Superfund Research Program
New Technologies for the Destructive Remediation of Halogenated Organics
Project Leader: Eric A. Betterton
Grant Number: P42ES004940
Funding Period: 2000-2010
Final Progress Reports
Year: 2009 2004
The most commonly used methods for remediating groundwater and soils contaminated with PCE and TCE are pump and treat and soil vapor extraction technologies (SVE), which have faults due to high costs and production of contaminated waste streams. Innovative technologies have been developed to convert chlorinated solvents in ground water and gas-phase streams to innocuous products. One method involves catalytic removal of chlorine from gas-phase contaminants. Catalysis takes place on heated metal surfaces, and chlorine removal occurs only in the presence of a gas-phase reductant. Initially H2(g) was introduced into the gas stream as the reductant but recently gas-phase hydrocarbons like methane and propane were used since they are cheaper and are frequently present as co-contaminants at Superfund sites (thus cost-free). The catalytic conversion technology described here was deployed at a local (state) Superfund site in Tucson where PCE and diesel components were present as co-contaminants in a SVE gas stream. The catalytic reactor has performed well for months with no sign of poisoning by the contaminants. Electrolytic methods for destroying trace-level chlorinated organic contaminants in ground water are also under investigation. Complete dehalogenation of the target compounds occurs with half-times of minutes. The primary product is ethane, and power costs are minimal. New electrode arrangements have greatly improved the overall reactor performance (kinetics) during the last year. This process will be utilized in the field in the near future.