Efficient Removal of Hexavalent Chromium from an Aquatic System Using Nanoscale Zero-Valent Iron Supported by Ramie Biochar

Nanomaterials

Muhammad Shaaban¹  Yajun Cai²  Xiangpeng Tan²  Jianwei Yang²  Buyun Wang²  Qi-An Peng² 

[1] Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China;School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China;

关键词: heavy metals;    hexavalent chromium;    nanoscale zero-valent iron;    biochar;    removal mechanism;   

DOI  :  10.3390/nano11102698

来源: DOAJ

【 摘 要 】

In this study, ramie biochar (RBC) was used to activate nano zero-valent iron (nZVI) to enhance hexavalent chromium (Cr(VI)) removal. The best results were obtained at a pyrolysis temperature of 600 °C, a biochar particle size of < 150 μm, and an iron to carbon ratio = 1:1. Under the optimal conditions, the removal of Cr(VI) by RBC600-nZVI (98.69%) was much greater than that of RBC600 (12.42%) and nZVI (58.26%). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) revealed that the reaction mechanism at the Fe and Cr interface was a multiple interaction mechanism with reduction dominated, adsorption, and co-precipitation simultaneously. The enhanced performance of RBC600-nZVI resulted from the effective dispersion of nZVI on the surface of RBC600, therefore increasing the adsorption activity sites. At the same time, RBC600 and nZVI exerted a synergistic influence on the composite structure, which jointly promoted the reduction reaction of Cr(VI) and removed more Cr(VI). This study shows that RBC-nZVI is a potentially valuable remediation material that not only provides a new idea for the utilization of ramie waste, but also effectively overcomes the limitations of nZVI, thus, achieving efficient and rapid remediation of Cr(VI).

【 授权许可】

Unknown