Abstract:

In order to increase the retardance of soil-bentonite slurry wall backfill materials to pollutants, activated carbon was used to modify it. Through slump test and simulation column experiments, the influence of activated carbon (AC) addition on the workability, permeability and compatibility of soil-bentonite slurry wall were studied, and the effect law of AC addition on the permeability and compatibility was clarified. The results indicated that the water content required to achieve a target slump increased with the AC content. The hydraulic conductivities of soil-bentonite slurry wall materials with 2%-10% AC were less than 1.0×10-7   cm/s, which met the requirement of hydraulic conductivity of vertical cut-off wall. When the content of AC was less than 2%, the addition of AC had no effect on the compatibility of the barrier materials with phenol solution. With the increase of the amount of AC, the adverse effect of phenol solution on the barrier materials was intensified. When the content of AC increased to 10%, the AC modified soil-bentonite slurry wall wasn not suitable for phenol contaminated groundwater environment.

Key words: polluted groundwater, soil-bentonite slurry wall, activated carbon, permeability, compatibility