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941.
O. Connan D. Boust G. Billon L. Solier M. Rozet S. Bouderbala 《Journal of environmental radioactivity》2009,100(10):905-913
A sequential extraction protocol has been used to determine the solid-phase partition of 210Po and 210Pb in anoxic marine sediment from the roads of Cherbourg (France) in the central English Channel. Measurements were also obtained in pore waters, in which 210Po activities range between 1 and 20 mBq L−1 and 210Pb activities between 2.4 and 3.8 mBq L−1, with highest activities in the topmost layer. These activities are higher than in seawater, suggesting that sediment act as a source of both 210Po and 210Pb for overlying water. The 210Po profile in the pore waters is apparently correlated with those obtained for Fe, Mn and SO42−, suggesting an influence of early diagenetic processes on the 210Po solid-liquid distribution. In the sediment, 210Po is predominantly bound to organic matter or chromium reducible sulphides, and residuals (clay minerals and refractory oxides). Our results indicate that 210Po is not significantly bound to AVS, i.e. acid volatile sulphides: bioturbation could play a role by the early redistribution of 210Po bound to acid volatile sulphides in the sediment. 210Po, 210Pb and Pb exhibit differences in terms of distribution, probably due to a different mode of penetration in the sediment. This work provides information on solid and liquid distribution of 210Po and 210Pb in marine sediment. These data are very scarce in the litterature. 相似文献
942.
Cailleaud K Forget-Leray J Peluhet L LeMenach K Souissi S Budzinski H 《Environmental pollution (Barking, Essex : 1987)》2009,157(1):64-71
To elucidate tidally related variations of hydrophobic organic contaminant (HOC) bioavailability and the impact of these contaminants on estuarine ecosystems, both PCB and PAH concentrations were investigated in the dissolved phase and in the suspended particulate material (SPM) of the Seine Estuary. Both PAH and PCB highest levels were observed in surface and bottom water when SPM remobilizations were maximum, in relation to higher speed currents. In parallel, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities were investigated in the copepod Eurytemora affinis. Significant decreasing AChE levels were measured during the tidal cycle and between surface and bottom copepods related to salinity and to HOC concentration variations. Significant increasing GST levels were also observed when HOC concentrations in the water column were the highest. This study underlined the need to standardize sampling procedures for biomonitoring studies in order to avoid interfering factors that could modify biomarker responses to chemical exposure. 相似文献
943.
García R Rubio V Vegas I Frías M 《Environmental science and pollution research international》2009,16(3):274-277
Background, aim and scope One of the problems to affect Portland cement matrices is low resistance to aggressive agents, due principally to the presence
of a high content of portlandite in the hydrated cements. Pozzolanic materials have played an important role in the improving
the durability of cement-based materials for decades. This work studies the behaviour of cement mortar matrices blended with
10% calcined paper sludge (source for metakaolinite) and exposed to different environmental conditions (saline and non-saline
environments) after 6 and 12 months of exposure.
Materials and methods Two cements were studied: an ordinary Portland cement (CEM 1, 42.5R), acting as reference cement, and a blended cement formulated
by mixing 90% (by mass) of CEM 1, 42.5R with 10% (by mass) of paper sludge calcined at 700°C for 2 h. The specimens were exposed
1 year to saline and non-saline environments. All the mineralogy samples were studied through X-ray diffraction and scanning
electron microscopy (SEM) equipped with an energy dispersive X-ray analyser. The in-depth study on ionic mobility was performed
on samples subjected to natural exposure (coast and tableland) for 6 and 12 months.
Results Portland cement was composed of quartz, calcite, calcium hydroxide and tobermorite gels. The pozzolanic cement (10% calcined
paper sludge) is of the same composition but a high calcite concentration and barium carbonate. SEM analysis from coastline
show deposits of variable composition. The deposits are identified on the surface of different mineral components. The minerals
from tableland are much fractured, i.e. calcite and feldspars. Inside the fractures, the deposits and the ions are located
and trapped superficially.
Discussion SEM analysis of control cement Portland and 10% calcined paper sludge shows deposits on quartz and calcite with a very high
concentration of Pb, Zn, Cl and barium sulphate. A very porous aspect is due to the presence of the different aggregate types.
This porous configuration permits retention of the ion environment. The pozzolanic cement in environments subject to the saline
mist favours the retention and transport of ions observed. Something similar also happens with the increase in exposure to
outdoor weather. Non-saline samples show temperature changes (ice or thaw cycles). Barium retention is kept on the surface
in fracture lines by the gelification processes. In general, it may be inferred that an increase in exposure time increases
the diffusion of ions towards test piece interiors. The chemical composition profiles show that the ions present different
penetration speeds.
Conclusions The results indicate the better vulnerability of pozzolanic cements from calcined paper sludge in saline and non-saline environments.
The cements with a 10% addition of calcined paper sludge favour retention and transport of ion has been observed.
Recommendations and perspectives Today, projects are centred on a new recycling line for industrial waste of this kind, with special attention on its incorporation
in cement manufacture as a pozzolanic material, setting the most appropriate activation conditions of the mineralogical compound
in this waste (kaolinite and metakaolinite) and taking them as a starting point for this project. The use of pozzolanic cement
with 10% addition of calcined paper sludge is a system which favours ionic retention. 相似文献
944.
The toxicities and bioavailabilities of total mercury (THg) and methylmercury (MeHg) in aquatic systems have made them the subjects of recent research. In this study, we collected a lake sediment core from Ny-Ålesund in Svalbard and analyzed the distributions of THg and MeHg in the sediments. The increased trend of THg was caused by anthropogenic contamination since the 14th century through long-range transportation, especially after the industrial era. However, the peak values of Hg in surface sediment samples could be explained by the increased algal scavenging process in recent decades. All the biogeochemical proxies (e.g., pigments and diatom biomass) revealed recent sharp increases in aquatic primary production due to the current climate warming. Rock-Eval analyses indicated that algal-derived organic matter took up a large portion, and quantitative calculation showed that 89.6-95.8% of the Hg in post-1950 could be explained by scavenging. The distribution of MeHg has a close relationship with total Hg and organic matter. The oxidation-reduction condition is one of the possible factors affecting the methylation rates in H2 lake sediments. Higher algal productivity and organic matter actually led to the increased trend of methylation in the uppermost sediment. This study supports some new key hypotheses on climate-driven factors affecting Hg and MeHg cycling in High Arctic lake sediments. 相似文献
945.
Improved benthic conditions compared to the 1990s were found during benthic investigations, including sediment and benthic
macrofauna in the inner Stockholm archipelago during 2008. In the 1990s, these areas were dominated by black and laminated
surface sediments and very sparse fauna. A clear relationship was found when comparing sediment status with the benthic macrofauna.
Reduced surface sediment and impoverished macroinvertebrate community was only found at one sampling station representing
an enclosed part of the inner archipelago, whereas the other seven stations, with depths ranging from 20 to 50 m, had oxidized
surface sediments and considerable biomasses of benthic macrofauna (6–65 g m−2) dominated by the invading polychaete Marenzelleria neglecta. An extrapolation of the results shows that, within the investigated area, the coverage of reduced surface sediments had decreased
from approximately 17% in the late 1990s to 4% in 2008. 相似文献
946.
Khoroshko LO Petrova VN Takhistov VV Viktorovskii IV Lahtiperä M Paasivirta J 《Environmental science and pollution research international》2007,14(6):366-376
Background, Aims and Scope Despite the large number of studies on the forms of sulfur in marine deposits, investigations on sulfur organic compounds
are still rare. It is known that the processes leading to formation of intermediate and final sulfur compounds (including
organic ones) in modern deposits are the results of microbiological transformation of sulfur containing proteins, as well
as the microbiological reduction of sulfate ions. The latter are finally reduced by anaerobic sulfate-reducing bacteria to
H2S, HS− and S2−; the total sum of these is referred to as ‘hydrogen sulfide’ in chemical oceanography. Further, the formation of reduced
sulfur organic derivatives (sulfides and polysulfides) is the result of interaction of the organic substance destruction products
with the sulfide ions. In such cases, the main source of organic substances, as well as sulfates for the sulfur reducing processes,
is the pore water in the sediments. The choice of the target of our study is based on the fact that the eastern part of the
Gulf of Finland water area receives the bulk of the anthropogenic load of the St. Petersburg region. Low vertical intermixing
of the water thickness is observed there (thus creating a deficiency of oxygen near the bottom), and the bottom sea current
transfers the polluted salty water of the Baltic Sea into the Neva Bay. The whole of the above are the preconditions for the
formation of sulfur-bearing organic compounds.
A great number of bottom sediment samples for analytical surveys were collected in the Eastern Gulf of Finland during research
expeditions in the years of 1997 and 2001. These were screened for structures of sulfur organic microcontaminants, including
organic forms of sulfur, using advanced instrumentation and experienced personnel in our two, cooperating laboratories. This
work is a part of the research being carried out on organic micro-admixtures present in bottom sediments, and is the summary
of our findings on previously unstudied sulfur organic substances there.
Materials and Methods A number of sulfur organic compounds present in nineteen bottom sediment samples from the Eastern Gulf of Finland (EGF) were
characterized by high performance gas chromatography connected to low and high resolution mass spectrometers (GC/LRMS and
GC/HRMS). The structure screening was carried out as compared with literature and library mass spectra, and taking the GC
retention times into account. In the cases of an absence of mass spectra not in the literature, interpretation of the most
probable structures was performed with the help of high resolution mass-spectrometric data, fragmentation rules for sulfur-bearing
organic substances and ICLU simulation of spectra. These data were registered to form a conclusive ‘fingerprint’ for identification
and confirmation of the structure of each novel compound found, e.g. by later syntheses of authentic model compounds. The
relative contents of sulfur organic compounds were determined from MS response ratios of each compound to 2-fluorine naphthalene
(internal standard).
Results This paper is a completion of work, which has been published in part as three papers in the European Journal of Mass Spectrometry.
As the total study result, 43 sulfur-bearing compounds were characterized. The mass spectra of 20 of them were found in the
literature. The most probable structures for the 23 compounds whose mass-spectra were not available in the literature data
were proposed. All of those 23 compounds were detected in bottom sediments for the first time, and 5 of them were described
as originating from plants or being generated by chemical synthesis products, while the remaining 18 substances were previously
unknown. The structures of these were deduced to be most probably the following (in order of their GC retention): dichloromethyl
thiylsulfenylchloride, chloromethyl dichloromethyl disulfide, 3,4-dithiacyclohexene, 1,2,4-trithiacycloheptane, 1,2,3-trithiacyclohexane,
tetrathiacyclopentane, 3,4,5-trithiacyclohexene, 1,2,4-trithiacyclohexane, cyclopropylhydrotrisulfide, 1,2-dithiane-3-thiol,
1,3-dithiane-2-thiol, bis(trichloromethyl)-tri-sulfide, 1,2,4,5-tetrathiacyclohexane, 1,2,3,4-tetrathiacycloheptane, 1,2,3,4-tetrathiacycloheptane,
1,2,3,4-tetrathia-cyclo-hexane, pentathiacyclohexane, and 1,2,4,6-tetrathiacyclooctane. The highest amounts of sulfur organic
compounds were found in the deepest, bottom areas in the open part of the sea, where the salinity was highest, and oxygen
deficiency occurred as well. Also, some coastal places with a high solid matter deposition rate had elevated contents of sulfur
organic compounds.
Discussion From the 43 sulfur organic compounds found, the HRMS data provided the atomic composition of the molecular ions for 16 compounds
with a high confidence (see Table 3). The LRMS spectra could be identified with catalogue or literature spectra in 29 cases.
The MS information obtained was insufficient in two cases: 1) The obvious molecular ion (at m/z 110) of compound 1 was not
visible in LRMS. 2) For compound 43, the HRMS measurement, due to the low intensity (2%) of the molecular ion (m/z 210), could
not exclude the presence of 2 oxygen atoms (instead of one sulfur atom) in the molecule. Major fragments, however, of our
43, certainly contained no oxygen atoms according to HRMS. The limited LRMS data in the literature, for an isomer of 43, had
m/z values of all fragments different from those of the compound found by us.
The retention times (RT) formed one more evidence for identity between compounds in different samples. The use of different
non-polar columns in GC and similar, but not identical, temperature programs produced eluted peaks of novel and known compounds
in each sample (mixture) in GC/HRMS and GC/LRMS. These gave sets of RTs which were in a very significant linear correlation
(measured example R = 0.999866, p = 1.85E-06, N = 5). Therefore, the RTs in the HRMS analysis systems could be converted to
values comparable with those from the LRMS device.
The RT values, HRMS m/z values, LRMS spectra, and ICLU simulation results for each organic sulfur compound form an identification
‘fingerprint’. The interpretation of these experimental data, with supporting use of fragmentation rules, allow the giving
of a provisional name and structure to the ‘suspect’. In this study and in environmental surveys of micropollutants in general,
the compounds suspected of anthropogenic or natural origin occur at low levels in complex mixtures. Therefore, no bulk amount
of an authentic, pure model substance for the suspect is available quite often. The most probable name and structure from
the fingerprint data are very useful in guiding the preparation of the model substance for a conclusive identification. Similarly,
the unknown criminal can be identified in advance by forensic science and his fingerprint, DNA, etc. as registered before
the arrest. The analogy can be found in the literature and CAS register of organic polysulfides, which in great part consists
of the results of sensitive mixture analysis methods.
Conclusions Sediment of the Eastern Gulf of Finland is over large areas anaerobic, as indicated by the existence of novel, non-oxygenated
sulfur organic microcontaminants. These substances were most abundant in anoxic and saline, deep bottom regions, and, in addition,
in one coastal area near industrial discharges. This occurrence, and also the limited information about sulfur organic compounds
in scientific literature, is considered evidence for the dominantly natural processes in their formation.
Recommendations and Perspectives The importance and necessity of investigating the sulfur organic compounds in the bottom sediments, result from the fact that
their presence can be an indicator of stable anaerobic processes. Similarly, the oxygen disappearance (anoxia) in the marine
water, due to a high concentration of the sulfate ions and relatively high content of organic matter, is practically always
connected with the appearance of hydrogen sulfide and sulfides. The generation of sulfur organic compounds precedes the formation
of the new, or expansion of the existing anaerobic (‘hydrogen sulfide’) zones, which lead to such environmental disasters
as mass destruction of hydrobionts. Many organic compounds of sulfur, including sulfides and polysulfides, are toxic to the
aquatic organisms. Therefore, in addition to the danger of mass wholesale deaths of marine fauna in the bottom sediments region,
there exists a probability of secondary pollution of the water thickness as well, due to the entry of those substances from
bottom sediments in the water when the environmental conditions are changed (stormy weather, floods, geological activity of
the earth’s crust, etc.). 相似文献
947.
Sakan S Grzetić I Dordević D 《Environmental science and pollution research international》2007,14(4):229-236
Introduction In this work, sediments of the River Tisa (Tisza) are studied to assess their environmental pollution levels for some major
heavy metals, as well as to predict the investigated elements’ mobility on the basis of their association type with the substrate.
The Tisa River catchments area is a subbasin of the River Danube. Part of this river, 166 km long, belongs to the Serbian
province of Vojvodina, before it flows into the Danube. It has been chosen for our investigation, because it has been exposed
to intense pollution in the last decades.
Materials and Methods The river sediment samples were collected at 32 locations. The proportions of sand, silt and clay fractions were determined.
The sequential extraction procedure following a modified Tessier method was applied for speciation of the metal forms in the
collected samples. The metal concentrations of Zn, Cd, Pb, Ni, Cu, Cr, Fe and Mn in extracts were determined by atomic absorption
spectroscopy.
Results and Discussion Granulometric analysis showed that some 50% of the Tisa River sediments were silt and clay, while the rest was sand with quartz,
as the main constituent. The average metal content of the surface river sediment samples for every fraction of sequential
extraction was presented and discussed in relation to pH, Eh and metal fractionation. The average metal content from the Tisa
River sediments, obtained as an average of the metal’s concentration released in all five sequential extraction fractions
was compared with: average metal contents of the Tisa River sediments in Hungary, metal content in soils formed on the Tisa
River alluvium of Vojvodina, average metal content in soils of Vojvodina, and average metal content in soils of Hungary. An
assessment of metal pollution levels in Tisa River sediments was made by comparing mean values for obtained results for the
Tisa River sediments with the freshwater sediment’s Quality Guidelines as published by US EPA, Environment Canada and soil
standards for Serbia.
Conclusion According to US EPA and Canadian Quality Guidelines for freshwater sediments, the concentration of heavy metals in Tisa sediments
were: (a) much higher than defined concentrations below which harmful effects on river biota are unlikely to be observed,
(b) below defined concentrations above which harmful effects on river biota are likely to be observed. The concentration levels
of Pb, Ni, Cu and Cr in Tisa River sediments are safe when compared with Serbian MAQ (Maximum Allowed Quantity) standards
for soils, but they are unsafe in the case of Zn and Cd.
Recommendations and Outlook The quality of sediments in the Tisa River was on the border line between potentially polluted and polluted. This line could
very easily be exceeded since the quality of sediments in the Tisa River in Hungary was already worse than in Serbia. These
results indicated the need for further monitoring of heavy metals in that locality. 相似文献
948.
滇池宝丰湾疏浚区底泥污染程度评价及环保疏浚深度的确定 总被引:1,自引:0,他引:1
根据滇池外海主要入湖河口及重点区域底泥疏浚工程,宝丰湾疏浚区设计阶段勘察结果,采用内梅罗污染指数法及Lars Hakanson的重金属潜在生态风险指数法对疏浚区底泥进行了污染程度评价。针对底泥污染空间分布特征,确定疏浚深度,为环保施工提供依据。 相似文献
949.
北方某水库表层沉积物重金属的赋存形态及其环境影响因子分析 总被引:1,自引:0,他引:1
徐景阳 《环境监测管理与技术》2012,24(5):28-33
为了解北方某水库重金属污染状况,采用BCR连续提取法对该水库表层沉积物中Cu、Pb、Zn、Cd的赋存形态进行了分析,对其含量及空间分布进行了研究,结合重金属总量讨论了各元素的潜在环境风险。结果表明,该水库表层沉积物中Cu、Pb、Zn、Cd的平均质量比分别为65.20 mg/kg、36.69 mg/kg、137.5 mg/kg、2.38 mg/kg,与该地区土壤元素背景值、该地区水系沉积物平均值及全国水系沉积物平均值相比,4种重金属元素均有一定程度的累积,其中Cd累积最为严重。形态分析结果表明,Cd主要以醋酸可提取态及可还原态存在,具有很高的环境风险;Pb主要以极高比例的可还原态存在,潜在风险较高;Zn和Cu存在较大比例的酸可提取态及可还原态,也具有一定程度的潜在风险。各元素生物有效性即可提取态含量排序为:Cd>Cu>Pb>Zn。 相似文献
950.
Akbar Gholampour Ramin Nabizadeh Mohammad Sadegh Hassanvand Shahrokh Nazmara 《毒物与环境化学》2017,99(1):17-31
Atmospheric particulate matters and their elements were concurrently measured at two sites located in the north and southeast parts of Urmia Lake from January to September 2013. At both sampling sites, average concentrations of total suspended particulate, particles with the aerodynamic diameter of smaller than 10 µm, smaller than 2.5 µm, and smaller than 1 µm were 260 ± 106, 180 ± 73, 30 ± 8, and 25 ± 7 µg m?3, respectively. The analyzed water soluble ions accounted for approximately 11%–13% mass concentrations of total suspended particulate and 8%–9% of particles smaller than 10 µm, and the sum of the concentrations of the analyzed elements associated with both ranged from 9 to 41 µg m?3 (6.5%–9.6% in mass) and 7 to 26 µg m?3 (5.5%–11.3% in mass), respectively. Thus, particulate matter was composed of a complex mixture of minerals such as halite, quartz, gypsum, hexahydrite, and Bassanite. 相似文献