Study On Simulating Semi-aerobic Landfill By Recycling Leachate To The Landfill

With the city development and improvement of standard of people living , municipal solid waste is increasing day and day . How to dispose the waste is increasingly becoming urgent . Sanitary landfill is economic comparatively at present, so it is and will be a main way to dispose municipal solid waste . Fukuoka city and Fukuoka college developed the technique of semi-aerobic landfill , it changed the landfill structure . It can form semi-aerobic conditions in the landfill , at the same time leachate (coming from bottom of landfill) is recycled to landfill itself by the collecting gas system , It gets over much shortcomings that we must invest much more money in anaerobic landfill and that we must invest more money in order to maintain and operate the aerobic landfill .It have much advantages that cost is cheaper , material can acquire widely , and constructing and maintenance is much convinent . It has been successfully taken in many landfills of different countries .But the studies about recycling to semi-aerobic landfill itself is in the beginning and is fewer about it . The paper takes semi-aerobic landfill and anaerobic landfill two landfill structures and analyse leachate qualities , waste components and the variations of quantities and species of microorganism in the landfill during the stabilization process . It bring forward that semi-aerobic can accelerate degradation velocity of COD and ammoniac nitrogen and promote the stabilization process of landfill , which also affords technic guidance for accelerating landfill stabilization and leachate self-purity . It reveals the degradation mechanism of waste in semi-aerobic landfill , analyses the factors affecting degradation ,provides theoretical basis and technical support for the deep reseach and engineering appilication of semi-aerobic landfill ,and offers ideas for the reconstruction of anaerobic landfill .The paper introduces to mathematics models and predicts the variational rules of leachate qualities in semi-aerobic landfill and anaerobic landfill ,by the way of analyzing the measured data . It finds that the leachate's COD of semi-aerobic landfills decrease to National Discharge Standard Class I (100mg/L) in 3 years or so . Ammoniac nitrogen reduce to the standard (15mg/L) in less than 3 years in the condition of lesser hydraulic loading ,but in the conditions of larger hydraulic loading and times of recycling , it may take 10 years or so . In contrast , the leachate's COD and ammoniac...