Ag_x/Zn_((1-x))BiVO_4光催化氧化罗丹明B废水研究

为更好地处理色度高,有机污染物浓度大,可生化性差的染料废水,采用自制的Ag_x/Zn_((1-x))BiVO_4为光催化剂,氙灯为光源,研究了催化剂Ag_x/Zn_((1-x))BiVO_4对可溶性染料罗丹明B废水的光催化降解情况.试验考察了Ag与Zn的不同配比、催化剂用量、溶液的pH值和光照时间等对罗丹明B光催化降解过程的影响,并对反应动力学做了初步探讨.结果表明,模拟太阳光照射下,罗丹明B质量浓度为5 mg/L、催化剂(Ag_x/Zn_((1-x))BiVO_4)用量为1 g/L、pH值为2.0、反应时间为30 min条件下,罗丹明B的脱色率达99.7%.与P_(25)-TiO_2催化剂对罗丹明B废水的降解情况进行了比较研究,表明Ag_(0.6)/Zn_(0.4)BiVO_4具有较好的光催化活性,可用于染料类废水的处理.动力学拟合结果表明,该光催化反应近似为一级动力学,其动力学方程为y=-3.06353-0.02146x.

Photocatalytic oxidation of Rhodamine B sewage by using Ag_x/Zn_((1-x))BiVO_4

This paper is aimed to introduce its author's renovated method of photocatalytic oxidation of dye sewage under the xenon lamp as a light source by using our self-made Ag_x/Zn_((1-x))BiVO_4 photocatalysts through co-precipitation. We have also conducted the photocatalytic reaction with the SGY-I multi-functional photochemical reaction instrument to study the effects of various reaction conditions on the degradation rates of Rhodamine B, including the Ag/Zn ratio, the dosage of catalysts, pH of the solution, the concentration of sewage as well as illumination time. The results of our research prove that the best reaction conditions can be shown as follows: (1) Rhodamine B concentration should be at 5 mg/L;(2) Catalyst (Ag_x/Zn_((1-x))BiVO_4) dosage is 1 g/L;(3) pH value of 2.0;(4) Reaction time is 30 min. Under the optimal reaction conditions, the decolorization rate of Rhodamine B sewage can reach 99.7% by simulated sunlight irradiation. The photocatalytic activity of Ag_x/Zn_((1-x))BiVO_4 proves to be equivalent to the P_(25)-TiO_2 photocatalysts under the irradiation of xenon lamp. Besides, kinetic studies of the photocatalytic reaction also suggest that the decoloration rate of Rhodamine B roughly follows the first-order reaction with the reaction rate equation y=-3.06353-0.02146x. Thus, it indicates that the photocatalyst (Ag_x/Zn_((1-x))BiVO_4) enjoys nice catalytic activity under the simulated sunlight, which makes it suitable for treating the dye sewage. At the same time, Ag_x/Zn_((1-x))BiVO_4 photocatalysts also proves promising to the other kinds of sewage treatment through further necessary regulation.