Biosorption of Basic Red 46 using raw cactus fruit peels: equilibrium, kinetic and thermodynamic studies

Because of their detrimental impacts on water quality and human health, dyes' ubiquitous presence in the aquatic environment has aroused concerns over the last few decades concerning the methods to be employed to eradicate these emerging pollutants. In the ongoing study, raw cactus fruit peel (RCFP) is used as a low-cost, environmentally friendly sorbent to remove the hazardous dye Basic Red 46 (BR46) from aqueous solutions in the current study. The raw biosorbent was firstly characterized using FTIR spectroscopy, SEM, BET, pH(pzc) and Boheme titration techniques. Respectively, the influencing operational parameters such as pH, biosorbent dosage, stirring speed, temperature, contact time and initial dye concentration were tweaked to obtain a maximum adsorption capacity of 82.58 mg g(-1). The Freundlich model was found to better represent the biosorption isotherm, whereas the pseudo-second-order model describes well the kinetic biosorption data obtained. The biosorption process of BR46 onto RCFP was spontaneous and exothermic, and the reuse study revealed the possibility of regeneration of RCFP after 3 successive cycles using HCl as a chemical reagent. Furthermore, the results revealed that raw cactus fruit peel is an untapped potential supply in Algeria, with the potential to provide low-cost environmental removal of additional toxins in the wastewater treatment domain.