An efficient and reversible sorptive removal of arsenic (III) from aqueous solution by the biosorbent <i>Cupressus Female Cone</i>

Abstract

Biosorbent <i>Cupressus Female Cone </i>(CFC)<i> </i>has been investigated for the sorptive removal of As(III) from aqueous solution both by batch and column mode techniques. Sorption process was found to be influenced appreciably by pH, temperature, initial concentration of As(III) and sorbent particle size and dosage. Also the sorption process was endothermic with a maximum sorption of 260.4 mg/g of As(III) at 30^oC for an initial concentration of 800 mg/L at pH10.0. It followed first order kinetics and the equilibrium sorption capacity data conformed to Langmuir isotherm. The pore diffusion and mass transfer coefficients of As(III) species were significant and contributive to the sorption rate. All these studies and characterisation of free and As(III)–loaded CFC materials by SEM, FTIR and XRD methods led to the suggestion of a plausible mechanism involving complex formation between the two components. The As(III)-CFC sorption system was further investigated by dynamic column study invoking Thomas model. Finally, the desorption studies revealed that the adsorbent CFC could be effectively regenerated by 0.1 M hydrochloric acid, making it a viable and reusable system for As(III) removal.