Biological decontamination of soil - by aerating mixt. of soil and substrate contg. specified microorganisms, e.g. Actinomyces globisporus

摘要

Biological decontamination of soil, esp. contaminated with hydrocarbons, is effected by mixing the soil with a substrate contg. microorganisms, and aerating the mixt. in a vessel with an air inlet and air outlet. The microorganisms include Actinomyces globisporus, Actinomyces albus and Penicillium sp. (white). The air supply is pref. controlled in response to the O2 and/or CO2 content of the waste air. The waste air is treated in a biological filter (e.g. as described in DE 3841804). The temp. of the mixt. is maintained at 35-70 deg.C. by controlling the air supply. The substrate is one produced by a composting process involving a heating phase at 65-72 deg.C. for at least 12 hr. (e.g. as described in EP 1198465). The mixt. contains 10-70% substrate. The air supply is 0.2-2 m3/hr. per m3 of mixt.. Also claimed is an appts. having a vessel (1) having a perforated base (3), an air inlet (16) below the base, an air outlet (17) above the mixt. (10), and a biological filter (20) in the air outlet line. A water separator (18) is pref. located between the air outlet and the filter. USE/ADVANTAGE - The treatment is capable of reducing levels of hydrocarbons and halogenated hydrocarbons, e.g. MeCl, CH2CL2, xylenes, ethylbenzene, chlorobenzene and chlorotoluene.