Sequestration of Pb–Zn–Sb- and As-bearing incidental nanoparticles by mineral surface coatings and mineralized organic matter in soils. Issue 8 (9th August 2017)

• Record Type: Journal Article
• Authors: Schindler, Michael; Hochella, Michael F.
• Is Part Of: Environmental science. Volume 19:Issue 8(2017)
• Page Start: 1016
• Page End: 1027
• Publication Date: 2017-08-09
• Subjects: Environmental monitoring -- Periodicals; Biological monitoring -- Periodicals; Environmental chemistry -- Periodicals; 363.7363
• DOI: 10.1039/c7em00202e
• Languages: English
• ISSNs: 2050-7887

Abstract

Abstract : Nanoparticles often play significant roles in dictating the transport, distribution, bioavailability and toxicity of contaminants in the environment. Abstract : Nanoparticles (NPs) often play significant roles in dictating the transport, distribution, bioavailability and toxicity of contaminants in the environment. Incidental NPs ( i.e. NPs of anthropogenic origin but not purposely engineered) are often overlooked in contaminant transport and fate studies; yet in many systems they dominate contaminant transport processes. Using surficial contaminated regosols from Trail, British Columbia, Canada, a metal smelting and refining area along the banks of the Columbia River, we show that sequestration of Pb-, Zn-, Sb-, and As-bearing incidental NPs is strongly influenced by their aggregation, crystal growth, and/or particle attachment to mineral surface coatings (MSC) and in mineralized organic matter (MOM). Transmission electron microscopy shows the occurrence of NPs of anglesite (PbSO4 ), Fe–As-phosphate, kintoreite (Pb[(Fe, Al)3 (P(As)O4 )(PO3 (OH))(OH)6 ]), and franklinite (ZnFe2 O4 ) in matrices of amorphous silica which retain different stages of their agglomeration and aggregation. Other identified nano-size phases in the MSC and MOM indicate a complex and previously unrecognized mineralogy of Pb-, Zn-, Sb-, and As-phase in surficial soils. Mineralogical complexity and the various sequestration processes observed in this study indicate a new dimension of nano-scale processes on mineral surfaces and organic matter that have been previously overlooked when studying the fate of contaminants with bulk-analytical tools such as micro-X-ray diffraction or synchrotron-based spectroscopic methods.