The Research Of Photoelectrocatalysis Degradation Of Sulfadimidine In Aqueous Solution

Pharmaceutical and personal care products?PPCPs?are a series of emerging pollutions.Sulfadimidine?SM2?as a kind of typical PPCPs were detected in different water environment,it has threaten human health and ecological system.While the prevailing sewage treatment is not effective to remove the antibiotics,develop efficient treatment of this pollution is particularly important.Photoelectrocatalysisis a new advanced oxidation technology,can produce reactive oxygen species such as hydroxyl radicals which can mineralize antibiotics.This thesis uses anodic oxidation to fabricate titanium dioxide nanotubes?TiO₂-NTs?in four common systems containing fluorine.TiO₂-NTs are characterized by chronoamperometry?CA??electrochemical impedance spectroscopy?EIS?to chose the TiO₂-NTs which have best photoelectronchemical response.Then modify this TiO₂-NTs to TiO₂-NTs/Fe₃O₄ by dope Fe,simultaneously concern the change of photoelectron-catalysis activity.The results are follows:the TiO₂-NTs fabricated in the system contain ammonium fluoride?0.5 wt%??glycerol?75%??water?25%?has the best photoelectric catalytic activity,and dope with Fe can significantly improve the electrode photoelectrocatalysis activity,improve the SM2 degradation rate compare with TiO₂-NTs.Besides,in photoelectroncatalysis experiment,photoelectrocatalysis activity of catalysts is not in conformity with photocatalytic activity.The thesis describes photoelectrocatalysis degradation of sulfadimidine by TiO₂-NTs/Fe₃O₄ under simulated sunlight,and the effect of pH?concentration of SM2?bias potential?kinds and concentration of electrolyte?light intensity?Fe2+?Fe3+ influence on photoelectrocatalysis are investigated.The thesis uses electrochemical analysis technology,from the aspects such as semiconductor physics and electrochemistry reaction mechanism to explain the mechanism of these factors.The results show that degradation rate increases as the concentration of SM2 and Na2SO4 increase,though a high concentration blocks reaction.Lower solution pH is suitable for SM2 degradation,and higher bias potential?light intensity and concentration of NaCl can promote degradation.The addition of FeSO4?Fe2?SO4?3 exist a optimum and other concentration may block reaction.Under the condition of 10mg·L-1 SM2?0.05 mol·L-1NaCl?98mW·cm-2light intensity?10V bias potential,SM2 can be removed completely in 30 minutes.As the reaction progress,SM2 finally mineralized to NH4+?NO3-etc.