Mussel-inspired synthesis of magnetic polydopamine-chitosan nanoparticles as biosorbent for dyes and metals removal

A novel magnetic polydopamine (PDA) and chitosan (CS) hybrid nano-biosorbent was fabricated by assembling biomimetic polymer (PDA) and CS onto magnetic nanoparticles (NPs). The resulting PDA/CS/Fe3O4 nano-absorbent was characterized by means of the Fourier transform infrared spectra (FTIR), transmission electron microscope (TEM), elemental analysis, vibrating sample magnetometer (VSM), and X-ray photoelectron (XPS). Based on the high surface area of nanoparticles and high-level active sites from polydopamine and chitosan, a multiple interactions to absorb pollutants with of resulted biosorbent can be anticipated. Demonstrated by batch tests, the nano-absorbent showed highly effective adsorption ability for target heavy metals and dyes, the maximum adsorption capacity was up to 245.6 mg g(-1), 47 mg g(-1), 151.6 mg g(-1), 204 mg g(-1) and 61 mg g(-1) and the removal percentage reached 98.4%, 92%, 95.8%, 96.9% and 92.5% for Hg(II), Pb(II), Cr(VI), Methylene blue and malachite green, respectively. Consequently, PDA/CS/Fe3O4 with excellent absorbability, stability and reusability could be used as a promising adsorbent for removal multiple pollutants in wastewaters. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.