Removal of Cr(Ⅵ) in aqueous solution by amorphous zero-valent iron supported on attapulgite

Amorphous zero-valent iron (AZVI) was loaded on the surface of attapulgite (ATP) by liquid phase reduction method to prepare ATP-loaded AZVI composite (ATP-AZVI). We investigated the removal characteristics of Cr(Ⅵ) by ATP-AZVI, and characterized the composite materials by means of scanning electron microscope(SEM), atomic force microscope(AFM), X-ray diffraction(XRD) and N2 adsorption-desorption measurement(BET) to verify the reliability of loading and the mechanism of Cr(Ⅵ) removal. The results show that the AZVI is dispersed on the surface of the attapulgite, and the agglomeration effect is relieved. Compared with the crystalline zero-valent iron loaded ATP composite (ATP-ZVI), ATP-AZVI has a larger specific surface area and better hydrophilic property. ATP-AZVI has good removal effect on Cr(Ⅵ), 97.4% of Cr(Ⅵ) can be removed after 30 min of reaction, and experiments proves that AZVI-loaded attapulgite has strong applicability. The removal mechanism study shows that ATP slows the agglomeration of AZVI and accelerates the electron transfer. Cr(Ⅵ) is reduced to Cr(Ⅲ) and then precipitates with Fe(Ⅲ) on the surface of the material, thus achieving the purpose of removal. © 2022, China Science Publishing & Media Ltd. All right reserved.