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61.
Daniel G. Strawn Patrick Hickey Andrew Knudsen Leslie Baker 《Environmental Geology》2007,52(1):109-122
To remediate Pb contaminated soils it is proposed that phosphorus can be amended to the soils to transform the Pb into poorly
soluble Pb-phosphate mineral phases. However, remediation strategies must account for variable Pb speciation and site-specific
factors. In this study soil mineralogy and Pb speciation in soils from P-amended field trials at sites within the Coeur d’Alene
River Basin in Idaho, USA were investigated. The soils are contaminated from mining activities and are enriched with Fe and
Mn. Selective extraction of the soils indicated that the Fe oxides are poorly crystalline. XRD of the soil clay size fractions
identified quartz, muscovite, kaolinite, siderite, lepidocrocite, and chlorite minerals. Amendment with P fertilizer dissolved
the siderite. No Pb–phosphate minerals were detected by XRD. Electron microprobe analysis showed direct correlations between
Pb, Fe, and Mn in the unamended soils, and negative correlations between Pb and Si. Lead and Mn were strongly correlated.
In the amended soils Fe and P were strongly correlated. Results indicate that the Pb is associated with poorly crystalline
Fe and Mn oxides, and that added P is primarily associated with Fe oxide phases. Comparisons of pore water Pb concentrations
with chloropyromorphite and plumbogummite solubility suggest that in the phosphate-amended soils the pore waters are undersaturated
in these phases, whereas several of the control soil pore waters were oversaturated, indicating the added phosphate suppressed
the Pb solubility. Results from this research provide insight into the geochemistry occurring in the P-remediated soils that
will help in making management and remediation decisions. 相似文献
62.
Lead isotopic compositions of mineral separates are presented from the mineralized zones (Roby, Twilight, and High Grade zones)
of the Lac des Iles palladium deposit (approximately 2.69 Ga) and tonalitic country rocks (approximately 2.727 to 2.775 Ga)
in the Wabigoon subprovince of the western Superior Province of Canada. Plagioclase separates show Pb isotope ratios similar
to those of the late Archean depleted mantle. Sulfide minerals coexisting with plagioclase have a more radiogenic Pb isotope
composition, but very low concentrations of U (<0.2 ppb U) and Th (<0.01 ppb) compared to Pb (≫50 ppb). The isotope data are
consistent with a model involving the incorporation of radiogenic Pb from country rocks to sulfide melt near the base of the
magma chamber or along the conduit of the parental magmas. The proposed interpretation is also supported by decreasing Cu/Pd
ratios from earlier barren to late fertile gabbro intrusions in the complex. The ponding sulfide melt became enriched in platinum
group elements, as it was interacting with a large magma volume during the evolution of the Lac des Iles igneous complex. 相似文献
63.
W. C. Sidle 《Environmental Geology》2007,52(1):51-62
Dissolved Pb in 32 wells associated with corroding submersible pumps is examined within a rural water district after almost
20 years (1984–2002). Groundwater Pb ranged from 0.4–24.9 μg L−1 after 24 h pump flushing. Preliminary geochemistry and representative borehole lithology examinations were extrapolated by
Markov chain modeling. The first-order geostatistical realizations of glacial sediments coupled with the Monte Carlo Metropolis-Hasting
method suggest that elevated trace Pb persists in sand and gravel units, and continues at least to 40 m depth in the catchment.
The 207Pb/206Pb and 208Pb/206Pb isotope compositions of groundwater Pb were decisive in discriminating the importance of leached Pb from submersible pump
materials among geogenic sources. 相似文献
64.
Fabien Arnaud Joël Serralongue Thierry Winiarski Marc Desmet Martine Paterne 《Comptes Rendus Geoscience》2006,338(4):244-252
In Lake Anterne (NW French Alps), the Roman period is characterised by a lead contamination more important than that of the 1970s, due to the use of leaded gasoline. The maximum of this contamination period has been varve-dated 220 AD, i.e., during the optimum of Roman civilization in the Alps. Crossing palaeoenvironmental and archaeological evidences points out the economic importance of the town of Passy for the City of Vienne and yields a new example of lead contamination due to local metallurgical activity rather than distant impact of the exploitation of the Spanish Rio Tinto mine. To cite this article: F. Arnaud et al., C. R. Geoscience 338 (2005). 相似文献
65.
A radiotracer technique using 210Pb was applied to quantify the transfer and distribution of lead in the asteroid Asterias rubens following a single ingestion of radio-labelled mussels under controlled laboratory conditions. Approximately 50% of the 210Pb accumulated by mussels in their soft tissues from seawater was transferred to the asteroid through the food pathway resulting in a transfer factor less than unity. Loss kinetics of 210Pb in the asteroid were best described by a two-component exponential model. A. rubens eliminated 56% +/- 5% of the ingested 210Pb in a few days while the remaining fraction (42% +/- 5%), was absorbed and eliminated very slowly. Following ingestion, 210Pb was accumulated in the pyloric caeca and the body wall with little radioisotope found in the coelomic fluid. Lead-210 was then transferred to the organic matrix of the body wall through the general body cavity via the coelomic fluid, and then to the skeleton. In this way, lead appears to be progressively eliminated from the organic matrix of the body wall while it is efficiently trapped in the calcite skeleton. The sequestration and retention of lead in the skeleton is considered as a detoxification process, but it also prevents lead transfer to higher trophic levels of the marine food chain since the skeleton is not digested by higher consumers. In addition, the skeleton of asteroids can be regarded as a bioindicator of long-term dietary lead contamination. 相似文献
66.
云南会泽铅锌矿床构造控矿及断裂构造岩稀土元素组成特征 总被引:22,自引:3,他引:19
云南会泽超大型铅锌矿床是川滇黔铅锌成矿区大型富铅锌矿床的典型代表,本文在研究矿区成矿地质背景,划分断裂构造岩类型及构造体系的基础上,提出NE构造带(华夏系)是会泽铅放离主要的成矿构造体系,概括了构造控矿特征,以控矿断裂带中的构造岩、矿及为主要研究对象,分析不同方向断裂的构造岩的稀土元素组成特征,按其特征和酝酿民分模式,将构造岩(矿石)划分为7种类型:Eu富集-开阔“W”型、Ce富集-Eu弱亏损-平缓型、平缓型、HREE-LREE较富集-开阔“V”字型、Eu强亏损-下斜型,Eu亏损-下斜型、Eu亏损-平缓型、其中NE向断裂带中的Ce富集-Eu弱亏损-平缓型与Eu富集-平缓型模式的构造岩是成矿预测的微观标志之一。 相似文献
67.
The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ∼9 (Cd), ∼3 (Pb) and ∼5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed. 相似文献
68.
69.
Anthropogenic activities have become an important source of heavy metals to the marine environments. Biological sentinels like seabirds’ chicks have been widely used to monitorize the levels of some heavy metals. Due to its mainly marine foraging habits, Audouin’s gull fits well for this purpose. Mercury and lead levels were measured in mantle feathers of Audouin’s gull chicks from two colonies in NE Iberian Peninsula: the Ebro Delta and the Llobregat Delta. Both are anthropized areas subject to differential pollutant inputs. Lead levels were significantly higher in the Llobregat Delta probably due to the use of leaded fuel in the nearby Barcelona airport. On the other side, mercury concentrations were higher in the Ebro Delta, in relation with the disposal of the toxic sediments at the Flix site carried down by the Ebro River. These mercury levels in the Ebro chicks reached values that have been described as toxic. 相似文献
70.
《Chemie der Erde / Geochemistry》2014,74(4):601-613
The occurrence of Pb–Zn deposits of Jalta district (northern Tunisia) as open space fillings and cements and breccia in the contact zones between Triassic dolostones and Miocene conglomerates along or near major faults provides evidence of the relationship between the mineralization and tectonic processes. Pb isotopes in galena from the deposits yielded average 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of 18.821, 15.676 and 38.837, respectively, implying a well-mixed multi-source upper crustal reservoir of metals. Magmatism and compressional tectonism during the Alpine orogeny favored Pb–Zn mineralization in the Jalta district. The enrichment in Pb, Zn, Cd and Co of the Triassic carbonates and enrichments in Pb, Zn and Cd in Triassic clayey shales is associated with hydrothermal alteration around faults. Alunite in the deposit has δ34S values (−2.5 to −1.5‰ VCDT), which could have been formed at and above the water table in a kind of steam-heated environment, where fluids containing H2S mixed with fluids containing K and Al. The H2S could have been produced by TSR of sulfates at high temperature at depth and then leaked upward through deep-seated faults, whereas the K and Al could have been acid-leached from Miocene volcanic rocks. 相似文献