Optimization of reactive black 5 dye removal onto kaolin filter cake activated carbon using response surface methodology

Abstract This work investigates the removal of reactive black 5 (RB5) dye from textile wastewater, which poses significant environmental hazards, using kaolin filter cake (KFC), a new, affordable, and environmentally friendly adsorbent. The effectiveness of KFC's decolorization was assessed by adsorption tests that looked at batch process variables, such as pH, adsorbent dosage, contact time, and beginning dye concentration. FTIR, SEM, XRD, and BET techniques described the adsorbent's morphological and physicochemical characteristics. The adsorption data closely fit the Langmuir isotherm model, indicating a maximum adsorption capacity of 60.24 mg g-1. Kinetic studies revealed that the adsorption process followed a pseudo-second-order model. Response surface methodology (RSM) was employed to optimize the removal of RB5. Remarkably, KFC demonstrated excellent regeneration potential, retaining 60.52% of its adsorption capacity after five cycles. These findings suggest that KFC is a highly promising adsorbent with significant potential for sustainable, cost-effective, environmentally friendly, and efficient applications in textile wastewater treatment.