新型可见光催化剂BiVO4降解中成药制药废水

以Bi（NO3）3.5H2O和NH4VO3为原料,采用水热法制备了新型可见光BiVO4催化剂,并用X-射线衍射（XRD）、扫描电子显微镜（SEM）、红外光谱（IR）和紫外-可见光漫反射光谱（UV-vis DRS）对产品进行了结构表征,并将其应用于光催化降解中成药制药废水降解反应中,通过正交实验和单因素分析,考察了催化剂用量、空气流量、溶液pH值和助氧化剂H2O2对制药废水COD去除率、脱色率的影响。实验结果表明,水热产品属于单斜晶系BiVO4,其带隙能为2.41 eV,并具有良好的可见光催化活性。对于经10倍稀释的制药废水,BiVO4添加量为2 g/L,通氧量为120 L/h,助氧化剂H2O2添加量为1 mL,不改变废水pH值,在400 W金属卤化物灯离液面11 cm照射反应180 min的条件下,制药废水的COD去除率为94.3%,脱色率为95.6%,得到了较好的降解。

Degradation of Chinese traditional medicine wastewater by novel visible light sensitive BiVO_4 photocatalyst

The novel visible light sensitive BiVO4 photocatalyst was synthesized via hydrothermal process using Bi（NO3）3·5H2O and NH4VO3 as starting materials.Its structure was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,infrared spectroscopy（IR） and UV-vis diffuse reflectance spectroscopy（UV-vis DRS）,and the photocatalytic activity of the BiVO4 powders was determined by degradation of Chinese traditional medicine wastewater.The effects of BiVO4 dosage,air flow rate,pH of wastewater,H2O2 dosage on the wastewater degradation were investigated in detail through the orthogonal experiment and single-factor experiment.The results reveal that the as-prepared BiVO4 is monoclinic structure with a band gap of 2.41 eV and exhibits an excellent visible-light photocatalytic activity.For the Chinese traditional medicine wastewater with the initial pH value,when the flow rate of air is adjusted to 120 L/h,the amount of added H2O2 modulated at 1.0 mL,and the concentration of BiVO4 controlled to 2 g/L,the COD removal rate of the wastewater is 94.3% and the decolorization rate is 95.6% after irradiation by metal halide lamp of 400 W visible light for 180 min.It shows that the Chinese traditional medicine wastewater can be degraded efficiently by BiVO4 photocatalyst.