In Situ Preparation Of H₂O₂ By Electrolysis And Experimental Study On The Degradation Of Phenol Simulated Wastewater

For the treatment of refractory organic wastewater,the electro-Fenton oxidation technology of producing H₂O₂ in situ in the reactor,especially the research of cathode materials,is a hot topic in the recent years.In this paper,the performance of different electro-Fenton cathode materials producing H₂O₂ was studied and compared.The carbon black-PTFE gas diffusion electrode with excellent performance was optimized,and the preparation conditions and technological parameters were investigated,and it was applied to the degradation of simulated wastewater of phenol and the degradation effect was investigated.Using platinum electrode as anode,compare the performance of producing H₂O₂ of carbon felt,activated carbon fiber brush,foam copper,nickel foam and carbon black among the 120min reaction time,in the 0.05 mol/L Na₂SO₄ neutral solution.The result showed that carbon black was a better cathode material.The main optimum preparation parameters of carbon black-PTFE gas diffusion electrode are as follows:the mass volume ratio of carbon black and the concentration of 60%PFTE emulsion is 3:4?g/mL?,no pore forming agent is added,and it is calcined under 350 centigrade nitrogen protection for 1h.Carry out an experiment to evaluate the performance about producing H₂O₂ in situ of the self-made carbon black-PTFE gas diffusion electrode,and the result shows that the current density,pH,electrolyte concentration,plate spacing and aeration will all affect the performance of the carbon black-PTFE gas diffusion electrode.The best performance was obtained at electricity density of 6.67 mA/cm²,pH of 3,Na₂SO₄concentration of 0.05 mol/L,plate distance of 2 cm and gas rate of 120 mL/min,after reacting 3 h the H₂O₂ concentration can reach 341.09 mg/L.Use the self-made carbon black-PTFE gas diffusion electrode as the cathode,the platinum electrode as the anode and the external dosage of Fe²⁺,to degradate phenol.The results showed that the electrolysis time was 90 min,the initial phenol concentration was 50 mg/L,the initial pH=3,the Fe²⁺concentration 0.1 mmol/L,the current density 10mA/cm² and the phenol removal rate reached 89.16%.