IMPACTS OF SEWAGE CONCENTRATION ON METHANE EMISSION AND MICROBIOLOGICAL MECHANISMS IN SEWAGE COLLECTION SYSTEMS
-
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)。Abstract: 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).
-
[1] 杨温娜. 城市污水输送过程中管网内温室气体的产生机制[D]. 西安:西安建筑科技大学.硕士,2018. [2] GU D, LIU Y, ZHAO W, et al. Status of research on greenhouse gas emissions from wastewater collection systems[J/OL]. 2023, 15(14):2512. [3] 许小冰, 王怡, 王社平,等.城市排水管道中有害气体控制的国内外研究现状[J].中国给水排水,2012,28(14):9-12. [4] 刘伟, 石烜, 徐栋伟,等.流速对污水管道中甲烷与硫化物生成的影响[J].中国环境科学,2023,43(6):2938-2947. [5] 时红, 郑杰荣.碳硫质量比及碳源种类调控重力排水管道内甲烷及硫化氢排放特征[J].科学技术与工程,2020,20(13):5437-5442. [6] 汪钟凝, 陈浩, 周雅菲,等.水力水质条件对重力排水管道碳排放的影响研究[J].能源环境保护,2019,33(3):15-22. [7] FEDERATION W E, ASSOCIATION A. Standard Methods for the Examination of Water And Wastewater[M]. Washington, DC: American Public Health Association (APHA), USA 2005, 21. [8] LIU Y, NI B J, GANIGU R, et al.Sulfide and methane production in sewer sediments[J].Water Research,2015,70:350-359. [9] OOSTERKAMP M J, MNDEZ-GARCA C, KIM C H, et al.Lignocellulose-derived thin stillage composition and efficient biological treatment with a high-rate hybrid anaerobic bioreactor system[J].Biotechnology for Biofuels,2016,9(1):120. [10] 王健, 刘国华, 齐鲁,等.城市排水管道沉积物与污水间物质转移转化研究进展[J].中国给水排水,2021,37(24):34-44. [11] 承磊, 郑珍珍, 王聪,等.产甲烷古菌研究进展[J].微生物学通报,2016,43(5):1143-1164. [12] SUN J, HU S, SHARMA KESHAB R, et al.Stratified microbial structure and activity in sulfide- and methane-producing anaerobic sewer biofilms[J].Applied and Environmental Microbiology,2014,80(22):7042-7052. [13] GUO L, LU M, LI Q, et al.Three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy with regional integration analysis for assessing waste sludge hydrolysis treated with multi-enzyme and thermophilic bacteria[J].Bioresource Technology,2014,171:22-28. [14] 郝晓地, 杨振理, 张益宁,等.排水管道中CH4、H2S与N2O的产生机制及其控制策略[J].环境工程学报,17(1):1-12. [15] 陈浩.市政排水管道CH4产排及其影响因子研究综述[J].能源环境保护,2020,34(6):14-20. [16] 郝晓地, 孙群, 李季,等.排水管道甲烷产生影响因素及其估算方法[J].中国给水排水,2022,38(20):1-7. [17] XU R Z, FANG S, ZHANG L, et al.Distribution patterns of functional microbial community in anaerobic digesters under different operational circumstances: a review[J].Bioresource Technology,2021,341:125823. [18] ARIESYADY H D, ITO T, OKABE S.Functional bacterial and archaeal community structures of major trophic groups in a full-scale anaerobic sludge digester[J].Water Research,2007,41(7):1554-1568. [19] 王洪臣, 汪俊妍, 刘秀红,等.排水管道中硫酸盐还原菌与产甲烷菌的竞争与调控[J].环境工程学报,2018,12(7):1853-1864. [20] LIU X, XU Q, WANG D, et al.Enhanced short-chain fatty acids from waste activated sludge by heat-CaO2 advanced thermal hydrolysis pretreatment: parameter optimization, mechanisms, and implications[J].ACS Sustainable Chemistry & Engineering,2019,7(3):3544-3555. [21] LYU Z, SHAO N, AKINYEMI T, et al.Methanogenesis[J].Current Biology,2018,28(13):727-732. [22] ZHAO Y, XU C, AI S, et al.Biological pretreatment enhances the activity of functional microorganisms and the ability of methanogenesis during anaerobic digestion[J].Bioresource Technology,2019,290:121660. [23] ZHANG L, LI F, TSUI T H, et al.Microbial succession analysis reveals the significance of restoring functional microorganisms during rescue of failed anaerobic digesters by bioaugmentation of nano-biochar-amended digestate[J].Bioresource Technology,2022,352:127102. [24] 黄帅辰, 左剑恶, 陈磊,等.排水管道沉积物微生物群落及环境因子分析[J].中国环境科学,2020,40(12):5369-5374. [25] LUO J, WEI Z, CHENG X, et al.Surfactant and antibiotic co-occurrence reshaped the acidogenic process for volatile fatty acids production during sludge anaerobic fermentation[J].Science of the Total Environment,2023,905:167064. [26] FANG S, GUO W, FENG Q, et al.Surfactants aggravated the biotoxicity of Fe2O3 nanoparticles in the volatile fatty acids’ biosynthesis during sludge anaerobic fermentation[J].ACS ES&T Water,2022,2(12):2686-2697. [27] LUO J, CAO W, GUO W, et al.Antagonistic effects of surfactants and CeO(2) nanoparticles co-occurrence on the sludge fermentation process: novel insights of interaction mechanisms and microbial networks[J].J Hazard Mater,2022,438:129556. [28] LUO J, WU Q, FANG S, et al.Recycling crawfish shell waste as co-digestion substrates to promote methane recovery and the underlying mechanisms[J].Journal of Cleaner Production,2023,428:139555. [29] XIANG Y, XIONG W, YANG Z, et al.Coexistence of microplastics alters the inhibitory effect of antibiotics on sludge anaerobic digestion[J].Chemical Engineering Journal,2023,455:140754. [30] 曹业始, CHRISTIAN A, 刘智晓,等.改造当前国内污水管网需要综合考虑的四个因素[J].给水排水,2021,47(8):125-137.
点击查看大图
计量
- 文章访问数: 135
- HTML全文浏览量: 22
- PDF下载量: 15
- 被引次数: 0