Cr(VI)Removal from Aqueous Solution with Nanoscale Zero-valent Iron

Nanoscale zero-valent iron(NZVI)was synthesized in aqueous solutions by reduction of Fe3+ with NaBH4.The samples were characterized with XRD and SEM.Adsorption of Cr(Ⅵ) ions on NZVI was investigated to understand the effect of dosages of NZVI,initial concentrations of C(rⅥ)ions and temperature on the adsorption kinetics.It was found that removal efficiency of C(rⅥ)containing 20.0 mg/L was higher than 99.5% with NZVI adsorbent 0.15 g/L and contact time 210 min.Kinetics of Cr(Ⅵ) removal was found to follow the pseudo-second-order rate equation,with the maximal adsorption capacity of 198.02 mg/g.The experimental data showed that the new type of adsorbent is very attractive for removal of C(rⅥ)from wastewater.