Superfund Research Program
Portable, Self-Cleaning Advanced Electro-Oxidation Systems for Distributed and Point-of-Use Water Treatment
Final Progress Reports
Year: 2019 2013
Building on prior work on transformation of trichloroethylene, Akram Alshawabkeh, Ph.D., and his team investigated transformation of PCE, TCE parent compound, in a saturated porous matrix and the influence of design parameters on the removal performance. A removal of 86 percent was reached in the fully liquid-filled, at a current of 120 mA across a cathode → bipolar electrode → anode arrangement with a Darcy velocity of 0.03 cm/min (150 m/yr). The results prove that PCE can be electrochemically transformed in reactor designs replicating that of a potential field-implementation. In previous years, the team found that when the carbon-based cathodes are employed as O2 diffusion electrodes, H2O2 generation increased up to 25 mg/L compared with three mg/L formed via Pd catalysis. Recent work proves that O2 diffusion electrodes have better performance under neutral and alkaline pH which is at the pH range of groundwater. A dampproof coating layer was designed for the O2 diffusion electrodes, which stabilized and extended H2O2 generation in lab-scale. Project researchers found that low cost, activated carbon cathode simultaneously support H2O2 formation and activation to hydroxyl radicals under neutral pH, which are very significant findings for lowering the technology costs, maintenance, and operation requirements. The team also continued to apply advanced bioinformatics tools and alternate clustering analysis to characterize and predict water toxicity. Together with the results of quantitative toxicogenomics-based biomarkers ensemble assays used to investigate the toxicity mechanisms of the contamination mixtures (as in PR water sources), these findings are used to further understand the impacts of electrochemical remediation strategies on changes in water toxicity. Ultimately, researchers tested the technology in the field and applied solar-powered system with the cloud based Wireless Environment Sensor Network for real-time water monitoring, which provided valuable information for improved pilot and full-scale application. Finally, the team implemented a comprehensive theoretical model that integrates coupled effects of chemical and electrochemical processes facilitates the design, analysis, and implementation focusing on the kinetics of hydrogen peroxide generation in electrochemical batch reactor with porous carbon-based electrode. The result of the model is evaluated through experimental observations.