The application of chitosan-based materials for the separation
of uranium from wastewater was limited due to the lack of active sites.
In this work, a chitosan-based composite (CaCO3@aCS/PA)
was effectively created by modifying chitosan with CaCO3 and phytic acid to enhance the adsorption performance of chitosan
materials. CaCO3@aCS/PA showed no significant changes and
no Ca2+ was detected in the solution after stirring for
10 h in a solution with pH > 3, indicating good stability of CaCO3@aCS/PA, which was beneficial for use in adsorption. Moreover,
the adsorption capacity and adsorption percentage of CaCO3@aCS/PA for uranium reached 842.0 mg/g (298 K, pH = 4) and 95.4%
(C
0 = 10 mg/L, pH = 4) and the adsorption
equilibrium time was significantly shortened, indicating that the
modification with CaCO3 and phytic acid enhanced the adsorption
ability of chitosan for uranium, which was related to the synergistic
effect of various active sites (CO3
2–, PO4
3–, −OH, and –NH2) on CaCO3@aCS/PA for uranium adsorption.