环丙沙星调控制备γ-Al_(2)O_(3)/SiO_(2)及吸附机制研究

Preparation ofγ-Al_(2)O_(3)/SiO_(2)controlled by ciprofloxacin and study on its adsorption mechanism

采用环丙沙星(CIP)生物矿化调控制备γ-Al_(2)O_(3)/SiO_(2)吸附剂,研究所制备吸附剂的形貌与微结构变化及对CIP的吸附作用机制。在浸渍法制备γ-Al_(2)O_(3)/SiO_(2)的过程中,采用不同浓度的CIP调控γ-Al_(2)O_(3)/SiO_(2)的形貌与微结构。结果表明,采用0.1 mg/L CIP调控制备的吸附剂表面活性位密度(N_t)由6.68×10^(-4)mol/g增加到7.48×10^(-4)mol/g,平衡吸附量由8.60 mg/g增加到9.30 mg/g。pH=7.0时平衡吸附量最大,此时CIP 98%以分子形态存在、吸附剂表面形态98%为≡AlOH。从两者之间的分子形态作用结合傅氏转换红外线光谱(FTIR)分析,推测吸附作用机制是γ-Al_(2)O_(3)/SiO_(2)表面的≡AlOH与CIP中性分子之间以表面络合和金属离子配位作用为主。

Theγ-Al_(2)O_(3)/SiO_(2)adsorbent was prepared by biomineralization regulating ciprofloxacin,whose morphology and microstructure were characterized and its absorption mechanism to CIP was investigated.During the preparation ofγ-Al_(2)O_(3)/SiO_(2)by impregnation method,different concentrations of CIP were used to control the morphology and microstructure ofγ-Al_(2)O_(3)/SiO_(2).The results showed that with 0.1 mg/L of ciprofloxacin,the surface active site density Nt of the adsorbent increased from 6.68×10-4 mol/g to 7.48×10-4 mol/g,while the equilibrium adsorption amount increased from 8.60 mg/g to 9.30 mg/g.The adsorption reached the maximum value at pH=7.0,98%of ciprofloxacin exists in molecular form and 98%of the adsorbent surface is in≡AlOH form.From the molecular morphology interaction and the FTIR analysis,it was speculated that the main adsorption mechanism was the surface complexation and metal ion coordination between≡AlOH on the surface ofγ-Al_(2)O_(3)/SiO_(2)and CIP neutral molecules.