Remediation of heavy metal contamination of sediments and soils using ligand-coated dense nanoparticles

• Published in: PloS one Vol. 15; no. 9; p. e0239137
• Main Authors: Huang, Yuxiong, Keller, Arturo A
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 30.09.2020; Public Library of Science (PLoS)
• Subjects: Bioaccumulation; Bioavailability; Biological magnification; Biology and Life Sciences; Cadmium; Chelating agents; Contaminated sediments; Contamination; Earth Sciences; Ecology and Environmental Sciences; Engineering and Technology; Environmental aspects; Environmental remediation; Environmental science; Ethylenediaminetetraacetic acids; Fourier transforms; Health risks; Heavy metals; Lead; Ligands; Ligands (Chemistry); Medicine and Health Sciences; Metal ions; Methods; Microscopy; Nanoparticles; Physical Sciences; Public health; Remediation; Sediment pollution; Sediments; Sediments (Geology); Soil contamination; Soil pollution; Soil remediation; Soils; Terrestrial environments; Water circulation; Water column; Water pollution; United States; United States > US; Santa Barbara California; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0239137

Sediment and soil contamination with toxic heavy metals, including cadmium (Cd.sup.2+) and lead (Pb.sup.2+ ), represents a major long-term remediation challenge. Resuspension of contaminated sediments into the water column, or the uptake of toxic metals from top soil, can lead to exposure of aquatic or terrestrial organisms, followed by bioconcentration, bioaccumulation and biomagnification, which may pose a threat to public health. We have developed a novel nanoscale engineered material, namely ligand-coated dense nanoparticles (Ligand DNPs), which contain a dense WO.sub.3 nanoparticle core and a shell functionalized with a metal-binding organic ligand (EDTA), to effectively sequester heavy metal ions deeper into the soil and sediments. We demonstrate that one application of Ligand DNPs can remove from 60% to almost 80% of the Cd and Pb in two different soil matrices, driving these metal ions deeper into the sediment or soil column via gravity, and making them less bioavailable. Ligand DNPs can provide a relatively fast, convenient, and efficient in-situ approach for the remediation of sediments and soils contaminated with heavy metals.