Preparation Of Electrocatalytic Oxidation Anode And Deg-radation Of Perfluorooctanoic Acid In Water

Perfluorooctanoic acid（PFOA）,as the most widely used Perfluorinated compound,is considered as a persistent and refractory pollutant due to its unique structure and high stability,which has caused great harm to ecosystems and various life forms.Due to the limitations and drawbacks of existing treatment technologies,the efficiency of PFOA wastewater treatment is constrained.Advanced electrochemical oxidation technology achieves the goal of degrading organic pollutants through electrode reactions.Due to its advantages of high efficiency,convenience,and cleanliness,it is considered an effective method for difficult to degrade organic pollutants.This paper is based on the Ti/SnO₂electrode,which is modified to prepare an efficient electrocatalytic electrode.The modified carbon based electrode is used as the cathode to construct a new efficient electrochemical system.Advanced oxidation electrochemical methods are used to degrade PFOA wastewater,and the degradation mechanism is analyzed.The main achievements of the paper include:A binary oxide coated Ti/SnO₂-Ru O₂electrode has been prepared by doping metal Ru into the active layer of the Ti/SnO₂electrode using a thermal decomposition method.The effect of metal Ru doping on the original electrode is analyzed and studied through characterization of electrochemical performance and surface morphology structure.The results show that when the molar ratio of Sn to Ru is 5:1,the binary oxide cation of Ti/SnO₂-Ru O₂prepared has the strongest electrocatalytic oxidation activity.Based on the binary oxide anode of Ti/SnO₂-Ru O₂,the preparation method has been updated by replacing the coating process with electrodeposition.By changing the sedimentary fluid system and introducing additives,while taking into account its catalytic activity,stability can be improved as much as possible.Ti/CNT-SnO₂+Ru O₂+Ni-DES electrodes are prepared by electrodeposition using the deep eutectic solvent system of choline chloride+urea as the electrodeposition solution and carbon nanotubes as the growth template of metal oxides.Through characterization analysis,the microscopic effects of metal doping on electrodes are studied.It is found that both Ru and Ni entered the SnO₂lattice as ions,replacing Sn⁴⁺.This co doped electrode has high reaction efficiency and prolongs the electrode acceleration life by nearly 20%.A new electrode system is formed by using polytetrafluoroethylene（PTFE）and carbon black modified graphite felt（CB-GF）electrodes as cathodes,with three cathodes and two anodes arranged in a staggered manner,and self-made anodes to form a synergistic anode and cathode electrode system.The degradation experiments on various wastewater are conducted to investigate the effects of current density,aeration rate,and Fe²⁺dosage on the degradation effect,and to determine the optimal degradation conditions under different conditions.The experiment finds that the degradation efficiency of organic matter in this system is significantly higher than that in unipolar systems.Especially under neutral conditions,due to the in-situ generation of hydrogen peroxide by carbon based cathodes being converted into hydroxyl radicals by ferrous ions,the efficiency of the electrochemical system can be doubled,indicating that the synergistic electrochemical treatment of cathode and anode can become a new way to treat refractory organic compounds.The electrochemical system has been optimized through experiments,and the degradation efficiency of PFOA can reach 90%under various conditions.Research has found that the constructed new electrode system synergizes the anodic electrocatalytic oxidation reaction with the cathodic electro Fenton reaction,improving the reaction efficiency of the electrochemical system while also expanding the p H applicability of the electrochemical system.A new electrochemical system has been used to treat the adsorbed blue carbon wastewater,and the experiment found that the COD and ammonia nitrogen content in the wastewater decreased significantly.In addition,the detection of wastewater after electrochemical treatment showes that the biodegradability of the wastewater is greatly improved,proving that electrochemical treatment can become a necessary pre-treatment method for blue carbon wastewater before entering microbial treatment.The degradation of PFOA is investigated through a new electrochemical system,and the effects of current density and initial p H on electrode performance are investigated,optimizing the degradation conditions.At the same time,liquid chromatography mass spectrometry（HPLC-MS）has been used to detect the intermediate substances of PFOA at different stages in the electrochemical degradation system.It is speculated that the degradation mechanism of PFOA is that PFOA experiences multiple electrode reaction processes,repeates cycle defluorination,and finally is mined into CO₂and F^-by shortening the carbon chain.