Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 44 for “"trihalomethanes"”.
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Process Modeling of Trihalomethanes During Aquifer Storage and Recovery
… periods and recovering water during dry periods. Trihalomethanes are the most common disinfection by-products found in chlorinated water, a result of chlorine reacting with dissolved organic matter, and are linked to adverse human health effects. The study objective is to examine processes …
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The management of Trihalomethanes in water supply systems preferred access arrangement
The formation of potentially harmful trihalomethanes (THM) when using chlorine as a disinfectant in potable water supplies has led to tighter regulatory controls and hence a need for better models for THM management. The prediction of THM concentration is difficult due to the complex and changing …
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Characterization of natural organic matter and precursors to trihalomethanes using spectral flourescence signatures
… The major chlorination DBPs are dominantly Trihalomethanes (THMs). However, not all organic compounds are equally reactive to THMs formation. NOM in water samples collected from the Delaware & Raritan Canal and its tributaries (Central New Jersey) was isolated by resin adsorption into six …
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Algal and bacterial interactions in producing precursors of trihalomethanes and other halogenated organics
The objectives of this study were to determine: (1) whether or not heterotrophic microorganisms exert an effect on the trihalomethane (THM) or total organic halogen (TOX) formation potentials of algal extracellular products (ECP), and (2) whether or not diurnal cycling of THM and TOX precursors …
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The Effect of Predisinfection with Chlorine Dioxide on the Formation of Haloacetic Acids and Trihalomethanes in a Drinking Water Supply
… governing haloacetic acids (HAAs) and trihalomethanes (THMs), the Blacksburg, Christiansburg, VPI (BCVPI) Water Authority in Radford, Virginia elected to eliminate prechlorination and replace it with preoxidation using chlorine dioxide (ClO2). Prior to full-scale application at the …
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Gas chromatographic-electron capture analysis of disinfection byproducts from the chlorination of swimming pools and lake water
Trihalomethanes are a class of compounds that are restricted by the Environmental Protection Agency for drinking water. Water sources that contain a high amount of water life increase the amount of trihalomethanes produced when the water is chlorinated. Following the methods utilized by the …
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Impacts of Sludge Volume and Sludge Age on Disinfection By-Product Formation in a Full-Scale Water Treatment Facility
… Protection Agency. Water samples were tested for trihalomethanes and haloacetic acids at both ends of the sedimentation process to evaluate formation over the length of the basin. Sludge volume and other important water quality parameters were also measured at the time of sample collection. …
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Analysis and occurrence of disinfection by-products in fresh and salt water
<p>"Haloacetic acids, trihalomethanes, and bromate are important toxic water disinfection by-products (DBPs) that the US Environmental Protection Agency (USEPA) regulates in drinking water. Iodoacetic acids and halonitromethanes (HNMs) are the unregulated emerging DBPs that have been recently found …
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The Occurrence and Control of Disinfection By-Products (DBPs) in Two Water Treatment Plants Utilizing the Same Source
… increasing since the early studies by Rook on trihalomethanes (THMs) (Stevens, 1977). Work conducted in the 1980s identified the existence of nonvolatile halogenated organics (non-THM organics), of which the majority produced by chlorination were haloacetic acids (HAAs), within the HAAs, …
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Seepage of Groundwater into the St. Clair River Near Sarnia, Ontario, Canada
… hydrocarbons, polychlorinated biphenyls, trihalomethanes, EPA Priority Pollutants (extractables), total organic halides (TOX), chloride, and natural isotopes (oxygen-18, deuterium, and tritium). The average observed seepage rate of l. u x 10-8 m 3/s/m2 suggests higher chan expected …
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PHOTOELECTROCATALYTIC OXIDATION OF MUNICIPAL REVERSE OSMOSIS CONCENTRATE
… of halogenated disinfection byproducts (DBPs), trihalomethanes and haloacetic acids. The results show that PEC could be an economically viable alternative for ROC treatment with proper control of DBPs formation.
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Removal of organic contaminants from groundwater by reverse osmosis
… by the membrane to meet either the MCL for total trihalomethanes or trichloroethene. Sorption onto the poly(ether/urea) was found to occur for several of the aromatic compounds tested in this research. This prevented developing any relationship between membrane performance and physical/chemical …
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The influence of algal growth and related ecological factors in reservoirs on the production and control of trihalomethane precursors
… of organic compounds, especially those that form trihalomethanes upon chlorination and 2) to evaluate the effectiveness of alum coagulation, followed by clarification, for removing THM precursors from lake water. The weekly grab samples provided evidence of a general relationship between algal …
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Trihalomethane Removal and Re-Formation in Spray Aeration Processes Treating Disinfected Groundwater
… health protection by limiting exposure to four trihalomethanes (THM) and five haloacetic acids (HAA5), formed when chlorine is used for microbial pathogen control. This thesis examines post-aeration TTHM formation when employing spray-aeration processes to remove semi-volatile TTHMs from …
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Impact of bromide ion concentration, time, dissolved organic carbon and molecular weight cutoff on haloacetonitrile, haloketone, chloropicrin and trihalomethane formation potentials
… haloketones (HKs), chloropicrin (CP) and trihalomethanes (THMs) under conditions of constant DOC, constant Cl:DOC ratio, variable [Br] and variable apparent molecular weight (AMW) for coagulated water from a full-scale water treatment plant. Coagulated, high humic water (4.5 mg DOC/L) was …
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Trihalomethane-forming potential of algal extracellular products and biomass
… be important as precursors in the formation of trihalomethanes during water treatment.
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Drinking water disinfection by-products detection, formation and the precursors removal study
"Haloacetic acids (HAAs) and trihalomethanes (THMs) are two groups of commonly found disinfection by-products (DBPs). Iodinated THMs and HAAs were observed after disinfection of water containing high level of iodide and are proved to be more toxic than their corresponding chlorinated and brominated …
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Management of disinfection byproduct production in small drinking water systems
… (DBPs) currently regulated in drinking water are trihalomethanes (THMs) and haloacetic acids (HAAs). The objective of this research was to better understand how the water treatment processes employed at four smaller municipal water treatment utilities affects THM and HAA formation by measuring the …
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A Non-Biological Inhibition Based Sensing Technique (NIBS) for the Detection of Halogenated Disinfection By-Products in Water
… organic compounds with a specific focus on trihalomethanes (THMs). To achieve effective detection of halogenated organics, the effects of reaction temperature and reactant concentrations on the NIBS reaction were studied and optimized. In the present NIBS method, a pyridine-catalyzed …
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