Electrocatalytic Oxidation Treatment Of Wastewater Containing Nitrobenzene

As an environmental friendly technology, electro-catalytic oxidation is an effective method for organic compound degradation. The high-efficiency electrode such as the DSA (Dimensionally Stable Anode) is the pivotal part for this method. In this thesis, the SnO₂^--Sb₂O₅/Ti electrode was prepared by coat of the corresponding metal chlorides on titanium substrates and thermal decomposition. The electrode was used for the electro-catalytic oxidative degradation of nitrobenzene in aqueous solution. The bulk electrolysis was performed under the constant current operation in the two-dimensional reactor. It was observed that the removal rate of nitrobenzene was 70.65% after 1h electrolysis under the following conditions: Na2SO₄=17.75g/L; pH=5; current density= 20mA/cm^-2; initial nitrobenzene concentration=240mg/L. It was indicated by the research that the degradation of the nitrobenzene and the chemical oxygen demand (CODcr) both conform to the first order kinetics. With GC-MS results, a mechanism of nitrobenzene degradation was preliminarily discussed: the deoxidization of the cathode played an important part in the nitrobenzene degradation.Based on the experiments carried out above, the three-dimensional electrodes reactor was preliminarily researched. It was observed that the removal rate of nitrobenzene was 90% in this reactor after 1h electrolysis under the following conditions: the active carbon and the aqueous solution was 1:1 by volume, voltage= 8V, Na₂SO₄=2g/L; pH=5; initial nitrobenzene concentration=240mg/L, coated film active carbon and active carbon were 7: 3 by volume. The result also showed that: the three-dimensional electrodes reactor had better treatment effect on the nitrobenzene.