Remediation of Lead and Nickel Contaminated Soil Using Nanoscale Zero-Valent Iron (nZVI) Particles Synthesized Using Green Leaves: First Results

Abstract

Nanoscale zero-valent iron (nZVI) particles have proved to be effective in the remediation of chlorinated compounds and heavy metals from contaminated soil. The present study aimed to analyze the performance of nanoparticles synthesized from low-cost biomass (green leaves) as chemical precursors, namely Azadirachta indica (neem) and Mentha longifolia (mint) leaves. These leaves were chosen because huge amounts of them are present in the region of Vellore. These nanoparticles were used to remove lead and nickel from contaminated soil. Characterization of nZVI particles was conducted using the Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Brunauer–Emmett–Teller isotherm (BET) techniques. Remediation was performed on two different soil samples, polluted with lead or nickel at an initial metal concentration around 250 mg/kg of soil. The results revealed that after 30 days, the lead removal efficiency with 0.1 g of nZVI particles/kg of soil was 26.9% by particles synthesized using neem leaves and 62.3% by particles synthesized using mint leaves. Similarly, nickel removal efficiency with 0.1 g of particles/kg of soil was 33.2% and 50.6%, respectively, by particles using neem and mint leaves. When the nanoparticle concentration was doubled, Pb and Ni removal improved, with similar trends obtained at a lower dosage (0.1 g of particles/kg of soil). These first results evidenced that: (1) the nZVI particles synthesized using green leaves had the potential to remove Pb and Ni from contaminated soil; (2) the neem-derived particles gave better Ni removal efficiency than Pb one; (3) the mint-derived particles showed better Pb removal efficiency than Ni one; (4) the highest removal efficiency for both metals was achieved with the mint-derived particles; (5) double higher dosage did not greatly improve the results.

Application of nanotechnology for remediation drill cutting soil

“…Percentage removal rate of contaminant used to distinguish the volume of the removed contaminant between heavy metals and petroleum hydrocarbons in drill cutting soil (Francy et al, 2020).…”

Enhanced Adsorption of Cd on Iron–Organic Associations Formed by Laccase-Mediated Modification: Implications for the Immobilization of Cadmium in Paddy Soil

“…Lin et al synthesized GION (green synthesized iron oxide nanoparticles) using OM extracted from red-backed laurel ( Excoecaria cochinchinensis ) leaves and iron, which reduced exchangeable Cd and carbonate-bound Cd in the soil by 14.2–83.5% and 18.3–85.8%, respectively [ 44 ]. Francy et al synthesized nanoscale zero-valent iron (nZVI) from Azadirachta indica (neem) and Mentha longifolia (mint) leaves, which successfully reduced the active Pb and Ni in the soil by 66.1% and 56.8%, respectively [ 45 ].…”

Influence of the Alcoholic/Ethanolic Extract of Mangifera indica Residues on the Green Synthesis of FeO Nanoparticles and Their Application for the Remediation of Agricultural Soils

“…The absorption of Cr (VI) in sandy loam soil was stable up to a concentration of 100 mg/L; subsequently it decreased as a result of the availability of active sites for the adsorption of Cr, deducing an increase in the particle dose for higher concentrations of pollutant. The estimated pH to achieve good results is between 2-6 on the acid scale, and [29] obtained iron nanoparticles and carried out a comparative analysis of chemically synthesized nanoparticles with extracts of neem and mint leaves; the removal of lead and nickel at a concentration of 0.1 g NP/Kg of soil shows that the NP by NaBH 4 removed 21.6% Pb and 18.5% Ni; while with neem extract 26.9% Pb and 33.2% Ni. The low removal efficiency is the product of agglomeration and exposure to the atmosphere resulting in oxidation of the surface of the particles.…”