Development of sustainable magnetic chitosan biosorbent beads for kinetic remediation of arsenic contaminated water.

We report the preparation of both control chitosan and magnetic chitosan beads as biosorbents using chitosan as matrix and magnetite (Fe3O4) nanoparticles as reinforcement followed by detailed advanced characterization. The batch trials were performed to study the adsorption kinetics of biosorbents by removing As(III) and As(V) species from water systems. The experimental data was inserted into Langmuir and Freundlich's isotherms to undertake the mechanism and adsorption capacity of the test biosorbents. Under Langmuir's isotherm, maximum monolayer adsorption capacity (qmax) of the biosorbent was observed to be 73.69 and 79.49 mg/g for As(III) and As(V) species, respectively, under specified conditions. The optimum doses of 1.5 and 2 g/L of MCBB at pH 6.7 showed 99.5 and 99% removal of As(V) and As(III), respectively. The analysis demonstrated that the biosorption process obeyed pseudo 2nd order kinetics with linear regression coefficient (R2) of >0.999. The regeneration and reusability of biosorbents were also assessed.