Application of fuzzy control on wastewater treatment plant for P-removal

Due to the complex and non linear character, wastewater treatment process is difficult to be controlled. And the demand for removing the pollutant, especially for nitrogen (N) and phosphorus (P), as well as reducing the cost of wastewater treatment plant (WWTP) is an important research theme. This paper presents a comparison between PI and fuzzy logic control applied to the combined phosphorus removal Benchmark Simulation Model 1 (BSM1-P) wastewater treatment process to enhance the P removal. A default control strategy which contains two control loops and is similar to the one given by the original version of BSM1 was tested on BSM1-P. In addition, another control strategy that contains three dissolved oxygen (DO) controllers for all the aerabic tanks was also applied. For each control strategy, at first the conventional PI controllers were applied to see the performance. Secondly fuzzy logic controllers replaced the PI controllers with the purpose of enhancing P removal. The simulation results showed that both control strategies were able to improve the performance of WWTP and the application of fuzzy controllers was more beneficial for the P removal.