Mango Seed Kernel as an Eco‐Friendly Adsorbent for Congo Red Dye Removal: Process Parameters Optimization and Reusability Evaluation

ABSTRACT

This study explores the potential of untreated mango seed kernel (MSK) as an adsorbent for removing Congo red (CR) dye from aqueous solutions. The adsorption conditions were optimized using response surface methodology with a Box‐Behnken design (RSM‐BBD), with the percentage removal of CR dye as the response variable. The findings revealed that the adsorption process follows a quadratic model, with R ² and adjusted R ² values of 0.9979 and 0.9952, respectively. Optimal conditions were determined as 0.137 g of MSK, an initial CR dye concentration of 20 ppm, and a contact time of 106 min. The adsorption data aligned closely with the pseudo‐second‐order model, with an R ² value closed to unity, providing the best description of the kinetics equilibrium. Reusability studies showed that MSK maintained its adsorption capacity over four cycles, with ethanol used as a desorbent at 60°C for 120 min. Characterization of MSK before and after adsorption and desorption was conducted using field emission scanning electron microscope (FESEM) and Fourier transform‐infrared (FT‐IR).