有机酸淋洗修复复合重金属污染河道底泥研究

针对高粘性Ｃｕ、Ｚｎ复合重金属污染河道底泥，采用酒石酸、草酸、柠檬酸三种有机酸作为淋洗剂对污染土进行淋洗修复，通过振荡淋洗方法，探究淋洗剂浓度、淋洗时间对重金属去除率的影响规律，采用ＢＣＲ三步提取法对淋洗前后土壤重金属形态进行分析。研究结果表明:3种有机酸对Ｚｎ的去除率优于对Ｃｕ的去除率，得到最佳淋洗方案为浓度0．4ｍｏｌ／Ｌ的酒石酸淋洗2．0ｈ，对Ｃｕ、Ｚｎ的去除率分别为29．19％、67．8％。通过ＢＣＲ形态分析发现有机酸可有效降低重金属弱酸提取态、可还原态浸提浓度，并能一定程度上提高残渣态含量，这有利于降低重金属环境风险。

Remediation of Sediment in Complex Heavy Metals Polluted River channel by Organic acid Leaching

Focusing on the high viscosity Cu,Zn compound heavy metals pollution of river sediment,three kinds of organic acids,tartaric acid,oxalic acid and citric acid were used as leaching agents for the leaching of contaminated soil.By oscillation leaching method,the influence of eluent concentration and leaching time on heavy metal removal rate was analyzed.The morphology of heavy metals in soil before and after leaching was analyzed by BCR three-step extraction method.The research results show that the removal rate of 3 organic acids to Zn is better than that to Cu,the best leaching solution was tartaric acid at a concentration of 0.4mol/L for 2h,for Cu and zinc removal rate of 29.19%,67.8%respectively.Through BCR morphological analysis,it was found that organic acids could effectively reduce the concentration of weak acid and reducible leaching of heavy metals,and it can increase the content of residue to a certain extent,which is beneficial to reduce the environmental risk of heavy metals.