Green approach based on Micellar -Modified Kalonji seeds waste for removal of hexavalent chromium ions and methyl orange dye from aqua

Abstract

This study focuses on utilizing de-oiled Kalonji seed waste (KS) as a green approach, transforming it into sustainability adsorbent for removal methyl orange dye (MO) and Cr (VI)ions from aqua The adsorbent performance was enhanced by modification of surface using Cetyltrimethylammonium bromide (CTAB) micelles were used to produce M-MKS adsorbent, the adsorbent was characterized by (FT-IR, SEM-EDX, XRD, Zeta potential, and BET analysis). Additionally, the ideal parameters pH solution, initial concentration, adsorbent dosage, contact time, and temperature were examined. BET analysis found that M-MKS has an appropriate surface area of around (27m²/g), with an average pore diameter of (11.17) nm. The removal efficiencies for MO dye and Cr (VI) ions were determined to be (95.90 and 99.04%), respectively, at starting concentrations of (200 and 70 mg/L). The Temkin model was shown to be more appropriate for the experimental adsorption data than the other isotherm models. while, the P–SO model was better matched than the other kinetic models. Thermodynamic analysis demonstrated spontaneous and exothermic adsorption events. According to regeneration demonstrated that M-MKS adsorbent could sustain around (73.70 and 84.93%) for dye and Cr (VI) at the fifth consecutive cycle of regeneration. The proposed mechanism for dye and Cr (VI) removal involves electrostatic reactions, hydrogen bonding, ion exchange, and π-π reactions between the cationic surface of the adsorbent and anionic molecules of the pollutants. Furthermore, M-MKS was applied to actual water samples, where the adsorbent its efficiency in water samples, confirming its applicability on an industrial scale. Finally, M-MKS adsorbent represents a sustainable, low-cost, highly efficient green solution for treating polluted water, and is a promising option for large-scale environmental applications.