The Preparation And Application Research Of Functional Superparamagnetic Nanoparticles In The Field Of Wastewater Purification

Magnetic nanometer material because of its unique easy magnetic recovery has attracted extensive interest.Different molecular materials modified magnetic Fe3O4 have been widely used in the biomedical field,the field of environment,drug targeting and magnetic seals and other fields.In this thesis,we synthetic two kinds of functional molecular modification of coated Fe3O4 nanoparticles.According to different functional molecules were used to removal different heavy metals in wastewater.The main research contents are as follows:Amino-functionalized Fe3O4/SiO2 magnetic nano-adsorbent was used as a novel sorbent to highly selective removal of Zn(II)ion from hot-dip galvanizing pickling waste in the presence of Fe(?).These hot-dip galvanizing pickling waste mainly contain ZnCl2 and FeCl2 in aqueous HCl media.The properties of this magnetic adsorbent were examined by transmission electron microscopy(TEM),powder X-ray diffraction(XRD),infrared spectrometer(FT-IR)and BET surface area measurements.Various factors influencing the adsorption of Zn(II)ion such as initial concentration of metal ions,the amount of adsorbent,pH value of the solutions,the concentration of coexisting iron ion were investigated by batch experiments.The results indicated that the adsorption equilibrium data obeyed the Freundlich model with maximum adsorption capacities for Zn(II)to 169.5 mg/g.The maximum adsorption occurred at pH 5±0.1 and Fe(II)interferences had no obvious influence.This work provides a potential and unique technique for zinc ion removal from hot-dip galvanizing pickling waste.A novel hybrid material was fabricated using mercapto-amine functionalized silica-coated magnetic nanoparticles(MAF-SCMNPs)and was demonstrated to be effective for extracting and recovering mercury and lead ions from wastewater.The properties of this new magnetic material were explored using various characterisation and analysis methods.Adsorbent amounts,pH levels and initial concentrations were optimised to improve removal efficiency.Additionally,kinetics,thermodynamics and adsorption isotherms were investigated to determine the mechanism by which the fabricated MAF-SCMNPs adsorbed heavy metal ions.The results revealed that MAF-SCMNPs were acid-resistant.Sorption likely occurred by chelation through the amine group and by ion exchange between heavy metal ions and thiol functional groups on the nanoadsorbent surface.The adsorption kinetics was determined to be pseudo-second-order.The mercury and lead adsorption isotherms were in keepingwith the Freundlich model with maximum adsorption capacities of 355 and 292 mg/g.respectively.The adsorption process was endothermic and spontaneous.This work provides a unique magnetic nano-adsorbent for the removal of Hg(?)and Pb(?)from wastewater.The thesis synthesized Fe3O4 nanomaterials by coprecipitation and solvothermal method,then two different modifying agent was applied to modified Fe3O4 nanomaterials for the removal of zinc,mercury and lead in wastewater.We researched the effect of adsorbent account,solution pH,reaction temperature,contact time.In order to investigate the effect of adsorption efficiency and mechanism for heavy metal adsorption.The Fe3O4,after modified Fe3O4 and loading heavy metals adsorbent were characterized by TEM and BET,XPS,VSM,XRD and other technologies.