship between DOM and HOPs in equilibrium with DOM-HOPs needs definition on a seasonal basis to understand the bioavailability of HOPs in dry weather flow and stormwater runoff events. The determination of free and total HOPs has not been considered in the California "State Implementation Plan" for water quality-based effluent limits of HOPs. A method using a standard probe- perylene has been developed to be able to evaluate these situations on a site specific basis since DOM is site specific. Key findings of this study were: 1) DOM characteristics are different from site to site and affect pollutants removal and formation. 2) Bulk SUVA shows a positive correlation with Log KDOM (R2=74%). Thus, DOM with more aromatic structure can result in higher binding between HOPs and DOM. 3) DOM with higher concentration, aromaticity, and molecular weight can have more ability to form THMs. 4) Under the conditions studied, PAC (20 mg/L) is an effective method to control both THMs and the hazard potential of HOPs. 5) DOM in urban runoff with higher molecular weight and aromaticity can associate with more HOPs. As a result, the distribution of HOPs affected by DOM in urban runoff needs definition on a seasonal basis and runoff types.
Book Synopsis Fate of Natural Organic Matter and Formation of Disinfection By-products in a Conventional Water Treatment Plant by : Noha Hesham Abdel Halim
Download or read book Fate of Natural Organic Matter and Formation of Disinfection By-products in a Conventional Water Treatment Plant written by Noha Hesham Abdel Halim and published by . This book was released on 2014 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Elevated levels of disinfection by-products (DBPs), detected in Cairo residential water supply during the past decade, were the motivation to study the process of DBP formation at the water treatment plant (WTP) stage. It is hoped that an in-depth understanding of natural organic matter (NOM) characteristics and DBP formation/removal in an existing WTP will yield a baseline as well as insights for the development of optimum strategies for cost-effective reduction of potentially harmful drinking water compounds such as Trihalomethanes (THMs) and Haloacetic acid (HAAs). The objectives of this research were to: investigate the degree of removal of the various NOM fractions in conventional WTPs and identify the factors that may possibly enhance their removal; and investigate the levels of formed DBPs within conventional WTPs when pre-chlorination and post-chlorination are applied. Water samples were collected from El-Fustat WTP in Cairo from 4 different points along the treatment process and covering the four different seasons of a year. NOM was quantified by classical surrogate parameters such as total organic carbon (TOC), dissolved organic carbon (DOC), and ultraviolet absorbance (UVA254); and characterized more precisely according to its hydrophobic-hydrophilic properties using resin fractionation. THMs, HAAs and other water quality analyses were conducted for all collected samples. Measurements of NOM fractions following each treatment unit indicate that the hydrophobic fraction is significantly removed by the coagulation/flocculation/ sedimentation processes (56% to 13% in the various seasons) whereas the transphilic, and hydrophilic fractions were removed to much lower degree (51% to 10%) and (15% to 4%), respectively. The hydrophobic fraction had formed flocs with the added alum more than the other two fractions. No further removal of NOM takes place in rapid sand filtration or post-chlorination units. Although the THMs values recorded for the entire study were complying with the Egyptian guidelines, it is not guaranteed that tap concentrations will comply to the guidelines limits. This is because THM/THMFP does not exceed 39%, leaving room for 61% to be reacted in pipe lines and storage tanks until it reaches the customers taps. In addition, HAAs concentrations at the plant effluent were much higher than the regulating limits, alarming the WTP to exert more effort to reduce THMs, and HAAs values. On an attempt to identify the relative importance of NOM fractions in THMs formation, the measured values of the THMs were regressed to each NOM fraction and the coefficient of determination (R2) was calculated. Results showed that unlike hydrophobic fraction and transphilic fractions (R2 = 0.01, 0.14), respectively, hydrophilic NOM fractions are consistently most responsible for THM and HAAs production at the plant effluent (R2 = 0.77, 0.62. Although, hydrophilic fraction was the main contributor to THMs and HAAs formation in El-Fustat WTP; coagulation/flocculation and sedimentation could not successfully remove it during treatment. Accordingly, the processes of coagulation/flocculation/sedimentation/filtration are not guaranteed to be useful in decreasing the DBPs levels. El-Fustat WTP does not technically implement "Enhanced Coagulation"; however, initial results from this study shows that the hydrophillic DOC fraction is less likely to be removed during Enhanced Coagulation but the major DOC contributor to DBPs formation. Future work should test this hypothesis through a bigger and wider sample size. Free chlorine concentrations are responsible for the high THM levels at the plant effluent, which implies its responsibility on THMs formed in the plant and the formation potential in distribution pipelines. Therefore, reducing the chlorine doses as much as possible to reach zero free chlorine before post-chlorination and the minimum acceptable free chlorine residual for secondary disinfection is going to reduce the THMs and HAAs levels substantially.
Book Synopsis New Insights Into Disinfection Byproduct Formation and Control by : Ashley Dale Pifer
Download or read book New Insights Into Disinfection Byproduct Formation and Control written by Ashley Dale Pifer and published by . This book was released on 2012 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods were developed for application of asymmetric flow field-flow fractionation (AF4) and fluorescence parallel factor (PARAFAC) analysis to raw and treated samples from drinking water sources to improve characterizations of dissolved organic matter (DOM) and discover DOM properties correlated to disinfection byproduct (DBP) formation potential (FP). Raw water samples were collected from a reservoir, adjusted to pH 6, 7, and 8 and subjected to (1) jar tests using aluminum sulfate (alum) and (2) treatment with magnetic ion exchange (MIEX®) resin. Both treatments were followed by DBPFP tests at pH 7. AF4 was used to size DOM in raw and alum treated samples at pH 6 and 8. AF4 fractograms showed that DOM removal was more effective at pH 6 than at pH 8, and preferential removal of larger-sized DOM occurred at pH 6 but not at pH 8. A fluorescence-PARAFAC model was constructed using excitation-emission matrices (EEMs) from all samples. A strong linear correlation (r 2 = 0.87) between chloroform FP and a humic-like PARAFAC component (C1) was developed. This correlation was a significant improvement over the correlation (r 2 = 0.03) between chloroform FP and specific ultraviolet absorbance at 254 nm (SUVA254), a DBPFP surrogate commonly used in drinking water treatment plants to optimize DOM removal processes. This indicated that chloroform FP-C1 correlations were not treatment-specific. Alum coagulation at pH 6, 7, and 8 and DBPFP tests at pH 7 were performed on a set of raw waters from eleven drinking water treatment plants from across the United States. AF4 was used to size DOM before and after alum coagulation, and showed similar results to the earlier study, i.e., increased removal at pH 6 compared to pH 8. A fluorescence-PARAFAC model was constructed and total trihalomethane (TTHM) FP was strongly correlated (r 2 = 0.91) to C1 for eight water sources. TTHMFP-SUVA254 correlations for ten locations were weak (r 2 = 0.15), which indicated that C1 was an improved DBPFP surrogate relative to SUVA254 and could be used as a surrogate to select and optimize DBP precursor removal processes.
Book Synopsis Drinking Water Disinfection Byproduct Formation Assessment Using Natural Organic Matter Fractionation and Excitation-emission Matrices by : David W. Johnstone
Download or read book Drinking Water Disinfection Byproduct Formation Assessment Using Natural Organic Matter Fractionation and Excitation-emission Matrices written by David W. Johnstone and published by . This book was released on 2009 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Disinfection byproducts (DBP) pose a major problem for the drinking water industry due to their carcinogenic nature and formation when natural organic matter (NOM) reacts with chlorine. This study investigates the formation of individual DBP compounds within waters containing various NOM characteristics. Water from the Iowa River was concentrated through reverse osmosis and NOM fractions were isolated using resin separation. In addition, waters from the city of Barberton water treatment plant were collected prior to and subsequent to coagulation. Experiments were conducted on each water source under variable chlorine doses and pH, with and without the presence of model iron oxides. The purpose of this study was to investigate the role of NOM and the surrounding environment on DBP formation and develop measures for the prediction of byproduct formation. Fluorescence excitation-emission matrices (EEM) of NOM were quantified and characterized using fluorescence regional integration (FRI) and parallel factor analysis (PARAFAC). Changes in FRI of five operationally defined regions coupled with chlorine consumption showed strong linear relationships to the formation of chloroform (CHCl3), dichloroacetic acid (Cl2AA), and trichloroacetic acid (Cl3AA). Stepwise regression of fluorescence regions revealed the use of only one region coupled with chlorine consumption to predict DBP formation, yet this region varied depending upon the individual compound assessed. This technique provides an effective tool that can utilize both chlorine reactivity and functional group properties of the NOM to predict DBP formation. PARAFAC analysis of EEM yielded three statistically significant components providing relative concentrations of fluorophores within each sample. While this technique has previously been used for NOM characterization, it has yet to be utilized to assess DBP formation. Multi-factor linear regression of select component scores showed strong linear relationships to individual DBP compounds providing insight to organic compound characteristics responsible for DBP formation. These finding suggest that fluorophore component scores may be an effective parameter used to estimate DBP precursor concentration. In doing so, water plants can evaluate the fluorescence components and assess the effects of various treatment schemes on NOM, providing a more specific approach to precursor removal and a better understanding of DBP formation."--Abstract.
Book Synopsis Watershed Analysis of Dissolved Organic Matter and Control of Disinfection By-products by :
Download or read book Watershed Analysis of Dissolved Organic Matter and Control of Disinfection By-products written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Coagulation and Disinfection By-products Formation Potential of Dissolved Organic Matter Fractions by : Neeraj S. Pipada
Download or read book Coagulation and Disinfection By-products Formation Potential of Dissolved Organic Matter Fractions written by Neeraj S. Pipada and published by . This book was released on 1999 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both the proposed United States Environmental Protection Agency (USEPA) Disinfectants- Disinfection By-Products and Enhanced Surface Water Treatment rules have provisions for minimizing the formation of undesirable precursors of disinfection by-products (DBPs) in drinking water Natural Organic Matter (NOM) contains many of the precursors to the DBPs formed following disinfection of drinking water. DAX-8 resin procedures were used to isolate and fractionate NOM into six dissolved organic matter (DOM) fractions; Hydrophobic acid (FA), base (FB), neutral (FN), and hydrophilic acid (PA), base (PB) and neutral (PN). Aluminum sulfate (alum) jar coagulation tests were performed to determine the optimum coagulation ranges of each fraction. Different levels of pH, fraction concentrations, and coagulant levels were used in the experiments. Trihalomethane formation potential tests were performed on all the samples to check the removal of DBP precursors. Given the reactivities of the individual fractions to the formation of selected DBPs (i.e. trihalomethanes, halo acetonitriles, haloacetic acids), one can optimize on the removal of specific problematic fractions. Hence, if minimization of DBP formation was solely due to specific removal of precursors, microbial inactivation issues would be resolved due to the fact that CT may be increased without an increase in DBP formation.
Book Synopsis Investigation of Influence of the UV/H2O2 Advanced Oxidation Process on Dissolved Organic Matter's Characteristics and Disinfection Byproduct Formation Potential Using UHRMS Methods by : Yingying Xiang
Download or read book Investigation of Influence of the UV/H2O2 Advanced Oxidation Process on Dissolved Organic Matter's Characteristics and Disinfection Byproduct Formation Potential Using UHRMS Methods written by Yingying Xiang and published by . This book was released on 2020 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Relationship Between Structural Characteristics of Natural Organic Matter and the Formation of Disinfection By-products by : Wasinton Simanjuntak
Download or read book The Relationship Between Structural Characteristics of Natural Organic Matter and the Formation of Disinfection By-products written by Wasinton Simanjuntak and published by . This book was released on 2005 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: while the samples from the other three sources appeared to display more profound similarities than differences. Overall, the Darkan River NOM was most problematic in terms of THM formation, presumably as a result of a higher aromatic and phenolic content, as indicated by higher SUVA254 and SUVA272 values and a higher relative contribution of aromatic and phenolic pyrolysis products. Since NOM is such a complex mixture of simple and macromolecular organic compounds, having different chemical composition and structural characteristics, its characterisation has been acknowledged to be a very difficult and demanding study. This was also found with the NOM samples investigated in the present study. The results obtained clearly suggest that more work should be devoted to development of analytical methods which lead to improved structural information to characterise NOM in source waters.
Book Synopsis Dissolved Organic Matter Fluctuations in an Intermittent Headwater Stream by : Alba Guarch Ribot
Download or read book Dissolved Organic Matter Fluctuations in an Intermittent Headwater Stream written by Alba Guarch Ribot and published by . This book was released on 2017 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Dissolved organic matter (DOM) is an important source of carbon for aquatic microorganisms and it regulates many biogeochemical processes. Therefore, changes in river DOM concentration and properties could notably affect the functioning of fluvial and coastal ecosystems and alter the global carbon cycle. The DOM in headwater streams is strongly influenced by hydrology, as a consequence of the modification of catchment flow paths with high discharges. During storm events, the catchment hillsides are washed and terrigenous DOM is transported to rivers. In the Mediterranean region, the precipitation regime and evapotranspiration strongly modulate fluvial hydrology, which shows low discharges in summer and even flow disappearance. These dry–wet cycles of conditions affect many ecological and biogeochemical processes. In this thesis, I analyse a long time series of discharge and DOM data from Fuirosos, an intermittent headwater stream in NE Spain. My aim is to examine the relationship between DOM and hydrology at different temporal scales. First, I characterise the hydrological regime of this Mediterranean stream. A decrease in discharge was revealed, although trends in temperature and precipitation were not significant. In contrast, I did not find a clear temporal trend in dry period duration. However, rewetting has been significantly delayed, moving from September to October. The frequency of storm events decreased over the interval 1998–2015, showing a significant positive relationship with solar activity with a 2-year lag. Dissolved organic carbon (DOC) concentration saw a slight decrease during the study period, which was opposed to that observed in boreal systems. This pattern might respond to a reduction of terrigenous DOC input from forest hillsides as a consequence of the decrease in flushing episodes. The DOC temporal dynamics during the rewetting was regulated by dry period duration. Discharge oscillations explained up to 50% of total DOC variability during the wet period. Notably, this weight of discharge increased significantly over the years. DOM quality was also explored, and described in terms of absorbance and fluorescence properties. Most of the DOM properties were strongly related to discharge, revealing the input of allochthonous, degraded, aromatic, humic and large-molecular DOM under high flow conditions. However, these relationships were altered during drying and rewetting periods. The DOM responses at the individual storm event scale were highly heterogeneous. Multiple linear regression and commonality analyses showed that, in addition to the magnitude of storm episodes, antecedent hydrological conditions, namely pre-event basal flow and the magnitude of the previous storm event, played a significant role in regulating the trends and shapes of DOM–discharge hysteresis. Finally, I identified the differences and similarities in the DOM–discharge relationships between the intermittent Mediterranean stream analysed herein and a perennial Alpine stream with higher mean discharge (Oberer Seebach). The DOM in Fuirosos was significantly more concentrated, more terrigenous, more degraded, more aromatic and more humified. The sign of the global DOM–discharge response was the same in both streams. However, discharge was a more robust predictor of DOM variability in Oberer Seebach. In fact, low flow and rewetting periods in Fuirosos introduced considerable dispersion into the relationship. During snowmelt in Oberer Seebach the sensitivity to discharge also decreased or disappeared. The flushing/dilution patterns were essentially associated with the magnitude of storm events in Fuirosos. In contrast, the DOM quality change was more coupled to basal flow conditions in Oberer Seebach, while the storms were behind the DOC oscillations. This study attests to the importance of generating and analysing long-term and high-frequency biogeochemical series, which allow relationships between DOM and hydrology to be explored in intermittent headwater streams that are subjected to extreme hydrological regimes." -- TDX.
Book Synopsis Natural Organic Matter and Disinfection By-products Characterization and Control in Drinking Water by : Sylvia E. Barrett
Download or read book Natural Organic Matter and Disinfection By-products Characterization and Control in Drinking Water written by Sylvia E. Barrett and published by . This book was released on 2000 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are many by-products of water disinfection that are still not fully understood and can be potentially harmful. In this volume all the current research in this area is discussed, along with an examination of the role of NOM (natural organic matter) and its relationship to DBP (disinfection by-product) formation and control in drinking water. Understanding the relationship of NOM to DBP may well lead to new techniques for analyzing and treating water and enable reasonable choices to be made for source-water protection, treatment plant process optimization, and distribution system operation to control DBP's. This volume emphasizes the characterization and reactivity of polar natural organic matter. It examines analytical methods which better characterize NOM and determines some of the polar and nonvolatile DBP forms. It presents innovative new methods, sich as capillary electrophoresis for haloacetic aceids and LC/MS for the identification of polar dinking water DBPs.
