The Preparation Of Modified Chitosan Biomimetic Bone Composites And Its Application In Tetracycline And Lead Removal

Water pollution has always been a problem to be solved urgently,which has caused serious harm to the ecological environment and human health.Among them,pharmaceuticals pollutants and heavy metals pollutants are two important pollutants in water pollution,which can destroy microbial communities,reduce soil enzyme activity,increase bacterial drug resistance,and induce a variety of human diseases.Chitosan is a class of natural multifunctional material with excellent properties of biocompatibility,environmental-friendly and degradability,which can be used in the preparation of adsorbents.In this paper,modified chitosan was used as adsorbent material to investigate its effect on the removal of antibiotics and heavy metals from aqueous solution.The main contents were summarized as follows:（1）Based on the bionic concept,Polypropylene Glycol-Maleic Anhydride-Chitosan-Hydroxyapatite（PMCH）,a biomimetic bone composites,was designed and synthesized,and its physicochemical properties were investigated by various characterization techniques showed that PMCH was a composite material with homogeneous structure,large specific surface area and high stability.The effects of different environmental factors on the adsorption of Tetracycline（TC）and Lead（Pb）ions by PMCH were investigated by batch adsorption experiments.The test results showed that PMCH had good affinity for TC and Pb（Ⅱ）,and the pseudo-second-order kinetic model was well adapted to the adsorption process of both pollutants.（2）To enhance the fast separation of adsorbent in aqueous solution,magnetic Fe₃O₄ composite nanoparticles were introduced to successfully prepare magnetic biomimetic bone composites Ferric Tetroxide-Silica@Polypropylene Glycol-Maleic Anhydride-Chitosan-Hydroxyapatite（FS@PMCH）.The hysteresis curve reflected the fact that FS@PMCH was a superparamagnetic material capable of rapid separation by external magnetic fields.The test results of TC and Pb（Ⅱ）also indicated that FS@PMCH was an excellent adsorbent,capable of rapid adsorption of TC and Pb（Ⅱ）in aqueous solution with maximum adsorption capacities of 73.09 mg/g and 300.83mg/g,respectively.The possible adsorption mechanisms of the adsorption process were analyzed by XPS characterization,which mainly involved H-bonds andπ-πinteractions in the adsorption of TC,and electrostatic interactions,complexation,and ion exchange in the adsorption of Pb（Ⅱ）.This study provided a new method for the removal of pharmaceuticals and heavy metals from aqueous solutions,which has some prospects for industrial application.