纳米Fe3O4/皂石复合材料的制备及去除2,4-二氯苯酚的性能研究

本文以水热合成法和共沉淀法制备了纳米Fe₃O₄/皂石复合材料,并用于去除水中2,4-二氯苯酚(2,4-DCP)。采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、透射电子显微镜(TEM)和X射线荧光光谱(XRF)等表征手段测试了纳米Fe₃O₄/皂石复合材料的物相组成、结构、形貌和元素组成,并考察了纳米Fe₃O₄/皂石复合材料在不同2,4-DCP溶液浓度、反应时间和pH等条件下对2,4-DCP的去除效果。结果表明,在皂石表面原位生长的纳米Fe₃O₄分散较为均匀,有效降低了Fe₃O₄的团聚现象。纳米Fe₃O₄/皂石复合材料在溶液pH值为6时,对2,4-DCP的最大去除量为178.46 mg/g,在反应时间为5 min时,对2,4-DCP去除量达到饱和。纳米Fe₃O₄/皂石复合材料对2,4-DCP的去除动力学符合准二级动力学模型。在此基础上,通过液相质谱联用(LC-MS)检测出2,4-DCP被降解后生成了氯酚等中间产物。本研究成果为水中有机污染物的降解提供了一种新型、环保且高效的环境功能材料。

Preparation of Nano-Fe3 O4/Saponite Composites and Removal Performance of 2 ,4-Dichlorophenol

In this study, the nano-Fe₃O₄/saponite composites were prepared by hydrothermal synthesis and coprecipitation method, and used to remove 2,4-dichlorophenol (2,4-DCP) from water. The phase composition, structure, morphology and elemental composition of nano-Fe₃O₄/saponite composites were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray fluorescence (XRF). The removal efficiency of 2,4-DCP by nano-Fe₃O₄/saponite composites under solution with different 2,4-DCP concentration, reaction time and pH were investigated. The results show that the in-situ growth of nano-Fe₃O₄ on the surface of saponite is more evenly dispersed, which effectively reduces the agglomeration of Fe₃O₄. The maximum removal of 2,4-DCP by nano-Fe₃O₄/saponite composites is 178.46 mg/g when the pH value is 6, and the removal of 2,4-DCP reaches saturation when the reaction time is 5 min. The removal kinetics of 2,4-DCP by nano-Fe₃O₄/saponite composites accords with the pseudo-second-order kinetic model. On this basis, liquid chromatography-mass spectrometry (LC-MS) analysis shows that 2,4-DCP is degraded into chlorophenol and other intermediate products. The research results provide a new, environmentally-friendly and efficient environmental functional material for the degradation of organic pollutants in water.