Study On The Degradation Of Safranine T In Aqueous Solution By Electrochemical Advanced Oxidation Technology

Safranine T is one of the most commonly used synthetic azine dyes and has been widely used in the dye industry.However,long-term exposure to safranine T can cause gastrointestinal discomfort,oral mucosal irritation,throat discomfort,skin damage and other harmful health effects.Therefore,many researchers are working on the removal of ST from environmental water.In this paper,a Ti/PbO₂ electrode was used as an anode for the electrocatalytic oxidation degradation of low-concentration safranine T simulated wastewater in an aqueous solution,and the Electro-Fenton with hydrogen peroxide was used to degrade safranine T simulated wastewater.The optimal method and conditions for safranine T wastewater degradation.The electrochemical degradation of safranine T aqueous solution by Ti/PbO₂electrode was studied.The effects of current density,initial safranine T concentration,and initial pH and Na₂SO₄ concentration on degradation of safranine T were analyzed.Experimental results show that the electrochemical oxidation reaction conforms to a pseudo-first-order kinetic model.With the Ti/PbO₂ electrode as the anode,99.96%of safranine T in the aqueous solution can be eliminated in 120 minutes.It shows that the Ti/PbO₂ electrode is very effective for the electrochemical degradation of safranine T in aqueous solution.The optimal reaction conditions were the applied current density was 40 m A cm^-2,initial ST concentration was 100 mg L^-1,and the Na₂SO₄ concentration was 0.20 mol L^-1,and an initial pH=6.From the UV-vis and HPLC tests during the reaction,it can be known that intermediate products will be formed,and possible intermediate structures were studied by HPLC-MS test.But as the degradation reaction proceeds,the intermediate products will eventually be oxidized to CO₂ and H₂O.Cyclic voltammetry and fluorescence experiments prove that ST is indirectly oxidized by generating hydroxyl radicals.Under the optimal reaction conditions,the energy required to completely remove ST is 17.92 k Wh m^-3.The cast iron plate is used as the anode,the stainless steel plate is used as the cathode,and externally added H₂O₂,the anode is dissolved to obtain Fe²⁺,and the electric Fenton process is used to process ST water in order to reduce the investment of the electric Fenton process and improve the processing efficiency.The effects of current density,initial pH,H₂O₂,ST concentration,and Na₂SO₄ dosage on the treatment of ST wastewater by electro-Fenton were mainly studied.The results show that the treatment of safranine T wastewater by electric Fenton accords with the first-order kinetic model.Under the conditions of H₂O₂ dosage of0.35 m L L^-1,current density of 15 m A cm^-2,pH=3.0,and Na₂SO₄ concentration of 0.05 mol L^-1,After 30 minutes of reaction,the maximum removal rate of saffron T can reach 99.95%,and the maximum removal rate of COD can reach 89.96%.At the same time,the energy consumption during the reaction was 8.51 k Wh m^-3.During the reaction,the pH was gradually increased,and flocculent precipitates appeared during the reaction.Through the detection of iron ions and total iron,it was found that electro-Fenton will be accompanied by flocculation during the reaction,which can promote the Removal of safranine T in aqueous solution.