溶液pH和TiO2浓度对直接蓝15染料光催化降解的影响

Effects of pH value and TiO2 concentration on the photocatalytic degradation of direct blue 15

为了实现对偶氮型合成染料废水的有效处理,以直接蓝15染料溶液模拟染色废水,使用光催化氧化技术对其进行氧化降解,并讨论溶液pH和TiO_2浓度对光催化降解作用的影响。结论认为:直接蓝15染料溶液在光催化氧化条件下可以实现很好的氧化降解;降低溶液的pH虽可以增加直接蓝15染料在二氧化钛上的吸附,但不利于光催化降解反应的进行;在中性条件下,光催化降解反应速率最快,当增加二氧化钛质量浓度至0.5 g/L时,直接蓝15染料溶液的COD去除率可达71.4%;反应后溶液基本呈无色透明状态,取得了良好的处理效果。

In order to achieve effective treatment of azo dye wastewater,the direct blue 15 dye solution is used to simulate the dyeing wastewater,and the photocatalytic oxidation technology is used to oxidize the wastewater.The effects of pH value of the solution and TiO2 concentration on the photocatalytic degradation are discussed.It is found that the direct blue 15 dye solution could be oxidized under the condition of photocatalytic oxidation.Reducing the pH value of the solution could increase the adsorption of direct blue 15 dye on TiO2,but it is not conducive to the photocatalytic degradation reaction.Under neutral condition,the photocatalytic degradation rate is the fastest.When the concentration of TiO2 increases to 0.5 g/L,the COD removal rate of direct blue 15 dye solution could reach 71.4%.After the photocatalytic oxidation reaction,the solution is basically colorless and transparent,and good treatment effect is achieved.