Biogas Recovery from MSW using Different Aeration Pretreatments

Aeration pretreatment has been proven to be an efficient technology to facilitate waste stabilization in bioreactor landfills. In order to investigate the effects of different aeration pretreatments on biogas recovery, three simulated columns (A1, C1 and C2) were constructed and operated for 130 days. A1 simulated an anaerobic bioreactor. C1 was pretreated with a constant daily aeration frequency in the upper layer, while C2 had various daily aeration frequencies. Results indicated that aeration could effectively remove high volatile fatty acid (VFA) in leachate and accelerate methane productions in bioreactors. At the end of operation, about 44 L/kgdry mass and 53 L/kgdry mass methane were collected in C1 and C2, respectively, while nearly no methane was produced in A1. Correspondingly, aerobically pretreated bioreactors dramatically decreased their COD and VFA concentrations. In terms of methane formation in aerobically pretreated bioreactors, C2 was changed quickly from aerobic phase to methanogenic phase. Due to larger area affected by aeration pretreatment, biogases in C1 were generated in much greater rate. The total amount of methane generated from C2 was greater than that from C1.