The humic acid influenced the behavior and reactivity of Ni/Fe nanoparticles in the removal of deca-brominated diphenyl ether from aqueous solution.

The removal of contaminants by iron-based nanomaterials was inevitably affected by the natural organic matter (NOM), which is one of the most abundant material on earth and exists in natural waters. This study was performed to investigate the main influence of humic acid (HA, representing NOM) on the behavior and reactivity of Ni/Fe nanoparticles in the removal of deca-brominated diphenyl ether (BDE209). Generally, the inhibitory effect of HA on the removal of BDE209 by Ni/Fe showed greater significance with an increase of HA concentration. The zeta potential and sedimentation experiments showed that the HA enhanced the dispersion and stabilization of Ni/Fe particles; however, the removal of BDE209 was found to be inhibited. Moreover, the corrosion capacity of the Ni/Fe nanoparticles showed a positive correlation with the effect of HA on the reactivity of Ni/Fe nanoparticles. Meanwhile, typical quinone compounds in HA had an adverse effect on the removal of BDE209. Additionally, the competitive adsorption experiments and characterization illustrated that the adsorption of HA by Ni/Fe nanoparticles was superior to BDE209. Overall, it was proposed that the corrosion of Ni/Fe was reduced as the contact between the nanoparticles and HO was hindered due to the surface of Ni/Fe was occupied by the adsorbed HA, and thus inhibited the reactivity of Ni/Fe nanoparticles in the removal of BDE209.