Reductive dechlorination of trichloroethene and carbon tetrachloride using iron and palladized-iron cathodes
This research investigated the effectiveness of electrochemical reduction for removing trichloroethylene (TCE) and carbon tetrachloride (CT) from dilute aqueous solutions. The kinetics, reaction mechanisms, and current efficiencies for TCE and CT reduction were investigated using flow-through, iron electrode reactors and with amperometric measurements of reduction rates. The electrode reactors were operated over a range of flow rates, pH, ionic strength, dissolved oxygen concentration, and working electrode potentials. Typical reduction half-lives for TCE and CT in the iron reactor were 9.4 and 3.7 min, respectively. The addition of palladium as an electrocatalyst at a level of 1 mg of Pd per m{sup 2} of electrode surface area increased the reaction rates by a factor of 3. When operated continuously, reaction rates in the palladized-iron reactor were stable over a 9-month period of operation, indicating that there was no loss of palladium from the electrode. In both the iron and Pd-iron reactors, TCE was reduced primarily to ethane and ethene, while CT was reduced almost exclusively to methane. Under all operating conditions, chlorinated compounds accounted for less than 2% of the total reaction byproducts.
- Research Organization:
- Univ. of Arizona, Tucson, AZ (US)
- OSTI ID:
- 20014627
- Journal Information:
- Environmental Science and Technology, Vol. 34, Issue 1; Other Information: PBD: 1 Jan 2000; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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