[Influences of matter variations on pollution buffer capacity of landfill leachate polluted subsurface environment]

Columns filled with fine sand were constructed to investigate influences of subsurface environment and main constituent variations caused by landfill leachate pollution on pH buffer capacity and redox buffer capacity of sediments. Experimental results indicated that the subsurface environment had significant impacts on pH and redox buffer capacity. The pH buffer capacity increased 12.4%, 10.8%, 19.8% and 11.1% in MGZ/SRZ, IRZ, NRZ and ORZ compared with background value, respectively. pH buffer and redox buffer were interaction and inter-promotion, which influenced natural attenuation processes of pollutants in subsurface directly. Content of iron oxides, organic substrate, SOC2(2-) and NH4+ -N in sediments had different impacts on pH buffer and redox buffer capacity, and the overall pollution buffer capacity of system was comprehensive results of constituents.