卫生和生物反应器填埋场夏季N_2O释放的研究

N_2O Fluxes from Sanitary and Bioreactor MSW Landfill in the Summer

采用静态箱/气相色谱(GC)法现场监测了杭州市天子岭废弃物处理总场卫生填埋场和生物反应器填埋单元夏季的N2O释放通量,并讨论了相关影响因素.研究发现:卫生填埋场覆土后N2O释放通量(以N2O-N计)随垃圾填埋龄的增加而大幅降低,其均值(18.07μg/(m2.h))为生物反应器填埋单元(5.57μg/(m2.h))的3倍多.垃圾填埋龄、覆土土质与结构及填埋场操作方式是影响填埋场N2O释放的主要因素,这些因素均主要通过改变覆土的理化特性而影响N2O的释放.采用多元线性逐次回归分析得到:卫生填埋场N2O与覆土含水率和有机碳(SOC)质量分数构成的线性方程显著相关(R2=0.86,P<0.01);生物反应器填埋单元N2O的释放通量与覆土含水率、碳氮比(w(C)/w(N))和w(NO3-)构成的线性方程显著相关(R2=0.89,P<0.01).

A field scale experiment on N2O fluxes from sanitary and bioreactor landfill located in Hangzhou Tianziling MSW disposal center was conducted using static chamber and gas chromatography （GC） based techniques in the summer, and influencing factors on N2O emission were extensively investigated as well. The results showed that N2O emission from sanitary landfill decreased dramatically with increasing MSW landfill age after soil cover and its average value, 18.07μg/（m2·h）, was 2-folds more than that of bioreactor landfill, 5.57μg/（m2·h）. Landfill age, texture and structure of cover soll and operational practice were the dominant factors influencing N2O fluxes “by regulating the psychochemical properties of soil cover in sanitary and bioreactor landfill. N2O fluxes from sanitary and bioreactor landfill had significant correlations with soil water content, soil organic carbon （ R^2 = 0.86, P 〈 0.01 ） and soll water content, w （ C ）/w （N）, w （ NO3 - ） （ R^2 = 0.89, P 〈 0.01 ）by stepwise multiple regression analysis, respectively.