TiO_2太阳光催化降解敌百虫废水的研究

Solar Photocatalytic Degradation of Trichlorfon Wastewater over TiO_2

采用溶胶-凝胶法制备TiO_2光催化剂,利用太阳光照射下催化降解敌百虫废水为模型反应,以钼蓝比色法测定敌百虫溶液矿化为无机磷的降解率,用KMnO_4法测定降解过程中溶液COD的变化,以液体紫外追踪反应过程中有机磷中间产物的变化,采用红外(IR)、X-衍射(XRD)和固体紫外(UV-vis)对催化剂进行了物相表征。结果表明:催化剂最佳焙烧温度为500℃、焙烧时间为2 h、催化剂的用量为4 g/L、有机磷的初始浓度为4 mg/L;在该反应条件下,反应90 min后,纯TiO_2在太阳光下对敌百虫溶液的降解率为91.8%,COD降解率为76.6%;同时溶胶-凝胶法制备的TiO_2(500℃,2 h)催化剂呈锐钛矿相,UV-vis光谱表明TiO_2(500℃,2h)的紫外吸收能力最强,佐证了TiO_2(500℃,2 h)具有良好光催化性能。

TiO2 was prepared by sol-gel method,and used for solar photocatalytic degradation of trichlorfon wastewater.Molybdenum blue colorimetric method was used to determine trichlorfon mineralized to inorganic phosphorus rate.COD value in the degradation process was determined by KMnO4 method in acid solution,and UV trace organic phosphorus changes during the reaction of the intermediate product.The obtained sample was characterized by 1R and X-ray Diffraction(XRD)and UV-vis.The results showed that the optimum roasting temperature of catalyst is 5002 h,the dosage of catalyst is 4^^L and the initial concentration of phosphorus is 4 mg^L.Un der the condition of reaction 90 min,the photocatalytic activity of pure TiOg was 91.8%and COD conversion is 76.6%under sunlight.Characterization results showed that TiO2(5002 h)prepared by sol-gel method was anatase,and had the strongest uv-light absorption capacity,resulted the best photocatalytic activity.