不同水质条件下污水管道甲烷排放规律及微生物作用机制  

IMPACTS OF SEWAGE CONCENTRATION ON METHANE EMISSION AND MICROBIOLOGICAL MECHANISMS IN SEWAGE COLLECTION SYSTEMS

作　　者：赵刚 蒋明 韦志成 王凤 罗景阳 唐建国 ZHAO Gang;JIANG Ming;WEI Zhicheng;WANG Feng;LUO Jingyang;TANG Jianguo(Shanghai Urban Construction Design&Research Institute Groups Co.,Ltd.,Shanghai 200125,China;College of Environment,Hohai University,Nanjing 210098,China)

机构地区：[1]上海市城市建设设计研究总院(集团)有限公司,上海200125 [2]河海大学环境学院,南京210098

出　　处：《环境工程》2024年第4期22-30,共9页Environmental Engineering

摘　　要：城市污水管道是甲烷等温室气体的重要潜在来源,影响因素繁多。目前,不同水质条件对管道甲烷产排特性、底物的转化规律和微生物作用机制仍有待进一步解析。通过静态模拟试验探究了污水管道系统中不同污水浓度下(100~700 mg COD/L)挥发性脂肪酸(VFAs)含量及甲烷排放特征。结果表明:管道系统中污水COD浓度越高,VFAs和甲烷产量越高。与低浓度污水(100 mg COD/L)相比,高浓度污水管道系统中(500,700 mg COD/L)VFAs产量增长了2.4,4.1倍,甲烷排放量增加了8.1,21.0倍。机理分析发现,管道系统内高浓度污水有利于水解、酸化和产甲烷等厌氧微生物的富集,并导致与胞外水解(如dacC)、胞内代谢(如yhdR)、脂肪酸生成(如pta)和甲烷生成(ftr、fwd)等相关的功能基因表达的上调,进而提升微生物产甲烷代谢活性。偏最小二乘路径模型(PLS-PM)分析表明:功能微生物群落(λ=0.721)和相关代谢基因的表达(λ=0.640)是影响污水管道甲烷产排的主要因素,而污水COD浓度为次要因子(λ=0.623)。Municipal sewers are an important potential source of greenhouse gases such as methane,with a wide range of influencing factors.The characteristics of methane production and discharge in pipelines,the transformation of substrates and the microbial function mechanisms under different water quality conditions still need to be further analyzed.This study investigated the volatile fatty acids(VFAs)content and methane emission characteristics in sewage pipeline systems under different sewage concentrations(100~700 mg COD/L)via static simulations.The results showed that the higher the effluent COD concentration in the pipeline system,the higher the production of VFAs and methane.Compared with low-concentration sewage(100 mg COD/L),the VFAs production in high-concentration sewage pipeline systems(500 and 700 mg COD/L)was increased by 2.4,4.1 times,respectively,while the methane emission was increased by 8.1 and 21.0 times.Mechanism analysis revealed that high-concentration sewage in the pipeline system favored the enrichment of anaerobic microorganisms involved in hydrolysis,acidogenesis,and methane production.This led to the upregulation of functional gene expression associated with extracellular hydrolysis(e.g.,dacC),intracellular metabolism(e.g.,yhdR),fatty acid generation(e.g.,pta),and methane generation(e.g.,ftr,fwd),thereby enhancing microbial methane production metabolism.Partial least squares path modeling(PLS-PM)analysis indicated that the functional microbial community(λ=0.721)and the expression of related metabolic genes(λ=0.640)were the main factors influencing methane production and emission in sewage pipelines,while sewage COD concentration was a secondary factor(λ=0.623).

关 键 词：城市污水管道 污水浓度 底物转化 甲烷排放通量 功能基因 

分 类 号：TU992.23[建筑科学—市政工程] X51[环境科学与工程—环境工程]