椰壳活性炭对加替沙星的吸附及缓释性能研究

研究了水溶液中椰壳活性炭对喹诺酮药物加替沙星（GTFX）的吸附性能，测定了不同温度下的吸附等温线并分析了其吸附热力学参数。结果表明：活性炭对加替沙星的吸附符合Freundlich方程，ΔH=-1.7374kJ/mol，说明活性炭对GTFX的吸附过程为放热过程，且ΔH<20kJ/mol，表明吸附过程主要为物理吸附。同时，测得吉布斯自由能ΔG<0，表明吸附质从溶液到吸附剂表面的吸附过程是自发过程，其吸附主要是熵驱动。对椰壳活性炭进行了硝酸及氨水改性，研究了3种不同活性炭对GTFX的缓释性能，结果显示，与椰壳活性炭相比，经硝酸氧化改性后的活性炭缓释性能有较大的提升，而经氨水改性的活性炭缓释性能有所下降，3种不同活性炭对GTFX的缓释均符合Higuchi方程释药模式。

Adsorption and Controlled Release of Gatifloxacin by Coconut Shell Activated Carbon

The adsorption and controlled release of gatifloxacin(GTFX) from aqueous solution by coconut shell activated carbon were studied. The adsorption isotherms were measured at different temperatures. The standard changes of free energy, enthalpy and entropy in adsorption processes were calculated from the Freundlich equation. And the adsorption of GTFX was in accord with Freundlich equation. The ΔH of absorption was -1.7374kJ/mol, which demonstrated that the absorption was an exothermic process, and ΔH with less than 20kJ/mol indicated that the adsorption process was mostly physical adsorption. Meanwhile, Gibbs free energy(ΔG) was determined to be less than zero. This indicated that the adsorption was a spontaneous process. The results indicated that the value of ΔS was the main driving force of adsorption. Compared with the original activated carbon, the controlled release capacity of nitrate modified sample increased and that of ammonia water modified sample decreased. The different activated carbon controlled release processes marched with Higuchi equation.