Performance And Mechanism Of Antiviral/Antibiotic Removal From Water By Bimetallic Catalytic Electrode Coupled With Advanced Oxidation Technology

Antiviral/antibiotic wastewater discharged without deep treatment can accumulate in agricultural products,livestock and poultry products and even drinking water,causing serious food safety problems.The coupling of electrocatalytic,photocatalytic and Fenton technologies for the treatment of antiviral/antibiotic drug wastewater is characterized by high oxidation capacity and fast reaction rate,which has great application prospects for deep degradation of antiviral/antibiotic drug wastewater.Constructing photocatalytic electrodes with high catalytic activity and stability is the key to achieve efficient electron transfer and rapid pollutant removal.Metal oxides have the advantages of high stability,low price,and easy preparation,but they also suffer from insufficient catalytic performance.The current single form of advanced oxidation technology has relatively limited effect on the treatment of antiviral/antibiotic drug wastewater.To address the problems described above,novel bimetallic polycrystalline catalytic electrodes,including Ag@ZOF cathode,S-MFO cathode and（CMNW）_CNcathode,were prepared in this study,and their electron cycling transfer characteristics and effects on the catalytic activity of refractory organic pollutants were investigated in electrocatalytic,photocatalytic and Fenton-coupled systems.The treatment efficiency and coupling mechanism of the catalytic electrode combined with Fenton coupling system for the treatment of antiviral/antibiotic drug wastewater were also analyzed.The main research contents and results are as follows:（1）PbO₂/SnO₂ anode based on titanium mesh was prepared by electrodeposition,and silver doped zinc-based organic framework（Ag@ZOF）hybrid crystal was synthesized by precipitation.A dual catalytic electrode assisted self-generated Fe²⁺electro-Fenton system was constructed at room temperature,which was able to degrade tetracycline and norfloxacin in wastewater rapidly and effectively.Meanwhile,a sacrificial iron anode without power supply was introduced into the system to realize the endogenous supply of Fe²⁺.The results showed that the system was able to produce H₂O₂ and Fe²⁺autonomously to maintain the continuous reaction at p H 3.5～4.0,sacrificial iron anode area of 10 cm² and current intensity of 9 m A.Ag@ZOF electrode degraded tetracycline（TC）and norfloxacin（NOR）well with the degradation efficiency of 99.1%and 92.8%,respectively.The possible degradation pathways of TC and NOR were proposed by analyzing the intermediate products.（2）A photo-bioelectric Fenton system（PBEF）was formed to degrade the antiviral drug ribavirin using sulfur-doped MnFe₂O₄（S-MFO）as the cathode and carbon brushes as the anode and coupled by a dual-chamber microbial fuel cell（MFC）and cathodic photoelectric Fenton.Through Box-Behnken（BDD）three-dimensional model analysis,it was determined that the degradation rate of ribavirin reached a maximum of 26.59%at 2 h of experiment under the conditions of initial p H of 3.82,Fe²⁺addition of 20m M,and aeration rate of 0.32 L·min^-1.The system was able to regenerate and recycle Fe²⁺stably and efficiently,which provided a guarantee for the subsequent ribavirin degradation experiments.The reaction mechanism of the PBEF system and the degradation process of ribavirin were further analyzed,and the S-MFO-assisted PBEF system exhibited high stability,good recyclability,and low cost.（3）A novel CuMn₂O₄@WO₃/g-C₃N₄(（CMNW）_CN)dual cathode electrode with CuMn₂O₄（CMO）as the electrocatalytic electrode and WO₃/g-C₃N₄（WCN）as the photocatalytic electrode was developed for the degradation of acyclovir in a photo-bioelectric Fenton（PBEF）system.The electrochemical properties,surface morphology and photocatalytic activity of the（CMNW）_CN electrode were investigated,showing excellent redox performance and efficient electron transfer efficiency.Density functional theory（DFT）calculations confirmed that the CMO electrode adsorbed PMS through a unique"T"mode,which enhanced the ability to adsorb PMS and increased the number of electron transfers.Meanwhile,the WCN electrode exhibited high photocatalytic activity,generating many photogenerated electron-hole pairs under light conditions.The degradation efficiency of acyclovir in PBEF reached 100%within 30min and possessed a high cycling stability in multiple replicate experiments.Finally,the reaction mechanism and degradation pathway of acyclovir are proposed,and the potential of PBEF system in degrading antiviral drugs is demonstrated.