University of California, Los Angeles
Jerry Ngo is a Master’s student conducting research with Professor Shaily Mahendra at the University of California, Los Angeles. His research focuses on design treatment trains for 1,4-dioxane in chlorinated solvent mixtures using sorption-assisted biodegradation of contaminants by microbes via metabolic and co-metabolic mechanisms. During his undergraduate career, Jerry was awarded the Chancellor’s Service Award for his advocacy work with the Vietnamese Student Union. As a graduate student, he remains actively engaged with student funding committees on campus and is a teaching assistant for Introductory Vietnamese. Jerry hopes to conduct research abroad and aspires to be an environmental consultant.
BioGAC systems for simultaneous removal of 1,4-dioxane and chlorinated solvents
1,4-Dioxane is a widespread, carcinogenic groundwater contaminant typically treated with cost-prohibitive advanced oxidation processes. Bioremediation presents a more sustainable alternative but suffers from the inhibitory effects of chlorinated solvents found co-occurring with 1,4-dioxane. Here we demonstrate bioaugmented granular activated carbon (BioGAC) as a synergistic treatment technology employing abiotic removal of chlorinated solvents combined with the biological destruction of 1,4-dioxane. Fixed bed flow-through and recirculating column studies were conducted with 1,4-dioxane-metabolizing strain Pseudonocardia dioxanivorans CB1190 adhered to GAC surface and fed with synthetic groundwater containing 1,4-dioxane, 1,1-dichloroethene, cis-1,2-dichloroethene, and trichloroethene. The BioGAC columns significantly outperformed abiotic column controls and planktonic batch reactors with respect to 1,4-dioxane removal. Optimization of nutrient and oxygen dosing was crucial. These results underscore the resiliency of biofilms in resisting inhibitory conditions, highlight the potential synergy between physical-chemical and biological processes, and will serve as the foundation for an ex-situ pilot-scale reactor for contaminated groundwater remediation.