纳米晶TiO_2光催化处理含锌废水的研究

On the application of nanometer TiO_2 to the photocatalytic treatment of Zn^(2+) containing sewage

采用溶胶-凝胶法制备锐态型纳米TiO_2,并利用XRD、SEM对TiO_2粉体进行表征,在紫外光的作用下将自制纳米TiO_2光催化处理含锌废水。考察废水pH值、废水负荷、催化剂用量、光照时间等因素对锌离子去除率的影响。结果表明,在废水锌质量浓度为50 mg/L,纳米TiO_2投加量为0.01 g/L,含锌废水的pH值为12,反应时间为30min时,废水中锌的去除率可达98.73%。

The paper is inclined to present our innovated efficient technology for treating the Zinc ions sewage. In proceeding with our research, we have prepared nano-titanium dioxide characterized by XRD and SEM, the nanometer TiO2 （made by ourselves） so as to remove the Zinc ions from the sewage by photocatalytic action with the UV excitation. Furthermore, we have also investigated factors influencing the removal efficiency, such as the amount of the catalyst used, the excitation time, the sewage pH and initial concentration of Zn^2 ＋ . The experimental results we have gained show that nanometer TiO2 can be used as efficient photocatalyst to remove Zn^2＋ from the sewage with the UV excitation. The sewage pH value, the initial concentration of Zn^2＋ , the amount of catalyst, the reaction time and other factors are the chief factors affecting the treating efficiency. The sequential order of the factors affecting the photocatalytic effect can be shown as follows： pH of sewage 〉 the amount of TiO2 used 〉 the concentration of sewage 〉 illumination time. The optimal experimental conditions for photocatalytic treating of the sewage with Zinc ions can be stated as follows： when the concentration of Zn^2＋ in the sewage is 50mg/L, the amount of TiO2 proves to be 0.01 g/L and the pH in the sewage is 12. If the reaction time may last 30 min, the removal rate of Zn^2＋ from the sewage is expected to reach 98.73%.