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Environ Sci Technol. 2015 Mar 17;49(6):3375-82. doi: 10.1021/es505662q. Epub 2015 Feb 25.

Importance of a nanoscience approach in the understanding of major aqueous contamination scenarios: case study from a recent coal ash spill.

Author information

1
†The Center for NanoBioEarth, Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, United States.
2
§Department of Geosciences, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China.
3
∥Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, North Carolina 27517, United States.
4
‡Biology Department, Duke University, Durham, North Carolina 27708, United States.

Abstract

A coal ash spill that occurred from an ash impoundment pond into the Dan River, North Carolina, provided a unique opportunity to study the significance and role of naturally occurring and incidental nanomaterials associated with contaminant distribution from a large-scale, acute aquatic contamination event. Besides traditional measurements of bulk watercolumn and sediment metal concentrations, the nanoparticle (NP) analyses are based on cross-flow ultrafiltration (CFUF) and advanced transmission electron microscopy (TEM) techniques. A drain pipe fed by coal ash impoundment seepage showed a high level of arsenic, with concentrations many times over the EPA limit. The majority of the arsenic was found sorbed to large aggregates dominated by incidental iron oxyhydroxide (ferrihydrite) NPs, while the remainder of the arsenic was truly dissolved. These ferrihydrites were probably formed in situ where Fe(II) was leached through subsurface flowpaths into an aerobic environment, and further act as a significant contributor to the elevated As concentrations in downstream sediments after the spill. In addition, we discovered and describe a photocatalytic nano-TiO2 phase (anatase) present in the coal ash impacted river water that was also carrying/transporting transition metals (Cu, Fe), which may also have environmental consequences.

PMID:
25688977
DOI:
10.1021/es505662q
[Indexed for MEDLINE]

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