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As a significant greenhouse gas, nitrous oxide (N2O) has about310times the warming potential of CO2. The sequential batch bioreactor landfill (SBBR) exists nitrification and denitrification during the stabilization of municipal solid waste (MSW), which can produce N2O. Research results indicate that in the prior period, nitrate is an important factor that causes the production of N2O in a SBBR.The impact of different concentrations of nitrate on N2O in the same age of the landfill bioreactor landfill is different, as well as the same concentration of nitrate on N2O in the different age of the landfill bioreactor landfill. This paper sets up two kinds of sequencing batch type bioreactor landfill units including five groups, injects leachate respectively containing nitrate concentration of50,100,300,100,300mg/L to the five groups of reactors sequentially, monitors the leachate effluent water quality and the production characteristics of N2O in each reaction column during the experimental process, discusses the effects of nitrate on N2O. The results are as follows:(1) For the three fresh refuse columns, the production trends of N2O are broadly consistent, which are all the initial N2O concentration is very high, then decreasing rapidly, in the later experiment, N2O production amount rises to a higher level. In the different stages of the experiment, the related degree between NO3--N concentration and N2O is different, the correlation in the early stage of the experiment is small, while in the late is bigger. As a whole, the higher adding the nitrate concentration, the more the production of N2O, the average production of N2O of the three columns are respectively256.85ppm,314.89ppm and579.73ppm.(2) In the aged refuse columns, the N2O concentration is less and the production is stable in the early stage of the experiment, while in the late, the gas production rises to a higher level and the fluctuation range is larger. Compared two aged refuse columns, the column adding higher concentration of nitrate produces the larger of N2O than that of the low one. Besides of the factor of nitrate, C/N and N2O has a significant negative correlation relationship. (3) Whether adding a high concentration of nitrate or not, the production of N2O in the aged refuse columns is all more than the fresh ones. Compared with the fresh refuse, the aged contains lower organic matter, which limits the thorough process of the denitrification and causes the more production of N2O.
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