Author: S. Susilowati, M. A. Nafii’u Hafid, H. Z. Syadana, K. Sumada, A.P.Bayuseno and W. W. Schmahl

DOI: http://doi.org/10.31788/RJC.2026.1939731

The batik industry generates highly polluted wastewater containing recalcitrant organic compounds and intensecolor, which are inadequately treated by conventional methods. This study addresses this limitation by developingahybrid ozonation–adsorption process using HCl-activated natural zeolite in a packed-bed systemto enhancepollutant removal efficiency. The integration of advanced oxidation and adsorption is designed to overcome masstransfer limitations and incomplete degradation commonly observed in single-treatment processes. Under optimal conditions (packing height of 25 cm and contact time of 40 min), the system achieved removal efficiencies of 93.27% for COD, 93.39% for TDS, 99.98% for TSS, and 98% for color. Acid activation increased the zeolitesurface area, improving adsorption capacity, while ozonation generated hydroxyl radicals that enhancedthebreakdown of complex organics. FTIR analysis confirmed structural and functional group changes, including shiftsin hydroxyl (–OH), carbonyl (C=O), and Si–O–Si/Si–O–Al bands, indicating interactions between the zeolitesurface and organic pollutants during the treatment process. The adsorption process followed the Langmuir isothermmodel (R² = 0.9998), indicating monolayer adsorption on a homogeneous surface. This study contributes towastewater treatment by demonstrating a synergistic mechanism between oxidation and adsorption that enhancestreatment performance compared to conventional approaches. The findings provide a scalable, efficient solutionfor dye-containing industrial wastewater and lay a foundation for future studies on process optimization and reactor scale-up.

Keywords: Adsorption, Batik Wastewater, COD, Color Removal, Hybrid Ozonation, Packed Bed Reactor.