Insight into adsorption mechanism, modeling, and desirability function of malachite green by sediment of Oued Sebou (Morocco): Box-Behnken design application

Abstract

Dye pollution represents an important portion of the pollutants in industrial wastewater. Sediment from the Sebou River was utilized in this investigation to adsorb malachite green in aqueous solution. The optimization of parameters associated with adsorption was achieved by conducting batch adsorption studies and utilizing the response surface approach. The adsorption process was accurately described by both the Langmuir isotherm model and the pseudo-second-order kinetic model, and the maximum capacity for adsorption was determined to be 5.98 mg g−1. In addition, the adsorption rate was effectively determined by intraparticle diffusion. The thermodynamic parameters determined in the study revealed that the adsorption of MG dye by sediment was unspontaneous and endothermic in nature. In three cycles, the regeneration of sediment following adsorption was confirmed. The adsorption process of MG dye onto sediment was found to be driven by two types of interactions - electrostatic and H-bonding. These results indicate that sediment has the potential to be an effective adsorbent for removing dyestuffs from contaminated industrial effluent. Moreover, the ready availability of sediment in the area further enhances its suitability for this purpose.