Abstract: Preparation of complex detergent and experiments for the optimization of washing condition were conducted by treating the heavily oil-contaminated soil from an oilfield in Xinjiang. Orthogonal experiments were carried out to investigate the influence of concentrations of anionic surfactant，nonionic surfactant and the assistant washing agents （sodium silicate） on the residual oil content in the sample. It was found that there was a strong interaction between LAS and APEO，which enhanced washing effect and reduced the amount of detergent. The best detergent formulations were：sodium dodecyl benzene sulfonate （LAS） 2g/L，alkyl phenol ethoxylates （APEO） 3g/L，Na2SiO3 3g/L. The optimal liquid-solid ratio，temperature and washing time were 10∶1，70℃ and 1h. The oil content in sludge sample reduced from 26.07% to 1.21% by washing. The components removed by washing were analyzed by infrared spectroscopy （IR）. It showed that most saturates，aromatics，resin，asphaltene in oily sludge were removed，which were considered as four main components in oil. Especially，saturates were removed obviously.

Key words: oily sludge, thermochemical washing, anionic/nonionic mixed surfactant

摘要： 针对新疆某油田重度石油污染土壤，进行了洗涤剂的复配及洗脱条件的优化研究。考察了阴离子表面活性剂浓度、非离子表面活性剂浓度以及硅酸钠助剂浓度对残油量的影响。正交实验结果表明，十二烷基苯磺酸钠（LAS）与烷基酚聚氧乙烯醚（平平加，APEO）间存在着较强的交互协同作用；两者复配可以增强洗涤效果，并减少药剂用量。优化的复配洗涤剂配方为： LAS 2g/L，平平加3g/L，Na2SiO3 3g/L。复配洗涤剂洗涤含油污泥的最佳操作条件为：液固质量比10∶1、洗涤温度70℃、洗涤时间1h，在此条件下污泥含油量从26.07%降低至1.21%。对污泥洗涤前后的红外光谱检测表明该复配洗涤剂对于污泥中原油的饱和分、芳香分、胶质和沥青质都有洗涤效果，特别是对饱和分的去除效果尤为显著。

关键词: 石油污染土壤, 热化学洗涤, 阴离子/非离子表面活性剂