Abstract: Halogenated contaminants are removed from soil by reaction schemes which are carried out in a slurry of the soil and a reagent mixture. The latter is made up of an alkaline constituent--an alkali metal hydroxide, an alkali metal hydroxide/alcohol or alkali metal hydroxide/glycol mixture, or an alkoxide--and a sulfoxide catalyst.

Abstract: A reagent mixture is admixed with soil to first desorb and then hydrolyze and thereby increase the biodegradability of a toxic or otherwise hazardous polyhalogenated organic compound with which the soil is contaminated. Essential constituents of the reagent mixture are: (1) an alkali metal hydroxide, an alkali metal hydroxide/alcohol or alkali metal hyroxide/glycol mixture, or an alkoxide; and (2) a sulfoxide catalyst. The hydrolyzed compounds can be biologically degraded into compounds which pose little if any hazard to the environment or its inhabitants by naturally occurring or artifically introduced Pseudomonas sp. and other microorganisms with adjustment of soil pH (and perhaps orther parameters) to provide a viable environment for the bacteria being carried out after the chemical treatment if inoculation with bacterial cultures is employed.