Colorado State University
Dr. Nasim Pica is a postdoctoral researcher with Dr. Jens Blotevogel in the Department of Civil and Environmental Engineering at Colorado State University. She has a BS in Civil Engineering and an MS in Environmental Engineering from Sharif University of Technology and a PhD in Environmental Engineering from Colorado State University.
Dr. Pica's research interests include fate and transport of emerging contaminants, sustainable water reuse, the food-energy-water nexus and non-traditional water resources. Currently, she is working on developing sustainable and promising solutions for the treatment of 1,4-dioxane, perfluorinated and chlorinated compounds.
Coupling Electrochemical with Biological Oxidation of 1,4-Dioxane: Impacts on Degradation Rates, Co-Contaminant Removal, and Disinfection By-Product Formation
1,4-dioxane is a persistent organic pollutant (POP) that frequently co-occurs at sites impacted by chlorinated volatile organic compounds (CVOCs) due to its widespread use as solvent stabilizer. Its water miscibility and low sorption affinity to sediment make 1,4-dioxane highly mobile in groundwater, leading to large plume development. Our previous research has shown that electrochemical oxidation is an effective technology for the mineralization of POPs both ex and in situ. Here, we explore the benefits of coupling electrochemical oxidation of 1,4-dioxane on novel doped tin oxide mesh electrodes with aerobic biodegradation by Pseudonocardia dioxanivorans CB1190, a microaerophilic bacterium that can grow on 1,4-dioxane as its sole electron donor. While biodegradation of 1,4-dioxane in groundwater is often hindered by the absence of dissolved oxygen, electrolysis of water leads to generation of oxygen, supplying aerobic microorganisms with a potent electron acceptor. Furthermore, electrolysis concurrently removes chlorinated co-contaminants, known to inhibit 1,4-dioxane degraders. These synergistic effects enable rapid mineralization of 1,4-dioxane at substantially lower potentials than with electrochemical oxidation alone, decreasing the formation of disinfection by-products such as perchlorate. Finally, quantitative real-time polymerase chain reaction (qPCR) counts will reveal impacts on P. dioxanivorans CB 1190 distribution along the flow path, yielding critical information on process scale-up and design. Our results will establish that coupling electrochemical oxidation with aerobic biodegradation is a promising synergistic approach for the treatment of groundwater contaminated with persistent organic pollutants in mixed contaminant plumes.