Carbon emission analysis of municipal wastewater treatment plants and discussion on synergistic path of pollution and carbon reduction
-
摘要:
污水处理行业是全球十大温室气体排放行业之一,其碳排放量占全球碳排放总量的2%~3%,且仍呈逐年增长的趋势,因此开展污水处理行业碳减排并实现减污降碳协同增效是实现我国“双碳”目标的必经之路。系统分析了我国污水处理厂碳排放状况,结果表明:生化池产生的CO2是导致直接碳排放的关键,且生化池的好氧区直接碳排放量最大;由电耗和药耗产生的间接碳排放在总碳排放量中占比较大,是污水处理厂碳减排的关键环节;在污泥处理处置过程中,采取厌氧消化+沼气发电方式时温室气体排放量较少。指出了当前我国污水处理行业碳减排面临的问题,主要包括碳排放核算不精准、碳减排技术研发与应用仍处在起步阶段、顶层设计及管理水平薄弱。在此基础上,提出了适用于我国污水处理厂减污降碳协同增效的路径方案,指出污水处理厂碳减排需多处着力,在碳排放量精确核算的基础上,加强污水处理行业节能降耗、减碳、替碳、固碳技术的研发与应用及多维度控碳方案设计,构建以技术创新为行动力、政策支持为推动力的碳减排总体框架,形成污水处理厂碳减排的闭环,助力我国污水处理厂低碳化发展。
Abstract:The wastewater treatment industry is one of the top ten CO2 emission industries, the carbon emissions of which account for 2%-3% of the total global carbon emissions, and its carbon emissions show an increasing trend year by year. So, carrying out carbon emission reduction in the wastewater treatment industry and achieving the synergistic effect of pollution reduction and carbon reduction is the necessary path to promote the realization of the "double carbon" goal in China. The carbon emission situation of the wastewater treatment plants (WWTPs) of China was systematically analyzed. The result showed that direct CO2 emissions produced by the biochemical treatment process occupied a large proportion of that in the whole processing section, and among them, the direct CO2 emission in the aerobic area was the largest. Meanwhile, the indirect carbon emissions resulting from power and drug consumption accounted for a large proportion of whole direct and indirect carbon emissions, which was the key link of carbon emission reduction of WWTPs. Additionally, the way of anaerobic digestion + biogas power generation was the recommended low-carbon treatment of sludge. The problems of carbon emission reduction in WWTPs mainly included inaccurate carbon emission accounting, the lack of development and application regarding the low-carbon wastewater treatment technology, and inadequate top-level design and management. Based on this, the possible pathways suitable for the synergistic reduction of pollution and carbon of WWTPs in China were put forward, which needed multiple efforts. These efforts included accounting the carbon emission accurately, strengthening the development and application of energy-saving, carbon reduction, carbon replacement and carbon sequestration technology, and designing a multi-dimensional carbon control scheme. Moreover, an overall framework for carbon reduction driven by technological innovation and policy support should be built, thus forming a closed-loop system for carbon reduction in WWTPs, and assisting the low-carbon development of WWTPs of China.
-
图 3 2005—2020年我国污水处理厂温室气体排放量年际变化及不同温室气体排放量占比[13]
注:CO2-Electricity为电力消耗的CO2排放量。
Figure 3. Yearly variations of GHGs emissions of China's WWTPs from 2005 to 2020 and the proportion of different GHGs emissions
图 4 不同污水生化处理工艺去除单位COD的CO2排放量对比分析[14]
注:A2O为厌氧-缺氧-好氧污水处理工艺;SBR为序批式活性污泥法;MBR为膜生物反应器。
Figure 4. Comparative analysis of CO2 emission per unit of COD removal of different biochemical treatment processes
图 5 UCT工艺中不同污水处理工段CO2排放体积分数[15]
Figure 5. CO2 emission volume fraction of different treatment sections in UCT process
图 6 A2O工艺中厌氧-缺氧-好氧区温室气体排放量[17]
Figure 6. GHGs emissions in the anaerobic-anoxic-aerobic zone of A2O process
表 1 不同污泥处理处置方式的碳排放量及低碳化程度对比
Table 1. Comparative analysis of carbon emission and low carbonization level of different sludge treatment methods
污泥处理处置方式 碳排放量/
(kg/kg,
以CH4计)碳排放量/
(kg/kg,
以CO2计)碳减排量/
(kg/kg,
以CO2计)低碳化
程度/%厌氧消化+沼气发电 0.215 0.133 89.6 余热干化+焚烧 0.340 0.184 80.3 余热干化+混烧 0.340 0.152 76.6 好氧堆肥 0.246 68.9 湿污泥混烧 0.490 38.1 干化+焚烧 0.691 0.184 36.0 填埋 0.033 0.792 表 2 污水处理厂碳排放核算方法对比分析[20]
Table 2. Comparative analysis of carbon emission accounting methods in WWTPs
项目 质量平衡法 模型法 实测法 排放因子法 原理 质量守恒定律 模拟碳循环过程 连续对点源进行实时测量 根据统计数据进行计算 优点 较为准确,明确区分各处理设施和排放源之间的差异 对特定系统使用,中间步骤少,方便计算 最准确,最接近真实结果 使用方便且便于理解,有核算公式 缺点 计算过程复杂,需考虑的中间排放过程较多,结果容易出现系统误差,数据获取困难且不具有权威性 局限性较大,数据获取相对困难且模型各种参数的可靠性不高 须具备试验条件和大量工作人员,监测结果受样品代表性和仪器精度的影响 排放因子地区差异性较大,需详细的活动数据 适用对象 适用于排放非CO2温室气体、物质化学成分和转化准确可靠的情况 局部区域、过程简单的碳排放源,或局部区域、可以获取准确排放源的相关数据 有可靠的监测仪器并由国家相关部门支持 使用对象广泛,对各种情况下的温室气体排放都具有适用性 应用现状 初步兴起,方法结论不完善,具体操作方法众多,结论不可靠 应用时间较长,方法缺陷较少;但数据获取较难,应用范围较窄 应用时间较长,数据获取过程难 广泛应用,方法总结全面,结论可靠 表 3 我国部分污水处理厂低碳工艺碳减排情况[28]
Table 3. Carbon emission of low-carbon treatment process used in some WWTPs of China
污水处理厂名称 处理工艺 节约电耗/
(104 kW·h/a)CO2减排
当量/(t/a)吴家村城市污水
处理项目好氧颗粒污泥 146 882 小红门再生水厂 厌氧氨氧化 263 1 587 高碑店再生水厂 厌氧氨氧化 383 2 314 槐房再生水厂 厌氧氨氧化 350 2 116 高安屯再生水厂 厌氧氨氧化 504 3 043 清河第二再生水厂 厌氧氨氧化 241 1 455 表 4 国内外污水处理厂热能利用案例
Table 4. Thermal energy utilization case of WWTPs in China and abroad
国家 污水处理厂 用途/效果 美国 加州污水处理厂[4] 太阳能可以为每天流量大于18.9万m3的工厂提供8%~30%的电力需求,而为每天流量小于18.9万m3的工厂提供30%~100%的电力需求 挪威 Asker污水处理厂[33] 作为空调系统为28个商业
建筑供热/制冷德国和瑞士 某污水处理厂[34] 约3%的建筑可以通过废水源热泵加热或冷却 瑞典 Hammarbyverket
污水处理厂[33]为95 000个住宅建筑供热 荷兰 Rijnlanden污水
处理厂[33]为10 000个家庭供热 芬兰 Kakolanmäki污水
处理厂[35]产能是运行能耗的10倍,供热/制冷能量回收近90% 中国 潍坊市污水
处理厂[36]利用污水热能为办公或住宅类
建筑供冷供暖 -
[1] 钱中兵. 习近平在第七十五届联合国大会一般性辩论上的讲话(全文)[EB/OL]. (2020-09-22)[2023-02-15]. www. xinhuanet. com/politics/leaders/2020-09/22/c_1126527652. htm. [2] National Research Council. Advancing the science of climate change[M]. Washington, DC: National Academies Press, 2010. [3] 姜华, 吴静, 吕连宏.升级“环保管家”服务助力减污降碳协同增效[J]. 环境工程技术学报,2022,12(6):2027-2031. doi: 10.12153/j.issn.1674-991X.20220092JIANG H, WU J, LÜ L H. Upgrading “environmental butler” service to help reduce pollution and carbon synergy[J]. Journal of Environmental Engineering Technology,2022,12(6):2027-2031. doi: 10.12153/j.issn.1674-991X.20220092 [4] HAO X D, LIU R B, HUANG X. Evaluation of the potential for operating carbon neutral WWTPs in China[J]. Water Research,2015,87:424-431. doi: 10.1016/j.watres.2015.05.050 [5] 郭盛杰, 黄海伟, 董欣, 等.中国城镇污水处理行业温室气体排放核算及其时空特征分析[J]. 给水排水,2019,55(4):56-62. doi: 10.13789/j.cnki.wwe1964.2019.04.009GUO S J, HUANG H W, DONG X, et al. Calculation of greenhouse gas emissions of municipal wastewater treatment and its temporal and spatial trend in China[J]. Water & Wastewater Engineering,2019,55(4):56-62. doi: 10.13789/j.cnki.wwe1964.2019.04.009 [6] 陆家缘. 中国污水处理行业碳足迹与减排潜力分析[D]. 合肥: 中国科学技术大学, 2019. [7] STRUTT J, WILSON S, SHORNEY-DARBY H, et al. Assessing the carbon footprint of water production[J]. American Water Works Association,2008,100(6):80-91. doi: 10.1002/j.1551-8833.2008.tb09654.x [8] 邱德志, 陈纯, 郭丽, 等.基于排放因子法的中国主要城市群城镇污水厂温室气体排放特征[J]. 环境工程,2022,40(6):116-122.QIU D Z, CHEN C, GUO L, et al. Greenhouse gas emission characteristics of urban sewage plants in major urban agglomerations of China based on emission factor method[J]. Environmental Engineering,2022,40(6):116-122. [9] LÜ Z Q, SHAN X Y, XIAO X L, et al. Excessive greenhouse gas emissions from wastewater treatment plants by using the chemical oxygen demand standard[J]. Science China Earth Sciences,2022,65(1):87-95. doi: 10.1007/s11430-021-9837-5 [10] CZEPIEL P, CRILL P, HARRISS R. Nitrous oxide emissions from municipal wastewater treatment[J]. Environmental Science & Technology,1995,29(9):2352-2356. [11] 任佳雪, 高庆先, 陈海涛, 等.碳中和愿景下的污水处理厂温室气体排放情景模拟研究[J]. 气候变化研究进展,2021,17(4):410-419.REN J X, GAO Q X, CHEN H T, et al. Simulation research on greenhouse gas emissions from wastewater treatment plants under the vision of carbon neutrality[J]. Climate Change Research,2021,17(4):410-419. [12] 王洪臣.我国城镇污水处理行业碳减排路径及潜力[J]. 给水排水,2017,53(3):1-3. doi: 10.3969/j.issn.1002-8471.2017.03.001WANG H C. Path and potential of carbon emission reduction in urban sewage treatment industry in China[J]. Water & Wastewater Engineering,2017,53(3):1-3. doi: 10.3969/j.issn.1002-8471.2017.03.001 [13] YANG M J, PENG M, WU D, et al. Greenhouse gas emissions from wastewater treatment plants in China: historical emissions and future mitigation potentials[J]. Resources, Conservation and Recycling,2023,190:106794. doi: 10.1016/j.resconrec.2022.106794 [14] XIE T, WANG C W. Impact of different factors on greenhouse gas generation by wastewater treatment plants in China[C/OL]//2011 International Symposium on Water Resource and Environmental Protection. [2023-01-12]. DOI: 10.1109/ISWREP.2011.5893297. [15] 孙宝雯.城镇污水处理系统的节能低碳技术分析[J]. 现代工业经济和信息化,2022,12(7):76-77. doi: 10.16525/j.cnki.14-1362/n.2022.07.027SUN B W. Analysis of energy-saving and low-carbon technologies for urban sewage treatment system[J]. Modern Industrial Economy and Informationization,2022,12(7):76-77. doi: 10.16525/j.cnki.14-1362/n.2022.07.027 [16] 鲍志远. 典型城市污水处理工艺温室气体排放特征及减排策略研究[D]. 北京: 北京林业大学, 2019. [17] RODRIGUEZ-CABALLERO A, AYMERICH I, POCH M, et al. Evaluation of process conditions triggering emissions of green-house gases from a biological wastewater treatment system[J]. Science of the Total Environment,2014,493:384-391. doi: 10.1016/j.scitotenv.2014.06.015 [18] 柴春燕. 城镇污水处理厂温室气体排放规律及热岛效应研究[D]. 哈尔滨: 哈尔滨工业大学, 2017. [19] 张秀梅.污水处理厂温室气体减排研究[J]. 武昌理工学院学报,2017(1):96-98. [20] 张星. 城镇生活污水处理系统碳排放研究[D]. 南京: 南京信息工程大学, 2018. [21] DAELMAN M R J, van VOORTHUIZEN E M, van DONGEN L G J M, et al. Methane and nitrous oxide emissions from municipal wastewater treatment: results from a long-term study[J]. Water Science and Technology,2013,67(10):2350-2355. doi: 10.2166/wst.2013.109 [22] SINGH P, KANSAL A, CARLIELL-MARQUET C. Energy and carbon footprints of sewage treatment methods[J]. Journal of Environmental Management,2016,165:22-30. [23] de HAAS D W, PEPPERELL C, FOLEY J. Perspectives on greenhouse gas emission estimates based on Australian wastewater treatment plant operating data[J]. Water Science and Technology,2014,69(3):451-463. doi: 10.2166/wst.2013.572 [24] GITARSKIY M L. The refinement to the 2006 IPCC guidelines for national greenhouse gas inventories[J]. Fundamental and Applied Climatology,2019,2:5-13. doi: 10.21513/0207-2564-2019-2-05-13 [25] XI J R, GONG H, ZHANG Y J, et al. The evaluation of GHG emissions from Shanghai municipal wastewater treatment plants based on IPCC and operational data integrated methods (ODIM)[J]. Science of the Total Environment,2021,797:148967. doi: 10.1016/j.scitotenv.2021.148967 [26] TSENG L Y, ROBINSON A K, ZHANG X Y, et al. Identification of preferential paths of fossil carbon within water resource recovery facilities via radiocarbon analysis[J]. Environmental Science & Technology,2016,50(22):12166-12178. [27] LAW Y, JACOBSEN G E, SMITH A M, et al. Fossil organic carbon in wastewater and its fate in treatment plants[J]. Water Research,2013,47(14):5270-5281. doi: 10.1016/j.watres.2013.06.002 [28] 常纪文, 井媛媛, 耿瑜, 等.推进市政污水处理行业低碳转型, 助力碳达峰、碳中和[J]. 中国环保产业,2021(6):9-17. doi: 10.3969/j.issn.1006-5377.2021.06.002CHANG J W, JING Y Y, GENG Y, et al. Promote the low-carbon transformation of municipal sewage treatment industry and help peak carbon dioxide emissions and carbon neutrality[J]. China Environmental Protection Industry,2021(6):9-17. doi: 10.3969/j.issn.1006-5377.2021.06.002 [29] DU W J, LU J Y, HU Y R, et al. Spatiotemporal pattern of greenhouse gas emissions in China's wastewater sector and pathways towards carbon neutrality[J]. Nature Water,2023,1(2):166-175. doi: 10.1038/s44221-022-00021-0 [30] 马博雅, 孙立坤, 杨春维.碳中和背景下我国污水处理技术思考[J]. 应用化工,2022,51(10):2997-3000. doi: 10.3969/j.issn.1671-3206.2022.10.039MA B Y, SUN L K, YANG C W. The feasible wastewater treatment technology in China under the background of carbon neutrality[J]. Applied Chemical Industry,2022,51(10):2997-3000. doi: 10.3969/j.issn.1671-3206.2022.10.039 [31] ZHANG O W, GAO L J, LI W Y, et al. Predicting sludge generation patterns and carbon reduction potential under Shared Socioeconomic Pathways[J]. Journal of Environmental Management,2022,322:116088. doi: 10.1016/j.jenvman.2022.116088 [32] HAO X D, LI J, van LOOSDRECHT M C M, et al. Energy recovery from wastewater: heat over organics[J]. Water Research,2019,161:74-77. doi: 10.1016/j.watres.2019.05.106 [33] 郝晓地, 叶嘉洲, 李季, 等.污水热能利用现状与潜在用途[J]. 中国给水排水,2019,35(18):15-22. doi: 10.19853/j.zgjsps.1000-4602.2019.18.004HAO X D, YE J Z, LI J, et al. Status and potential applications of thermal energy from wastewater[J]. China Water & Wastewater,2019,35(18):15-22. doi: 10.19853/j.zgjsps.1000-4602.2019.18.004 [34] HEPBASLI A, BIYIK E, EKREN O, et al. A key review of wastewater source heat pump (WWSHP) systems[J]. Energy Conversion and Management,2014,88:700-722. doi: 10.1016/j.enconman.2014.08.065 [35] 郝晓地, 赵梓丞, 李季, 等.污水处理厂的能源与资源回收方式及其碳排放核算: 以芬兰Kakolanmäki 污水处理厂为例[J]. 环境工程学报,2021,15(9):2849-2857. doi: 10.12030/j.cjee.202106073HAO X D, ZHAO Z C, LI J, et al. Analysis of energy recovery and carbon neutrality for the Kakolanmäki WWTP in Finland[J]. Chinese Journal of Environmental Engineering,2021,15(9):2849-2857. doi: 10.12030/j.cjee.202106073 [36] 李超.污水处理厂中水余热利用案析[J]. 城乡建设,2014(7):87-88. doi: 10.3969/j.issn.1002-8455.2014.07.032LI C. Case analysis of waste heat utilization of reclaimed water in sewage treatment plant[J]. Urban and Rural Development,2014(7):87-88. doi: 10.3969/j.issn.1002-8455.2014.07.032 [37] 罗雨莉, 潘艺蓉, 马嘉欣, 等.污水再生与增值利用的碳排放研究进展[J]. 环境工程,2022,40(6):83-91.LUO Y L, PAN Y R, MA J X, et al. Research advances on carbon emission of wastewater resource recovery and valorization[J]. Environmental Engineering,2022,40(6):83-91. [38] 何良年.二氧化碳化学: 碳捕集、活化与资源化[J]. 科学通报,2021,66(7):713-715. doi: 10.1360/TB-2021-0157HE L N. Carbon dioxide chemistry: carbon capture, activation and resource utilization[J]. Chinese Science Bulletin,2021,66(7):713-715. doi: 10.1360/TB-2021-0157 [39] ZHANG Z H. Emerging atmospheric carbon dioxide removal and utilisation techniques[J]. International Journal of Global Warming,2020,22(4):375. doi: 10.1504/IJGW.2020.111514 [40] REGUFE M J, PEREIRA A, FERREIRA A F P, et al. Current developments of carbon capture storage and/or utilization: looking for net-zero emissions defined in the Paris agreement[J]. Energies,2021,14(9):2406. doi: 10.3390/en14092406 [41] 张楠, 吕连宏, 王斯一, 等.基于文献计量分析的碳中和研究进展[J]. 环境工程技术学报,2023,13(2):464-472. doi: 10.12153/j.issn.1674-991X.20220275ZHANG N, LÜ L H, WANG S Y, et al. Analysis of research progress in carbon neutrality based on bibliometrics[J]. Journal of Environmental Engineering Technology,2023,13(2):464-472. doi: 10.12153/j.issn.1674-991X.20220275 [42] 姜华, 李艳萍, 高健.双碳背景下煤基产业绿色低碳转型之路[J]. 环境工程技术学报,2022,12(5):1580-1583. doi: 10.12153/j.issn.1674-991X.20220001JIANG H, LI Y P, GAO J. The road of green and low-carbon transformation of coal-based industry under carbon peak and carbon neutrality background[J]. Journal of Environmental Engineering Technology,2022,12(5):1580-1583. doi: 10.12153/j.issn.1674-991X.20220001 [43] NIU Z Z, CHI L P, LIU R, et al. Rigorous assessment of CO2 electroreduction products in a flow cell[J]. Energy & Environmental Science,2021,14(8):4169-4176. [44] 付加锋, 冯相昭, 高庆先, 等.城镇污水处理厂污染物去除协同控制温室气体核算方法与案例研究[J]. 环境科学研究,2021,34(9):2086-2093. doi: 10.13198/j.issn.1001-6929.2021.06.19FU J F, FENG X Z, GAO Q X, et al. Collaborative control method and case study of greenhouse gases in urban sewage treatment plants[J]. Research of Environmental Sciences,2021,34(9):2086-2093. doi: 10.13198/j.issn.1001-6929.2021.06.19 [45] 陈敏敏, 吴琼, 张震, 等.我国城镇污水处理厂环境绩效评价研究[J]. 环境科学研究,2020,33(12):2675-2682. doi: 10.13198/j.issn.1001-6929.2020.11.12CHEN M M, WU Q, ZHANG Z, et al. Environmental performance assessment of municipal wastewater treatment plants in China[J]. Research of Environmental Sciences,2020,33(12):2675-2682. ◇ doi: 10.13198/j.issn.1001-6929.2020.11.12