Abstract: Chromite ore processing residue（COPR） is the waste residue in the production process of chromium compounds with chromite ore.Due to the presence of toxic hexavalent chromium，COPR is classified as hazardous solid waste.COPR is easily poisoning the environment when it is stacking outdoor.Seeking for economical and efficient pollution control methods is of great interests for the chromium workers.The study of using biomass，such as banana peel，to detoxify COPR was made.The results showed that the optimum conditions were as follows：temperature was 90 ℃，banana dosage was 10% by weight of COPR，reaction time was 1.5 h，amount of acid was 4 mol H+ per kilogram of COPR，and liquid-solid ratio（mL/g） was 3∶1.Under the optimum conditions，the leaching toxicity of treated COPR can meet the environmental requirements of general industrial solid waste.The treated COPR can be landfilled as the general industrial solid waste.Through investigations on the chromium distribution in process flows and the valence change of chromium，the mechanism of the detoxification process was found as adsorption coupled with reduction.

Key words: aqueous oxidation, COPR, hexavalent chromium, biomass, detoxification