# EMPIRICAL MODELLING OF ACTIVATED SLUDGE PROCESS VIA SYSTEM IDENTIFICATION

## Authors

• 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

## Keywords:

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

## Abstract

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 Â reduction error between frequencies 0.05 rad/s and 1.4 rad/s.

## References

S. R. Qasim. 1998. Wastewater Treatment Plants: Planning, Design, and Operation. Edisi Ke-2. Taylor & Francis.

Chen, J., Gao, Y., Zhang, Z., Shi, D. and Xi, D. 2006. Integrated Modeling And Simulation Of Activated Sludge Process. Control Conference (CCC), 2006 Chinese. 1382-1386.

Mulas. M. 2006. Modelling And Control Of Activated Sludge Processes. PhD Thesis, Universita Degli Studi Di Cagliari.

Wu, J. and Luo, J. 2012. Aeration Control Of Activated Sludge Wastewater Treatment Process Using Optimal Control. Intelligent Control and Automation (WCICA), 2012 10th World Congress. 6July 2012. 4969-4973.

Bechtold. T. 2005. Model Order Reduction Of Electro-Thermal MEMS. Ph. D. Thesis.

Saragih, R. 2013. Singular Perturbation Approximation of Balanced Infinite-Dimensional Systems. International Journal of Control and Automation. 6(5): 409-420.

Ishizakiy, T., Sandberg, H., Johansson, K. H., Kashima, K., Imura, J. I. and Aihara, K. 2013. Singular Perturbation Approximation Of Semistable Linear Systems. Control Conference (ECC), 2013 European. & July 2013. 4508-4513.

Kumar, D. and Nagar, S. K. 2013. A New Frequency Weighted Model Reduction Technique Using Balanced Singular Perturbation Approximation. India Conference (INDICON), 2013 Annual IEEE. 13 December 2013. 1-5.

Enns, D. F. 1984. Model Reduction With Balanced Realizations: An Error Bound And A Frequency Weighted Generalization. Decision and Control, 1984. The 23rd IEE Conference. 12 December 1984. 127-132.

Ghafoor, A. and Sreeram, V. 2008. A Survey/Review Of Frequency-Weighted Balanced Model Reduction Techniques. Journal of Dynamic Systems, Measurement, and Control. 130(6): 061004.

Ghafoor, A. and Sreeram, V. 2008. Model Reduction Via Limited Frequency Interval Gramians. Circuits and Systems I: Regular Papers, IEEE Transactions. 55(9): 2806-2812.

Sun, X., Sun, Y., Wang, H. and Yu, D. 2009. Experimental Study On Shortcut Nitrification Of Sewage From Flushing Toilet With Seawater. Environmental Science and Information Application Technology, (ESIAT), 2009. 4 July 2009. 273-276.

Choo, H. P., Sahlan, S. and Wahab, N. A. 2012. System Identification Of Activated Sludge Process. Control, Systems & Industrial Informatics (ICCSII), 2012. 23 September 2012. 137-140.

Banadda, N., Nhapi, I. and Kimwaga, R. 2011. A Review Of Modeling Approaches In Activated Sludge Systems. African Journal of Environmental Science and Technology. 5(6): 397-408.

Bolmstedt, J. 2000. Dynamic Modelling Of An Activated Sludge Process At A Pulp And Paper Mill. Master Thesis, University of Oulu.

Nuhoglu, A., Keskinler, B. and Yildiz, E. 2005. Mathematical Modelling Of The Activated Sludge Process-The Erzincan Case. Process Biochemistry. 40(7): 2467-2473.

S. R. Weijers. 2000. Modelling, Identification And Control Of Activated Sludge Plants For Nitrogen Removal. Technische Univ. Eindhoven.

Rustum, R. 2009. Modelling Activated Sludge Wastewater Treatment Plants Using Artificial Intelligence Techniques (Fuzzy Logic And Neural Networks). Doctoral Dissertation, Heriot-Watt University.

Kumar, D. and Nagar, S. K. 2014. Square-Root Frequency Weighted Balanced Model Reduction Via Singular Perturbation Approximation. Electrical Engineering Congress (iEECON), 2014. 19 March 2014. 1-4.

Abo-Hammour, Z. S., Alsmadi, O. M. and Al-Smadi, A. M. 2011. Frequency-based Model Order Reduction Via Genetic Algorithm Approach. Systems, Signal Processing and their Applications (WOSSPA), 2011. 9 May 2011. 91-94.

SeliÅŸteanu, D., Petre, E., Roman, M. and BobaÅŸu, E. 2010. Structural Properties And Reduced Order Modeling Of A Class Of Bioprocesses. Modelling, Identification and Control (ICMIC), 2010. 88-93.

Liu, Y. and Anderson, B.D. 1989. Singular Perturbation Approximation Of Balanced Systems. International Journal of Control. 50(4): 1379-1405.

Lee, T. T., Wang, F. Y. and Newell, R. B. 2002. Robust Model-Order Reduction Of Complex Biological Processes. Journal of Process Control. 12(7): 807-821.

Gawronski, W. and Juang, J. N. 1990. Model Reduction In Limited Time And Frequency Intervals. International Journal of Systems Science. 21(2): 349-376.

GaÅ¡perin, M., VreÄko, D. and JuriÄiÄ‡, D. 2010. System Identification Of Nonlinear Dynamical Models: Application To Wastewater Treatment Plant. Control Applications (CCA), 2010. 8 September 2010. 695-700.

Muhammad, Z., Yusoff, Z. M., Rahiman, M. H. F. and Taib, M. N. 2012. Modeling Of Steam Distillation Pot With ARX Model. Signal Processing and its Applications (CSPA), 2012. 23 March 2012. 194-198.

2016-07-24

## Section

Science and Engineering

## How to Cite

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