纤维素基磁性水凝胶对左氧氟沙星的吸附

Adsorption of Levofloxacin by Cellulose-Based Magnetic Hydrogels

针对传统吸附材料吸附容量低、难以固液分离且易导致二次污染等缺点,以羧甲基纤维素(CMC)、聚乙烯醇(PVA)、丙烯酸(AA)和铁酸锌(ZnFe_(2)O_(4))为单体,通过水溶液聚合法,制备易成型、毒性低、吸附容量大且可磁性遥控分离的CMC/PVA/PAA/ZnFe_(2)O_(4)纤维素基磁性水凝胶.采用扫描电子显微镜(SEM)、Fourier变换红外光谱(FT-IR)、X射线衍射(XRD)和振动样品磁强计(VSM)等表征其形态结构并测试其结构性能,通过吸附动力学和吸附热力学考察其对水中左氧氟沙星(LEV)的吸附性能和吸附机制.结果表明:负载ZnFe_(2)O_(4)磁性纳米粒子可增加水凝胶磁性遥控分离能力和吸附能力;在25℃、pH=5、吸附4 h时,水凝胶对LEV的最大吸附量可达405 mg/g,5次吸附解吸实验后其吸附能力仍可达原吸附能力的84%;水凝胶对LEV的吸附过程更符合准二级反应动力学和颗粒内扩散模型,遵循Freundlich等温线模型.

Aiming at the shortcomings of traditional adsorption materials,such as low adsorption capacity,difficulty in solid-liquid separation,and easy to lead to secondary pollution,carboxymethyl cellulose(CMC),polyvinyl alcohol(PVA),acrylic acid(AA),and zinc ferrite(ZnFe_(2)O_(4))were used as monomers to prepare CMC/PVA/PAA/ZnFe_(2)O_(4) cellulose based magnetic hydrogels that was easy to form,low toxicity,large adsorption capacity,and could be separated by magnetic remote control through aqueous solution polymerization.Their morphological structure and structural performance were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),and vibrating sample magnetometer(VSM).The adsorption kinetics and thermodynamics were used to investigate their adsorption performance on levofloxacin(LEV)in water and adsorption mechanism.The results show that loaded ZnFe_(2)O_(4) magnetic nanoparticles can increase the magnetic remote separation ability and adsorption ability of hydrogels.The maximum adsorption capacity of the hydrogel for LEV can reach 405 mg/g at 25℃,pH=5 and 4 h of adsorption,and its adsorption capacity can still reach 84%of the original adsorption capacity after five adsorption and desorption experiments.The adsorption process of hydrogel for LEV is more in line with the quasi second order reaction kinetics and intraparticle diffusion model,and follows the Freundlich isotherm model.