硝化渗滤液回灌对填埋垃圾反硝化、产甲烷及稳定化的影响

Effect of Nitrified Leachate Recirculation on In-situ Denitrification, Methanogenesis and Stabilization of Landfill

垃圾填埋场是重要的甲烷释放源,其有效管理是减缓温室效应的重要环节.通过硝化渗滤液回灌模拟垃圾填埋柱,研究硝化渗滤液在新鲜垃圾和老龄垃圾填埋柱中的脱氮及对垃圾稳定化和产甲烷的影响.结果表明,回灌的硝化渗滤液在不同填埋龄垃圾柱中,均可实现总氧化态氮(Total oxidation nitroge,TON)完全还原.当回灌TON负荷分别达到14.19 g t-1(TS)d-1和10.45 g t-1(TS)d-1时,新、老垃圾柱中甲烷产生开始受到抑制.实验后期,回灌TON负荷增至38.78 g t-1(TS)d-1和30.62 g t-1(TS)d-1时,新、老垃圾填埋柱产甲烷相对抑制率分别达54.10%和95.77%.同时,回灌反硝化对新、老垃圾柱中垃圾降解贡献率(Rd)分别达85%和93%,能有效促进垃圾稳定.

Landfill has been considered an important source of methane emission,so its effective management plays a key role in slowing down the pace of greenhouse effect.In this paper,nitrogen removal,methanogenesis and stabilization of municipal solid waste（MSW） were studied in two series of lab-scale MSW bioreactor landfill（BL） with fresh and old refuse,respectively,where nitrified leachate was recirculated.The results indicated that total oxidation nitrogen（TON） of the nitrified leachate was completely reduced in the simulated BLs,and methanogenesis in the fresh and old BL would be inhabited when TON load was increased to 14.19 g t-1（TS） d-1 and 10.45 g t-1（TS） d-1,respectively.At the later period of operation,while TON loading from the nitrified leachate increased to 38.78 g t-1（TS） d-1 and 30.62 g t-1（TS） d-1,the relative inhibition rate of methanogenesis reached 54.10% and 95.77% in fresh and old BL,respectively.Meanwhile,it was be proved that in-situ denitrification could promote the decomposition of the MSW,in which the contribution of denitrification to MSW decomposition（Rd） would be 85% and 93%.