Study On The Simultaneous Removal Of 17α-ethynyl Estradiol And Escherichia Coli By TNTs-Ag/SnO₂-Sb Anode Photoelectrocatalysis

Now water shortages have become a global problem,and the use of recycled water has also attracted the attention of many scholars.Of course,there are many residual pollutants in the recycled wastewater in the environment,such as 17α-ethynyl estradiol（EE2）.These trace organic substances will cause damage to human body and ecology at a small concentration.In addition,there are many pathogenic microorganisms in the reclaimed water,which also pose a health threat.The two most important types of pollutants are difficult to remove by ordinary processes in wastewater treatment plants.Therefore,in this paper,TNTs-Ag/SnO₂-Sb,a new type of anode,is formed by loading antimony-doped tin oxide（SnO₂-Sb）and nano-silver particles（Ag）on the surface of TNT.The anode achieves inactivation of E.coli and degradation of EE2 under a photoelectrocatalysis system（PEC）,and studies the removal effect,degradation mechanism,and final removal effect.The results show that the photochemical and electrochemical properties of the anode plates are improved when Ag and SnO₂-Sb are loaded on TNTs.This is because Ag ions can make TNTs have the ability to absorb and absorb visible light,SnO₂-Sb can make TNTs a semiconductor with a certain redox capacity,and Ag and SnO₂-Sb as metals can further improve the resistance of TNTs.Using TNTs-Ag/SnO₂-Sb as the anode and C-PTFE as the cathode to build a photoelectrocatalysis system,it was found that 68%of EE2 can be removed within an hour（the initial concentration is 1.2 mg/L）,and the photoelectrocatalysis effect is much higher than that effects of electrocatalysis and photocatalysis alone.After adding EE2 and E.coli pollutants under the same conditions,the degradation effect decreased,but it is still better than other common methods.This also shows that E.coli and EE2 have a competitive relationship,and it is speculated that the system produced More ROS（HO·,H₂O₂,etc.）.To this end,the HO·generated in the photovoltaic system was measured,and the resulting HO·concentration reached 4μM,which was much higher than the results of other people’s research,which also proved the guesswork.Many studies have shown that HO·can not only degrade pollutants,but also damage the cell membrane and DNA of E.coli.The amount of intact DNA in E.coli has been measured,and the number of intact DNA has been significantly reduced.The toxicity test of EE2 degradation products also found that its toxicity has decreased.These results further prove the superiority of the system.Finally,the degradation products were identified by LC-MS,and the envisaged EE2degradation pathway was proposed,which provided experience and assistance for subsequent research.In general,the photoelectrocatalytic system constructed by improving the anode electrode plate in this study has a strong ability to degrade pollutants,and the removal effect is very thorough,which provides effective technical support for the reuse of recycled water.