筑堆淋洗工艺处理某氰化物污染土壤工程实践

采用筑堆淋洗工艺处理氰化物污染土壤,并开展了工业试验。结果表明:经过45 d的淋洗,土壤中氰化物浓度从114.30 mg/kg降至5.57 mg/kg,满足《建设用地土壤污染风险筛选指导值(三次征求意见稿)》中住宅类用地要求(9.86 mg/kg);土壤氰化物浸出毒性为0.017 mg/L,达到GB 14848—93《地下水环境质量标准》中Ⅳ类标准;同时,碱性水淋洗还可以去除土壤中的部分有机物。采用碱性氯氧化法处理淋洗废水,最终废水中氰化物浓度为0.05 mg/L,COD为30.52 mg/L,氯浓度为0.06 mg/L,重金属浓度较低,全部低于GB 8978—1996《污水综合排放标准》排放限值,废水可达标排放。

Engineering application of heap elution process to deal with cyanide pollution oil

The heap elution process was used to treat cyanide pollution soil, and industry experiment was finished. Results showed that after 45 days of washing, cyanide content in the soil can be reduced from 114.30 mg/kg to 5.57 mg/kg, reaching the risk screening guideline value of less than 9.86 mg/kg. The cyanide leaching toxicity of the soil was 0.017 mg/L, reached Class Ⅳ of Groundwater Environment Quality Standard (GB 14848-93). At the same time, alkaline water washing can remove part of organic matter in the soil. The alkaline chlorine oxidation method was adopted to detoxicate the wastewater. Finally, the concentration of cyanide in wastewater was 0.05 mg/L, COD was 30.52 mg/L, chlorine concentration was 0.06 mg/L, and the concentration of heavy metals was low, all meeting the emission limit in Comprehensive Wastewater Discharge Standard (GB 8978-1996). Eventually the wastewater can be discharged directly.