Cost reduction of the wastewater treatment plant operation by MPC based on modified ASM1 with two-step nitrification/denitrification model.
ABSTRACT The Activated Sludge Model No. 1 (ASM1) considers that nitrification and denitrification are single step processes and nitrite nitrogen (NO2–N), which is an intermediate for the two processes, is not accounted for. The first part of this paper presents the development of an enhanced ASM1 with two step nitrification/denitrification processes and its implementation in the Benchmark Simulation Model No.1 wastewater treatment plant (WWTP). The secondary settler was considered to be reactive in order to achieve a better fit between the simulation model and the behavior of the real WWTP. The second part presents the investigation of Model Predictive Control approach for the advanced control of the WWTP. Two control strategies are implemented for the wastewater treatment plant and they are analyzed from the perspective of the benefits brought to the WWTP operation. The proposed control strategy shows a reduction of the operational costs and the improvement of the effluent quality index.
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ABSTRACT: The first part of this paper presents the development of a 4-stage Bardenpho wastewater treatment plant simulator model. The simulator model is an adaptation of the Benchmark Simulation Model No. 1 for the 4-stage Bardenpho process, and it consists of seven reactor arranged in series followed by a secondary settler. The bio-kinetic model used to describe the biological processes in the reactors is a modified Activated Sludge Model No. 3 that considers parallel growth of the heterotrophic biomass on both biodegradable substrate and internal storage products. The secondary settler was considered to be reactive and the biological processes that occur in the settler were accounted for. The second part of the paper focuses on the analysis of the benefits that decentralized control has on the operation of the 4-stage Bardenpho process. Four control strategies of the 4-stage Bardenpho are analyzed from a control performance, operational costs and effluent quality perspective. The control strategies are based on PI controller designed using the Internal Model Control principle. In order to make the simulation more realistic the sensors and reactors were not considered being ideal and their complex behavior was considered in the simulator model.16th International Conference on System Theory, Control and Computing (ICSTCC 2012); 10/2012
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ABSTRACT: Wastewater treatment plant is a large-scale system and highly known with the nonlinearity of the parameters, making them a challenge to be controlled. In this paper, enhanced nonlinear PI (EN-PI) controller is developed for activated sludge process where a sector-bounded nonlinear gain with automatic gain adjustment is cascaded to conventional static-gain PI. The importance in controlling the dissolved oxygen concentration and the improvement of nitrogen removal process are discussed. The effectiveness of the proposed EN-PI controller is validated by comparing the performance of local control loops and the activated sludge process to the benchmark PI under three different weathers. The EN-PI controller is effectively applied in improving the performances of the static-gain PI, hence controlling the dynamic natures of the plant. Itwas proved by significant improvement in effluent violations, effluent quality index and energy saving of the Benchmark Simulation Model No.1.ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 07/2014; 39(8):6575-6586. · 0.39 Impact Factor
Article: Aeration control - a review.[Show abstract] [Hide abstract]
ABSTRACT: This review covers automatic control of continuous aeration systems in municipal wastewater treatment plants. The review focuses on published research in the 21st century and describes research into various methods to decide and control the dissolved oxygen (DO) concentration and to control the aerobic volume with special focus on plants with nitrogen removal. Important aspects of control system implementation and success are discussed, together with a critical review of published research on the topic. With respect to DO control and determination, the strategies used for control span from modifications and developments of conventional control methods which have been explored since the 1970s, to advanced control such as model-based predictive and optimal controllers. The review is supplemented with a summary of comparisons between control strategies evaluated in full-scale, pilot-scale and in simulations.Water Science & Technology 01/2013; 67(11):2374-98. · 1.10 Impact Factor