Acceleration the stabilization of waste in bioreactor landfill by sequential anaerobic and semi-aerobic operation

Based on the comparison between anaerobic, aerobic and semi-aerobic bioreactor landfill, the method to acceleration the stabilization process of waste in bioreactor landfill by sequential anaerobic and semi-aerobic operation mode was brought forward and put into practice in simulated experiment. When the operation mode was changed from anaerobic mode to semi-aerobic mode in the 710th day, the COD concentration of simulated bioreactor landfill column D1 (leachate recirculation once everyday) and D4 (leachate recirculation twice every week) was dropped from 705 mg/L, 669 mg/L to 135 mg/L, 178 mg/L and the ammonia-N concentration was dropped from 650 mg/L, 877 mg/L to undetectable level after 360 days. At the same time, the COD concentration of control column D2 and D3 was dropped from 435 mg/L, 852 mg/L to 295 mg/L, 596 mg/L and the ammonia-N concentration was dropped from 654 mg/L, 1107 mg/L to 469 mg/L, 783 mg/L. The rate of COD and ammonia-N concentration drop in leachate was enhanced largely after the operation mode of simulated bioreactor landfill column was changed from anaerobic mode to semi-aerobic mode. It was also shown that higher leachate recirculation frequency is more favorable for this process.