Cr (Ⅵ) Removal from Aqueous Solution Using Starch and Sodium Carboxymethyl Cellulose-Coated Fe and Fe /Ni Nanoparticles

摘要

Starch and sodium carboxymethyl cellulose-coated Fe and Fe/Ni nanoparticles were synthesized and their Cr (VI) removal capabilities were evaluated and compared. We found that starch and sodium carboxymethyl cellulose-coated nanoscale zero-valent iron-nickel (SS-nZVI-Ni) showed the better Cr (VI) removal performance. The effect of acidic conditions on Cr(VI) removal by SS-Nzvi-Ni revealed that the Cr (VI) removal efficiency by SS-nZVI-Ni reached the maximum of 95.70% at pH = 2. The effect of different initial Cr (VI) concentrations showed that SS-nZVI-Ni performed well at a high Cr(VI) concentration. Langmuir-Hinshelwood first-order kinetic model could describe the reduction process well. SEM images revealed that SS-nZVI-Ni had a large surface area, which discarded the problem of aggregation. XRD and XPS analysis of SS-nZVI-Ni showed that SS-nZVI-Ni and Cr (III) formed an alloy on the surface of SS-nZVI-Ni after the reaction. The study provides an option for practical application of SS-nZVI-Ni in Cr (VI) removal.