Green and Sustainable in situ Remediation of Heavy Metals Contaminated Soils and
Aqueous Systems
Project Summary: This SBIR phase I project will demonstrate the feasibility of in situ
remediation of heavy metals Pb(II), Cd(II), Cu(II), Hg(II), Ni(II), Cr(VI), As(V), and Sb(V)
contaminated soils and aqueous systems using novel green Fe-P nanoparticles synthesized using
a proprietary (US Patent Pending) process. The widespread contamination of soils, surface
waters, and ground water with heavy metal(loid)s currently represents one of the most severe
environmental problems that can seriously affect environmental quality and human health. The
project is particularly pertinent to contaminated soils, sediments and groundwater such as for the
USS lead superfund site. Current and ongoing clean up of the USS lead superfund site located in
East Chicago and Indiana is via direct excavation of contaminated soils to landfills costing in
excess of 100 million dollars. The disturbance to the environment and workers exposure to toxic
metals is much higher during the excavation, removal, and storage of contaminated soil to
landfills w/o solving the contamination problem. Thus next generation, green, and cost-effective
in situ remediation approaches with a clear impact on human health are needed. As part of the
proposed SBIR phase I work, we will determine optimal Fe-P dosage to achieve remediation
efficacy in soil and aqueous systems to meet EPA mandated MCL for respective metalloids and
show the efficacy of this approach in real world samples of contaminated ground water.
Unique advantages of our technology include: 1) The proposed Fe-P nanoparticles unlike current
Fe based nanoparticles are based on a new paradigm and are effective in remediating all trace
metals in contaminated soils and groundwater; 2) while being an order of magnitude more cost-
effective than current state of the art; it's synthesis is simple using a green process. They are
similar to natural minerals found in soils (unlike nanozerovalent Fe) thus there is no concern
with bioaccumulation or other adverse effects on human health; and 3) Fe-P nanoparticles utilize
dual Fe-OH2+ and O-PO43- functional groups enabling permanent binding of cationic and anionic
metalloids enabling a one step solution to mixed metal contamination (as is often the case).
Unlike nZVFe and other iron based nanoparticles, they do not aggregate or need external
stabilizers and do not corrode. This would guarantee stability compared to the current state of the
art where immobilized phases are not very stable with low dissociation energies. Finally,
reductive immobilization of Cr(VI) to Cr(III) and As(V) to As(III) is not uniformly helpful
because while the reduced Cr(III) is less toxic than Cr(VI); the reduced As(III) is much more
toxic than As(V) form.
