[Aerogenesis evolution of the anaerobic-semiaerobic bioreactor landfill].

A novel bioreactor landfill, the anaerobic-semiaerobic bioreactor landfill (AN-SABL), was devised by combining an anaerobic bioreactor landfill (ANBL) with a semi-aerobic aged refuse biofilter (SAARB). Meanwhile, relevant parameters such as gas production volume and rate, and gas constituents were investigated to provide a theoretical foundation for the collection, utilization and treatment of landfill gas. Results indicated that the gas production of the anaerobic units was inhibited in the AN-SABLs. The gas production rates in the ANBL2 unit and the ANBL3 unit were 49 L x kg(-1) and 39 L x kg(-1) respectively, which were only 94.2% and 75.0% of that in the ANBL1. However, the gas production in the anaerobic unit could be accelerated by increasing the recirculation frequency. The maximum methane content could reach up to 62.67%. Moreover, the gas production volume and velocity in the ANBL were much higher in summer than those in winter, and the gas production peak could be observed with a 12-hour cycle. Besides, the nitrification and the denitrification in the anaerobic units would be enhanced remarkably in the AN-SABLs. It resulted that the content of N2O, which fluctuated between 0.0017% and 4.0179%, was influenced obviously by the seasonal variation and the landfill types. Based on the mathematical model of aerogenesis, the cumulative gas volume of the ANBL increased logarithmically in the initial aerobic phase, then increased linearly in the anaerobic acid phase, and increased exponentially in the methane production of acid phase afterwards.