Utilization of argan nut shells as a bioresource for efficient malachite green oxalate adsorption

Recent concerns about environmental pollution have highlighted the need for effective treatment of tannery effluents, which often carry high loads of malachite green oxalate (MGO), a harmful micro-pollutant in aquatic ecosystems. This study explores the use of argan nut shells (ANSs) as an adsorbent for MGO, aiming to develop an efficient method for mitigate its spread in water bodies. The adsorption process parameters were thoroughly examined to optimize ANS usage for maximum efficiency. Results showed that 0.08 g of ANS could effectively adsorb MGO and demonstrate that a small quantity of ANS, just 0.08 g, is capable of effectively adsorbing MGO, achieving a maximum adsorption capacity of 7.22 mg/g and the equilibrium time for the adsorption of MGO onto ANS was 40 min at both 35 °C and 45 °C and 50 min at 25 °C, indicating slight temperature dependence. The increase in temperature positively affected adsorption, confirming the endothermic nature of the process. Kinetic analysis revealed that the adsorption follows pseudo-second-order kinetics, with intraparticle diffusion not being the sole rate-controlling step. The adsorption behavior aligned with the Freundlich isotherm model, with significant adsorption occurring at pH 4–8. Thermodynamic parameters indicated a spontaneous (Δ G ° 0) process, with a pH pzc value of 3.6. surface characterization using FTIR, XRD, SEM, and EDS confirmed the interactions between MGO and ANS, establishing confirming the efficacy of argan nut shells as a promising material for removing malachite green oxalate from aqueous solutions.