In order to develop the high photocatalytic activity of TiO2 under visible light as that under ultraviolet light and make it easy to be separated from treated liquor, a visible light response and spherical activated carbon （SAC） supported photocatalyst doped with upconversion luminescence agent Er3＋：YAlO3 was prepared by immobilizing Er3＋：YAlO3/TiO2, which was obtained by combination of Er3＋：YAlO3 and TiO2 using sol-gel method, on the surface of SAC. The crystal phase composition, surface structure and element distribution, and light absorption of the new photocatalysts were examined by X-ray diffraction （XRD）, energy dispersive X-ray spectra （EDS） analysis, scanning electron microscopy （SEM） and fluorescence spectra analysis （FSA）. The photocatalytic oxidation activity of the photocatalysts was also evaluated by the photodegradation of methyl orange （MO） in aqueous solution under visible light irradiation from a LED lamp （λ400 nm）. The results showed that Er3＋：YAlO3 could perform as the upconversion luminescence agent which converts the visible light up to ultraviolet light. The Er3＋：YAlO3/TiO2 calcinated at 700 °C revealed the highest photocatalytic activity. The apparent reaction rate constant could reach 0.0197 min-1 under visible light irradiation.
以城市污水为处理对象,以絮状污泥为接种污泥,在连续流气提式好氧颗粒污泥流化床(CAFB)反应器中成功培养得到好氧颗粒污泥。探讨了CAFB中颗粒污泥的形成过程、生物多样性、有机物的去除行为及氮转化特性。研究结果表明,CAFB运行第7天颗粒污泥占主要优势,系统中依次出现原、后生动物,表明颗粒污泥趋于成熟。CAFB反应器中培养的好氧颗粒污泥具有良好的COD及NH4+-N去除能力。稳定运行阶段,当进水的COD容积负荷在1.5～3.5 kg COD/(m3·d)的范围时,COD的去除负荷稳定在1.0～2.0 kg COD/(m3·d)。控制水力停留时间为(4±0.25)h、溶解氧质量浓度为(5±0.5)mg/L,可达到最高的硝化效率,但此控制条件下反硝化作用不明显。分析认为,作为完全混合式反应器的CAFB,需要较严格的控制溶解氧才能实现同步硝化反硝化作用。
