Polyethylene glycol-stabilized bimetallic nickel-zero valent iron nanoparticles for efficient removal of Cr(vi)

In order to solve the agglomeration of nanoscale zero-valent iron (nZVI) and improve its performance in pollutant treatment, polyethylene glycol-stabilized nickel modified nZVI (Ni/Fe-PEG) was synthesized by a liquid-phase reduction method and used to treat Cr(vi) solution for the first time. The main influencing factors were optimized as follows: a Ni/Fe-PEG dosage of 0.6 g L-1, an initial pH value of 5.0, and an initial Cr(vi) concentration of 50 mg L-1. More than 99% of Cr(vi) is removed in 60 min. The excellent performance of Ni/Fe-PEG is attributed to its strong adsorption, reduction and co-precipitation. More specifically, Cr(vi) is first adsorbed on the surface of Ni/Fe-PEG, then reduced to Cr(iii) by nZVI, and finally, Cr(iii) and Fe(iii) are co-precipitated. In Ni/Fe-PEG, PEG can disperse nZVI, while Ni can weaken the oxidation of nZVI and facilitate the reduction of Cr(vi).

Automated summary

Ni/Fe-PEG was synthesized and used for the first time to treat Cr(vi) solution, showing high removal efficiency under optimized conditions. The excellent performance of Ni/Fe-PEG in pollutant treatment is mainly attributed to its adsorption, reduction, and co-precipitation abilities for removing Cr(vi).