Effects of different carbon and nitrogen ratio on the quantity of nitrogen cycle bacteria in the landfill unit

摘要

Landfill cell microbial carbon metabolism is not only organically influenced by the impact of landfill unit, but also closely related to the levels of landfill unit nitrogen. In this paper, we regard the landfill layer which is landfill in the surrounding black soil of Jilin Agricultural University as the research subjects, and we use laboratory experiments to comparative and study four kinds of nitrogen treatment (natural statecarbon nitrogen ratio which is not adjusted, carbon and nitrogen ratio of 5: 1, carbon nitrogen ratio 20: 1 carbon nitrogen ratio: 50: 1) which are used to collect samples periodically. Using MPN measured the number of microorganisms of the unit of landfill and studying different carbon nitrogen ratio ratio of landfill unit ammonifiers affect the activity of denitrifying bacteria. Experimental results show: (1)Different carbon nitrogen ratio has different influence onthe number of denitrifying bacteri and, ammonifiers in he unit of the landfill. The number of ammonifiers, nitrobacteria and denitrifying bacteria is large of low carbon nitrogen ratio landfill, but high carbon nitrogen ratio is opposite.(2)Over time, different carbon nitrogen ratio changed the number of ammonifiers, nitrobacteria and denitrifying bacteria of the unit of the landfill which showed the trend of the first increase and then decrease. From this, we know the number of ammonifiers, nitrobacteria and denitrifying bacteria of the unit of the landfill is related to the ratio of carbon and nitrogen of the unit of the landfill. Leachate is a high-concentration waste which is produced and exist in the landfill unit during the process of the landfill, which is harmful, improper handling can cause soil and water pollution and the impact on the environment, especially ammonia is one of the major harmful substances which is more intractable. Currently using nitrification/denitrification as the core of biological treatment at the time of treatment of landfill leachate is the most cost-effective method. According to normal conditions the landfill unit ammoniated process is the main source of ammonia and part ammonia involved in the nitrification process to produce nitrate nitrogen. Finally denitrifying bacteria utilize organic as electron donor, and nitrate respiration as electron acceptor, then reduced it to N2O, N2, and nitrobacteria and denitrifying bacteria is the main principle of nitrogen degradation process. In this experiment, study the mechanism of action from the number of the main microbial of landfill unit nitrogen cycle that ammonifiers, nitrobacteria and denitrifying bacteria, essentially explain variation of bacteria in landfill unit nitrogen cycle. Now domestic and international research pay more attention to the aspects of harmful substances in landfill leachate, but combined effects of nitrogen levels and organic carbon levels on landfill unit microorganisms of landfill unit is still rarely reported. The experimental simulation of landfill process, by adjusting the ratio of different carbon and nitrogen microbial metabolism, affecting the amount variation of microbes. The landfill unit is adjusted into high, medium and low (50: 1, 20: 1, 5: 1), three different carbon nitrogen ratio of the landfill cell, and regularly measured the number of the bacterial in nitrogen cycle to explore the influence and the laws of the high, medium and low carbon-nitrogen ratio on the number of ammonifiers, nitrobacteria denitrifying bacteria and the time goes on, the number of nitrobacteria and denitrifying bacteria of landfill unite under different carbon nitrogen ratio. In order to avoid the process of landfill leachate cause soil, water pollution and provide the basis for biological nitrogen removal.