Zero-valent iron (ZVI) nanoparticles tend to agglomerate, resulting in a significant loss in reactivity. To address this issue, synthesized low-cost natural clay (HJ clay)-supported nanoscale zero-valent iron (B-nZVI) was used to remove azo dye methyl orange (MO) in aqueous solution. At a 5:1 HJ/nZVI mass ratio (HJ-nZVI5), the best dispersity, reactivity and the highest MO decolorization efficiency was achieved. The characterization and MO decolorization experiments showed that the presence of HJ clay decreased aggregation of iron nanoparticles and increased their reactivity. Under the same Fe0 dosage, the MO decolorization efficiency of the HJ-nZVI sample was superior to physical mixing of HJ clay and nZVIs, or the sum of HJ clay and nZVIs alone. Batch experiments also showed that higher decolorization efficiency of MO was obtained at larger HJ-nZVI dosage, higher temperature and under N2 atmosphere, while the efficiencey decreased as the MO initial concentration and pH increased. An “adsorption-enhanced reduction” mechanism is proposed, which means that HJ clay not only works as a carrier for nZVI nanoparticles, but also contributes to the decolorization. This provided a new environmental pollution management option for dyes-contaminatedsites.

Removal of methyl orange from aqueous solution using HJ clay-supported nanoscale zero-valent iron

252nd National Meeting (2016)

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