A box filled with sandy soil was constructed to investigate the redox zones of landfill leachate pollution plume and the distribution and varying characteristics of contaminants and redox sensitive substrates. Results indicated that the distribution and variation of pollutants and redox sensitive substrates were influenced by redox environment; Eh of water in methanogenic/sulfate reduction zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone is -148.2, -95.4, 30.6 and 223.2 mV; conductivity is 211.4, 55.2, 29.4 and 17.8 mS/m, and pH is 7.13, 6.49, 6.38 and 6.21, respectively. Methanogenic/sulfate reduction zone play significant roles for attenuation of the most organic pollutants such as ethylbenzene, dimethylbenzene, benzene, and TCE etc. Most heavy metals could deposit in methanogenic/sulfate reduction zone sediments, except As and Cd, and the highest content of Cr, Ni, Pb and Zn is 28.21, 11.58, 9.05 and 23.5 mg/kg, respectively. Concentration of CO2, sulfide, HCO-3, NH+4, TOC, Fe2+,NO-2 and SO2-4 are decrease with the distance away from the pollution source. |