磁性壳聚糖重金属吸附剂的制备及其吸附性能的研究

Low cost,biocompatible heavy metal removal with magnetic Fe_3O_4 loaded chitosan microparticles

为了有效吸附水体中重金属,使用离子交联法合成制备了一种低成本、低毒性的磁性壳聚糖纳米重金属吸附材料。调节多聚磷酸钠与壳聚糖溶液的比例,制备得到一系列不同粒径大小的重金属吸附材料并比较其吸附性能的差异。通过电子透射显微镜、傅里叶红外光谱仪、粉末X射线衍射仪等一系列表征,确定壳聚糖纳米微粒成功包裹磁性Fe_3O_4纳米粒子,并得到粒径范围介于164.05~768.69 nm尺寸颗粒。重金属吸附铜、镉、锌实验结果表明,小粒径重金属材料的吸附效果优于大粒径吸附材料,其最大吸附效率分别为51.66%,97.86%及82.24%。此外,该材料吸附原理符合准二级动力学模型(R^2=0.998-0.999),属化学吸附类型。通过与人乳腺癌细胞MCF-7细胞共培养验证其生物相容性及毒性,细胞活性达到100%。该研究阐明小尺寸壳聚糖磁性纳米颗粒可作为一种低成本、低毒性且吸附率高的重金属吸附材料,基于该优势其在污水处理及农业环境治理具有潜在价值。

Here we report the synthesis and characterization of magnetic Fe_3O_4loaded chitosan microparticles for low cost,biocompatible heavy metal removal.Magnetic Fe_3O_4loaded chitosan microparticles are prepared based on ionic gelation and characterized by Transmission electron microscope（TEM）,Fourier transform infrared spectroscopy（FT-IR）and X-ray diffraction（XRD）respectively,which confirm that magnetic Fe_3O_4nanoparticles have been incorporated into chitosan microparticles successfully and the particle size falls into the range of 164.05-768.69 nm.Their adsorption efficiencies for Cu（Ⅱ）,Cd（Ⅱ）and Zn（Ⅱ）have been investigated,in which small size magnetic Fe_3O_4loaded chitosan microparticles present higher adsorption efficiency than that of other ones.And their maximum adsorption capacity for Cu（Ⅱ）,Cd（Ⅱ）and Zn（Ⅱ）could reach 51.66,97.86 and 82.24%respectively.Moreover,the adsorbing mechanism can be well explained by pseudo-second-order model（R^2=0.998-0.999）.Notably,magnetic Fe_3O_4loaded chitosan microparticles also exhibited excellent biocompatibility when co-cultured with MCF-7 cells with nearly 100%viability.This study demonstrates that small size magnetic Fe_3O_4loaded chitosan microparticles is an effective,low cost and bio-compatible heavy metal adsorbent and could potentially be widely used in many different fields,for example,wastewater treatment in food and agriculture.