Modeling and Regeneration Studies for the Removal of Crystal Violet Using Balanites aegyptiaca Seed Shell Activated Carbon

Abstract

Activated carbon derived from Balanites aegyptiaca seed shell (ACBS) was employed to removecrystal violet (CV) from aqueous medium. The characterization of this ACBS has been conducted using analyticaltechniques such as SEM, EDS, and Brunauer-Emmett-Teller (BET) surface area analysis. The adsorptionparameters investigated were as follows: contact time (5-120 min), temperature (303-333 K) and initialconcentration (100-500 mg/L). The adsorption data were interpreted by using kinetic, isotherms andthermodynamic equations. The kinetic data matched the pseudo-second-order model well, and both externaldiffusion and internal diffusion influenced the adsorption of the dye onto the adsorbent. The isotherm data wasin concurrence with the Freundlich model intimating the multilayer coverage of CV on the heterogeneoussurface of the ACBS. The thermodynamic quantities like ∆S°, ∆H° and ∆G° were computed using Gibbs plot. Theresults implicated the practicability and endothermicity of the dye adsorption process. Regeneration studiesshow the effectiveness of CH3COOH solution in CV recovery from ACBS than distilled water, H2SO4, HCl, HNO3,and NaOH solutions. The regenerated ACBS was recycled five times and sustained an adsorption efficiency of92.08%.