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《国际泥沙研究》2023,38(5):724-738
Freshwater reservoirs are essential owing because of their ecological, economic, and social importance. They are particularly vulnerable to contamination, as of metal and metalloids, derived from anthropogenic activities like mining. The temporal variations in trace element concentrations (arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)), enrichment, fluxes, and possible sources were evaluated by studying two sediment cores from the La Angostura (ANG) Reservoir (northwest Mexico), using 210Pb geochronology. The enrichment factors showed from null to minor enrichment for most elements, but moderate to severe enrichment of mercury (Hg). Most trace element concentrations had a detrital origin, and notable Hg concentration increases since the past decade were associated with severe drought periods, likely resulting from wildfires. The observed sediment concentrations of As and Hg can cause adverse effects on biota in the ecosystem since they are above the probable effect level (PEL). Development of strategies for metal attenuation in this reservoir is recommended and metals should be controlled until specific ecotoxicological studies are performed. 相似文献
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《Polar Science》2014,8(1):40-52
The tellurium oxyanion, tellurite, is extremely noxious to most living organisms. Its toxicity has been mainly related to the generation of reactive oxygen species (ROS) as well as to an unbalancing of the thiol:redox buffering system. Nevertheless, a few bacteria are capable of thriving at high tellurite concentrations. One mechanism of resistance is the enzymatic and non-enzymatic reduction of tellurite to the less toxic elemental tellurium. This reduction generates nano- to micrometric tellurium crystals that display different shapes and sizes.To date, a very limited number of highly tellurite-resistant and tellurite-reducing bacterial species are available from international culture collections. In this work, we decided to look for tellurite-reducing bacteria from an extreme environment, Antarctica. This environment exhibits a combination of several extreme factors such as high UV-radiation and desiccation and freezing conditions that impact directly on the local biodiversity. Since, as does, all these factors induce ROS formation, we hypothesized that Antarctic bacteria could also exhibit tellurite-resistance. In this context, we isolated 123 tellurite-resistant bacteria, and characterized six new tellurite-resistant and tellurite-reducing bacterial strains from samples collected in Antarctica. These strains were identified according to their 16S rRNA gene sequence as Staphylococcus hameolyticus, Staphylococcus sciuri, Acinetobacter haemolyticus, Pseudomonas lini, and two strains of Psychrobacter immobilis.The isolates display tellurite-resistance about 35- to 500-fold higher than Escherichia coli (Te-sensitive organism), and a high level of tellurite reduction which might be interesting for an application in the field of bioremediation or nanoparticle biosynthesis. 相似文献
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The contaminated sediment serves as a long-term source of toxic elements,since that mobility and transport in the environment of these elements are strongly influenced to associated solid phase.In this study,the modified Tessier sequential extraction procedure was applied for the fractionation of Cd,As,Hg,Cu,Zn,Cr,Pb,Ni and V in the sediments（Tisa River and canal sediments - Danube alluvial formation）,to obtain an overall classification of trace element pollution in these areas through its spatial distribution.Investigations of this region are important due to the widespread occurrence of metal mining activities throughout the Tisa and Danube drainage basins and possibilities of contamination with toxic elements at studies localities.Five steps of the sequential extraction procedure partitioned elements into CH3COONH4 extractable（F1）,NH2OH·HC carbonate extractable and easily reducible（F2）, H2C2O4/（NH4）2C2O4 moderately reducible（F3）,H2O2-HNO3 organic extractable（F4）,and HCl acid soluble residue （F5）.Analyses of the extracts were performed by flame atomic absorption spectrometry.To indicate the degree of risk of toxic elements,risk assessment code and contamination factor have been used.The results of partitioning study indicate that more easily mobilized forms（metals in adsorbed/exchangeable/carbonate forms or bound to amorphous Fe and Mn oxyhydroxides and Fe and Mn oxides） were predominant for copper,zinc,cadmium and lead,which can be used as indicators for input from anthropogenic source.In contrast,the largest amount of chromium and nickel were associated with the inert fraction,which reduced their solubility and rendered them immobile under natural conditions and indicative of natural origins.Most of remaining portion of metals was bound to ferromanganese oxides fraction.It is concluded that sequential extraction results proved useful to distinguish between anthropogenic and geochemical sources of elements in the sediments. 相似文献
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Douglas B.Sims Amanda C.Hudson John E.Keller Michael Strange Andressa Cristhy Buch David Ferrari Giavanna M.Fernandez Juan Garcia-Hernandez Bailey D.Kesl Sean Torres 《国际泥沙研究》2022,37(2):202-213
The dispersion and influence of soluble and particulate trace elements(TEs) present in the materials from abandoned mines is an imminent problem on terrestrial and aquatic environments.The goal of this research is to provide a broader view of such transport,assessing particle size distribution and TE interactions(e.g.,scavenging) with mine tailings and locally derived sediments transported by water in arid region.Sand grains from wash sediment were collected from a dry ephemeral wash in Nelson,N... 相似文献
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P. Szefer G. P. Glasby J. Geldon R. M. Renner E. Björn J. Snell W. Frech J. Warzocha 《Environmental Geology》2009,57(4):847-862
Analysis of 59 surface sediment samples from the Polish exclusive economic zone (EEZ) shows that Szczecin Lagoon sediments
are the most polluted by heavy metals and that the degree of heavy-metal pollution decreases substantially on passing from
the Szczecin Lagoon to the Pomeranian Bay and the inner shelf area and then on passing to the Bornholm Deep and Słupsk Furrow.
Heavy-metal pollution in the sediments of the western part of the Polish EEZ therefore appears to follow the dispersion of
the Oder River. Fluffy material from the Oder estuary appears to be the main source of heavy metals in the muddy sediments
of the Bornholm Deep. The formation of sulphides is therefore not the principal factor controlling the enrichment of heavy
metals in the sediments of this anoxic basin, although it may be responsible for the uptake of Mo, Sb and As. Two main factors
control the distribution of the rare earth elements (REE) in sediments of the Polish EEZ: the input of Fe-organic colloids
from rivers and the presence of detrital material in the sediments. 相似文献
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Environmental geochemistry of the derelict Webbs Consols mine,New South Wales,Australia 总被引：3，自引：3，他引：0
P.?M.?AshleyEmail author B.?G.?Lottermoser A.?J.?Collins C.?D.?Grant 《Environmental Geology》2004,46(5):591-604
Small-scale mining and mineral processing at the Webbs Consols polymetallic PbZnAg deposit in northern New South Wales, Australia has caused a significant environmental impact on streams, soils and vegetation. Unconfined waste rock dumps and tailings dams are the source of the problems. The partly oxidised sulphidic mine wastes contain abundant sulphides (arsenopyrite, sphalerite, galena) and oxidation products (scorodite, anglesite, smectite, Fe-oxyhydroxides), and possess extreme As and Pb (wt% levels) and elevated Ag, Cd, Cu, Sb and Zn values. Contemporary sulphide oxidation, hardpan formation, crystallisation of mineral efflorescences and acid mine drainage generation occur within the waste repositories. Acid seepages (pH 1.9–6.0) from waste dumps, tailings dams and mine workings display extreme As, Pb and Zn and elevated Cd, Cu and Sb contents. Drainage from the area is by the strongly contaminated Webbs Consols Creek and although this stream joins and is diluted by the much larger Severn River, contamination of water and stream sediments in the latter is evident for 1–5 km, and 12 km respectively, downstream of the mine site. The pronounced contamination of local and regional soils and sediments, despite the relatively small scale of the former operation, is due to the high metal tenor of abandoned waste material and the scarcity of neutralising minerals. Any rehabilitation plan of the site should include the relocation of waste materials to higher ground and capping, with only partial neutralisation of the waste to pH 4–5 in order to limit potential dissolution of scorodite and mobilisation of As into seepages and stream waters. 相似文献
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