Model Reference Adaptive Control for pH Neutralization in Batik Wastewater Treatment
Keywords:
pH neutralization, wastewater treatment, adaptive control, MRAC, chemical process controlAbstract
The batik industry generates wastewater with elevated pH levels due to sodium hydroxide usage in dyeing processes, frequently exceeding the regulatory standard of pH 6–9. Traditional dilution methods prove economically inefficient, necessitating more adaptive control strategies. This research designs and simulates a nonlinear adaptive control system based on Model Reference Adaptive Control (MRAC) for pH neutralization using acetic acid. The Continuous Stirred Tank Reactor (CSTR) mathematical model was developed from mass balance, acid-base equilibrium, and electroneutrality principles, then simulated using Ordinary Differential Equation (ODE) functions in MATLAB. MRAC performance was compared with conventional PI controller across various initial wastewater pH conditions. Simulation results demonstrate that MRAC achieves faster convergence, reaching pH 7 in 2488.68 seconds from initial pH 9, compared to PI controller (3080.96 seconds) or uncontrolled system (10225 seconds). With settling time of 2377 seconds versus 2566.4 seconds for PI, MRAC reduces neutralizer consumption by 0.61% (9.5380 L versus 9.5969 L) while maintaining safety criteria above the lower pH bound of 6.80. Lyapunov stability analysis confirms the asymptotic stability of the adaptive controller. This study demonstrates that MRAC offers superior performance for batik wastewater pH control while reducing dependency on uneconomical dilution methods.
References
A. P. Siregar et al., “Upaya pengembangan industri batik di Indonesia,” Dinamika Kerajinan dan Batik: Majalah Ilmiah, vol. 37, no. 1, pp. 79–92, 2020. https://doi.org/10.22322/dkb.v37i1.5945.
L. Indrayani, “Teknologi pengolahan limbah cair batik dengan IPAL BBKB sebagai salah satu alternatif percontohan bagi industri batik,” Prosiding Seminar Nasional Teknik Kimia “Kejuangan,” no. April, pp. 1–9, 2019. [Online] Available : https://jurnal.upnyk.ac.id/index.php/kejuangan/article/view/2847
Peraturan Menteri Lingkungan Hidup dan Kehutanan Republik Indonesia Nomor P.16/MENLHK/SETJEN/KUM.1/4/2019 tentang Perubahan Kedua atas Peraturan Menteri Lingkungan Hidup Nomor 5 Tahun 2014 tentang Baku Mutu Air Limbah, MENLHK, Jakarta, 2019. [Online] Available : https://ppkl.menlhk.go.id/website/filebox/784
N. Apriyani, “Industri batik: kandungan limbah cair dan metode pengolahannya,” Media Ilmiah Teknik Lingkungan , Volume 3, Nomor 1, vol. 3, no. 1, pp. 21–29, 2018. https://doi.org/10.33084/mitl.v3i1.640
Nazuwatussya’Diyah, T. Ratuannisa, E. Ekawati, E. Yulia, B. S. Purwasasmita, and A. B. Nugraha, “Studi pengolahan air limbah batik pada skala Industri Rumah Tangga dan Usaha Kecil Menengah di Cirebon, Indonesia,” Jurnal Dampak, vol. 20, no. 1, pp. 8–15, 2023. https://doi.org/10.25077/dampak.20.1.8-15.2023.
Kiswanto, L. N. Rahayu, and Wintah, “Pengolahan limbah cair batik menggunakan teknologi membran nanofiltrasi di kota Pekalongan,” Jurnal LITBANG Kota Pekalongan, vol. 17, pp. 72–82, 2019, [Online]. Available: https://jurnal.pekalongankota.go.id/index.php/litbang/article/download/109/107
N. A. Salehah, Q. M. Hikmah, and E. Ekawati, “Perancangan dan implementasi aktuator sistem kontrol pH menggunakan on-off solenoid valve pada purwa rupa instalasi pengolahan limbah tekstil,” Seminar Nasional Instrumentasi, Kontrol dan Otomasi (SNIKO), pp. 241–246, 2018. https://doi.org/10.5614/sniko.2018.28
B. Efendy, E. Ekawati, Nazuwatussya’diyah, and E. M. Budi, “Assessment of electrocoagulation control system strategy in textile wastewater treatment plant,” 2020 International Electronics Symposium (IES), pp. 96–101, 2020. https://doi.org/10.1109/IES50839.2020.9231838.
N. D. Jespersen, J. E. Brady, and A. Hyslop, Chemistry: The Molecular Nature of Matter, 6th ed. New York: John Wiley and Sons, Inc., 2012.
Nazuwatussya’diyah, E. Ekawati, J. Pradipta, and E. Yulia, “Automation system architecture of pH neutralization process in batik wastewater treatment plant,” J Phys Conf Ser, vol. 2673, pp. 1–9, 2023. https://doi.org/10.1088/1742-6596/2673/1/012020
E. Yulia, E. Ekawati, and E. M. Budi, “Plant redesign for pH neutralization process of textile wastewater treatment,” IOP Conf Ser Earth Environ Sci, vol. 794, no. 1, 2021. https://doi.org/10.1088/1755-1315/794/1/012055.
T. J. McAvoy, E. Hsu, and S. Lowenthal, “Dynamics of pH in controlled stirred tank reactor,” Industrial and Engineering Chemistry Process Design and Development, vol. 11, no. 1, pp. 68–70, 1972. https://doi.org/10.1021/i260041a013.
E. Yulia, E. Ekawati, and E. M. Budi, “perancangan sistem aktuator laju aliran masuk dan simulasi proses netralisasi pH pada plant simulator instalasi pengolahan air limbah industri tekstil (Iplit),” Seminar Nasional Instrumentasi, Kontrol dan Otomasi (SNIKO), pp. 85–90, 2019, https://doi.org/10.5614/sniko.2018.13.
K. Bingi, R. Ibrahim, M. N. Karsiti, T. D. Chung, and S. M. Hassan, “Optimal PID control of pH neutralization plant,” 2016 2nd IEEE International Symposium on Robotics and Manufacturing Automation, ROMA 2016, September 2016. https://doi.org/10.1109/ROMA.2016.7847812.
M. F. Zanil and M. A. Hussain, “Multivariable adaptive Lyapunov fuzzy controller for pH neutralisation process,” 12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering, vol. 37, pp. 1643–1648, June 2015. https://doi.org/10.1016/B978-0-444-63577-8.50119-4.
Y. Y. Nazaruddin, Chapter 4 “Strategi Sistem Kontrol Lanjut” in Kontrol Proses, Institut Teknologi Bandung, 2019, pp. 26–36.
C. Sansaridis and P. Andersen, Modelling and Control for Industrial Neutralization Water Unit, Autumn Ed. Aalborg: Institute of Automation and Control Control Engineering, Aalborg University, 2016. [Online]. Available: http://es.aau.dk
C. Lazar, R. Pintea, and R. De Keyser, “Nonlinear predictive control of a pH process,” Computer Aided Chemical Engineering, vol. 24, pp. 829–834, 2007. https://doi.org/10.1016/S1570-7946(07)80161-1.
Peraturan Menteri Lingkungan Hidup Republik Indonesia Nomor 5 tahun 2014, Kementerian Lingkungan Hidup Republik Indonesia, 2014.
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