Waste stabilization mechanism by a recirculatory semi-aerobic landfill with the aeration system

The main purpose of this research is to clarify and compare the mechanism of waste stabilization by a recirculatory semi-aerobic landfill with the aeration system. Our research is proposing the semi-aerobic landfill system for developing countries because of the simple and low-cost technology for the final disposal. Moreover, this system with leachate recirculation can be a more effective system for waste stabilization because of the improvement of leachate quality as an organic pollutant and, also, nitrogen removal. In this research, five different systems of landfill (Ae: aerobic, An: anaerobic, Se: semi-aerobic, SeR: recirculatory semi-aerobic landfill, and SeRA: recirculatory semi-aerobic landfill with aeration system) are compared with lysimeters which are 1 m high with a diameter of 0.3 m. The results of the leachate quality shows that the leachate treatment effect of the SeRA system can be observed to be as high as the Ae system. To determine the mechanism of this process, all lysimeters are dismantled after 1,100 days in the experimental period and the waste composition, the dissolution test, the mass balance of carbon and nitrogen, the determination of bacterial counts, etc., were analyzed. In this research, it was proven that the SeRA system has an optimal leachate treatment effect that is the same as the Ae system. And, from the results of the mass balance of carbon and nitrogen, the SeR and SeRA systems show higher waste stabilization effectiveness and nitrogen removal than the other systems. Moreover, the number of the aerobic bacteria can be observed to be higher in the SeR and SeRA systems. To determine these results, the waste stabilization mechanism is considered by the results of leachate quality, the mass balance of carbon and nitrogen, and, also, the bacterial numbers.