Fe-MCM-41/CA共混膜的制备及其吸附NOR性能研究

Preparation of Fe-MCM-41/CA membrane material and its application in adsorption of NOR

采用水热合成法制备Fe-MCM-41介孔分子筛。以Fe-MCM-41和醋酸纤维素(CA)为原料,采用浸没相转化法制备Fe-MCM-41/CA共混膜,用以吸附去除溶液中的诺氟沙星(NOR)。SEM、FTIR和机械性能表征证实了Fe-MCM-41成功共混入膜中,且膜的综合性能得到改善.考察pH、离子强度和温度对共混膜吸附NOR的影响,并探讨了吸附动力学和热力学.结果表明:中性条件有利于Fe-MCM-41/CA膜对NOR的吸附;Na^+和Ca^(2+)均能抑制吸附过程的进行,且Ca^(2+)抑制作用更为明显;NOR吸附过程符合准二级吸附动力学模型和Freundlich吸附等温方程;升高温度有利于Fe-MCM-41/CA膜对NOR的吸附.吸附过程存在静电,氢键,表面络合等作用力.吸附/脱附实验表明共混膜具有良好的再生性能.

Fe- MCM- 41 was prepared by a hydrothermal synthesis method and then immersed with cellulose acetate （CA） to form Fe- MCM- 41/CA membrane by an immersion-precipitation phase transformation method. The prepared material was used as adsorbent to remove Norfloxacin （NOR）. The prepared membranes were characterized by scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR） and their mechanical properties, which indicated that Fe-MCM-41 was successfully incorporated into pure membrane and inhanced its perfromance, influence of pH value, ion strength and temperature were conducted to evaluate its adsorption capacity of NOR. The adsorption isotherms and adsorption kinetics were also studied. Neutral condition favored for NOR adsorption. Both Na＋ and Ca2＋ could inhibit the adsorption of NOR by Fe-MCM-41/CA membrane, and Ca2＋ had a greater inhibition influence. NOR adsorption by Fe-MCM-41/CA membrane was better fitted with the Freundlich isotherm and the Lagergren second-order model. NOR adsorption by Fe- MCM- 41/CA was better at higher temperature. The adsorption of NOR was mainly controlled by hydrogen bonds effect, electrostatic interactions and surface complexation. Adsorption/desorption test proved that Fe- MCM- 41/CA membranepossessed excellent regeneration performance.