Spatial Distribution and Speciation of Lead around Corroding Bullets in a Shooting Range Soil Studied by Micro-X-ray Fluorescence and Absorption Spectroscopy

University of Chicago, Chicago, Illinois, United States
Environmental Science and Technology (Impact Factor: 5.33). 08/2005; 39(13):4808-15. DOI: 10.1021/es0482740
Source: PubMed


We investigated the spatial distribution and speciation of Pb in the weathering crust and soil surrounding corroding metallic Pb bullets in a shooting range soil. The soil had a neutral pH, loamy texture, and was highly contaminated with Pb, with total Pb concentrations in the surface soil up to 68 000 mg kg(-1). Undisturbed soil samples containing corroding bullets were collected and embedded in resin, and polished sections were prepared for micro-X-ray fluorescence (micro-XRF) elemental mapping and micro-X-ray absorption near edge structure (micro-XANES) spectroscopy. Bullet weathering crust material was separated from the metallic Pb cores and analyzed by powder X-ray diffraction analysis. Our results show a steep decrease in total Pb concentrations from the bullet weathering crust into the surrounding soil matrix. The weathering crust consisted of a mixture of litharge [alpha-PbO], hydrocerussite [Pb3(CO3)2-(OH)2], and cerussite [PbCO3], with litharge dominating near the metallic Pb core and cerussite dominating in the outer crust, which is in contact with the soil matrix. On the basis of these results and thermodynamic considerations, we propose that the transition of Pb species after oxidation of Pb(O) to Pb(II) follows the sequence litharge --> hydrocerussite --> cerussite. Consequently, the solubility of cerussite limits the activity of Pb2+ in the soil solution in contact with weathering bullets to < or =1.28 x 10(-6) at pH 7, assuming that the CO2 partial pressure (PCO2) in the soil is equal or larger than in the atmosphere (PCO2 > or = 0.000 35 atm).

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    • "These phases are on the outer crust that covers ammunition, and their formation is favoured by acidity, organic matter, available P and microbial activity as well as by dissolved CaCO3 coming from the clay target residues (Lin 1996; Cotter-Howells et al. 1999; Hashimoto 2013). The difficulty in identifying the aforementioned phases is because the amount formed is scarce and they are usually not well crystallized (Vantelon et al. 2005; Ma et al. 2007). "
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    ABSTRACT: Pb pollution caused by shooting sport activities is a serious environmental problem that has increased considerably in recent decades. The aims of this study were firstly to analyze Pb pollution in soils from a trap shooting range abandoned in 1999, secondly to study the effectiveness of different extractants [CaCl2, DTPA, NH4OAc, low molecular weight organic acids (LMWOA), and bidistilled water (BDW)] in order to determine Pb bioavailability in these soils, and finally to evaluate the phytoremediation ability of spontaneous vegetation (Agrostis capillaris L.). To this end, 13 soils from an old trap shooting range (Galicia, NW Spain) were studied. It was found that Pb levels in the soils were higher than 100 mg kg(-1), exceeding the generic reference levels, and three of these samples even exceeded the USEPA threshold level (400 mg kg(-1)). In general, the reagent that best represents Pb bioavailability and has the greatest extraction efficiency was CaCl2, followed by DTPA, NH4OAc, LMWOA, and BDW. A. capillaris Pb contents ranged between 9.82 and 1107.42 mg kg(-1) (root) and between 6.43 and 135.23 mg kg(-1) (shoot). Pb accumulation in roots, as well as the presence of secondary mineral phases of metallic Pb in the adjacent soil, showed the phytostabilization properties of A. capillaris.
    Environmental Science and Pollution Research 09/2015; DOI:10.1007/s11356-015-5340-7 · 2.83 Impact Factor
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    • "Evidently, Pb and Cu are major elements of concern that cause serious heavy metal contamination in firing range soils. Lead and Cu concentrations in firing range soils can reach 20,000 mg/kg (Lin 1996; Stansley and Roscoe 1996; Dermatas et al. 2006) and 2,000 mg/kg, respectively (Vantelon et al. 2005) depending on length of range operations. There are more than 3,000 active small arms firing ranges in the USA (USEPA 2005) and approximately 1,400 active small arms firing ranges in Korea (MOE 2005). "
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    ABSTRACT: A stabilization/solidification treatment scheme was devised to stabilize Pb and Cu contaminated soil from a firing range using renewable waste resources as additives, namely waste oyster shells (WOS) and fly ash (FA). The WOS, serving as the primary stabilizing agent, was pre-treated at a high temperature to activate quicklime from calcite. Class C FA was used as a secondary additive along with the calcined oyster shells (COS). The effectiveness of the treatment was evaluated by means of the toxicity characteristic leaching procedure (TCLP) and the 0.1 M HCl extraction tests following a curing period of 28 days. The combined treatment with 10 wt% COS and 5 wt% FA cause a significant reduction in Pb (>98 %) and Cu (>96 %) leachability which was indicated by the results from both extraction tests (TCLP and 0.1 M HCl). Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses are used to investigate the mechanism responsible for Pb and Cu stabilization. SEM-EDX results indicate that effective Pb and Cu immobilization using the combined COS-FA treatment is most probably associated with ettringite and pozzolanic reaction products. The treatment results suggest that the combined COS-FA treatment is a cost effective method for the stabilization of firing range soil.
    Environmental Geochemistry and Health 05/2013; 35(6). DOI:10.1007/s10653-013-9528-9 · 2.57 Impact Factor
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    • "The main metals that we expect to find in this hunting field are generally Pb, Fe, Mn, Ni, Cu, As, and Sb. Lead, As, and Sb were the most critical contaminants at shooting ranges that were previously reported by other researchers (Sorvari 2007; Vantelon et al. 2005). All elements were analyzed using inductively coupled plasma (ICP) atomic emission spectroscopy. "
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    ABSTRACT: PurposeEnvironmental contamination of lead (Pb) in soils and sediments poses serious threats to human and ecological health. The objective of this study is to investigate the effect of seasonal dove sports hunting activities on Pb contamination in acid forest soils. Materials and methodsA grid sampling method was used to investigate the spatial distribution of Pb contamination in surface soils. Soils were analyzed for total metal(loid) concentration and characterized for physicochemical properties and mineralogy. Adsorption isotherm experiments were also conducted to understand the reactivity and retention capacity of Pb(II) in soils. Finally, synchrotron-based X-ray microprobe and X-ray absorption spectroscopy were used to understand the chemical speciation of Pb that controls the retention/release mechanisms of Pb in soils. Results and discussionThere was no excessive accumulation of Pb at the site. However, the concentration of Pb in surface soils was greater than the background level (<16mgkg−1). The contamination level of Pb was as high as 67mgkg−1 near a patch of corn field where lime was frequently applied. A microfocused X-ray microprobe analysis showed the presence of Pb pellet fragments that predominantly contain oxidized Pb(II), suggesting that oxidative dissolution was occurring in soils. Dissolved Pb(II) can be readily retained in soils up to ~3,600mgkg−1 via inner-sphere and outer-sphere surface complexation on carbon and aluminol functional groups of soil components, suggesting that partitioning reactions control the concentration of Pb in soil solution. ConclusionsThe fate of Pb is likely to be controlled by (1) oxidative dissolution process of Pb(0) pellets and (2) the release of outer-sphere and/or inner-sphere Pb surface complexes in humic substances and aluminosilicate/Al oxyhydroxides. Although no remedial actions are immediately required, the long-term accumulation of Pb in soils should be carefully monitored in protecting ecosystem and water quality at the dove hunting field. KeywordsAmmunition–Chemical speciation–Contamination–Fate–Lead–Soil–XAS–X-ray microprobe
    Journal of Soils and Sediments 09/2011; 11(6):968-979. DOI:10.1007/s11368-011-0374-z · 2.14 Impact Factor
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