RuOx-PdO/Ti电极上活性氯的生成及甲基橙模拟废水降解研究

以钛基RuOx-PdO为阳极,钛网为阴极,Na2SO4和NaCl为支持电解质,研究了NaCl质量浓度、电流密度和pH对活性氯生成的影响及活性氯的生成与甲基橙模拟废水降解之间的关系.实验发现,以Na2SO4为支持电解质时,甲基橙模拟废水的有限降解是该阳极直接电催化氧化作用的结果.NaCl质量浓度和电流密度对活性氯的生成有明显的影响,酸性溶液中活性氯的生成量直接决定了甲基橙模拟废水的脱色程度,两者之间呈现较好的线性关系,碱性条件下不仅不利于活性氯的生成而且活性氯物种对甲基橙模拟废水的降解基本不起作用.

Investigation on the Formation of Active Chlorine and Degradation of Methylorange Simulated Waste Water over RuOx-PdO/Ti Anode

The production of active chlorine and its effect on the degradation of methylorange simulated waste water using RuOx-PdO/Ti anode and reticulated titanium slice cathode were investigated. Na2SO4 and NaCl were used as the supporting electrolyte. The variations of NaCl concentration, current density and pH of the electrolyte solution on the production of active chlorine and then the degradation of simulated waste water were studied. It was found that when sodium sulfate is used as the electrolyte, the degradation of methylorange simulated waste water is due to the direct electrocatalytic oxidation over the RuOx-PdO/Ti anode, which shows limited performance. The concentration of NaCI and current density are the key factors that dominante the production of active chlorine. A nearly linear relationship between the colour removal of methylorange simulated waste water in acidic medium and the quantity of active chlorine formed is established. The production of active chlorine over the RuOx-PdO/Ti anode is significantly altered by the pH of the solution. Basic media is found unfavorable for the production of active chlorine and the active chlorine formed in basic media shows little colour removal performance. In addition, the removal of chemical oxygen demanded is not in step with the decoloration process of methylorange simulated waste water, that is to say, after decoloration, the intermediates formed are more difficult to be removed.