Study on the Adsorptive Performance of Landfill Liners Made from Modified Bentonite

A new type of polyacrylamide-modified impermeable bentonite material was prepared using polyacrylamide and natural bentonite as raw material.With Shenyang Daxin landfill leachate as treatment object and a static adsorption test,the adsorption mechanism of the new type polyacrylamide modified bentonite for leachate was studied.The test results show that the adsorption efficiency of the modified bentonite for organic pollutants is obviously better than that of the original bentonite.The maximum COD removal rate of leachate containing high concentrations of organic compounds could reach 30.73%.The isothermal adsorption curve shows that the adsorption process of modified bentonite for COD can be described appropriately with Freundlich model.The equation of the isothermal adsorption curve is y = 0.4211x-1.3787,r~2 =0.9921 and the static adsorption of modified bentonite for COD is mainly physical adsorption.