Abstract: To improve the chemical elution efficiency of heavy metal contaminated sites, this paper took electronic waste pickling site soil of Longtang Town, Qingyuan city, Guangdong Province as research object, and analyzed the effect of ultrasound and acidification elution, etc. parameters on elution efficiency of Cd, Cu, Pb, and Zn from soil contaminated by electronic waste pickling sites through indoor experiment. The results showed that ultrasonic treatment could effectively improve the elution efficiency of soil heavy metals, especially Cu and Zn. Their elution efficiency increased by 9.65% and 15.3%, respectively. After acidification pretreatment, the elution efficiency of Cd, Cu, Pb and Zn increased by 70.2%, 29.0%, 41.1% and 48.54%, respectively. After acidification treatment, the soil pH reduced from 6.89 to 4.00, and the contents of acid extractable of Cd, Cu, Pb and Zn increased by 10.8%、1.26%、11.1%、11.9%. Acidification treatment could turn reducible, which was difficult to be eluted by EDTA into acid extractable and oxidizable that can be eluted easily by EDTA, and thus enhanced the elution efficiency of EDTA on soil heavy metals. Therefore, ultrasound, acidification pretreatment could be used as assistive technology for improving the elution efficiency of soil heavy metals by EDTA.

Key words: ultrasound, acidification, heavy metal, removal rate, morphology

摘要： 为提高重金属污染场地的化学洗脱效率，以广东省清远市龙塘镇电子酸洗场地土壤为研究对象，通过室内实验，分析超声、酸 化等洗脱参数对电子酸洗场地污染土壤Cd、Cu、Pb和Zn洗脱效率的影响。结果表明，超声处理可有效提高土壤重金属的洗脱效 率，尤其Cu和Zn，其洗脱效率分别提高了9.65%和15.3%。对污染土壤进行酸化预处理，EDTA对土壤Cd、Cu、Pb和Zn的洗脱效率 分别提高了70.2%、29.0%、41.1%、48.5%。酸化处理后，土壤pH由6.89降低到4.00；Cd、Cu、Pb和Zn酸提取态分别提高了 10.8%、1.26%、11.1%、11.9%。酸化处理使不易被EDTA洗脱的可还原态转变为易被EDTA洗脱的酸提取态和可氧化态，进而提高 EDTA对土壤重金属的洗脱效率。因此，超声、酸化预处理可作为提高EDTA对土壤重金属洗脱效率的辅助技术。

关键词: 超声, 酸化, 重金属, 去除率, 形态