Modelling and optimization of energy consumption in the activated sludge biological aeration unit

The biological aeration unit consumes the highest energy (67.3%) in wastewater treatment compared with physical (18.8%) and chemical (13.9%) treatment processes. The high energy consumption is caused by the supply of oxygen using air pumps/blowers and temperature that controls microorganisms' g...

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Main Authors: Mpho Muloiwa, M. O. Dinka, Stephen Nyende-Byakika
Format: Article
Language:English
Published: IWA Publishing 2023-01-01
Series:Water Practice and Technology
Subjects:
Online Access:http://wpt.iwaponline.com/content/18/1/140
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author Mpho Muloiwa
M. O. Dinka
Stephen Nyende-Byakika
author_facet Mpho Muloiwa
M. O. Dinka
Stephen Nyende-Byakika
author_sort Mpho Muloiwa
collection DOAJ
description The biological aeration unit consumes the highest energy (67.3%) in wastewater treatment compared with physical (18.8%) and chemical (13.9%) treatment processes. The high energy consumption is caused by the supply of oxygen using air pumps/blowers and temperature that controls microorganisms' growth. The purpose of this study was to model and optimize energy consumption in the biological aeration unit. The multilayer perceptron (MLP) artificial neural network (ANN) algorithm was used to model energy consumption. The particle swarm optimization (PSO) algorithm was used to optimize the energy consumption model. Sensitivity analysis was performed to determine the percentage contribution of input variables towards energy consumption. The MLP ANN algorithm modelled energy consumption successfully and produced R², RMSE, and MSE of 0.89, 0.0265, and 0.00070, respectively, during the testing phase. The PSO algorithm optimized energy consumption successfully and produced a global solution of 0.993 kWh/m³. The percentage reduction between the lowest measured and optimized energy consumption was 38.4%. Aeration period (81%) and temperature (10.7%) contributed the highest towards energy consumption. In conclusion, temperature played a significant role in energy consumption compared with airflow rate (4.2%). When the temperature is conducive to allowing the growth of microorganisms, the removal of COD and ammonia will be rapid resulting in low energy consumption. HIGHLIGHTS Temperature is the driver of energy consumption compared with airflow rate in the biological aeration unit.; Temperature contributes 6.5% more than airflow rate towards energy consumption in the biological aeration unit.; Biological aeration unit should be operated at high temperatures (35 °C) in order to achieve low energy consumption.; A total of 38.4% reduction in energy consumption was achieved using the PSO algorithm.;
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spelling doaj.art-d2ef5bc8d0cc4140890408528bfa6ca42023-02-17T17:33:22ZengIWA PublishingWater Practice and Technology1751-231X2023-01-0118114015810.2166/wpt.2022.154154Modelling and optimization of energy consumption in the activated sludge biological aeration unitMpho Muloiwa0M. O. Dinka1Stephen Nyende-Byakika2 Department of Civil Engineering, Tshwane University of Technology, Private Bag X680 Pretoria 0001, Staatsartillerie Road, Pretoria West, South Africa Department of Civil Engineering Science, University of Johannesburg, Auckland Park Campus 2006, Box 524, Johannesburg, South Africa Department of Civil Engineering, Tshwane University of Technology, Private Bag X680 Pretoria 0001, Staatsartillerie Road, Pretoria West, South Africa The biological aeration unit consumes the highest energy (67.3%) in wastewater treatment compared with physical (18.8%) and chemical (13.9%) treatment processes. The high energy consumption is caused by the supply of oxygen using air pumps/blowers and temperature that controls microorganisms' growth. The purpose of this study was to model and optimize energy consumption in the biological aeration unit. The multilayer perceptron (MLP) artificial neural network (ANN) algorithm was used to model energy consumption. The particle swarm optimization (PSO) algorithm was used to optimize the energy consumption model. Sensitivity analysis was performed to determine the percentage contribution of input variables towards energy consumption. The MLP ANN algorithm modelled energy consumption successfully and produced R², RMSE, and MSE of 0.89, 0.0265, and 0.00070, respectively, during the testing phase. The PSO algorithm optimized energy consumption successfully and produced a global solution of 0.993 kWh/m³. The percentage reduction between the lowest measured and optimized energy consumption was 38.4%. Aeration period (81%) and temperature (10.7%) contributed the highest towards energy consumption. In conclusion, temperature played a significant role in energy consumption compared with airflow rate (4.2%). When the temperature is conducive to allowing the growth of microorganisms, the removal of COD and ammonia will be rapid resulting in low energy consumption. HIGHLIGHTS Temperature is the driver of energy consumption compared with airflow rate in the biological aeration unit.; Temperature contributes 6.5% more than airflow rate towards energy consumption in the biological aeration unit.; Biological aeration unit should be operated at high temperatures (35 °C) in order to achieve low energy consumption.; A total of 38.4% reduction in energy consumption was achieved using the PSO algorithm.;http://wpt.iwaponline.com/content/18/1/140artificial neural networkbiological aeration unitenergy consumptionmodellingparticle swarm optimizationwastewater treatment plant
spellingShingle Mpho Muloiwa
M. O. Dinka
Stephen Nyende-Byakika
Modelling and optimization of energy consumption in the activated sludge biological aeration unit
Water Practice and Technology
artificial neural network
biological aeration unit
energy consumption
modelling
particle swarm optimization
wastewater treatment plant
title Modelling and optimization of energy consumption in the activated sludge biological aeration unit
title_full Modelling and optimization of energy consumption in the activated sludge biological aeration unit
title_fullStr Modelling and optimization of energy consumption in the activated sludge biological aeration unit
title_full_unstemmed Modelling and optimization of energy consumption in the activated sludge biological aeration unit
title_short Modelling and optimization of energy consumption in the activated sludge biological aeration unit
title_sort modelling and optimization of energy consumption in the activated sludge biological aeration unit
topic artificial neural network
biological aeration unit
energy consumption
modelling
particle swarm optimization
wastewater treatment plant
url http://wpt.iwaponline.com/content/18/1/140
work_keys_str_mv AT mphomuloiwa modellingandoptimizationofenergyconsumptionintheactivatedsludgebiologicalaerationunit
AT modinka modellingandoptimizationofenergyconsumptionintheactivatedsludgebiologicalaerationunit
AT stephennyendebyakika modellingandoptimizationofenergyconsumptionintheactivatedsludgebiologicalaerationunit