Abstract: According to the laboratory experiments, 2 mol/L magnesium chloride, 0.5 mol/L sulfuric acid and 450℃ roasting were determined as the optimum conditions for the natural Na-bentonite by salt modification, acidification and roasting. The availability and feasibility of the 3 inorganic modified-layers to main contaminants removal in the leachate and leachate leaking control were investigated. The experimental results indicated that the adsorptive capacities and the capacities of the 3 inorganic modified bentonites were enhanced; the permeability of the layers was less than 1×10^-7 cm/s, therefore the layers could be used as the “reactive layer”. In the same leaked amount sample, the best removal efficiency of the main pollutants was the roasted bentonite, and next was the acidified bentonite, and the salty modified bentonite was the lowest one.

Key words: inorganic modified, bentonite, magnesium chloride, sulfuric, roasting