Removal of Cd, Cu, Ni, and Pb from Nanoscale Zero-Valent Iron Amended Soil Using 0.1 M Acetic Acid Solution

Abstract

The purpose of the study was to evaluate the possibility of removing heavy metal cations from single-metal spiked soil samples, which were pretreated with nanoscale zero-valent iron (nZVI) particles. Sandy soil was artificially contaminated with copper (Cu), cadmium (Cd), nickel (Ni), and lead (Pb). Contaminated soil samples were amended with different doses of nZVI (0.35, 0.70 and 1.05 %). A sequential extraction method was used to determine the fractionation of heavy metal cations in the control and nZVI amended soil samples. A solution of 0.1 M acetic acid (pH 3.0) was used to investigate the removal of heavy metals from control and nZVI-amended soil samples. The results showed that nZVI reduced the amount of metals in the exchangeable form and increased the proportion of these metals associated with amorphous iron (Fe) oxides. The results also showed that the removal efficiencies of heavy metals increased with increasing nZVI dose, that is, from 46.9 %, 5.77 %, 33.5 %, and 2.70 % to 55.9 %, 12.3 %, 46.2 %, and 3.79 % for Cd, Cu, Ni, and Pb, respectively. The study indicated that the application of nZVI in soil could be beneficial for subsequent removal of heavy metals from soil using 0.1 M acetic acid solution.

Keywords

• heavy metal removal
• immobilisation
• iron nanoparticles
• soil washing