Preparation Of Functionalized Nano-Hollow Carbon Sphere And Study On Multi-Effect Treatment Of Mixed Wastewater

With the continuous development of industry,the types of pollutants in wastewater are becoming more and more complicated.Among them,the co-contaminant of refractory organic pollutants and heavy metal pollutants are increasingly harmful to the environment.In recent years,there have been many studies on the combined pollution of organic matter and organic matter,heavy metals and heavy metals at home and abroad,and good results have been achieved.However,there is little research on the composite pollution between organic matter and heavy metals,the actual wastewater contains basically composite pollutants of organic matter and heavy metals.As we all know,the traditional wastewater treatment technologies are for single pollutant wastewater research and analysis.Therefore,it is of practical significance to explore a treatment technology for removing composite pollutants,combining the oxidation of organic pollutants with the reduction of heavy metal pollutants.The main research contents and results obtained in this thesis are as follows:（1）N-doped nano hollow carbon spheres（NHCS）were successfully prepared by template method and used as adsorbent materials to remove bisphenol A（BPA）from wastewater.The Microstructure and specific surface area of NHCS were analyzed by means of field emission scanning electron microscopy（FESEM）,high resolution transmission electron microscopy（HRTEM）and N₂ desorption testing techniques.In the adsorption experiment,the factors affected the adsorption of BPA including pH and dosage of adsorbent were investigated.Adsorption kinetics equations,adsorption isotherm and adsorption thermodynamics equations were used to investigate the adsorption behavior and mechanism.The experimental results showed that the maximum adsorption capacity reached 171.6 mg/g at pH of 6.Pseudo second order kinetics equations and the Freundlich adsorption model could describe the adsorption process of BPA,the negativeΔG values indicated that all the adsorption processes were spontaneous,which laid the foundation for the next experiment.（2）Manganese dioxide（MnO₂）was loaded onto NHCS by hydrothermal method based on redox principle,and MnO₂@NHCS was successfully prepared and used as an adsorption-oxidation material to degrade BPA in wastewater.MnO₂@NHCS materials were characterized by field emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,high resolution transmission electron microscopy（HRTEM）and X-ray photoelectron spectroscopy（XPS）.In the experiment of removing BPA,the effect of dosage of MnO₂@NHCS,pH,initial concentration of BPA,temperature and humic acid were investigated systematically.The results showed that the removal rate of bisphenol A reached 95.3%within 10 minutes,and it took only 30 minutes to completely degrade bisphenol A under the optimal reaction conditions.Additionally,the MnO₂@NHCS remained stable and had a high regeneration efficiency（more than 85%）after 3 cycles（360 minutes）.（3）Polyaniline（PANI）was successfully grown on the nano hollow carbon sphere（NHCS）by in situ polymerization method to prepare PANI@NHCS nanocomposites,which was applied to treatment of simulation Cr（VI）waste water.The effect of PANI@NHCS dosage,pH,initial Cr（VI）concentration,contact time and co-existing ions were investigated systematically.And field emission scanning electron microscopy（FESEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,specific surface area（BET）,Fourier transform infrared spectroscopy（FTIR）and Raman spectroscopy（Raman）were used to characterize the PANI@NHCS material.Moreover,the adsorption kinetics equations,adsorption isotherm and adsorption thermodynamics equations were used to investigate the adsorption behavior and mechanism.The results showed that the maximum adsorption capacity of PANI@NHCS for Cr（Ⅵ）reached 248.1 mg/g under the optimal condition.The data of adsorption equilibrium was in good agreement with the pseudo second order kinetics equation and the Langmuir adsorption isotherm model.The adsorption thermodynamics results showed that the adsorption process was a spontaneous endothermic reaction.The results of coexisting ions interference and cycling experiments showed that the PANI@NHCS material had good selectivity and stability.（4）Further,manganese dioxide（MnO₂）and polyaniline（PANI）were successfully grown on the nano hollow carbon sphere（NHCS）by hydrothermal method and in situ polymerization method,and ternary PANI@MnO₂@NHCS composite material was successfully prepared,which was applied to treatment of simulation Cr（VI）and BPA waste water.The effect of initial concentration ratio of pollutants,pH,the dosage of PANI@MnO₂@NHCS were investigated.And field emission scanning electron microscopy（FESEM）was used to characterize the PANI@MnO₂@NHCS material.The results showed that the removal rates of Cr（VI）and BPA were 90.4%and95.7%respectively under the optimal condition.Repeated experimental results show that PANI@MnO₂@NHCS has good stability and efficiency.