洗涤法处理含油土壤的研究

Research of the treatment of oily soil by washing method

研究了用洗涤法处理含油土壤，考察了洗涤剂种类与浓度、洗涤温度、液固比、洗涤时间、表面活性剂、洗涤液直接循环使用次数对洗涤效果的影响，结果表明：当混合减浓度为10000mg／L、洗涤温度为70℃、液固比2：1、洗涤时间20min时，可将含油量为30％的土壤洗至残油率仅为0．3％左右。OP、EL型表面活性剂的加入对洗涤效果没有改善，特别有意义的是洗涤液能够直接循环使用而对洗涤效果基本无影响，这不仅能够减少用水量，还可以大大减少废水的排放量，降低操作费用及废水处理费用。该洗涤法不涉及物质的相变过程，混合碱由廉价的无机碱和无机盐组成，故能量消耗低，处理费用也低，且洗脱下来的原油可回收。

Authors researched the treatment of oily soil by washing method andinvestigated the washing effects of different kinds and concentrations of abstergents,washing temperature, liquid/solid ratio, washing time, surfactants and the time of direct recycle of washing liquid, which demonstrates that a 30% oil-containing soil may bewashed down to only about 0. 3% oil content when mixing base concentration of10000mg/L,temperature of 70℃,liquid/solid ratio of 2: 1 and washing time of 20 min.were adopted. Adding OP or EL surfactants didn't improve the washing effects. It ismeaningful that the washing liquid may be recycled directly without obvious effect on the washing result, which will reduce not only the use level of fresh water, but also thedischarge level of waste water and, therefore, the cost of operating and waste water treating. Since this washing method isn't involved in phase transition process and the mixing base is composed of cheap inorganic base and salt, its energy consumption and processing cost are lower comparatively and, moreover, the washed-off oil may be retrieved.