Evaluation of Control Strategies in Activated Sludge Process for Biological Wastewater Treatment

Abstract

Abstract In this paper, benchmark simulation model no.1 (BSM1) of an activated sludge process is used to evaluate various control strategies. Control configurations such as feedback control and feed-forward plus feedback (FF-FB) control are applied and compared with respect to effluent discharge requirements under specified constraints and operating costs. Feed-forward control is incorporated in the PI control configuration for preventing the influent loading disturbance affecting the process. No case studies of BSM1 model have been reported in the literature for the Indian wastewater. In this work, the dynamic simulation of an activated sludge process is performed using the data collected from the sewage treatment plant, located in India. The influent load data are collected during the dry weather period. The influent fractionation is carried out using the activated sludge model no.1 (ASM1). The results of the dynamic simulation indicate that FF-FB control of the activated sludge process is more effective than feedback control in meeting the constraints, especially effluent ammonia concentration which is considered as very important. From the comparison of performance evaluation criteria, it is observed that FF-FB control has achieved almost the same operating costs as with feedback control.