The Photocatalytic Oxidation Properties of La~(3+)-doped and Ce~(4+)-doped ZnO-TiO_2 in Treating Pharmaceutical Wastewater

摘要

This experiment aims to prepare the Zn~(2+)-doped TiO_2 composite semiconductor materials by the sol-gel method and to characterize their crystal structures by X-ray diffraction and electron microscopy (SEM) scanning. The degradation target in this experiment is the pharmaceutical wastewater of a certain Chinese patent medicine, whose COD is as high as 300,000 mg/L and chroma is above 500 degrees. When the doping ratio of ZnO is 8%, the pharmaceutical wastewater's COD and chroma removal rates for 2h's degradation respectively reach 72.5% and 33.8%. The doping of Ce~(4+) or La~(3+) can improve the catalytic activity of ZnO-TiO_2. The cerium doped in can improve ZnO-TiO_2's catalytic property within 7%, and when the doping ratio of lanthanum is 0.4%, the chroma removal rate of the pharmaceutical wastewater reaches 65%, 31.2% more than that of the pure ZnO-TiO_2.