表面活性剂清洗处理重度石油污染土壤

Surfactant enhanced washing of heavily oil-contaminated soil

为了优化表面活性剂清洗处理重度石油污染土壤的方法和具体洗脱条件参数,采集山东省东营市胜利油田污染土壤,研究了阴离子-非离子混合表面活性剂对该土壤中石油类污染物的去除效果。应用化学热洗原理,主要考查了表面活性剂配比、投加量、清洗温度及清洗助剂对去除效果的影响。实验得到的清洗处理最佳条件为:使用LAS与TX-100质量比为8∶2的组合表面活性剂,总表面活性剂浓度为3 g/L,助剂硅酸钠浓度为5 g/L,75℃条件下搅拌1 h。清洗后土壤含油量从20%下降到4.6%,去除率达到76.9%。废水回用实验表明,清洗处理的废水对土壤中石油烃类物质仍有一定的去除效果。废水回用比从30%到100%时,对土壤中石油烃的去除率都可达到55%以上。对废水进行二次回用时仍能去除18.8%的污染物。

Four kinds of anionic-nonionic mixed surfactant were used in surfactant enhanced washing of oil- contaminated soil samples from Shengli Oilfield,in Dongying City of Shandong Province. The effects of different systems with various mass ratios of anionic and nonionic surfactants, total surfactant concentrations, temperatures and assistant washing agents on oil removal efficiency were studied. The optimum conditions are： mixed surfactants of LAS and TX100 with a mass ratio of 8： 2, total surfactant concentrations of 3 g/L, assistant washing agents concentration of 5 g/L, and a temperature of 75 %. After washing, the oil content of sample reduces from 20% to 4.6% , achieves an oil removal of 76.9%. The results from wash water reusing experiments show that reusing from 30% to 100% of the wash water can remove more than 55% of oil contaminants in the first reusing process. In wash water＇ s second time reusing, it can still achieve an oil removal of 18.8%.