A dual-permeability hydro-biodegradation model for leachate recirculation and settlement in bioreactor landfills

作者:Feng, Shi-Jin*; Bai, Zhen-Bai; Chen, Hong-Xin; Cao, Ben-Yi; Lu, Shi-Feng; Chen, Yun-Min
来源:Environmental Science and Pollution Research, 2018, 25(15): 14614-14625.
DOI:10.1007/s11356-018-1690-2

摘要

A dual-permeability hydro-biodegradation model is developed to describe the leachate flow in municipal solid waste (MSW) and predict the long-term settlement induced by biodegradation in bioreactor landfills. The model is verified against Hydrus-1D and a recirculation experiment conducted in a full-scale landfill. Preferential flow and mass transfer between fissure and matrix can be reasonably modeled by the proposed model. A higher recirculation flow rate can speed up the stabilization process of landfill. However, too much recirculation leachate is not economical and environmental friendly. A stabilization speed index and a leachate utilization index are adopted to evaluate the stabilization speed of bioreactor landfill and utilization rate of leachate, respectively, and the optimal recirculation flow rate is estimated. A flow rate of q = 5 x 10(-5)-5 x 10(-4) m/h (equivalent to recirculation intensity of Q = 15-150 L/ton(waste)/year) is recommended for recirculation, which has been verified by the field data in numerous bioreactor landfills.