以硫化纳米零价铁为催化剂类芬顿体系降解亚甲基蓝的研究

Study on Degradation of Methylene Blue in Fenton-like System Using Sulfidated Zero-Valent Iron as Catalyst

采用硼氢化钠液相还原法,以Na2S为硫源, FeSO4为铁源,通过一步法制备硫化纳米零价铁(sulfidated zero-valent iron, S-nZVI),利用X射线衍射仪(X-ray diffraction, XRD)、扫描电子显微镜(scanning electron microscopy,SEM)对S-nZVI进行表征。并考察以S-nZVI为催化剂类芬顿(Fenton)体系降解亚甲基蓝(methylene blue, MB)的性能研究和影响因素。SEM和XRD结果显示S-nZVI具有片状结构,主要成分为零价铁并含有少量的FeS和铁氧化物。MB降解研究表明,以S-nZVI为催化剂的类Fenton体系对MB具有良好的降解性能,有效解决了传统Fenton体系pH适用范围窄的问题, pH范围从3~5拓宽至3~9。当溶液初始呈近中性(pH=6)时,该体系对MB的降解率为80%;当溶液呈碱性时(pH=9), MB的降解率仍在70%以上。

The sulfidated zero-valent iron(S-nZVI) was prepared by one-step process using Na2 S as the sulfur source and FeSO4 as the iron source by liquid-phase reduction with sodium borohydride. The properties of S-nZVI were studied by X-ray diffraction(XRD)and scanning electron microscope(SEM). The performance and influencing factors of methylene blue(MB) degradation using S-nZVI as a catalyst Fenton system were investigated. SEM and XRD results show that S-nZVI has a flake structure and is mainly composed of zero-valent iron with small amounts of FeS and iron oxides. The results of MB degradation show that the Fenton-like system with S-nZVI as the catalyst effectively solves the problem of the narrow application range of the traditional Fenton system, and the pH range is widened from 3~5 to 3~9. When the solution is initially nearly neutral(pH=6), the degradation rate of MB by this system is 80%,when the solution is alkaline(pH=9), the degradation rate of MB is still above 70%.