黄铁矿催化类Fenton反应处理阳离子红X-GRL废水

基于对天然矿物黄铁矿进行SEM、EDS表征的基础上,以黄铁矿为非均相类Fenton催化剂,以偶氮染料阳离子红X-GRL为目标污染物,考察了催化剂双氧水用量、溶液初始pH值、阳离子红X-GRL初始浓度、反应时间等因素对染料脱色效果的影响.结果表明,在H2O2浓度为26.6mg/L、矿用量1g/L、溶液初始pH值6.4左右的条件下,反应2min后,染料脱色率达95%左右.进行了黄铁矿在水溶液中的酸性氧化实验并且考察了Fe2+、SO42-浓度及溶液pH随矿重复利用次数的变化规律.初次使用的黄铁矿具有很强的酸性氧化特性,反应过程中伴随着大量Fe2+、SO42-及H+的溶出.染料的快速脱色主要是均相Fenton反应作用的结果.黄铁矿作为一种新的催化剂大大提高了类Fenton反应的催化活性,而且该新型类Fenton反应能克服传统Fenton反应适用pH范围小的局限性,拓展了Fenton反应在废水处理中的应用.

Treatment of Cationic Red X-GRL wastewater by pyrite catalyzed Fenton-like reaction

The naturally occurring pyrite was characterized using scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS) and used as a Fenton-like catalyst to catalyze H2O2 oxidative discoloration of Azo dye.Factors(solution pH,pollutant initial concentration,H2O2 and pyrite dose,and reaction time) affecting the catalytic performance have been investigated.Results showed that about 95% of color removal rate can be achieved at pH 6.4 after 2min of reaction with 26.6mg/LH2O2 and 1g/L pyrite.To get a deeper understanding of the reaction mechanism,the acid oxidation of pyrite surface in water solution was examined.Results demonstrated that the reutilization times of pyrite has a significant effect on the performance of aid reaction,which was clearly indicated by the concentration change of leached ferrous iron,sulfate and variation of solution pH values.High level of ferrous iron and sulfate in solution along with a great decline in solution pH can be detected when raw pyrite was added to the water solution.Therefore,the observed rapid discoloration of Azo dye in this study was mainly attributed to the homogeneous Fenton reaction between dissolved ferrous iron and H2O2.This research revealed that the catalytic rate of Fenton-like reaction can be greatly improved using pyrite as a new kind of catalyst.Pyrite’s utilization as a catalyst contributes to overcome the limitation of traditional Fenton reactions,and expands the application of Fenton-like reaction in wastewater treatment.