比较两种表面活性剂淋洗去除土壤中的重金属

Washing removal of heavy metals from different soils by two surfactants

以停车场和湿地2种土壤为研究对象,分别使用表面活性剂鼠李糖脂和月桂基醚硫酸钠对土壤样品进行淋洗,考察2种表面活性剂对这2种土壤中重金属的去除能力差异及形态分布的影响,并分析淋洗后残留在土壤中表面活性剂的生物毒性。结果表明,2种表面活性剂均可在一定程度上去除2种土壤中的Cu、Cd、Pb和Zn。与湿地土壤相比,2种表面活性剂对停车场土壤中重金属的去除率均较高,且月桂基醚硫酸钠的去除能力优于鼠李糖脂。2种表面活性剂对可交换态重金属的去除效果最好,对残渣态重金属去除率较低。淋洗后2种土样中残留的鼠李糖脂及停车场土样中残留的月桂基醚硫酸钠的生物毒性低,湿地土壤中残留的月桂基醚硫酸钠具有一定生物毒性。

Surfactant rhamnolipid and Texapon were investigated to wash heavy metals in parking lot and wetland soil samples taken from a coastal city in our country. The capabilities of heavy metal removal and effect on heavy metal fraction distribution of the two surfactants on soil samples were studied. In addition, toxicities of residue surfactants in soil samples were investigated. It was indicated that both surfactants were able to remove Cu, Cd, Pb, and Zn in the two soil samples. Heavy metal removal by both surfactants from the parking lot soil sample was higher than that from wetland soil sample;and the removal rate of Texapon was higher than that of rhamnolipd. Both surfaetants exhibited best removal on the exchangeable fraction of heavy metals, yet minimum removal on residue fractions. The residues of rhamnolipid remained in both soil samples, and Texapon remained in the park- ing lot sample had low toxicities;while the residue of Texapon in the wetland soil sample was bio-toxic.