• Norul Ashikin Norzain Control & Mechatronics Engineering Department, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
  • Shafishuhaza Sahlan Control & Mechatronics Engineering Department, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
  • Fatah Ab Halim Control & Mechatronics Engineering Department, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
  • Norhaliza Abdul Wahab Control & Mechatronics Engineering Department, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia




Wastewater treatment plant, activated sludge process, system identification, singular perturbation approximation, frequency domain interval gramian


Activated sludge process is an important stage in Wastewater Treatment Plant (WWTP). In this study, model of the activated sludge process from Bunus Regional Sewage Treatment Plant Kuala Lumpur, Malaysia is developed. This paper focuses on modelling and model reduction of the WWTP system. The model with best fits of higher than 80% and the order of less than 10 is selected. For modelling purposes, data obtained is stimulated and modelled using System Identification technique which employ linear model ARX. For model reduction purposes, the high order model is reduced using model order reduction (MOR) of a combination of Singular Perturbation Approximation (SPA) and Frequency Domain Gramian based Model Reduction (FDIG) method. From the modelling results obtained, the ARX model with best fit of 85.11% is selected. Meanwhile, for the MOR FD-SPA technique, a 9th order model is selected with  reduction error between frequencies 0.05 rad/s and 1.4 rad/s.


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Science and Engineering

How to Cite

EMPIRICAL MODELLING OF ACTIVATED SLUDGE PROCESS VIA SYSTEM IDENTIFICATION. (2016). Jurnal Teknologi, 78(7-4). https://doi.org/10.11113/jt.v78.9435