Removal of boron from aqueous solution by composite chitosan beads.

Various metal-oxide nanoparticles and chitosan were blended to form new adsorbents (M-Oxide-CTS) for removing boron from aqueous solutions in a batch system. The maximum boron adsorption capacity (q= 7.8 mg/g) was reached at pH = 4 within 5 min. Calculations based on Langmuir, Freundlich, and Dubinin–Radushkevich models showed the heterogeneous and physical nature of boron adsorption on M-Oxide-CTS. Modeling of the thermodynamic date indicated the nonspontaneous and exothermic process. The pseudo-second-order model adequately described the boron adsorption on M-Oxide-CTS. Desorption by means of alkaline solution at pH = 12 was carried out successfully. [ABSTRACT FROM AUTHOR]