表面活性剂对污染土壤中重金属Cu(Ⅱ)的洗脱试验研究  

Washing Copper(Ⅱ)-contaminated Soil Using Surfactant Solutions

作　　者：赵保卫[1] 吴咏琪[1] 马婵媛[1] 朱瑞佳[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《环境科学》2009年第10期3067-3071,共5页Environmental Science

基　　金：国家自然科学基金项目(20577018);甘肃省中青年科技基金项目(3ZS042-B25-023);兰州交通大学"青蓝"人才工程项目

摘　　要：采用批平衡法比较研究了阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、非离子表面活性剂辛基酚聚氧乙烯醚(TX100)及其混合物(SDBS-TX100)对土壤中铜的洗脱作用.重点研究了表面活性剂浓度、清洗时间、溶液pH值、土水比、无机盐等因素对洗脱作用的影响.结果表明,表面活性剂对Cu(Ⅱ)污染土壤的洗脱作用存在较大差异.当表面活性剂初始浓度相同时,单一SDBS较不同质量配比的混合SDBS-TX100和单一TX100洗脱效果好;6 000 mg.L-1SDBS对Cu(Ⅱ)的洗脱效率达到46.3%,分别是同浓度SDBS-TX100(3∶1)、SDBS-TX100(1∶1)、SDBS-TX100(1∶3)和单一TX100洗脱效率的5.8、10.8、10.8和19.3倍;1∶10土水比条件下,清洗时间为24 h时,各表面活性剂体系都达到最好清洗效果;溶液pH值对表面活性剂洗脱Cu(Ⅱ)有显著影响,随着溶液pH值升高,表面活性剂的洗脱能力逐渐下降,强酸性条件下(pH=1.50),洗脱率最高可达95%;土水比越小表面活性剂对土壤中Cu(Ⅱ)的洗脱效果越好;无机盐对表面活性剂的洗脱能力影响不大,但是过量Mg2+(浓度>500 mg.L-1)会造成阴离子表面活性剂的沉淀损失.The batch equilibrium washing of copper（Ⅱ） in the soil matrix by anionic surfactant,sodium dodecylbenzyl sulfonate（SDBS）,nonionic surfactant,octylphenoxypolyethoxyethanol（TX100）,and their mixture（SDBS-TX100）,was studied and compared.The influences of surfactant concentrations,washing time,pH values of solutions,ratios of soil to water and inorganic salts on washing efficiency were investigated.It was shown that the washing efficiency differed with the kinds of surfactants.Given the initial surfactant concentrations,the washing of copper（Ⅱ） by single SDBS was greater than those by single TX100 and the mixed SDBS-TX100.The washing efficiency by 6000 mg·L^-1 of SDBS was up to 46.3%,which was 5.8,10.8,10.8 and 19.3 times as those by SDBS-TX100（3∶1）,SDBS-TX100（1∶1）,SDBS-TX100（1∶3） and single TX100 respectively.When the ratio of soil to water was 1 to 10 and washing time reached 24 h,the washing efficiency achieved the maximum.pH values of solutions had obvious effect on the washing of copper（Ⅱ）.The washing efficiency of copper decreased sharply with the increase of pH.At the high acidity（pH=1.50）,the washing efficiency of copper（Ⅱ） was up to 95%.The smaller the ratios of soil to water were,the higher the washing efficiencies would be.The existence of inorganic salts with the certain concentrations,such as Na^＋,Ca^2＋and Mg^2＋,could not influence the washing capacity of surfactants,but the excessive Mg^2＋（more than 500mg·L^-1） could resulted in the precipitation of SDBS.The results will make an implication for surfactant-enhanced remediation of soils contaminated with heavy metals.

关 键 词：表面活性剂 Cu(Ⅱ) 洗脱作用 土壤修复 

分 类 号：X131[环境科学与工程—环境科学]