污水处理行业温室气体核算模型开发及减排潜力分析

Development of Greenhouse Gas Accounting Model and Emission Reduction Potential Analysis in Wastewater Treatment Industry

中文关键词:  污水处理  温室气体  碳核算  排放因子法  模型

英文关键词:wastewater treatment  greenhouse gases  carbon accounting  emission factor method  model

中文摘要:

      城镇污水处理行业是我国现代化进程中不可或缺的一部分，它承担着城镇污水处理和减排的重要作用，在运行过程中不可避免会产生大量的温室气体。本研究基于污水处理过程中的温室气体排放机理及排放因子法，构建了污水处理温室气体核算模型，并应用于国内典型的某厌氧—缺氧—好氧工艺的污水处理厂。研究结果表明，开发的模型能够有效识别出厌氧—缺氧—好氧工艺温室气体排放占比较高的环节，该环节为污水处理过程中电耗和污水处理过程中的甲烷排放，其在整个温室气体排放系统内占比高达93.09%。污水处理厂可以采取减小曝气量的措施使溶解氧达到2 ～ 3 mg/L，从而降低污水处理系统曝气电耗；另外，优化泵及鼓风机的运行，选用变频调速水泵等措施，可以降低污水提升环节能耗，达到温室气体间接减排的目的。污水处理厂还可以采取甲烷产能回收利用措施，将CH₄燃烧产生的能量作为污水处理系统内的能源供应，这样不仅可以有效减少污水处理厂的能耗，而且可以实现污水处理过程中温室气体排放减量化。

英文摘要:

      The urban wastewater treatment industry is an integral part of China’s modernization process, and it assumes an important role in urban wastewater treatment and emission reduction, and inevitably generates a large amount of greenhouse gas in the operation process. In this study, a wastewater treatment GHG accounting model was constructed based on the GHG emission mechanism and emission factor method in the wastewater treatment process, and applied to a typical domestic wastewater treatment plant with anaerobic-anoxic- aerobic process (A²O). The research results showed that the developed model could effectively identify the high GHG emissions of the A²O process as the electricity consumption in the wastewater treatment process and the methane (CH₄) emissions in the wastewater treatment process, which accounted for 93.09% in the whole GHG emission system. The wastewater treatment plant could take measures to reduce the aeration volume to dissolved oxygen to 2 ～ 3 mg/L, so as to reduce the aeration electricity consumption of the wastewater treatment system; in addition, optimize the operation of the lifting pump and blower, select variable frequency speed control pumps, etc., so as to reduce the energy consumption of the sewage lifting link and achieve the purpose of GHG indirect emission reduction. Sewage treatment plants could also take measures to recycle CH₄ capacity, the energy generated by the combustion of CH₄ could be used as the energy supply within the sewage treatment system, which could not only effectively reduce the energy consumption of sewage treatment plants, but also achieve GHG emission reduction in the sewage treatment process.