Remediation of water tainted with noxious hexavalent chromium using cetylpyridinium-modified bagasse biomass: adsorption and regeneration studies

Abstract

Herein, cetylpyridinium-modified bagasse (SB-CPC) biomass was synthesized and applied for removal of noxious Cr(VI) ions from aqueous matrix. Batch mode analyses were conducted, and the results showed that SB-CPC adsorbent has a maximum uptake capacity (q_m) of 70.5 ± 3.2 mg g^-1 at 303 K. The adsorption isotherms and kinetics for elimination of Cr(VI) by SB-CPC were better fitted by Langmuir model and pseudo-second-order model, respectively. The occurrence of pseudo-second-order kinetic could be mainly influenced by the intra-particle diffusion mass transfer. Electrostatic attraction was the dominant underlying reaction mechanism followed by pore filing effect (minor). Thermodynamic study affirms the endothermic behavior and occurrence of physical adsorption process. SB-CPC adsorbent had exhibited an outstanding desorption-regeneration performance using NaOH solution; accordingly, it can practically be applied for remediation of wastewater tainted with Cr(VI) ions.

Keywords: Adsorption; Agricultural biomass wastes; Cetylpyridinium-modified bagasse (SB-CPC); Hexavalent chromium ions; Regeneration.