Discharge of synthetic dyes from industrial effluents represents a significant environmental concern due to their persistence, toxicity, and potential bioaccumulation in food chain. In present study, a sustainable bio catalytic system was developed using peroxidase extracted from discarded cabbage stems as an inexpensive and renewable enzyme source. Crude enzyme was covalently immobilized onto quartz particles to enhance operational stability and enable continuous application. Surface characterization of immobilized biocatalyst was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR), confirming successful enzyme attachment. Immobilization yield reached 82%, and immobilized peroxidase exhibited optimal catalytic activity at pH 6.0 and 40 °C. Biocatalyst retained more than 37% of its initial activity after four consecutive degradation cycles. Influence of selected metal ions on enzymatic activity was also evaluated. Continuous degradation of Reactive Red dye was investigated in a packed-bed reactor operated for 38 h. Lower flow rates and higher catalyst loading significantly improved dye removal efficiency. Breakthrough behavior was successfully described using Bohart–Adams and Clark models (R² > 0.99), indicating good agreement between experimental and predicted data. These findings demonstrate that quartz-immobilized peroxidase derived from agricultural waste provides a viable and sustainable approach for continuous enzymatic treatment of dye-contaminated wastewater.