Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment

The aim of wastewater treatment plants (WWTPs) is to clean wastewater before it is discharged into the environment. Real-time monitoring and control will become more essential as the regulations for effluent discharges are likely to become stricter in the future. Model-based soft sensors provide a p...

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Main Authors: Henri Pörhö, Jani Tomperi, Aki Sorsa, Esko Juuso, Jari Ruuska, Mika Ruusunen
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/13/13/7848
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author Henri Pörhö
Jani Tomperi
Aki Sorsa
Esko Juuso
Jari Ruuska
Mika Ruusunen
author_facet Henri Pörhö
Jani Tomperi
Aki Sorsa
Esko Juuso
Jari Ruuska
Mika Ruusunen
author_sort Henri Pörhö
collection DOAJ
description The aim of wastewater treatment plants (WWTPs) is to clean wastewater before it is discharged into the environment. Real-time monitoring and control will become more essential as the regulations for effluent discharges are likely to become stricter in the future. Model-based soft sensors provide a promising solution for estimating important process variables such as chemical oxygen demand (COD) and help in predicting the performance of WWTPs. This paper explores the possibility of using interpretable model structures for monitoring the influent and predicting the effluent of paper mill WWTPs by systematically finding the best model parameters using an exhaustive algorithm. Experimentation was conducted with regression models such as multiple linear regression (MLR) and partial least squares regression (PLSR), as well as LASSO regression with a nonlinear scaling function to account for nonlinearities. Some autoregressive time series models were also built. The results showed decent modelling accuracy when tested with test data acquired from a wastewater treatment process. The most notable test results included the autoregressive model with exogenous inputs for influent COD (correlation 0.89, mean absolute percentage error 8.1%) and a PLSR model for effluent COD prediction (correlation 0.77, mean absolute percentage error 7.6%) with 20 h prediction horizon. The results show that these models are accurate enough for real-time monitoring and prediction in an industrial WWTP.
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spelling doaj.art-185c97ec90d4491f9ab1cd22fa77e6712023-11-18T16:12:18ZengMDPI AGApplied Sciences2076-34172023-07-011313784810.3390/app13137848Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater TreatmentHenri Pörhö0Jani Tomperi1Aki Sorsa2Esko Juuso3Jari Ruuska4Mika Ruusunen5Control Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandControl Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandControl Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandControl Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandControl Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandControl Engineering Research Group, Environmental and Chemical Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014 Oulu, FinlandThe aim of wastewater treatment plants (WWTPs) is to clean wastewater before it is discharged into the environment. Real-time monitoring and control will become more essential as the regulations for effluent discharges are likely to become stricter in the future. Model-based soft sensors provide a promising solution for estimating important process variables such as chemical oxygen demand (COD) and help in predicting the performance of WWTPs. This paper explores the possibility of using interpretable model structures for monitoring the influent and predicting the effluent of paper mill WWTPs by systematically finding the best model parameters using an exhaustive algorithm. Experimentation was conducted with regression models such as multiple linear regression (MLR) and partial least squares regression (PLSR), as well as LASSO regression with a nonlinear scaling function to account for nonlinearities. Some autoregressive time series models were also built. The results showed decent modelling accuracy when tested with test data acquired from a wastewater treatment process. The most notable test results included the autoregressive model with exogenous inputs for influent COD (correlation 0.89, mean absolute percentage error 8.1%) and a PLSR model for effluent COD prediction (correlation 0.77, mean absolute percentage error 7.6%) with 20 h prediction horizon. The results show that these models are accurate enough for real-time monitoring and prediction in an industrial WWTP.https://www.mdpi.com/2076-3417/13/13/7848soft sensorwastewater treatmentmodellingresource efficiencyexhaustive search
spellingShingle Henri Pörhö
Jani Tomperi
Aki Sorsa
Esko Juuso
Jari Ruuska
Mika Ruusunen
Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
Applied Sciences
soft sensor
wastewater treatment
modelling
resource efficiency
exhaustive search
title Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
title_full Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
title_fullStr Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
title_full_unstemmed Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
title_short Data-Based Modelling of Chemical Oxygen Demand for Industrial Wastewater Treatment
title_sort data based modelling of chemical oxygen demand for industrial wastewater treatment
topic soft sensor
wastewater treatment
modelling
resource efficiency
exhaustive search
url https://www.mdpi.com/2076-3417/13/13/7848
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