Supervisory control strategies for the new WWTP of Galindo-Bilbao: the long run from the conceptual design to the full-scale experimental validation

Abstract

This paper presents the theoretical basis and the main results obtained during the development and full-scale experimental validation of the new supervisory control strategy designed for the Galindo-Bilbao wastewater treatment plant (WWTP). The different phases of the project have been carried out over the last 8 years, combining model simulations, pilot-plant experimentation and full-scale validation. The final control strategy combines three complementary control loops to optimise the nitrogen removal in pre-denitrifying activated sludge plants. The first controller was designed to maintain the average concentration of the ammonia in the effluent via the automatic selection of the most appropriate DO set point in the aerobic reactors. The second control loop optimises the use of the denitrification potential and finally, the third control loop maintains the selected amount of biomass in the biological reactors by automatic manipulation of the wastage rate. Mobile-averaged windows have been implemented to incorporate commonly used averaged values in the control objectives. The performance of the controllers has been successfully assessed through the full-scale experimental validation in one of the lines of the WWTP.

RGA analysis and decentralized control for a wastewater treatment plant

“…Other times, there are larger approaches being proposed: hierarchical control of the entire water sewage system and wastewater treatment system [6]. The methods of control include simple control [15], feedforward-feedback control [16], optimal control [17], [18], [19], linear and nonlinear control [4], [5] [20], [21], supervisory control [22], and predictive control [3], [6], [7], [13], [23], [24]. A global sensitivity analysis for control of biological wastewater treatment plant is done in [25], but it is noteworthy to mention that very few experimental validations were performed [22] mainly due to the lack of appropriate sensors, actuators and control systems of the process.…”

EPSAC for wastewater treatment process (BSM1)

“…The methods approached are also various: Proportional Integral and Derivative (PID) control, or feedforward integrated with feedback control [9], model predictive control (MPC) [4], [1], [10], [11], optimal control [13], fuzzy control [12] and nonlinear control. Experimental validation of those control strategies are few [14] due to the difficulty of applying those control algorithms on operational and running plants and also due to the lack of some parameters measurement.…”

“…Compliance with legal provisions related to discharge water quality standards is the first objective of MPC control [17]. The second objective is reducing operational costs [14] that are mainly generated by pumping and blowing. Thus, is very important to maintain a correlation between this two goals.…”

Potential of in-situ sensors with ion-selective electrodes for aeration control at wastewater treatment plants

“…In all case the target was to fulfill the Swiss effluent limits of 2 mg NH 4 -N/l as a daily mean value.For such cases of 24 h average limits a further optimization could be the addition of a DO controller based on moving average values of ammonium rather than a fix threshold (see e.g Ayesa et al 2006),. this was however not yet considered in our case.…”