Division of Industrial Electrical Engineering and Automation (IEA), Department of Measurement Technology and Industrial Electrical Engineering (MIE), Lund University, Box 118, SE-221 00 Lund, Sweden; Center for Process Engineering and Technology (PROCESS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, DK-2800 Kgs. Lyngby, Denmark.
Sci Total Environ. 2014 Jan 1;466-467:616-24. doi: 10.1016/j.scitotenv.2013.07.046. Epub 2013 Aug 19.
The objective of this paper was to show the potential additional insight that result from adding greenhouse gas (GHG) emissions to plant performance evaluation criteria, such as effluent quality (EQI) and operational cost (OCI) indices, when evaluating (plant-wide) control/operational strategies in wastewater treatment plants (WWTPs). The proposed GHG evaluation is based on a set of comprehensive dynamic models that estimate the most significant potential on-site and off-site sources of CO₂, CH₄ and N₂O. The study calculates and discusses the changes in EQI, OCI and the emission of GHGs as a consequence of varying the following four process variables: (i) the set point of aeration control in the activated sludge section; (ii) the removal efficiency of total suspended solids (TSS) in the primary clarifier; (iii) the temperature in the anaerobic digester; and (iv) the control of the flow of anaerobic digester supernatants coming from sludge treatment. Based upon the assumptions built into the model structures, simulation results highlight the potential undesirable effects of increased GHG production when carrying out local energy optimization of the aeration system in the activated sludge section and energy recovery from the AD. Although off-site CO₂ emissions may decrease, the effect is counterbalanced by increased N₂O emissions, especially since N₂O has a 300-fold stronger greenhouse effect than CO₂. The reported results emphasize the importance and usefulness of using multiple evaluation criteria to compare and evaluate (plant-wide) control strategies in a WWTP for more informed operational decision making.
本文旨在展示在评估污水处理厂（WWTP）中的（全厂范围）控制/操作策略时，将温室气体（GHG）排放添加到诸如出水质量（EQI）和运营成本（OCI）指数等植物性能评估标准中所带来的潜在额外见解。所提出的 GHG 评估基于一组综合动态模型，这些模型可估算 CO₂、CH₄和 N₂O 的最重要的潜在现场和场外来源。该研究计算并讨论了 EQI、OCI 和 GHG 排放的变化，这些变化是由于以下四个过程变量的变化引起的：（i）活性污泥段曝气控制的设定点；（ii）初沉池总悬浮固体（TSS）的去除效率；（iii）厌氧消化器的温度；以及（iv）来自污泥处理的厌氧消化器上清液的流量控制。基于模型结构中的假设，模拟结果突出了在活性污泥段进行曝气系统的局部能量优化和从 AD 中进行能量回收时增加 GHG 产生的潜在不良影响。尽管场外 CO₂排放可能会减少，但由于 N₂O 的温室效应比 CO₂强 300 倍，因此 N₂O 排放的增加抵消了这种影响。所报告的结果强调了使用多个评估标准来比较和评估 WWTP 中的（全厂范围）控制策略的重要性和有用性，以便做出更明智的运营决策。
