부산대학교 도서관

In this work, hydroxyapatite (HAP) was in situ synthesized on coal fly ash (CFA) to prepare hydroxyapatitemodified coal fly ash composite aerogel (HCFAA). The maximum removal efficiency and capabilityof uranium(VI) on HCFAA were 97.6 % and 205.7 mg g1, respectively, which was much higher than thoseof CFA (83.6 % and 59.1 mg g1) (pH = 3.0, m/V = 1.0 g/L and T = 298 K). The desorption efficiency of uranium(VI) by HCFAA was even more than 80 % after five cycles, demonstrating that the introduction ofHAP had improved uranium(VI) removal performances. Pseudo-second-order and Langmuir models werefitted better with the experimental data, indicating the uranium(VI) removal process was a homogeneousmonolayer chemisorption. Meanwhile, the uranium(VI) removal efficiency for HCFAA in actual wastewaterwas higher to 80.6 % and uranium(VI) could even be completely separated from actual wastewaterby HCFAA during dynamic adsorption (m = 50 mg, V = 400 mL, C0 = 10 mg/L), further illustrating that theintroduction of HAP was an available method to modify CFA. Characterizations results demonstrated thaturanium(VI) was successfully immobilized on HCFAA through ion exchange, dissolution-precipitationand surface complexation. In conclusion, HCFAA was a prospective adsorbent for uranium(VI) separationin practical application.