[Impact of depth and moisture to diesel degradation in sand layer of vadose zone].

Through the experiment simulated sand columns, the biodegradation characteristics of diesel in sand layers (including fine sand, medium sand and coarse sand) with different depths and moisture contents were studied. The results show that the depth and moisture content of medium are important factors in affecting the efficiency of diesel degradation. In the same medium conditions, the higher moisture content of the medium, the higher biological activity, and biological degradation efficiency of diesel are observed.

Study on mechanisms and effect of surfactant-enhanced air sparging.

In an attempt to enhance the effectiveness of air sparging, two sets of experiments were designed to investigate the mechanisms and effect of surfactant-enhanced air sparging (SEAS). The first set was performed at different surface tensions and with different kinds of surfactants (sodium dodecyl benzene sulfonate and Tween-80 [Uniqema Americas LLC, Wilmington, Delaware]), which were added into the contaminated aquifer of different media (particle distribution size = 0.25 to 0.

[Study on performance of double mineral base liner using modified bentonite as active material].

The absorbing capacity of clay,roasting bentonites by 450 degrees C and dual-cation organobentonites of the pollutions in landfill leachate was compared through static experiment, and investigations were conducted into availability of controlling the permeating of landfill leachate and feasibility of removing the main pollutants in leachate on the double mineral base liners of clay/roasting bentonites by 450 degrees C and clay/dual-cation organobentonites by using nice landfill leachate as the filter fluid. Experiment indicated that the adsorption equilibrium time of landfill leachate in clay, roasting bentonites by 450 degrees C and dual-cation organobentonites was 24 h; the absorbing capacity of roasting bentonites by 450 degrees C and dual-cation organobentonites was larger than that of clay. Simultaneous the penetration coefficients of the two liners were respective 1.

[Contamination removal in landfill leachate by biological effect in sand layer of vadose zone].

Through the test of two sand columns for comparing, the effect on removal of pollutants in landfill leachate by biological effect in sand layer of vadose zone was studied. First, HgCl2 was confirmed as inhibitor of biological effect, and its most suitable concentration was 10 mg/L. Then, sand column 1 was leached by landfill leachate, and sand column 2 was leached by landfill leachate added 10 mg/L HgCl2.