纳米α-Fe_2O_3合成及光催化法处理染料中间体废水

Synthesis of nano-sized α-Fe_2O_3 and treatment of dye-intermediate wastewater by photocatalytic method

用回流均匀沉淀法合成了纳米三氧化二铁粉体并对其进行了表征,所得产物均为高纯度纳米α-Fe2O3。探讨了干燥方式及煅烧温度等制备条件对催化剂性能的影响。以纳米三氧化二铁为催化剂,高压汞灯为光源,用光催化法处理染料中间体废水。考察了三氧化二铁用量、双氧水用量、pH、反应时间等因素对降解效果的影响,结果表明:Fe2O3/UV/H2O2体系能有效地降低废水中的CODCr,在三氧化二铁用量为1.50 g/L、双氧水用量为1.5‰(体积分数)、pH=3.0、300 W汞灯光照4 h的条件下,废水的CODCr从1 177 mg/L降到533 mg/L,去除率达到56.88%。太阳光/Fe2O3/H2O2体系处理废水,CODCr去除率也可达到48.50%。对处理前后废水中的有机污染物成分进行GC-MS分析,证明该法可有效地降解废水中大多数有害物质。

Nano-sized α-Fe2O3 powder was synthesized by refluxing homogeneous precipitation method and characterized subsequently.All the products were high-purity nano-sized α-Fe2O3.Influence of drying method and calcination temperature etc.on performance of catalyst was studied.Dye-intermediate wastewater was treated by photocatalytic method with nano-sized Fe2O3 as catalyst and high-voltage mercury lamp as light source.Influence of factors,such as the dosage of Fe2O3 and H2O2,pH,and reaction time,on degradation effect was investigated.Results indicated that the system of Fe2O3/UV/H2O2 could effectively decline CODCr in wastewater.Under the optimum conditions that the dosage of Fe2O3 was 1.50 g/L,V（H2O2）=1.5‰,pH=3.0,and radiation power and time were 300 W and 4 h,the CODCr of wastewater was reduced from 1 177 mg/L to 533 mg/L,and removal rate of CODCrwas 56.88%.Results also showed that even with sunlight the removal rate of CODCrcould also reach 48.50%.Organic pollutants in treated and untreated wastewater were analyzed by GC-MS and results showed that effective degradation of most pollutants could be reached using the above mentioned method.