Bifunctional Magnetic Nano-hybrid Materials Prepared With Reductive Polymers For The Removal Of Organic Pollutants

With the rapid development of economy and the advancement of urbanization,industrial,agricultural,domestic sewage was discharged,which accelerated the deterioration of water quality.Therefore,exploring how to scientifically and efficiently remove water pollutants has become one of the research hotspots at home and abroad.This academic dissertation reviewed the research progress of organic pollutants in the water environment and its removal methods at home and abroad.At the same time,based on the advantages of magnetic inorganic nanoparticles and polymers,we designed and synthesized a series of environmentally friendly,high-efficiency,bifunctional hybrid materials.These bifunctional materials were characterized by SEM,TEM,FTIR,XRD,BET.The obtained bifunctional magnetic nano-hybrid materials were used to adsorb or degrade pollutants in water.The influences of various factors on performance were researched and the removal mechanism was discussed.The main conclusions are as follows:1.Preparation of bifunctional magnetic hollow Fe⁰@C@MnFe₂O₄ by dopamine reduction as Fenton-like catalyst for degradation of Tetrabromobisphenol AFe²⁺was reduced by dopamine to prepare magnetic bimetallic Fe⁰@C@MnFe₂O₄microspheres.Fe⁰@C@MnFe₂O₄ was used as a heterogeneous Fenton-like catalyst to degrade TBBPA with the help of hydrogen peroxide and hydroxylamine hydrochloride.The experimental results showed that the prepared material could remove TBBPA by adsorption and catalytic synergism.The best degradation condition was pH=7,catalyst dose 0.3 g L^-1,H₂O₂ 0.17 g L^-1,NH₂OH 0.035 g L^-1.After 120 min,90%of TBBPA(10 mg L^-1)could be removed.At the same time,it was found that the pseudo-first-order kinetic model can best fit the experimental data,reaction rate constant k is 0.0089 min^-1.Fe⁰@C@MnFe₂O₄ can be effectively separated from the reaction medium by an external magnetic field.After ten cycles,the catalyst still has a good catalytic effect.The ESI-MS results showed that the reductive debromination of nZVI and?-cleavage are the main processes for degradation of TBBPA.2.Preparation of newly bifunctional magnetic hybrid CoFe₂O₄@ZIF-8/PEI microspheres for removal of organic pollutants from aqueous mediaZn²⁺and polyethylenimine?PEI?were loaded on the surface of CoFe₂O₄-COO^-particles by electrostatic interaction,then ZIF-8 was decorated on the surface of CoFe₂O₄ by self-assembly to obtained large specific surface area magnetic hybrid nanoparticles,CoFe₂O₄@ZIF-8/PEI.When the material was used as an adsorbent and methyl blue was used as the target pollutant,the maximum adsorption capacity could reach to 58.38 mg g^-1 after 180 min.The pseudo-second-order kinetics model and the Langmuir isotherm model can well fit the experimental data,it illustrated that the mainly adsorption process is chemical adsorption and single-layer adsorption.The electrostatic effect is the main process to remove methyl blue.The material could be used as a catalyst to activate permonosulfuric acid?PMS?to produce sulfate radicals(SO₄^-·)and hydroxyl radicals?·OH?,then oxidative degradation pollutants.Batch degradation experiments showed that the hybrid material has a wide applied range of pH?2-10?and can remove 200 mg L^-1 of methyl blue within 20 min.At the same time,this hybrid material could effectively remove five organic pollutants,including Methyl blue,Methylene blue,Malachite green,Rhodamine B,and Tetrabromobisphenol A,with good stability and reusability.