THESIS
2011
xix, 218 p. : ill. (some col.) ; 30 cm
Abstract
An advanced ozone membrane reactor was employed for treating endocrine disrupting compounds (EDCs) in water as they survived in state of the art water treatment processes. A reactor which combined ozone oxidation and membrane separation is designed for treating EDCs. Potassium hydrogen phthalate (KHP) was selected as the model pollutant since it is refractory and has a small molecular size. 1.5 μm thick ZSM-5 zeolite membrane was used because of its high chemical tolerance, good water permeability and excellent selectivity. The reactor removed 100 % of KHP and 83 % of TOC at 7.5 minutes residence time by feeding 250 ppmC KHP. The TOC removal enhancement was 64 % higher for ozonation alone and permeated clean water (TOC...[
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An advanced ozone membrane reactor was employed for treating endocrine disrupting compounds (EDCs) in water as they survived in state of the art water treatment processes. A reactor which combined ozone oxidation and membrane separation is designed for treating EDCs. Potassium hydrogen phthalate (KHP) was selected as the model pollutant since it is refractory and has a small molecular size. 1.5 μm thick ZSM-5 zeolite membrane was used because of its high chemical tolerance, good water permeability and excellent selectivity. The reactor removed 100 % of KHP and 83 % of TOC at 7.5 minutes residence time by feeding 250 ppmC KHP. The TOC removal enhancement was 64 % higher for ozonation alone and permeated clean water (TOC < 2 ppmC) continuously. Similar performances were observed for diclofenac sodium, carbamazepine and caffeine in which 100 % EDCs removal could be achieved within 2 minutes of treatment. In additions, powder activated carbon and hydrotalcite (Mg/Al =3) were successfully coated on the α-alumina support, serving as the contactor for catalytic ozone treatment. However, those adsorbents did not have observable catalytic effect on KHP but influence of the performance of the reactor. Hydrotalcite-coated ZSM-5 membrane showed a strong adsorption of organic acids within the support and enhanced the development of concentration polarization which lowered the permeate flux. Even the hydrotalcite coating has negative influence on treating KHP, it is thought to be capable of enhancing performance when treating positively charged carrying species.
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