垃圾渗滤液处理同步填埋气脱硫脱碳提纯

Simultaneous implementation for landfill leachate treatment anddesulfurization and decarbonization of landfill gas purification

为研究二级膜生物膜反应器(MBfR)在处理垃圾渗滤液协同垃圾填埋气脱硫脱碳提纯方面的效能与机制,依次考察了前置短程硝化MBfR和后置MBfR运行过程中有机物和氮素污染物的去除效能,以及垃圾填埋气中H_(2)S、CO_(2)和CH_(4)的转化特性。实验结果表明:在反应系统运行280 d后,成功实现了渗滤液深度处理协同填埋气高效脱硫脱碳。通过控制前置反应器低溶氧,亚硝化率可达85%以上,可实现短程硝化和DAMO-Anammox过程的耦合。系统对COD、NH_(4)^(+)和TN的平均去除率分别可达95%、99%和99%,可实现垃圾渗滤液高效减碳脱氮;垃圾填埋气经过净化后的CO_(2)和H_(2)S气体成分分别降低至0.2%以下和5%左右,而CH_(4)气体成分提高至80%左右,显著提升了垃圾填埋气的质量。反硝化型厌氧甲烷氧化古菌和产甲烷古菌在电子转移系统中表现出高活跃性,暗示其通过直接电子转移的种间关系,可强化CO_(2)还原产CH_(4)过程。本研究中,高效的填埋气升级效果一方面归功于富集了电活性产甲烷菌Methanothrix和硫自养反硝化细菌Thiobacillus;另一方面,高有机负荷的厌氧产甲烷过程消耗大量质子,从而提高体系碱性并增加液相中可吸收的CO_(2)量。这进一步促进了垃圾填埋气中CO_(2)含量减少和CH_(4)含量增加。

To investigate the efficiency and mechanism of treating landfill leachate by two-stage membrane biofilm reactor(MBfR)in cooperation with desulfurization and decarbonization of landfill gas,we sequentially examined the removal efficiency of organic matter and nitrogen pollutants,as well as the conversion characteristics of H_(2)S,CO_(2),and CH_(4)in landfill gas during the operation of pre-short-range nitrification MBfR and post-MBfR.After 280 days of operation,experimental results demonstrated that the reaction system successfully achieved high-efficiency desulfurization and decarburization for advanced treatment of leachate along with upgrading landfill gas.By controlling low dissolved oxygen levels in the pre-reactor,nitrosation rates exceeding 85%were achieved while enabling partial nitrification coupled DAMO-Anammox process.The average removal rates for COD,NH+4,and TN reached 95%,99%,and 99%respectively,thereby achieving efficient carbon and nitrogen reduction for landfill leachate.Following landfill gas purification processes,CO_(2)content was reduced to less than 0.2%,and H_(2)S content decreased to approximately 5%,while CH_(4)content increased to around 80%.This significant upgrade in landfill gas can be attributed to highly active denitrifying anaerobic methanogenic archaea species within the electron transfer system which enhance CO_(2)-reducing CH_(4)production through direct electron transfer between species.Furthermore,this study highlights how efficient landfill gas upgrading is facilitated by enrichment of electroactive Methanothrix and Thiobacillus organisms on one hand;additionally anaerobic methanogenesis processes with high organic loads consume many protons leading to increased alkalinity within the system thus enhancing absorption capacity for CO_(2)into liquid phase.This further facilitated the reduction of CO_(2)content and the elevation of CH_(4)content in landfill gas.