Experimental Research And Numerical Modeling Of Anaerobic-Aerobic Bioreactor Landfill

Landfill bioreactor is an improvement of traditional landfill, and the internal and external researches are focused on this technology.Purpose: A technology of anaerobic-aerobic bioreactor landfill is studied in this paper. It is based on the landfill bioreactor technology, and the technology is accord with the ideas of cycle economy and principles of ecological engineering.Contents & Measures: (1) Optimum biological transforming conditions of anaerobic-aerobic bioreactor landfill, rules of leachate degradation and landfill gas production in the anaerobic period, rules and influential factors of moisture and odor removal in aerobic period are studied by debugging and running a set of stimulating landfill equipment. (2) Microbial ecology in the bioreactor is studied by molecular biological measures. (3) Nnumerial modeling is studied with the synthesis of experimental datum, biological dynamics, and material calculation. (4) Technological and economic indexes to be applied in projects are discussed based on experimental results.Results: (1) The anaerobic landfill is based on leachate recirculation, recirculates leachate once per day and recirculates 10～13L leachate each time. The results are: volatile solids of wastes are reduced from 40.5% to 20% in 8 weeks, pH of the leachate can be adjusted to 6.7 from 6 in 6 weeks, COD concentration can be decreased to 6% of the maximum concentration, BOD5/COD is reduced to 0.1, NH3-N concentration fluctuates, and cumulating methane production is 44%. (2)The aerobic landfill is based on aeration, the aerating rate is 6～8×10-3m3/min. The results are: after 23 days'aerating, odor concentration can be reduced to 19, ammonia concentration can be decreased to 0.33mg/m3, and moisture of landfill wastes is reduced to 11%. The air used to aerating is piped to leachate sink, then 80% NH3-N concentration can be reduced. The wastes are close to the standards for agricultural use. (3) Analyzed RISA chart of anaerobic-aerobic reacting course by PCR of ITS segment, there are 4 dominant groups in anaerobic period, some facultative anaerobe played important roles when anaerobic period changed to aerobic period. Conclusion: Anaerobic-aerobic bioreactor landfill studied in this paper can accelerate stabilization of wastes, decrease difficulties of leachate treatment, product methane rapidly and stably. After aerating to the landfill wastes, odor concentration and ammonia concentration in the reactor can reach some correlative standards. The space of landfill can be reused when wastes are exploited and recycled. The Anaerobic-aerobic bioreactor landfill studied in this paper is available in technology, and can be industrialized. However, further studies on pilot-scale experiments are still necessary if the technology is to be applied in actual landfill sites.