Date of Award

Spring 2019

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Environmental Engineering - (Ph.D.)

Department

Civil and Environmental Engineering

First Advisor

Zhang, Wen

Second Advisor

Marhaba, Taha F.

Third Advisor

Sirkar, Kamalesh K.

Fourth Advisor

Basuray, S.

Fifth Advisor

Liu, Charles

Abstract

Micropollution in natural waters such as rivers and groundwater aquifers is a widespread problem that prevents these potentially potable sources from being used as drinking water. In the United States, approximately two-thirds of the over 1,200 most serious hazardous waste sites in the nation are contaminated with trichloroethylene (TCE), a potentially carcinogenic compound. Other emerging and environmentally persistent organic micropollutants include polyromantic hydrocarbons (PAHs), organophosphate flame retardants, endocrine disrupting compounds (EDCs), pesticides, herbicides, pharmaceuticals and personal care products (PPCPs). Membrane filtration is one of the most efficient separation processes widely used for water treatment and pollutant removal. However, traditional membrane separations suffer from membrane fouling due to either the formation of a cake layer of biomass or more commonly due to organic matter adsorption onto the membrane surface. Moreover, some trace level organic micropollutants are not effectively removed particularly in microfiltration processes, where pore sizes are not small enough to capture small molecular weight organics. This study demonstrated an innovative and multifunctional reactive electrochemical membrane (REM) that acts as both a filter and a reactive anode. REM filtration has significant mitigation of membrane surface and efficient degradation of water contaminant fouling through electrochemical oxidation powered by anodic polarization under a DC current. This research demonstrate: (1) the use of the Ti4O7 REM to separate and oxidize potentially pathogenic microorganisms (e.g., algal cells and bacteria) in aqueous suspension with evidence of cell damage and removal; (2) Evaluation of the performance of REMs for the removal of antibiotic compound (sulfamethoxazole) and 1,4-dioxane; (3) fouling mitigation and development of antifouling strategies via DC current applications and anode/cathode switch; (4) Radical formation mechanisms under DC currents in the REM filtration system. Overall, this project aims to demonstrate next generation reactive membrane filtration systems with high pollutant rejection or removal efficiencies toward water contaminants on electrochemical oxidation reactions on REM surfaces.

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