Wastewater treatment plant operation : Simple control schemes with a holistic perspective
Revollar, Silvana (Universidad de Salamanca. Departamento de Informática y Automática)
Vilanova i Arbós, Ramon (Universitat Autònoma de Barcelona. Departament de Telecomunicació i Enginyeria de Sistemes)
Vega, Pastora (Universidad de Salamanca. Departamento de Informática y Automática)
Francisco, Mario (Universidad de Salamanca. Departamento de Informática y Automática)
Meneses Benítez, Montserrat (Universitat Autònoma de Barcelona. Departament de Telecomunicació i Enginyeria de Sistemes)

Date:	2020
Abstract:	In this paper, a control approach for improving the overall efficiency of a wastewater treatment plant (WWTP) is presented. It consists of a cascaded control system that uses a global performance indicator as the controlled variable to drive the plant to operating conditions that satisfies trade-offs involved in the WWTP operation, improving the global performance of the plant. The selected global performance indicator is the N/E index that measures the ratio between the amount of nitrogenated compounds eliminated (kgN) and the energy (kWh) required to achieve that goal. This index links the variables of the activated sludge process with the energy consumed in the whole plant, thus the control strategy takes actions based on plantwide considerations. An external Proportional Integral (PI) controller changes the DO set point according to the N/E index and the basic dissolved oxygen (DO) control scheme in the activated sludge process follows this reference changes varying the aeration intensity. An outer loop with an event-based controller is used to compute the index values when the DO concentration is driven to excessively low limits, preventing long operation periods in this undesirable condition. Simple proportional integral controllers (PI) are used to adapt the strategy to the automation systems available in WWTPs. The implementation in the Benchmark Simulation Model 2 (BSM2) demonstrates the potential of the proposed approach. The results show the possibilities of the N/E index to be used as an indicator of global performance of WWTPs. It provides a link between water line objectives and energy consumption in the whole plant that can be exploited to introduce plantwide considerations in alternative control strategies formulated to drive the plant to operating conditions that optimize the overall process efficiency.
Grants:	Ministerio de Economía y Competitividad DPI2015-67341-C2-1-R Ministerio de Economía y Competitividad DPI2016-77271-R
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Wastewater treatment plants ; Environmental costs ; PID control ; Plantwide control ; Hierarchical control strategies
Published in:	Sustainability, Vol. 12, Issue 3 (February 2020) , art. 768, ISSN 2071-1050

DOI: 10.3390/su12030768

28 p, 2.9 MB

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Articles > Research articles
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