Preparation, characterization of corn stalk xanthates and its feasibility for Cd (II) removal from aqueous solution

A novel corn stalk xanthates (XMCS) was produced successfully after alkali treatment, crosslinking reaction, CS2 and Mg2+ substitution reactions, and then XMCS was characterized by elemental analysis, FT-IR, XRD, C-13 NMR, and SEM-EDS, which confirmed that substitution and crosslinking reactions occurred at C-6, or C-2, or C-3 of cellulose, to form the (Cell-OCS2)(2)Mg and cross linked structure. Therefore, XMCS exhibited the higher removal efficiency than unmodified forms, due to ion exchange and coordination. Adsorption capacity was dependent on pH values, adsorbent dosage and temperatures. The results showed that more than 90% removal of cadmium ions was achieved at pH 2.0-7.0, while the adsorption increased from 73.2% to 98.0% with increase of adsorbent dosages, and higher temperature was favored for the adsorption. In addition, compared with other seven isotherm models, Langmuir was analyzed to determine the best fit equation, and found that adsorption capacities of XMCS were 20.58 mg/g. Kinetic results were successfully modeled by means of the pseudo -second -order model. In desorption, 0.2 WI. EDTA had the best desorption capacity and least weight loss. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.