Benchmark Simulation Model No 2: finalisation of plant layout and default control strategy

Abstract

The COST/IWA Benchmark Simulation Model No 1 (BSM1) has been available for almost a decade. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the research work related to the benchmark simulation models has resulted in more than 300 publications worldwide demonstrates the interest in and need of such tools within the research community. Recent efforts within the IWA Task Group on "Benchmarking of control strategies for WWTPs" have focused on an extension of the benchmark simulation model. This extension aims at facilitating control strategy development and performance evaluation at a plant-wide level and, consequently, includes both pretreatment of wastewater as well as the processes describing sludge treatment. The motivation for the extension is the increasing interest and need to operate and control wastewater treatment systems not only at an individual process level but also on a plant-wide basis. To facilitate the changes, the evaluation period has been extended to one year. A prolonged evaluation period allows for long-term control strategies to be assessed and enables the use of control handles that cannot be evaluated in a realistic fashion in the one week BSM1 evaluation period. In this paper, the finalised plant layout is summarised and, as was done for BSM1, a default control strategy is proposed. A demonstration of how BSM2 can be used to evaluate control strategies is also given.

Greenhouse gases from wastewater treatment — A review of modelling tools

“…In 2007, the Benchmark Simulation Model No. 2 (BSM2) (Jeppsson et al, 2007;Nopens et al, 2010) was proposed by integrating the BSM1 with wastewater pre-treatment and a sludge train (Fig. 1).…”

“…on such performance indicators as EQI, OCI, and GHG emissions. Sweetapple et al (2013) presented the BSM-e, a modified version of BSM2 (Jeppsson et al, 2007) that is able to quantify on-site and off-site GHG emissions from a WWTP with the same configuration as the BSM2 (as detailed by Jeppsson et al, 2007 andNopens et al, 2010; Table 1). The BSM-e model differs from the BSM2G because it includes foursteps for denitrification, as detailed by Samie et al (2011), including stripping of N 2 O and CO 2 emissions, as suggested by Monteith et al (2005) (Table 1).…”

Implementation of Extended Statistical Entropy Analysis to the Effluent Quality Index of the Benchmarking Simulation Model No. 2

“…Originally, the same weighting factors were assigned to both TKN and NO 3 − , leading to the problem that a process control that achieves low concentrations of TKN in the effluent would not be rewarded. However, from an ecological point of view, low concentrations of TKN in the effluent are clearly preferential and, therefore, the weighting factors have been adapted accordingly [1,24].…”

“…Based on studies performed using the BSM No. 2, it was derived that the process control that regulates the O 2 concentration in two aeration tanks each to 2 gO 2 /m [24]. In their work, Vanrolleghem and Gillot conclude that the dissolved O 2 concentration should be controlled in every aeration tank as the performance, measured by the EQ improves significantly compared to the open-loop strategy [25].…”

Development and economic assessment of different WWTP control strategies for optimal simultaneous removal of carbon, nitrogen and phosphorus

“…Because the WWTP proved to be overloaded resulting in a violation of the effluent limits of more than 60%, the total volume of the reactors was increased from 6749 m 3 to 15000 m 3 . As a result, each aerated reactor (R5, R6 and R7) had a volume of 3000 m 3 and each anoxic reactor (R3 and R4) had a volume of 1500 m 3 as presented in Nopens et al (2010). The aeration was modeled using the volumetric mass transfer coefficient (k L a).…”