Synthesis of Zero-Valent Iron Nanoparticles Via Electrical Wire Explosion for Efficient Removal of Heavy Metals.

In this paper, electrical wire explosion (EWE) was used as a simple, clean, in situ method to synthesise nano zero-valent iron (nZVI) particles in liquid mediums. The structural and physical properties of the synthesised nZVI particles were characterised by x-ray diffraction, Brunauer-Emmett-Teller analysis, field emission scanning electron microscopy and transmission electron microscopy. The synthesised spherical nanoparticles, at a specific size of 10-50 nm, possessed large surface areas of approximately 13.27 m²/g, reinforcing the significant advantages of EWE, that is, less aggregation and in situ production of nanoparticles with enhanced removal efficacy, for groundwater treatment. After 1 h the adsorption capacity for Cr(VI), Ni(II), and Cd(II) ( Q₆₀ = C_ions/ C_iron (mg/g)) at pH 4 was approximately 143.4 (89.0%), 137.5 (79.0%), and 132.6 mg/g (72.0%), respectively. The effect of temperature was also examined at initial metal ions concentration of 70 mg/L, nZVI dosage of 0.2 g/L and pH 4. The results showed 45°C was the optimum temperature for adsorption of Cr(VI), Ni(II), and Cd(II) ions, and over a 60-min period at this temperature adsorption capacity increased to 153.56 (95.3%), 158.91 (91.3%), and 163.90 mg/g (89.0%), respectively. [ABSTRACT FROM AUTHOR]