Research On Bioaugmentation Denitrification In Landfill Leachate

Landfill leachate is one kind oofhigh COD(Chemical Oxigen Demanded) and high NH3-N characteristics of organic wastewater. A high eeficinncy strain was screened out from the waste transfer station experimental results showed that the strain had good anaerobic performance of removing ammonia nitrogen. Through adding the high efficiency strain into landfill leachate to enhance the effectiveeess of the nitrogen removal.The own design landfill simulation column were established, and during the in situ recirculation treatment of the leachate which was generated from homemade simulation of landfill components from anaerobic, semi-aerobic and oxidation landfill structure. In three different landfill structure of circulation injection, normal water index of leachate generated in all the treatment were tested and analyzed, Such as COD, ammonia nitrogen, pH et al. The removal rate of ammonia nitrogen and accelerating the stabilization process of the leachate in different landfill structure were investigated.In the anaerobic landfill structure, the air access to landfill in layer more or less. By the pressure diffusion and molecular diffusion it makes the landfill layer into semi-aerobic and oxidation state, landfill layer microbial use oxygen in biological redox reaction, can eliminate the phenomenon of accumulation and ammonia nitrogen accumulation in anaerobic landfill structure, the degradation of organic matter was fast.During the in situ recirculation treatment of full landfill leachate from semi-aerobic landfill structure, the ammonia nitrogen concentration was respectively dropped from1526ng/L at26th days to103mg/L at141st days. The removal rate respectively was88.9%. Since experimental deadline, ammonia nitrogen still continues to lower. pH was increased to about8.3and COD concentration appear larger fluctuation in the process of the decline.During the in situ recirculation treatment of full landfill leachate from oxidation landfill structure, Landfill system was easy to form the neutral partial alkali environment, most of the test period, good oxygen in the column of leachate ammonia nitrogen levels was better than semi-aerobic. In the later stage, ammonia nitrogen concentration reached in the minimum value is112mg/L, removal rate reached88.28%, then the concentration of ammonia nitrogen present trend in increaseing slowly; Must have good oxygen column of leachate ammonia concentration to at the end of experiment has been present slow drop trend. Through the15N-lablcd procedure based on isotopic ratio monitoring of N2by GC-isolink-IRMS(isotope ratio mass spectrometer) has proved there are isotope markers of N2generated in the experiment, which testified anaerobic ammonium oxidation phenomenon exists. Combined with the fourth chapter for A bacteria the optimal growth temperature and pH value test and denitrification test results, can assume that this bacterium should be anaerobic ammonium oxidation of bacteria in the mixed culture content.