Study On Degradation Of Orange G By Two Methods:electrochemical Oxidation Process And Nano Fe₃O₄ Catalytic Hydrogen Peroxide Oxidation Process

Electrochemical oxidation technology is a kind of relatively clean process, in this experiment I will use the electrochemical oxidation technology for the treatment of dye wastewater, and comprehensively examine the various factors of the electrochemical oxidation of the dye decolorization rate, including: pH, temperature, the distance between the electrode plates, the effect of electrolyte additive quantity, voltage, the effect of other anionic, and find the best conditions of the electrochemical oxidation of orange G. Due to the low efficiency of the electrochemical oxidation, the slow reaction rate, and too much gas such as hydrogen will release into the sky of the long time clectrochemical reaction. So looking for a way to shorten the reaction time, and improve the efficiency of the eletrochemical reaction is the focus of this experimental study. In this experiment, I will combine electrochemical oxidation and Fenton reaction by dosing FeSO4·7H2O and H2O2 combined with electrochemical reaction. In this conditions, orange G decoloring rate increases rapidly. And research the decolorization rate under the condition of iron anode, explore the effect of the electric Fenton reaction and compare the decoloring effect under the different time of using iron electrode. The experimental results show that at the condition of 10 V of voltage, 0.05 A of current, and 10 min of the use of iron anode. The experiment proved that it can provide enough iron for the oxidation reaction, and the long time use of iron electrodes will release too much iron, in fact, it is a kind of waste or secondary pollution, so after 10 min, use the graphite electrode to replace iron electrode. In fact this is a kind of piecewise electrochemical oxidation technology. It is beginning to use iron electrode to provide enough iron to start the Fenton reaction, followed by the joint of electrochemical and Fenton reaction, this experiments show that this method can reach very good decorizing rate of 95% within 30 min and good COD removal rate of 80% after 1 h. Then I tested the iron content in the solution, the result prove that there is 1.05 mg/L of iron in the solution after 10 min of using the iron electrode.Due to the homogeneous Fenton reaction requires the introduction of iron ion, so the research of heterogeneous Fenton reaction is more and more, so this experiment studied the nano Fe3O4 catalytic hydrogen peroxide oxidation degradation of orange G. Fe3O4 nano particles can catalytic hydrogen peroxide to produce hydroxyl radicals, because there is a structure named horseradish of nano Fe3O4 which is similar to the catalase, this structure is the key to the catalytic reaction. In this study, the Fe3O4 nano particles was prepared by coprecipitation method, and investigate the condition of different pH, hydrogen peroxide dosing quantity and temperature on the influence of dye degradation, and studied the COD degradation rate, and repeated utilization situation of Fe3O4 nano particles, it was found that there is a very high decolorization rate at the pH of 3, it also remains good effect at the p H of 5, but under the condition of neutral and alkaline, the decolorization rate drop a lot. And the experiment results prove that the nano Fe3O4 remains high catalytic activity after three times. Finally, These three methods were used in the actual printing and dyeing wastewater, and inspected their processing effect.