Abstract: 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.

Key words: organic contaminant, slurry, solidification/stabilization, pH, strength, cement, attapulgite