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Ozonation of sulfamethoxazole in wastewaterLeclair, Christine. January 2006 (has links)
Many studies have demonstrated that sewage treatment plants do not efficiently degrade pharmaceuticals such as antibiotics, hormones, and analgesics. Ozonation has been identified as a promising technique to degrade those compounds. A series of experiments was used to evaluate the impact of three parameters on the efficiency and kinetics of degradation of sulfamethoxazole, an antibiotic, by ozonation. An ozone reactor was designed to perform experiments. Analytical techniques, based on liquid and gas chromatography and mass spectrometry, were developed to measure concentrations of sulfamethoxazole and identify degradation products. / It was shown that the rate constant and the degradation efficiency are greater when the initial concentration of sulfamethoxazole is lower; the presence of other contaminants in solution decreases the percentage of degradation observed, and the concentration of hydrogen peroxide, used as catalyst, must be well adjusted since an inappropriate concentration hinders the reaction. Finally, the analysis of ozonated samples allowed the identification of degradation products and resulted in a proposed degradation mechanism.
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Ozonation of sulfamethoxazole in wastewaterLeclair, Christine January 2006 (has links)
No description available.
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An integrated computational fluid dynamics an kinetics study of ozonation in water treatment.Huang, Tzu Hua. January 2005 (has links)
Computational fluid dynamic (CFO) modelling has been applied to examine the operation of the
prc-ozonation system at Wiggins Waterworks, operated by Umgeni Water in Durban, South Africa.
Ozonation is employed in water treatment process primarily to achieve the oxidation of iron and
manganese, the destruction of micro-organisms and the removal of taste and odour causing compounds. It
also aids in the reduction of the colour of the final water, enhancement of algae removal and possible
reduction of coagulant demand.
A hydrodynamic model has been satisfactorily verified by experimental tracer tests. The effect of the gas
injection was modelled by increasing the level of turbulence intensity at the ozone contactor inlet. The
model prediction of the overall tracer response corresponded closely to the experimental results. The
framework of ozone reaction modelling was subsequently established using values of rate constants from
the literature. An accurate prediction of the ozone concentration profile requires the application of the
correct ozone kinetics involved. In raw waters, the depletion of ozone is influenced by the presence of
natural organic matters (NOM). The observed ozone decay was found in good agreement using the pseudo
first-order rate law. By measuring the total organic carbon (TOC) as a surrogate for NOM, the
experimentally determined rate constants can be calculated to account for the effects of the ozone doses and
the water quality. The characterisation study also aimed to provide sufficient information on ozone
depletion and to be operated easily, without the lengthy and costly analyses ofa detailed kinetics study.
The predicted profile of residual ozone concentration suggests the current operating strategy can be
improved to optimise the ozone utilisation. The proposed monitoring point was suggested to be at the end
of second companment where most ozone reactions have been completed. By coupling the transport
equations of the target compounds with their chemical reaction rates, the concentration profile of these
compounds such as ozone can be predicted in order to assist the understanding of an operation and to attain
better interpretation of experimental results. / Thesis (Ph.D.)-University of KwaZulu-Natal, 2005.
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The removal of color and DOC from segregated dye waste streams using ozone and Fenton's reagent followed by biotreatmentPowell, William W. January 1992 (has links)
The decolorization of reactive dye-containing waste streams using oxidizing chemicals and the determination of the effect of the oxidizing agents on the subsequent biotreatment of the streams was investigated. Three oxidizing schemes were chosen for study: molecular ozone, base-promoted ozonation, and Fenton’s reagent (Fe²⁺ and H₂O₂). The ADMI color value of the solutions was used as the primary parameter for color comparison and dissolved organic carbon (DOC) removal was the measure of the effect of biodegradation.
Three different waste streams from a textile dyeing facility were chosen: a Navy slack washer effluent from a pad-dyeing operation, a Navy dyebath effluent from a dyejet, and a Brilliant Blue dyejet effluent. Pure dye solutions were oxidized as well to determine the effect of interfering species in the waste streams.
The results demonstrated that base-promoted ozonation was more effective than molecular ozone for the decolorization of the Navy slack washer effluent. In both cases the ADMI color value could be decreased by 82% but almost half as much ozone was necessary for the high pH trials. The high pH ozonation proved more effective for the Navy jet-dye effluent, as well, achieving a much lower color value with less ozone. Greater decolorization (96%) of the Navy jet-dye effluent was achieved by Fenton’s reagent than for either of the ozonation schemes. Ozonation of the Brilliant Blue jet-dye bath showed no dependence on pH and the color value of the solution was reduced could be 63%.
The results indicate that the dyes were selectively oxidized by ozonation and the amount of ozone required for decolorization depended mainly the initial color of the dye waste stream. The amount of hydrogen peroxide required for Fenton’s reagent oxidation depended on the initial DOC of the dye waste stream.
Oxidation of the wastewater streams proved to neither enhance nor hinder the operation of the biological reactors. The color removals by biological activity were minimal for both control and experimental reactors. Dissolved carbon removal was not enhanced by oxidative pretreatment. / Master of Science / incomplete_metadata
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