The impact on the effects of leachate concentrates recirculation for different fill age waste

Abstract

To improve the effects of leachate concentrates recirculation, the quality of effluent is studied from three columns with different fill age waste. The leachate concentrate from a landfill in Chengdu is used for the recirculation experiments with columns of the 1, 5 and 15 years fill age waste, respectively. The characteristics of organic matter, salinity and heavy metals from the effluent are discussed, and the recirculation effect of different landfill bodies is evaluated based on the Gray Analytic Hierarchy Process (AHP). The results show that 1a fill age waste column is in methanogenic stage, with a best NO3 − removal rate of 88 %, but worst removal capacity for other indicators. The 5a fill age waste column is approximate to stabilization, and the removal capacity of the organic matter, salinity, Cr and Ni is poor. The 15a waste column has a good adsorption and complexion capacity, with the removal rate of 90, 78, 93 and 78 % of the organic matter, salinity Cr, and Ni, respectively, at the early stage, but would be approximate to or arrive at saturation with increase of recirculation time. A comprehensive evaluation shows that the effluent water effect is best for the 15a fill age waste column.