Аннотация:
In this study amphoteric cryogels were synthesized by the use of free-radical co-polymerization
of acrylate-based precursors (methacrylic acid and 2-acrylamido-2-methyl-1-propansulfonic acid) with
allylamine at different ratios. The physico-chemical characteristics of the cryogels were examined
using SEM/EDX, FT-IR, XPS and zeta potential measurements. The cryogels were tested toward Cd2+
removal from aqueous solutions at various pH and initial concentrations. Equilibrium studies revealed a
maximum sorption capacity in the range of 132–249 mg/g. Leaching experiments indicated the stability
of Cd2+ in the cryogel structure. Based on kinetics, equilibrium and characterization results, possible
removal mechanisms are proposed, indicating a combination of ion exchange and complexation of Cd2+
with the cryogels’ surface functional groups. The cryogels were compared to commercially available
adsorbents (zeolite Y and cation exchange resin) for the removal of Cd2+ from various water matrices
(ultrapure water, tap water and river water) and the results showed that, under the experimental
conditions used, the cryogels can be more effective adsorbents.