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Title: The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT

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Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Applied Geochemistry
Additional Journal Information:
Journal Volume: 82; Journal Issue: C; Related Information: CHORUS Timestamp: 2018-01-11 10:09:10; Journal ID: ISSN 0883-2927
Country of Publication:
United Kingdom

Citation Formats

Bromstad, Mackenzie J., Wrye, Lori A., and Jamieson, Heather E.. The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT. United Kingdom: N. p., 2017. Web. doi:10.1016/j.apgeochem.2017.04.004.
Bromstad, Mackenzie J., Wrye, Lori A., & Jamieson, Heather E.. The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT. United Kingdom. doi:10.1016/j.apgeochem.2017.04.004.
Bromstad, Mackenzie J., Wrye, Lori A., and Jamieson, Heather E.. Sat . "The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT". United Kingdom. doi:10.1016/j.apgeochem.2017.04.004.
title = {The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT},
author = {Bromstad, Mackenzie J. and Wrye, Lori A. and Jamieson, Heather E.},
abstractNote = {},
doi = {10.1016/j.apgeochem.2017.04.004},
journal = {Applied Geochemistry},
number = C,
volume = 82,
place = {United Kingdom},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.apgeochem.2017.04.004

Citation Metrics:
Cited by: 5works
Citation information provided by
Web of Science

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  • Approximately 20,000 tonnes of arsenic (As)-bearing emissions from roasting gold (Au)-bearing arsenopyrite ore were aerially released from 1949 to 1999 at Giant Mine, near Yellowknife, Canada. Soil samples collected within 4 km of the former roaster from sites undisturbed by mining or other human activity contain up to 7700 mg/kg total As. Total As concentrations are highest within a few cm of the surface, and particularly enriched in soil pockets on rock outcrops. Scanning electron microscopy and synchrotron microanalysis show that roaster-derived arsenic trioxide (As2O3) has persisted in shallow soils in the area. Roaster-generated maghemite and hematite are also present.more » These anthropogenic forms of As are much more common in near-surface soils than natural As-bearing minerals. Comparison of the proportions of As, Sb, and Au concentrations in outcrop soil samples and historic As2O3-rich dust captured by emission controls suggest most of the roaster-derived As in soils at Giant was likely deposited before 1964. Topographic restriction by rock outcrops and a dry, cold climate likely contribute to the persistence of As2O3 in outcrop soils.« less
  • The solid-state speciation of arsenic (As), iron (Fe), and lead (Pb) was studied in the mine waste-derived fertilizer Ironite using X-ray absorption spectroscopy, Moessbauer spectroscopy, and aging studies. Arsenic was primarily associated with ferrihydrite (60-70%), with the remainder found in arsenopyrite (30-40%). Lead was observed almost exclusively as anglesite (PbSO{sub 4}), with <1% observed as galena (PbS). The identification of As in oxidized Fe oxides and Pb as PbSO{sub 4} is in disagreement with the dominant reduced phases previously reported and suggests As and Pb contained within the mine waste-derived product are more bioavailable than previously considered. Aging studies inmore » solution result in Ironite granules separating into two distinct fractions, an orange oxide precipitate and a crystalline fraction with a metallic luster. The orange oxide fraction contained As adsorbed/precipitated with ferrihydrite that is released into solution when allowed to equilibrate with water. The fraction with a metallic luster contained pyrite and arsenopyrite. A complete breakdown of arsenopyrite was observed in Ironite aged for 1 month in buffered deionized water. The observations from this study indicate As and Pb exist as oxidized phases that likely develop from the beneficiation and processing of mine tailings for commercial sale. The potential release of As and Pb has important implications for water quality standards and human health. Of particular concern is the quantity of As released from mine waste-derived products due to the new As regulation applied in 2006, limiting As levels to 10 {micro}g L{sup -1} in drinking water.« less
  • Soils from many industrial sites in southeastern USA are contaminated with As because of the application of herbicide containing As{sub 2}O{sub 3}. Among those contaminated sites, two industrial sites, FW and BH, which are currently active and of most serious environmental concerns, were selected to characterize the occurrence of As in the contaminated soils and to evaluate its environmental leachability. The soils are both sandy loams with varying mineralogical and organic matter contents. Microwave-assisted acid digestion (EPA method 3051) of the contaminated soils indicated As levels of up to 325 mg/kg and 900 mg/kg (dry weight basis) for FW andmore » BH soils, respectively. However, bulk X-ray powder diffraction (XRD) analysis failed to find any detectable As-bearing phases in either of the studied soil samples. Most of the soil As was observed by scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy (SEM/EDX), to be disseminated on the surfaces of fine-grained soil particles in close association with Al and Fe. A few As-bearing particles were detected in BH soil using electron microprobe analysis (EMPA). Synchrotron micro-XRD and X-ray absorption near-edge structure (XANES) analyses indicated that these As-rich particles were possibly phaunouxite, a mineral similar to calcium arsenate, which could have been formed by natural weathering after the application of As{sub 2}O{sub 3}. However, the scarcity of those particles eliminated them from playing any important role in As sequestration. Synthetic acid rain sequential batch leaching experiments showed distinct As leaching behaviors of the two studied soil samples: BH soil, which has the higher As content, showed a slow, steady release of As, while FW soil, with a lower As content, showed a much quicker release and lower overall retention of As upon leaching. Sequential chemical extraction experiments were carried out using a simplified 4-step sequential chemical extraction procedure (SCEP) previously developed to characterize the fractionation of As and better understand the different leaching behaviors of the two studied soils. It was shown that only about 50% of the total extractable As was removed by the first two extraction steps, which represented the most weakly bonded and readily available As for environmental leaching. Compared with the sequential leaching experiments, it was further indicated that only half of the As associated with phases extracted by the second SCEP step was mobilized by SPLP leaching. Although microwave-assisted acid digestion results showed similar Al and Fe contents in both soils, the sequential chemical extraction experiments indicated that BH soil has a much higher content of amorphous Al and Fe phases and that a comparably higher portion of soil As was associated with those materials. The experimental results suggest that remediation efforts for the contaminated sites can be directed towards enhancing the formation of more stable As-bearing compounds in the soils to reduce the environmental leachability of As.« less
  • The mineral form, grain size and texture of As-bearing particles are important factors influencing the risk to human health associated with exposure to As-contaminated soils, sediments and mine wastes. Mining of arsenopyrite-bearing gold ores in Nova Scotia in the late 1800s and early 1900s has left a legacy of weathered, As-rich tailings deposits in more than 60 gold districts across the province. Fourteen samples of near-surface tailings and one of soil from several former gold mines frequented by the public were sieved to <150 {mu}m and characterized using conventional mineralogical techniques (XRD, microscopy and EPMA) and synchrotron micro-analysis ({mu}-X-ray diffraction,more » {mu}-X-ray fluorescence and {mu}-X-ray absorption spectroscopy). This study is part of a broader coordinated effort by a multi-department federal and provincial advisory committee formed to coordinate the study of ecosystem and human health risks associated with historical gold mine sites in Nova Scotia. Our study shows that (i) the mineralogy of As in weathered tailings is highly variable, with aggregates of more than one As-bearing phase common in a given sample, and (ii) major differences in As mineralogy in the tailings are mainly controlled by factors that influence the weathering history (e.g., presence or absence of mill concentrates, degree of water saturation, and abundance of relict carbonate minerals). The variable solubility of these primary and secondary As-bearing minerals influences both the environmental mobility and the bioaccessibility of As in near-surface tailings and soil samples.« less
  • Residues of nitrofen in farm soils, persistence of nitrofen in field microplots, mobility of nitrofen in natural soils and the role of microbial flora in its degradation were studied. Muck soils from vegetable farms in southwestern Ontario contained up to 35 ppm nitrofen in mid-season (August), which decreased to 18 ppm by October. The herbicide was less persistent in sand than in muck. Degradation was slightly faster in sand and muck soils receiving two sprays, than in those sprayed once. From an initial deposit of ca. 2 and 10 ppm resp., in sand and muck field microplots, ca. 2 andmore » 15% persisted after 16 wk. Leaching of nitrofen by water through sand was negligible, and it was even more strongly adsorbed onto organic soil. Natural microbial flora seemed to play an important role in the degradation of nitrofen in soil. Ca. 15 and 38% resp., of the initial concentration persisted in natural sandy loam and muck 16 wk after treatment at 10 ppm, whereas about 94 and 82% resp., persisted in sterilized sandy loam and muck at the same period.« less