![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Bench-Scale Electrochemical Degradation of PCBs in Water and Sediments
Bench-scale experimental ECD setup.
Hypothesis and Objectives
Electrochemical degradation (ECD) utilizes the high redox potential at the anode and the low redox potential at the cathode to oxidize or reduce contaminants. These experiments will study the effect of voltage and flow rates on the degradation rates of polychlorinated biphenyls (PCBs) and help scientists to identify and quantify the reduction products. The results may also demonstrate the feasibility of a system using cathodic reaction for treatment of chlorinated compounds in water, sediments, and soil.Research Drivers
Our research will examine ECD processes and mechanisms, test the effects of experimental parameters, and verify or disprove the hypothesis. We will design and conduct experiments at both pilot- and field-scales.
Current Approach
The following ECD of PCBs experiments have been conducted:-
In preliminary membrane reactors:
- PCB adsorption and dechlorination experiments were conducted on a glass reactor, with a membrane separating the cathodic and anodic chambers. The reaction was completed with K2PdCl6.
- In mini-platinum electrode reactors:
- with Palladium (Pd) coating on a 5 ml syringe-like mini-platinum and graphite combination reactor, in a 0.1 N NH4Ac matrix. Single experiment time was greatly reduced with this mini reactor, which we used as a preliminary investigation.
-
In a newly designed membrane reactor:
- in 0.1 N NH4Ac, 2.5% kaolin, humic acid, and 3.8% sediment matrices. We investigated experiment parameters like voltage, electric current, and electrolyte (Na2SO4, CuSO4, KNO3, NH4Ac). We examined different post-run extraction tests for mass balance and recovery, as well as graphite and membrane control experiments.
Contact: Souhail Al-Abed (EIMS#135927)