F-127改性纳米零价铁及对水中2,4-DCP的去除

Modified nano zero-valent iron by F-127 and its application in removal of 2,4-dichlorophenol in water

为了增强纳米零价铁的分散性,本研究采用环境友好型材料Pluronic F^-127对纳米零价铁(NZVI)进行表面改性,形成分散型纳米零价铁(F-NZVI),并用于水中2,4-DCP的去除.通过不同质量比的F-NZVI颗粒沉降试验和对2,4-DCP的去除试验,发现存在沉降去除和悬浮去除两个阶段,确定F^-127与NZVI颗粒的最佳质量比为2∶1,2,4-DCP最大去除率为72.32%.通过SEM、FTIR、XRD、XPS对样品进行表面形貌、组成和晶体结构分析,发现F^-127对提高NZVI分散性和抗氧化性有显著作用.通过控制不同因素研究F-NZVI去除水中2,4-DCP的最优条件,实验结果表明,当2,4-DCP初始浓度为20mg·L^-1时,F-NZVI去除2,4-DCP的最佳pH值为5,F-NZVI最佳投加量为3g·L^-1.

To enhance the dispersivity of nano zero-valent iron(NZVI) used for removing 2,4-DCP from water, the surfaces of NZVI was modified with F^-127 as an environmentally friendly organic stabilizer. Based on different mass ratio of F-NZVI particles sedimentation experiment and 2,4-DCP removal experiment,two-stage process(sedimentation removal and suspension removal) was found. The optimum mass ratio of F^-127 to NZVI particles was found to be 2∶1 and the maximum removal efficiency was 72.32%. The surface morphology, composition and crystal structure of the samples were analysed by using scanning electron microscope(SEM), Fourier Transform Infrared Spectroscopy(FTIR), X-Ray Diffraction(XRD) and X-ray photoelectron spectroscopy(XPS), respectively. Results show that F^-127 significantly improved NZVI dispersibility and oxidation resistance. Final,the main factors of F-NZVI for the removal 2,4-DCP in water were studied to find the optimal 2,4-DCP removal condition, which were pH=5, 3 g·L^-1 F-NZVI for 20 mg·L^-1 of 2,4-DCP.