MnO_(2)/Al_(2)O_(3)用于臭氧催化氧化处理难降解有机废水的研究

Study on MnO_(2)/Al_(2)O_(3)Ozone Catalyticoxidation Treatment of Refractory Organic Wastewater

本文以活性氧化铝为载体,采用浸渍法负载活性金属物质MnO_(2)制备MnO_(2)/Al_(2)O_(3)复合负载型催化剂,将其用于臭氧催化氧化降解甲基橙模拟废水。本文的研究考察了催化剂组成、催化剂用量、臭氧投加量等不同因素对甲基橙去除效率的影响。结果表明:甲基橙废水浓度CODCr为1400 mg/L,废水体积为1 L时,最佳工艺条件是载体Al_(2)O_(3)与活性组分MnO_(2)摩尔比为1:1,催化剂投加量为800 mL,臭氧投加量为50 mg/(L·h),反应时间为60 min。研究对比了四种氧化工艺降解甲基橙的效果,发现单独臭氧和臭氧+载体Al_(2)O_(3)两种情况去除CODCr效率相近且反应速率最慢,其次是臭氧+MnO_(2)。降解速率最快的是臭氧+催化剂,在反应30 min时就已经达到96.8%,说明在MnO_(2)/Al_(2)O_(3)复合催化剂的作用下,进一步强化了臭氧氧化能力。最后,经过6次重复实验后发现,臭氧催化氧化降解甲基橙仍然保持97.1%的去除效率,说明该催化剂具有良好的循环稳定性。

A composite catalyst of MnO_(2)supported on activated alumina was prepared by impregnation method for ozone catalytic oxidation of methyl orange simulatedwastewater.The effects of different factors such as catalyst composition,catalyst dosage,and ozone dosage on the removal efficiency of methyl orange were investigated.The results showed that the optimum molar ratio of Al_(2)O_(3)carrier to the active component MnO_(2)was 1:1,the catalyst dosage was 800 mL,the ozone dosage was 50 mg/(L·h)and the reaction time was 60 min when the concentration of CODCr in methyl orange wastewater was 1400 mg/L and the volume of wastewater was 1L.Comparing the effects of four different oxidation processes on removal of methyl orange,it was found that the removal efficiency of CODCr was similar and the reaction rate was the slowest in the cases of ozone alone and ozone+Al_(2)O_(3)carrier,and followed by ozone+MnO_(2).The fastest degradation rate was achieved by ozone+catalyst,which reached 96.8%within 30 minutes reaction,indicating that the ozonation ability had been further strengthened under the action of MnO_(2)/Al_(2)O_(3)adsorption-ozone catalytic oxidation treatment.Finally,it was found that the CODCr removal efficiency by the adsorption-ozone catalytic oxidation treatment still maintained 97.1%after 6-time cycle experiments,indicating that the catalyst had good cycling stability.