Application of real-time feedback control strategies based on effluent NH4-N and NOX -N concentrations in an A(2)/O process

作者：Kim Hyosoo; Kim Yejin; Trung Quang Hoang; Baek Gyeongdong; Kim Sungshin; Kim Changwon^*

来源：Korean Journal of Chemical Engineering, 2013, 30(8): 1578-1587.

DOI：10.1007/s11814-013-0084-x

• Real-time Feedback NH4-N Control Strategy
• Real-time Feedback NOX-N Control Strategy
• Modified Sigmoid Function
• Empirical Equation
• A(2)/O Process

This paper proposes two real-time feedback control strategies based on hourly measurements of effluent NH4-N and NO (X) -N concentrations. Using modified sigmoid functions to decide the DO setpoint, a control structure similar to the cascade-type control loop was selected as the real-time feedback NH4-N control strategy. For the realtime feedback NO (X) -N control strategy, a proper external carbon dose flow rate could be calculated based on the estimated NO (X) -N concentration in anoxic reactor by using the empirical equation. A control system, which included two proposed control strategies, was developed and applied in the pilot-scale A(2)/O process. As a result, the effluent NH4-N and NO (X) -N concentrations were maintained stably lower than the target values of 3 and 5 mg/L, respectively. Moreover, because the manipulated variables for removing the NH4-N and NO (X) -N concentrations were divided in the control strategies, the two different control strategies could be successfully applied together in the A(2)/O process.

• 出版日期2013-8