Effects of leachate irrigation and cover soil type on N2O emission from municipal solid waste landfill.
垃圾填埋场渗滤液灌溉及覆土土质对填埋场氧化亚氮释放的影响

By the method of static chamber, the seasonal and diurnal variations of N2O fluxes in two full-scale municipal solid waste (MSW) landfills covered with sandy and clay soils were measured to study the effects of leachate irrigation and cover soil type on the landfill N2O emission. The results showed that the N2O flux in the MSW landfill covered with sandy soil was (242 +/- 576) microg N2O-N x m(-2) x h(-1) in summer, being 3.2 times (P > 0.05) as high as that in spring (74.4 +/- 314) microg N2O-N x m(-2) x h(-1), while the N2O flux in the MSW landfill covered with clay soil was (591 +/- 767) microg N2O-N x m(-2) x h(-1) in summer, being 2.2 times (P < 0.05) as high as that in spring (269 +/- 335) microg N2O-N x m(-2) x h(-1)]. Leachate irrigation promoted the N2O emission from the soil cover of the landfill covered with sandy soil, and the N2O flux in the landfill was 1 time higher than that of the control (P > 0.05). Under leachate irrigation, the average N2O flux in spring and summer in the landfill covered with sand soil was (211 +/- 460) microg N2O-N x m(-2) x h(-1), being only 1/2 of that (430 +/- 605) microg N2O-N x m(-2) x h(-1)] in the landfill covered with clay soil without leachate irrigation (P > 0.05 ). Therefore, no matter leachate irrigation was conducted or not, the N2O emission from MSW landfill could be minimized by covering with infertile sandy soil.