Bentonite blended with bagasse ash as an adsorbent for reactive red 198 dyes

Abstract

Adsorption offers efficient, cost-effective, and eco-friendly method for the treatment of dye-laden wastewater. This work presents, reactive red 198 (RR198) removal by adsorption using bentonite clay (BC) blended with sugar cane bagasse ash (SCBA). The adsorbent's surface morphologies, crystalline phase structures, functional groups, and specific surface before and after adsorption were examined using SEM, XRD, FTIR, and BET respectively. Central composite design (CCD) under response surface methodology (RSM) was applied to optimize independent and dependent variable values. The optimal parameters for RR198 removal using the blended adsorbent were 107 minutes contact time, 0.934 g/L adsorbent dose, and 15 mg/L initial dye concentration, and 85.2% RR198 removal efficiency was achieved. The sorption isotherms and kinetics were evaluated using various existing models. The Freundlich isotherm model (R2 = 0.95) and the pseudo-second-order equation best described the adsorption parameters and the RR198 adsorption kinetic mechanism, respectively. Desorption and reusability experiments in batch study confirmed that BC blended with SCBA can be used multiple times for dye removal from wastewater.

Waste to resource: Utilization of waste bagasse as an alternative adsorbent to remove heavy metals from wastewaters in sub-Saharan Africa: A review

“…Bagasse is one of the largest agricultural residues and 1,869.7 million tonnes of bagasse was harvested worldwide in 2020 (Faostat 2022). In Ethiopia, annually about 4.6% of total bagasse produced from sugar industries is dumped in the compounds around the factory, posing serious environmental problems, including fire hazards (Getu et al 2021;Adane et al 2022). Despite the Ethiopian government's waste product reduction/reuse polices for sugar processing industries, there are still many unresolved environmental issues that are to be addressed through valorization of waste bagasse in the circular economy.…”