Malachite green adsorption by Oued Sebou sediment: optimization and desirability analysis

Abstract

Dye pollution represents an important portion of the pollutants in industrial waste water. Sediment from the Sebou River (Morocco) was utilised in this investigation to adsorb malachite green (MG) in aqueous solution. The optimisation of parameters associated with adsorption was performed by conducting batch adsorption studies and utilising 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. 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 the sediment was unspontaneous and endothermic in nature. The regeneration of the sediment in three cycles following adsorption was confirmed. The adsorption process of MG dye onto the sediment was found to be driven by two types of interactions – electrostatic and hydrogen (H) bonding. These results indicate that the sediment has the potential to be an effective adsorbent for removing dyestuffs from contaminated industrial effluent. Moreover, the ready availability of the sediment in the area further enhances its suitability for this purpose.