Zhu Kun, Hart William, Yang Jiantao
Department of Environmental Engineering, Lanzhou Jiaotong University, Lanzhou Gansu, 730070, China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2005;40(10):1877-93. doi: 10.1080/10934520500183899.
A laboratory study was carried out to evaluate the feasibility of in situ remediation of a loess soil site contaminated with diesel oil. Six nonionic and anionic surfactants were selected and compared. In experiments of diesel oil desorption using the anionic surfactants LAS and SDS, it was shown that diesel oil solubilization increased linearly with surfactant dose at bulk aqueous concentrations of the two surfactants in excess of the relative CMC. The slope of the organic compound concentration in the micellar phase versus the concentration in the aqueous phase was used to determine the molar solubilization ratio and the diesel oil mole fraction micelle-phase/aqueous-phase partition coefficient Km. The Km values calculated by an empirical model with diesel oil octanol-water partition were very similar to that derived using the curve slope approach. Aliphatic polyethenoxy ether (AEO9) and sodium alcohol polyethoxylated ether sulfate (AES) were chosen for soil flushing. Through column tests in the laboratory, the washing effectiveness of the two selected surfactants and the relevant optimal operation conditions were examined. The results showed that AEO9 was more effective than AES in the flushing of diesel oil from contaminated loess soil, whereas AES was still more than 10 times as effective than fresh water alone. A mixed surfactant solution of 0.8% (v/v) AEO9 and 0.1% (v/v) AES could significantly increase the removal efficiency by 10% when compared with that using AEO9 alone. It was estimated that using an amount of the mixed surfactant solution equal to 60 pore volumes would be able to remove 60% of the petroleum residue remaining in the contaminated unsaturated zone within 9 days. This laboratory study provided a suitable model for a "safe" remediation alternative in the contaminated loess soil field.
开展了一项实验室研究，以评估原位修复受柴油污染的黄土场地的可行性。选择并比较了六种非离子和阴离子表面活性剂。在使用阴离子表面活性剂LAS和SDS进行柴油解吸的实验中，结果表明，在两种表面活性剂的本体水相浓度超过相对临界胶束浓度（CMC）时，柴油的增溶作用随表面活性剂剂量呈线性增加。用胶束相中有机化合物浓度与水相中浓度的斜率来确定摩尔增溶比和柴油的胶束相/水相分配系数Km。通过柴油正辛醇-水分配的经验模型计算得到的Km值与使用曲线斜率法得到的值非常相似。选择脂肪族聚氧乙烯醚（AEO9）和醇醚硫酸钠（AES）进行土壤冲洗。通过实验室柱试验，考察了所选两种表面活性剂的冲洗效果及相关最佳操作条件。结果表明，AEO9在从受污染黄土中冲洗柴油方面比AES更有效，而AES的效果仍比单独使用淡水高出10倍以上。与单独使用AEO9相比，0.8%（v/v）AEO9和0.1%（v/v）AES的混合表面活性剂溶液可使去除效率显著提高10%。据估计，使用相当于60孔隙体积的混合表面活性剂溶液，能够在9天内去除受污染非饱和区内残留石油残渣的60%。这项实验室研究为受污染黄土场地的“安全”修复替代方案提供了一个合适的模型。
