Destruction of Disinfection By-product Precursors Using Photoassisted Heterogeneous Catalytic Oxidation PDF Download

Author: David William Hand
Publisher:
ISBN:
Category :
Languages : en
Pages : 410

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Author: M Fielding
Publisher: Elsevier
ISBN: 0857090321
Category : Technology & Engineering
Languages : en
Pages : 238

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This volume brings together contributors from water regulators, and water suppliers in Europe and North America to discuss the main issues associated with reaching a cost-effective balance between microbial and chemical risks. Overviews of research are presented alongside illuminating case studies of the practical approaches taken by water companies and regulators on both sides of the Atlantic.

Author: Roger A. Minear
Publisher: CRC Press
ISBN: 1351454854
Category : Technology & Engineering
Languages : en
Pages : 519

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Disinfection By-Products in Water Treatment describes new government regulations related to disinfection by-products. It explains the formation of microorganism by-products during water treatment and the methods employed to control them. The book includes several chapters on chlorine by-products and discusses techniques for the removal of chloroform from drinking water. It also describes gamma radiation techniques for removing microorganic by-product precursors from natural waters and the removal of bromate from drinking water.

Author: Philip C. Singer
Publisher:
ISBN:
Category : Medical
Languages : en
Pages : 456

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Written by more than 30 DBP experts, this technical and managerial reference tool provides essential background and addresses recent activities of the EPA and environmental consultants. It answers important questions, such as how to balance microbial and chemical risks, and includes information on new regulation and treatment costs.

Author: Julie Mialaret Davis
Publisher:
ISBN:
Category : Biodegradation
Languages : en
Pages : 250

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Author:
Publisher:
ISBN:
Category : Chemistry, Technical
Languages : en
Pages : 618

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Author: Erin Daugherty
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 171

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Disinfection byproducts are the result of reactions between natural organic matter (NOM) and a disinfectant. The formation and speciation of DBP formation is largely dependent on the disinfectant used and the natural organic matter (NOM) concentration and composition. This study examined the use of photocatalysis with titanium dioxide for the oxidation and removal of DBP precursors (NOM) and the inhibition of DBP formation. Water sources were collected from various points in the treatment process, treated with photocatalysis, and chlorinated to analyze the implications on total trihalomethane (TTHM) and the five haloacetic acids (HAA5) formations. The three sub-objectives for this study included: the comparison of enhanced and standard coagulation to photocatalysis for the removal of DBP precursors; the analysis of photocatalysis and characterization of organic matter using size exclusion chromatography and fluorescence spectroscopy and excitation-emission matrices; and the analysis of photocatalysis before GAC filtration. There were consistencies in the trends for each objective including reduced DBP precursors, measured as dissolved organic carbon DOC concentration and UV absorbance at 254 nm. Both of these parameters decreased with increased photocatalytic treatment and could be due in part to the adsorption to as well as the oxidation of NOM on the TiO2 surface. This resulted in lower THM and HAA concentrations at medium and high photocatalytic treatment levels. However, at no UV exposure and low photocatalytic treatment levels where oxidation reactions were inherently incomplete, there was an increase in THM and HAA formation potential, in most cases being significantly greater than those found in the raw water or control samples. The size exclusion chromatography (SEC) results suggest that photocatalysis preferentially degrades the higher molecular mass fraction of NOM releasing lower molecular mass (LMM) compounds that have not been completely oxidized. The molecular weight distributions could explain the THM and HAA formation potentials that decreased at the no UV exposure samples but increased at low photocatalytic treatment levels. The use of photocatalysis before GAC adsorption appears to increase bed life of the contactors; however, higher photocatalytic treatment levels have been shown to completely mineralize NOM and would therefore not require additional GAC adsorption after photocatalysis.

Author: Simon Parsons
Publisher: IWA Publishing
ISBN: 1843390175
Category : Science
Languages : en
Pages : 370

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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.

Author: Jie Chen
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Recently, a highly efficient photocatalyst consisting of amorphous manganese oxide (AMO) has been developed. Photoassisted catalytic oxidation of isopropanol has been studied by using amorphous manganese oxide catalysts with magnesium oxide as a diluent. When AMO or AMO/MgO is illuminated with UV-visible light in the presence of isopropanol vapor and oxygen at room temperature, the primary organic oxidation product is acetone. Enhanced yields for photooxidation of isopropanol with AMO/MgO mixtures have been observed. A continuous supply of oxygen may be achieved by adsorbing molecular oxygen on AMO and AMO/MgO during simultaneous irradiation in the UV-visible range. Temperature programmed desorption and oxygen isotopic exchange results support previously proposed mechanisms of photoassisted catalytic oxidation. Oxygen is adsorbed as O$\sb2\sp-$ species on the surface of the catalyst and plays an important role in this photooxidation. The observed effect of magnesium oxide suggests that hydroxyl groups promote the catalytic activity. The contamination of indoor air by volatile organic compounds (VOCs) has become a serious public health problem in recent years. The purpose of this study is to investigate photocatalytic activity of TiO$\sb2$ under kinetic conditions and the application of photocatalysts for decomposition of VOCs. The photocatalytic degradation of trichloroethylene, toluene, and triethylamine over TiO$\sb2$ (anatase) has been investigated by using a flat plate photochemical reactor. TiO$\sb2$ was used as a thin film coated on a microscope slide. The degradation of the three compounds, trichloroethylene, toluene, and triethylamine in a continuous flow mode, approximates first-order kinetics. The Langmuir-Hinshelwood kinetics have been used to rationalize the first-order behavior in solid-gas reaction. The deactivation of the catalyst also was investigated.

Author: American Chemical Society. Committee on Professional Training
Publisher:
ISBN: 9780841227231
Category : Science
Languages : en
Pages : 1700

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