酸浸-生物法处理铬渣

采用酸浸-生物法处理铬渣以进行有效的还原解毒. 首先分析了铬渣的物相和组成，然后鼓入CO2进行酸浸，再结合硫酸盐还原菌浸取和还原. 结果表明，经过生物反应36 h后，残渣中水溶性六价铬含量降到了2 mg/kg，达到了铬盐工业污染物排放标准GB4280-84的要求.

Acid Leaching and Bio-reduction of Chromite Ore Processing Residue

Chromite ore processing residue (COPR) is a kind of solid waste in the production of chromate by roasting with lime. There exists tremendous threat to environment owing to the oxidation of Cr(VI). In this work, a treatment scheme was developed using sulfate-reducing bacteria (SRB) as bio-reducing agent after HCl or CO2 was used to acidify the COPR to neutral state. The results showed that the leaching of water combined with CO2 blowing could gain an advantage over HCl leaching. Then SRB and substrates were added to the solid-liquid mixture after the acidifying for bio-reduction. It was found that water soluble Cr(VI) was lowered to 2 mg/kg of waste after 36 h treatment, which is below the GB4280-84 limit of 5 mg/kg.