Optimization of wastewater treatment plant operation for greenhouse gas mitigation

Abstract

This study deals with the determination of optimal operation of a wastewater treatment system for minimizing greenhouse gas emissions, operating costs, and pollution loads in the effluent. To do this, an integrated performance index that includes three objectives was established to assess system performance. The ASMN_G model was used to perform system optimization aimed at determining a set of operational parameters that can satisfy three different objectives. The complex nonlinear optimization problem was simulated using the Nelder-Mead Simplex optimization algorithm. A sensitivity analysis was performed to identify influential operational parameters on system performance. The results obtained from the optimization simulations for six scenarios demonstrated that there are apparent trade-offs among the three conflicting objectives. The best optimized system simultaneously reduced greenhouse gas emissions by 31%, reduced operating cost by 11%, and improved effluent quality by 2% compared to the base case operation.

Investigation of GHG emission sources and reducing GHG emissions in a municipal wastewater treatment plant

“…In this study, the aim was to find the minimized value. Also, Kim et al . conducted a study on the optimization of a WWTP in terms of GHG emissions.…”

“…In this study, the aim was to find the minimized value. Also, Kim et al 34 conducted a study on the optimization of a WWTP in terms of GHG emissions. They used the activated sludge model-nitrogen for greenhouse gases (ASMN_G) model to optimize the operating conditions in the plant.…”

Greenhouse gases from wastewater treatment — A review of modelling tools

“…The authors confirmed the importance of using plant-wide modelling and stressed the need for setting up dedicated databases for reliable and feasible WWTP analysis at the plant-wide scale. During the last years, the interest in moving towards a wastewater treatment plant-wide control (including GHG) with the use of BSM was emphasized in literature (Guo et al, 2012;Guo and Vanrolleghem, 2014;Kim et al, 2015b) (Fig. 1).…”

“…Furthermore, GHG measurements contain a large amount of uncertainty (especially in terms of N 2 O), which contrasts with the use of fixed emission factors . Measurement uncertainties and lack of transposable data still hinder a correct and required GHG emission quantification process (Sweetapple et al, 2013;Guo and Vanrolleghem, 2014;Caniani et al, 2015;Kim et al, 2015b).…”

“…The increasing interest in climate change due to GHG emissions has emphasized the need to establish innovative/comprehensive approaches to better design/control/optimize WWTPs at the plantwide scale. The traditional approaches that do not include GHG will likely lead to an undesirable increase of GHG emission when other process variables are optimized Kim et al, 2015b).…”