| Landfill is still the main way of municipal solid waste treatment and disposal,and its nitrogen pollution is one of the major problems faced by leachate treatment project.According to the different partial pressure of landfill,it can be divided into anaerobic bioreactor landfill(UABL),semi aerobic bioreactor landfill(SABL),aerobic bioreactor landfill(ABL).Due to the large differences in the microbial community structure of the three types landfill,the degradation rate,the transformation route and the removal efficiency of the nitrogen pollutants were different,Therefore,this article is based on indoor simulation experiment,three simulated bioreactor landfill(UABL,SABL,ABL)were established to analyze the conversion characteristics of nitrogen pollutants,and to provide some experimental parameters for the removal of nitrogen pollution in landfill and technical reference.After 300 d of the experiment,the UABL column was still in the acid-producing stage,and the SABL and ABL columns had stabilized.Through analyzing the monitoring indicators degradation dynamics show that the removal of CODCr in UABL,SABL and ABL leachate was consistent with log-exponential complex model,linear-exponential complex model and linear-exponential mode,the removal rate of 0.01232 d-1?0.02795 d-1?0.0392 d-1;The removal of VFA was consistent with log-exponential complex model,log-exponential complex model and linear-exponential model respectively.The removal rates were 0.00544d-1?0303018d-1?0.03225d-1;The total nitrogen and ammonia nitrogen removal were in accordance with log-exponential complex model,linear-exponential composite model and linear-exponential complex model.The removal rates of total nitrogen were 0.00459d-1?0.01142d-1?0.0206d-1?The removal rates were 0.00389d-1?0.0099d-1?0.0188d-1.The degradation kinetics of each index shows that the stabilization process of different types of bioreactor landfill is:UABL<SABL<ABL.In addition,the three-dimensional fluorescence analysis and elemental analysis also showed that the ABL column had the best degree of humification,and the humic degree of the SABL column was the second.The UABL column had the worst degree of humification.The correlation analysis showed that the nitrogen index and the organic matter index of UABL,SABL and ABL leachate was linearly related,and the total nitrogen and ammonia nitrogen of each leachate were highly linearly correlated,the results show that the main nitrogen pollutants in the leachate of the three kinds of landfill are ammonia nitrogen and the change trend of ammonia nitrogen is about the change of total nitrogen.At the end of the experiment,the residual rates of total nitrogen in UABL,SABL and ABL were 86.96%,80.38%and 63.98%respectively,and the liquefaction rates of total nitrogen were 0.71%,0.18%and 0.17%respectively,and the total nitrogen gasification rates were 12.33%,19.43%and 35.84%,respectively.The results showed that the denitrification rate of SABL column was 1.57 times of that of UABL column,and the denitrification rate of ABL column was 1.84 times of that of SABL column.And because the N2O emission flux is SABL>ABL>UABL,it indicates that SABL is not conducive to greenhouse gas(N2O)emission reduction.In addition,the percentages of nitrogen in UABL,SABL and ABL refuse were 2.58%,2.37%and 1.99%respectively,which indicated that the better the trash stability,the lower the nitrogen content and the higher nitrogen conversion. |
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