腐殖酸做表面活性剂对加油站油污土壤的修复

Remediation of Oily Soil in Gas Station Using Humic Acid as Surfactant

对比研究了腐殖酸、生物表面活性剂鼠李糖脂和阴离子表面活性剂十二烷基磺酸钠(SDS)溶液对加油站地下油污土壤的修复。实验发现,3种表面活性剂溶液去除土壤中污染油的效果与蒸馏水相比都有明显提高。鼠李糖脂的去除效果最好,除油率最高达到了61.4%;腐殖酸与SDS相比,除油率相差不多,最高分别达到56.6%和57.1%。表面活性剂溶液质量浓度和油污土壤性质都影响除油效果,在溶液质量浓度小于或等于临界胶团浓度(CMC)时,除油率随着溶液质量浓度的增加而增加,而当溶液质量浓度大于CMC时,除油率提高并不显著;3种表面活性剂溶液对新鲜土壤的除油效果都好于处理过的土壤。由于腐殖酸与化学合成表面活性剂相比易于生物降解,因此腐殖酸可以作为一种理想的化学表面活性剂的替代品来处理油污染比较严重的土壤。

The compared research on remediations of oily soil in gas station by using humic acid, biosurfactant (rhamnolipid) and synthetic surfactant (sodium dodecyl sulfonate, SDS) respectively was made. The results show that three surfactant solutions can remove significant amount of oil from soil compared with water alone. Rhamnolipid performs excellently with a maximum removal of 61.4%, the performance of humic acid is almost the same as SDS, with a maximum removal of 56.6% and 57.1%, respectively. Meanwhile surfactant solution concentration and oily soil type both have great effect on soil washing, the oil removal is increased with the increase of mass concentration of solution when mass concentration of solution is not above CMC, but when it is beyond the CMC, oil removal do not show further enhancement. Three surfactant solutions remove more oil from fresh soils than from weathered soil. Hence, the use of solutions of natural HAs appears as a better choice for soil washings of highly oil-polluted-soils due to their additional capacity to promote microbial activity in contrast to synthetic surfactants.