Application of Carboxymethyl Cellulose-Stabilized Sulfidated Nano Zerovalent Iron for Removal of Cr(Ⅵ) in Simulated Groundwater

摘要

Carboxymethyl cellulose-stabilized sulfidated nano zerovalent iron (CMC-S-nZVI) was tested for its capacity to the removal of Cr(VI) in this study. The effect of synthesis approaches on morphology and properties of CMC-S-nZVI was studied. Results revealed CMC-S-nZVI prepared by the surface corrosion method had favorable homogeneity and corrosion resistance. The structure and morphology of CMC-S-nZVI particles were investigated by transmission electron microscopy, X-ray powder diffraction, and Fourier-transform infrared spectrometry. Batch experiments showed that the removal efficiency of Cr(VI) by the CMC-S-nZVI particles was influenced by the S/Fe molar ratio, initial pH, initial Cr(VI) concentration, and the reaction temperature. Increasing S/Fe molar ratio from 0 to 0.35 enhanced Cr(VI) removal efficiency from 65.37 to 85.08%. Reducing pH value and improving the reaction temperature have a positive impact on Cr(VI) removal. The removal amount was 535mg/g (total iron) CMC-S-nZVI with initial Cr(VI) concentration of 50mg/L. Compared with CMC-nZVI, CMC-S-nZVI had better performance in Cr(VI) removal in a simulated groundwater system. The results indicated that CMC-S-nZVI might be applicable for in situ treatment of the Cr(VI)-containing groundwater.