Optimum Position of Air Injection in Aerobic and Anaerobic Refuse Lysimeters

In order to determine the optimum air injection craftwork for the aerobic-anaerobic landfill method, three pilot-scale lysimeters were constructed. Through experiment in the lysimeters, it was concluded that air injection at bottom layer (in this research it’s 2.5 m) is the optimum position in terms of improving on the solid organic matters stabilization, amelioration on leachate quality, the restraint of GHE (Green House Effect) by CH4. For instance, air injected at bottom layer may get more TOC minimization in leachate under lower temperature (-4-10°C) and high temperature (20-35°C) compared with other conditions. NH4+-N content expressed similar advantages with air injected at bottom layer case. Meanwhile, accompanied with the high dissolved oxygen (DO) and higher TOC consumption in leachate, aerobic fermentation was activated in this case, and most organic carbon was transformed in term of CO2, in which the goal of restraint on GHE was realized. On basis of mechanism assumption, mathematical model was developed and according to the simulated results for 5 years, air injected at 2.5 m achieved improvements on stabilization of solid phase organic carbon and nitrogen for 34 % and 13 %, amelioration on leachate quality for 35 % and 62 % of TOC and T-N, and the restraint of GHE for 14 times compared with no air injection case.