Synthesis, characterization and application of starch stabilized zerovalent iron nanoparticles in the remediation of Pb-acid battery soil

Arable and residential soils are being lost in major metropolitan cities and remote areas. The need for innovative and advanced materials that are cost effective and efficient in the environmental remediation of heavy metals continue to remain a major challenge both in developed and developing nations. In this regard, nanoparticles have received considerable attention for its potentials in the remediation of groundwater and sites. This study reports on the effect of starch supported zero-valent iron nanoparticles on Pb-acid battery soil physico-chemical properties. The starch stabilized zero-valent iron nanoparticles (nZVI-Starch) were synthesized using the chemical reduction method. The nZVI-Starch nanoparticles crystallographic, magnetic and particle size distribution properties were investigated using X-ray diffraction (XRD), physical property measurement system (PPMS) and zetasizer techniques. Composite soil samples were collected from a lead acid battery dump-site, characterized and used to evaluate effects of nZVI-Starch on the physic-chemical properties of Pb acid battery polluted soils. XRD pattern of S-ZVFe powder corresponds to that of pure nZVI-Starch nanoparticles, having an average diameter size 9.28 nm as calculated using the Debye Scherer equation. The hydrodynamic size distribution shows that the nanoparticles were mono-dispersed and superparamagnetic in nature with saturation magnetization of 27 emu/g. Speciation results showed that Zn was associated with the mobile fraction of the soil and Pb was fairly distributed in the organic, Fe-Mn, and residual fractions. After treatment of the parent soil with 1000 mg/kg of nZVI-Starch, the fractions of the heavy metals in the mobile fractions became redistributed in the less mobile/bioavailable fractions.