超声强化淋洗修复Pb、Cd、Cu复合污染土壤  

Remediation of Pb, Cd, Cu contaminated soil by ultrasonic-enhanced leaching

作　　者：高珂[1] 朱荣[1] 邹华[1,2] 程子波 GAO Ke;ZHU Rong;ZOU Hua;CHENG Zibo(School of Environmental and Civil Engineering,Jiangnan University,Wuxi 214122,China;Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,Suzhou 215009,China)

机构地区：[1]江南大学环境与土木工程学院,无锡214122 [2]江苏省水处理技术与材料协同创新中心,苏州215009

出　　处：《环境工程学报》2018年第8期2328-2337,共10页Chinese Journal of Environmental Engineering

基　　金：江苏省研究生科研与实践创新计划项目(SJCX18_0639);国家重点研发计划项目(2016YFE0123600)

摘　　要：针对传统淋洗法修复土壤中重金属效率较低的问题,研究了超声强化淋洗技术以提高重金属去除率。以铅(Pb)、镉(Cd)、铜(Cu)为目标污染物,在0.05 mol·L^(-1)柠檬酸、0.05 mol·L^(-1)EDTA和0.05 mol·L^(-1)皂角苷作为淋洗剂条件下,使用传统振荡、超声强化以及超声波加振荡3种不同的作用方式,对Pb、Cd、Cu的去除率进行比较,并对3种不同淋洗方式后Pb、Cd、Cu的形态变化进行了探讨。结果表明,当使用柠檬酸和皂角苷作为淋洗剂进行振荡淋洗时,重金属洗脱效果不理想。超声对于强化柠檬酸洗脱效果并不明显,而对于强化皂角苷洗脱重金属效果明显,平均去除率提高了120.47%。当淋洗剂为EDTA时,土壤样品在传统振荡2 h作用下,对Pb、Cd、Cu的去除率依次为50.33%、76.65%和47.35%,而在超声波30 min条件下对Pb、Cd、Cu的去除率依次为82.19%、83.31%和53.89%,平均去除率高出28.60%,可显著提高重金属去除率,缩短淋洗时间。但超声波30 min加传统振荡2 h相较于单纯超声强化效果提升不明显。通过对比3种淋洗方式后土壤中的Pb、Cd、Cu形态发现,酸可提取态的重金属在超声强化作用后有明显降低,同时超声强化对于铁锰氧化物结合态、有机物结合态和残渣态也具有较好的去除能力。因此,超声强化在化学淋洗中的应用具有一定的可行性,是一种简单、极快速去除污染场地中重金属Pb、Cd、Cu的增效手段。This study was undertaken to investigate an efficient soil remediation. A conventional vibrating experiment and an ultrasound-enhanced experiment were conducted to study the ultrasound enhancement of removal and morphological changes of heavy metals during the leaching process. Heavy mental leaching experiments were conducted by using deionized water, 0.05 mol·L^-1 citric acid, 0.05 mol·L^-1 ethylene diamine tetraacetic acid（EDTA） and 0.05 mol·L^-1 saponin under three different conditions（conventional vibrating, ultrasound and ultrasound-vibrating）. The removal efficiency of Pb, Cd and Cu was compared and the variation of Pb, Cd and Cu speciation was further explored.The results showed that by means of leaching with citric acid and saponin is not effective. There is weak influence of ultrasound on citric acid, while the effect of saponin was obvious, by which the average removal rate was increased by 120.47%. When leaching with 0.05 mol·L^-1 EDTA, the removal rate of Pb, Cd and Cu were 50.33%, 76.65% and 47.35%, respectively under the condition of conventional vibrating for 2 h while the removal efficiency of Pb, Cd and Cu were 82.19%, 83.31% and 53.89%, respectively under 30 min ultrasound-enhanced condition, with the average efficiency higher by 28.60%. Ultrasound-enhanced chemical leaching can improve the removal efficiency and reduce leaching time significantly. However, the removal of30 min ultrasound compound 2 h conventional vibrating is not obviously increased when compared with the simple 30 min ultrasound leaching. By comparing the speciation distribution of the three washing methods, it was found that the acid extractable content decreased a lot after 30 min ultrasound. Ultrasound leaching also showed a more efficient reduction effect of the Fe-Mn reducible form, organic bounded form and the residual form. Hence, it is feasible to improve the washing efficiency of heavy metal contained in soil by conducting the cleaning process with the help of ultrasonic wave,which is a simple and fast met

关 键 词：超声强化化学淋洗 传统化学淋洗 土壤修复 Pb、Cd、Cu复合污染 重金属形态分析 

分 类 号：X53[环境科学与工程—环境工程]