【摘要】 以亚甲基蓝(MB)作为表面修饰剂,采用简单的化学吸附法制备亚甲基蓝表面修饰的纳米TiO2光催化剂(TiO2-MB)。经表面修饰后,TiO2-MB光催化剂波长响应范围红移至可见光区575 nm处。探讨了光催化剂量、光照时间和溶液pH值对TiO2-MB光催化降解造纸废水的影响;研究了纳米TiO2-MB对造纸废水的暗吸附规律和光降解性能。结果表明:纳米TiO2-MB对造纸废水的吸附规律都较好地符合Langmuir和Freundlich吸附等温模型,属于吸热反应;光催化降解动力学符合Langmuir-Hinshelwood动力学模型。在160 W高压汞灯光照80 min,3.0 g/L纳米TiO2-MB光催化降解pH=2.0的造纸废水(COD:2 069.8 mg/L),COD去除率可达94.7%,处理效果远高于避光条件下。光催化剂经8次使用仍具有较高的催化活性。更多还原

【Abstract】 Nanometer size titanium dioxide modified with Methylene Blue(TiO2-MB)was prepared using chemical adsorption method.Through surface modification,the formation of TiO2-MB results in a red shift of UV-Vis reflectance spectra,towards the visible region,up to 575 nm.The influences of amount of catalyst,irradiation time and pH value on the photocatalytic degradation of papermaking wastewater on TiO2-MB were also studied.The adsorption and photocatalytic oxidation proceses of wastewater from papermaking on nano-TiO2-MB were studied.The results indicate that the adsorption law of wastewater from papermaking on nano-TiO2-MB fit in well with the Langmuir model and Freundlich model.Thermodynamic study showed the adsorption was an endothermic process.The photodegradation fits in with Langmuir-Hinshelwood kinetic mode.The optimal photodegradation conditions were obtained: catalyst amount of 3.0 g/L,papermaking wastewater’s pH value of 2.0,and irradiation time of 80 min with 160 W of high-pressure mercury lamp,the COD removal rate of papermaking wastewater reached 94.7%.The photodegradation efficiency was higher than the adsorption efficiency.The used photocatalyst could be used for the eighth time with high efficiency.更多还原