| abstract |
A process for purifying a substance polluted with organohalogen compounds, comprising the step of adding a reducing agent and a nutrition source for heterotrophic anaerobic microorganisms to the polluted substance, and a process as described above wherein the reducing agent is reduced iron, cast iron, an alloy such as iron-silicon alloy, or a water-soluble compound, by which the organohalogen compounds can be decomposed by virtue of both a chemical reaction and the action of the microorganisms; a process as described above wherein the nutrition source contains organic carbon and 20 to 50 wt.% of oxide-form nitrogen, which makes it possible to inhibit the generation of a nasty smell and the color change of soil occurring secondarily in the decomposition; and a process which comprises the step of mixing a substance polluted with organohalogen compounds with a nutriment solution and a reducing agent while adjusting the pH of the polluted substance to 4.5 to 9.0, and the step of allowing the resulting mixture to stand under lowly ventilated conditions, wherein the mixing may be conducted more uniformly at need when the amount of the polluted substance to be purified is large. |