膜曝气生物膜反应器处理生活污水N_(2)O等温室气体的排放特性

Emission characteristics of N_(2)O and other greenhouse gases from membrane aerated biofilm reactor treating domestic wastewater

针对生活污水处理减污降碳的需求,本研究采用膜曝气生物膜反应器(membrane aerated biofilm reactor,MABR)耦合厌氧氨氧化工艺处理低碳氮比生活污水,考察了水质污染物去除的同时,分析了甲烷(CH_(4))、氧化亚氮(N_(2)O)和一氧化氮(NO)的排放特性。结果表明,MABR实现了较好的碳氮污染物去除效果,当处理进水C/N为3.00±0.14的模拟污水时,COD、NH_(4)^(+)-N和TN去除率分别为85.24%、90.10%和64.35%;当处理进水C/N为1.67±0.07的实际污水时,COD、NH_(4)^(+)-N和TN去除率分别为75.39%、96.39%和81.88%。MABR具有较低的CH_(4)和N_(2)O排放因子,厌氧阶段分别为(0.0103±0.0105)%、(0.0050±0.0055)%,好氧阶段分别为(0.0015±0.0017)%、(0.0021±0.0015)%,厌氧阶段是CH_(4)和N_(2)O排放的主要阶段。气态NO和气态N_(2)O存在正相关关系,反硝化反应可能是N_(2)O产生的主要路径。NO是反硝化过程N_(2)O产生的前体物,对反硝化过程N_(2)O的释放具有指示作用。

In this study,a membrane aerated biofilm reactor(MABR)coupled with anaerobic ammonia oxidation process was used to treat domestic wastewater with low carbon to nitrogen ratio in order to meet the demand for reduction of pollutant and carbon emission.This study investigated the removal of pollutants in wastewater and the emission characteristics of methane(CH_(4)),nitrous oxide(N_(2)O)and nitric oxide(NO).The results showed that the MABR achieved a good performance on carbon and nitrogen pollutant removal.When treating synthetic wastewater with C/N of 3.00±0.14,the COD,NH_(4)^(+)-N and TN removal efficiencies were 85.24%,90.10%and 64.35%,respectively;when treating real domestic wastewater with C/N of 1.67±0.07,the COD,NH_(4)^(+)-N and TN removal efficiencies were 75.39%,96.39%and 81.88%,respectively.The MABR had low CH_(4)and N_(2)O emission factors of(0.0103±0.0105)%and(0.0050±0.0055)%in anaerobic stage and(0.0015±0.0017)%and(0.0021±0.0015)%in the aerobic stage,respectively,indicating anaerobic stage was the main source for CH_(4)and N_(2)O emissions.Gaseous NO was positively corelated with gaseous N_(2)O.Denitrification could be the main pathway of N_(2)O production.Gaseous NO was the precursor of N_(2)O production during denitrification process,which could indicate N_(2)O emission accordingly.