Degradation of Chinese traditional medicine wastewater by novel visible light sensitive BiVO4 photocatalyst
新型可见光催化剂BiVO4降解中成药制药废水

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.