Study On Electrochemical Detection And Fenton Oxidative Degradation Of Hydroquinone Isomers

In this paper,the electrochemical methods for the simultaneous detection of hydroquinone isomers,Fenton oxidation degradation of hydroquinone isomers,and improve traditional Fenton oxidation systems are studied.In addition,the experimental conditions,experimental methods and technical means are adjusted,and the reaction principle and degradation mechanism are explored and verified.The main contents are as follows:?.Electrochemical simultaneous detection of three hydroquinone isomersDifferent modified electrodes are prepared for electrochemical detection of hydroquinone isomers,and the reduced graphene oxide?rGO?modified electrode is selected as the best performance.After optimizing the detection conditions,the final experimental results show that the electrode modification material amount was 0.01 mg,using acetic acid-sodium acetate buffer solution as the electrolyte,pH=5.5,and preconcentration time of 300 s are the best detection conditions.The rGO modified electrode could be used for rapid and simultaneous detection of hydroquinone isomers.The detection limit for the individual detection of three types of hydroquinone is 10^-77 mol/L.Within a certain concentration range,the hydroquinone isomers concentration has a significant linear relationship with the electrochemical signal,and satisfactory results have been obtained for simulated water samples.?.Fenton oxidative degradation of three hydroquinone isomersThe traditional Fenton oxidation method was used for the oxidative degradation of hydroquinone isomers,and the hydroquinone isomers concentration that after degradation were monitored by the established electrochemical detection method.The experiments explored the various conditions effects on the oxidative degradation of the hydroquinone isomer and the hydroquinone isomers'degradation mechanism.The final experimental results show that the molar ratio of Fe²⁺to H₂O₂ in Fenton's reagent is about 5:4,the dosage is 9.8×10^-55 mol,the oxidative degradation time is 45 min,and the pH=4.5,the degradation rates of three hydroquinone isomers are above 85%.And the analysis of the solution after degradation shows that the hydroquinone isomers'degradation mechanism is as follows:the hydroquinone is first oxidized to benzoquinone,then the benzene ring is opened to form inorganic acids,which is finally mineralized into H₂O and CO₂ after repeated oxidation.?.Electroreduced iron promotes Fenton oxidation of three hydroquinone isomersAn Fe³⁺electroreduction system with Ti-Ag electrode as the anode and Graphite electrode-carbon nanotube-graphene?GE-CNT-GR?as the cathode was constructed through experiments.Under the conditions that the cathode potential is+0.2V,the reduction rate of Fe³⁺can reach 52.9%within 60 minutes.The electro-reduction system was combined with traditional Fenton oxidation system to conduct oxidative degradation of hydroquinone isomers,and the results show that the Fe³⁺electroreduction system can effectively promote the Fenton reaction,and can reduce the initial iron salt dosage by about 50%without affecting the hydroquinone isomers'degradation percentage.After the optimization of the conditions,the degradation percentages of the three hydroquinone isomers are98.20%?hydroquinone?,98.08%?catechol?and 94.96%?resorcinol?,and it has better results compared to the traditional Fenton system.