新型铁铈复合氧化物催化臭氧氧化工艺去除对硝基苯酚

Process of Catalytic Ozonation by Novel Fe-Ce Composite Oxides for P-Nitrophenol Removal

对硝基苯酚(4-NP)作为一种难降解的有机污染物,在自然环境中半衰期较长,对水生生物及水体环境均有不利影响。采用水热法制备新型铁铈复合氧化物,将其作为臭氧催化剂用于去除水中的4-NP。采用单因素试验,探究铁铈摩尔比、臭氧浓度、催化剂投加量、初始p H等因素对4-NP去除效果的影响。结果表明:在铁铈摩尔比为10∶1、水中臭氧浓度为7.0 mg/L、催化剂投加量为1.0 g/L、初始p H值为7时,催化臭氧法去除4-NP的速率最快,其反应假一级动力学常数为0.054 min-1,是单独臭氧氧化的4.2倍。添加Na HCO3可显著降低催化臭氧工艺的效率,间接证明了羟基自由基可能在有机物氧化过程中起到主要作用。

P-nitrophenol(4-NP),as a nonbiodegradable organic pollutant,has a long half-life in the natural environment,and has adverse effects on aquatic organisms and water environment.Novel Fe-Ce composite oxide was prepared by hydrothermal method,and it was used as a catalyst to remove 4-NP in water.The study used single-factor experiments to explore the effect of iron-cerium molar ratio,ozone concentration,catalyst dosage,and initial pH value on the removal of 4-NP.The results showed that when iron-cerium molar ratio was 10∶1,ozone concentration was 7.0 mg/L,dosage of the catalyst was 1.0 g/L,and initial pH value was 7,catalytic ozone method had the fastest removal rate of 4-NP,and pseudo-first-order kinetic constant of the reaction was 0.054 min^-1,which was 4.2 times that of ozone alone.NaHCO3 dosing could significantly reduce the efficiency of catalytic ozone process,which indirectly proved that hydroxyl radicals might play a major role in the oxidation of organic matter.