挥发性有机物污染泥浆固化稳定化试验研究

针对有机污染场地修复施工过程中出现的冒浆现象，选取2种典型有机污染泥浆，通过多组室内试验，对比分析了4种固化剂的固化稳定效果。结果表明：4种固化剂均有较好的减水效果，典型泥浆I的含水率28 d降幅可达45%，而典型泥浆II的28 d减水效果以固化剂A（5%水泥）最优，其含水率降幅为37%；固化土样孔隙水电导率EC随龄期先升高后降低，其峰值出现在3 d或7 d；固化土样pH值总体随龄期而增大，且典型泥浆II的pH值明显高于典型泥浆I；泥浆固化后qu值随龄期发展而快速增长，且典型泥浆I强度远高于典型泥浆II，并以固化剂A、C固化增强效果最佳，28 d时固化剂C固化的典型泥浆I、II的qu值分别达到233、48 kPa；添加固化剂尤其是含凹凸棒土的固化剂B、D能有效降低有机污染物的浸出，其28 d龄期对典型泥浆I、II的稳定率超过81%。固化泥浆EC、pH值与qu值关系具有明显规律，可反映其强度生长状况。

Experimental study of solidification/stabilization of VOCs contaminated slurry

To study the mud spillover problem in remediating the VOCs (volatile organic compounds) contaminated site, a series of laboratory tests was carried out on two typical types of VOCs contaminated slurry. The treatment effects of solidification/stabilization of 4 kinds of binding agents are studied. The results indicate that all the binding agents have strong water-reducing capacity and agent A (5% cement) performs best in slurry II with a water reducing rate of 37% after 28-day curing, while slurry I possesses a higher water reducing rate of about 45% for all the agents. The electrical conductivities of pore water solutions increase firstly and reach the maximum on the third day or seventh day, then decrease with the increase of curing time, and the pH value of slurry II is clearly higher than that of slurry I. The unconfined compressive strength qu of soil samples quickly increases with the curing time, and the qu of slurry I is much higher than that of slurry II. It is also shown that agents A and C have a significantly better reinforcing effect, and the qu values for slurry I and II treated by agent C can reach 233 and 48 kPa, respectively, after 28-day curing. Besides that, the addition of attapulgite-based agents B and D can reduce the total organic concentration of TCLP (toxicity characteristic leaching procedure) leachate and improve the environmental safety dramatically. There is also good correlation among the values of EC, pH and qu of stabilized soil, which can reflect the strength growth.