THESIS
2017
xv, 227 pages : illustrations (some color) ; 30 cm
Abstract
A catalytic polymer membrane reactor to treat water contaminated with endocrine disrupting
compounds with ozone continuously was fabricated and evaluated. The reactor consisted of a
graphene oxide surface-modified polyvinyledene fluoride (PVDF) ultrafiltration membrane,
serving as a water selective extractor, and an adsorbent catalyst-coated PVDF microfiltration
membrane, acting as an ozone gas distributor and catalytic membrane contactor. The addition of
catalysts helps to retain organic pollutants in the reaction zone, promotes ozone dissolution and
transformation to reactive hydroxyl radicals, and accelerates the conversion and mineralization of
organic compounds. The catalytic membrane contactor/distributor consistently displays a high rate
of conversion of organic pollutant...[
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A catalytic polymer membrane reactor to treat water contaminated with endocrine disrupting
compounds with ozone continuously was fabricated and evaluated. The reactor consisted of a
graphene oxide surface-modified polyvinyledene fluoride (PVDF) ultrafiltration membrane,
serving as a water selective extractor, and an adsorbent catalyst-coated PVDF microfiltration
membrane, acting as an ozone gas distributor and catalytic membrane contactor. The addition of
catalysts helps to retain organic pollutants in the reaction zone, promotes ozone dissolution and
transformation to reactive hydroxyl radicals, and accelerates the conversion and mineralization of
organic compounds. The catalytic membrane contactor/distributor consistently displays a high rate
of conversion of organic pollutants and reduction of total organic carbon (TOC) over the entire
range of ozone dosage and reaction residence time studied. The coupling of ozonation and selective
water removal by the membrane separator benefitted both processes. Selective removal water by
the membrane separator has the desired effect of concentrating the organic pollutants, resulting in
a higher conversion and mineralization rate, and greatly lowered toxicity of the treated water. The
compact membrane reactor unit equipped with a catalytic membrane contactor/distributor and a
membrane water separator converted 60% of DEET and reduced 30% of TOC, outperforming a
semi-batch ozone reactor which converted 20% of DEET and reduced 5% of TOC. The compact
membrane reactor unit achieved these conversion rates at a flux up to 120 L/(m
2h). This work has
achieved:
● The surface modification of a PVDF ultrafiltration membrane with graphene oxide as
membrane separator to concentrate the pollutants in the reaction zone and lower the
microtoxicity of treated water with high clean water production.
● The development of adsorbing catalysts for catalytic ozonation using metal oxide supported
on powdered activated carbon.
● The development of adsorbing catalyst coated PVDF microfiltration membranes as a
membrane distributor/contactor for ozone treatment of EDCs in water.
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