Effective adsorption/desorption of perchlorate from water using corn stalk based modified magnetic biopolymer ion exchange resin

In this work, a novel corn stalk based modified magnetic biopolymer ion exchange resin (CS-MAB) was prepared and used to remove perchlorate from aqueous solution. The physicochemical characteristics of CS-MAB were observed by SEM/EDS, BET, TEM, VSM, and XPS. The saturated magnetization and average pore diameter of CS-MAB were 3.82 emu/g and 4.83 nm. In adsorption batch experiments, the optimal adsorbent dosage and pH value for perchlorate removal are 1.0-1.5 g/L and 3.0-10.0. The adsorption kinetics fitted well with intraparticle-diffusion model in the first 90 min, and pseudo-second-order model in 90-360 min, which suggested that the potential mechanisms of perchlorate removal are physical adsorption and ion exchange reaction between CIO4- and Cl-containing groups of CS-MAB. Based on the analysis of Langmuir model, the maximum adsorption capacities of CS-MAB are 119.05 mg/g, 126.58 mg/g and 178.57 mg/g at 20 degrees C, 30 degrees C and 40 degrees C, respectively. The column adsorption of perchlorate could be described well by Thomas model, and the co-existing ions would restrain the perchlorate adsorption by the order of SO42- > Cl- > NO3-. Chemical and biological technologies both can be used to effectively regenerate CS-MAB with the efficiency of 70%-90%. (C) 2017 Elsevier Inc. All rights reserved.