Preparation of a biomass adsorbent for gallium(III) based on corn stalk modified by iminodiacetic acid

In order to replace extractant or resin prepared from petrochemical products, a series of carboxyl-functionalized materials based on natural corn stalk (x-IDA-EPI-OCS) were prepared. When the mass ratio of the EPI-OCS and iminodiacetic acid (IDA) was 1:3, the uptake capacity of Ga(111) on the modified corn stalk (3-IDA-EPI-OCS) from acidity solution could react 139.56 mg g(-1). More importantly, the 3-IDA-EPI-OCS could completely separate Ga(111) from Ga(111)-As(III) or/and Ga(111)-Ge(IV) binary mixtures at pH 2. By analyzing the results of acidity test as well as that of FT1R and XPS, the adsorption mechanism was deduced as cation exchange between Ga3+, Ga(OH)(2) or Ga(OH)(2)(+) and the hydrogen ions of carboxyl groups and/or hydroxyl groups. This study provided an effective and economical method for recovery of gallium ions from aqueous solution. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.