ABSTRACT
Direct Chemical Oxidation (DCO) is an ambient pressure, nonthermal process that was developed to destroy the organic contaminants in hazardous or mixed wastes by chemical oxidation. DCO uses solutions of the peroxydisulfate ion, the strongest known chemical oxidant (other than fluorine-based chemicals), to convert organic solids and liquids to carbon dioxide, water, and constituent minerals by oxidation at temperatures of 80 to 100°C. The process was developed for applications in bulk waste treatment, chemical demilitarization and decontamination, and environmental remediation by engineers and scientists at Lawrence Livermore National Laboratory, beginning in 1992. Peroxydisulfate has also been used alone or with an Ag(II) catalyst in decontamination and etching solutions for removing PuO2 (as dissolved plutonyl ion) from radioactively contaminated equipment. The process has been demonstrated in transportable pilot-scale operations (15 kg-C/day) on mixed chlorinated solvents. The expended oxidant can be regenerated by electrolysis to minimize secondary wastes. Off-gas volumes are minimal, allowing retention of volatile or radioactive components. For nearly all water-soluble organic liquids, the rate of destruction at 90 to 100°C is about 200 kg (as carbon) per cubic meter of reaction liquid per day.
