超声协同TiO_2/粉煤灰光催化联合处理垃圾渗滤液

Treatment of landfill leachate by combination of TiO_2-coated fly ash photocatalyst and ultrasonic technique

采用溶胶-凝胶法将TiO2负载到粉煤灰上,通过XRD、SEM对TiO2/粉煤灰催化剂进行了表征。用该光催化剂对垃圾渗滤液进行了超声辅助光催化降解,比较了不同催化剂种类、催化剂的用量、酸度、催化剂重复使用次数等因素对垃圾渗滤液COD降解率的影响。结果表明:煅烧温度对催化剂的晶型有一定影响,550℃煅烧条件下,TiO2平均晶粒尺寸为11.12 nm,锐钛相占约80%。在超声波协同作用下,TiO2/粉煤灰对垃圾渗滤液COD的光催化降解效果良好,当催化剂加入量为2 g/L,溶液pH为10时,100 min降解率可达73.3%。催化剂经活化处理后,相同条件下重复使用5次,对渗滤液的降解率仍达68.4%。

TiO2-coated fly ash catalyst（ TiO2/ FA photocatalyst） is prepared by sol-gel method and characterized by XRD and SEM. The degradation of landfill leachate by combination of ultrasound and light is carried out. The effects of catalyst type and dosage,pH and reusing times of TiO2/ FA catalysts on degradation ratios are performed. The results show that the calcination temperature has the influence on crystal phase. The average particle size of TiO2is 11. 12 nm and anatase phase is about 80% when calcination temperature is 550℃. The TiO2/ FA catalysts are very effective for the degradation of landfill leachate under the light and ultrasonic wave. About 73. 3% of landfill leachate can be degraded after 100 minutes when catalyst dosage is 2 g / L and pH is 10. The TiO2/ FA catalyst can be recovered by filtration and regain the photocatalytic activity by calcination. The degradation ratio is still about 68. 4% even if the catalyst is reused for 5 times.