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1.
Lambert O Veyrand B Durand S Marchand P Le Bizec B Piroux M Puyo S Thorin C Delbac F Pouliquen H 《Chemosphere》2012,86(1):98-104
Three beehive matrices, sampled in six different apiaries from West France, were analyzed for the presence of four polycyclic aromatic hydrocarbons (PAH4: benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene). Samples were collected during four different periods in both 2008 and 2009. Honey samples showed the lowest levels of PAH4 contamination (min = 0.03 μg kg−1; max = 5.80 μg kg−1; mean = 0.82 μg kg−1; Sd = 1.17). Bee samples exhibited higher levels of PAH4 contamination (min = 0.32 μg kg−1; max = 73.83 μg kg−1; mean = 7.03 μg kg−1; Sd = 17.83) with a great dispersion of the concentrations due to four main events of high concentrations. Pollen samples showed only one major episode with the highest PAH4 concentration found (min = 0.33 μg kg−1; max = 129.41 μg kg−1; mean = 7.10 μg kg−1; Sd = 22.28). The PAH4 concentrations found were significantly influenced by the landscape context for all beehive samples. 相似文献
2.
Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements 总被引:4,自引:0,他引:4
Gomez-Eyles JL Sizmur T Collins CD Hodson ME 《Environmental pollution (Barking, Essex : 1987)》2011,159(2):616-622
Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306 mg kg−1) and bioavailable (cyclodextrin extractable) (276 to 182 mg kg−1) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2 mg kg−1), Cu (60.0 to 120.1 mg kg−1) and Ni (31.7 to 83.0 mg kg−1) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37 mg kg−1). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed. 相似文献
3.
R. Herterich 《Umweltwissenschaften und Schadstoff-Forschung》1991,3(4):196-200
Am Beispiel des Wirkstoffes Atrazin wird die atmosph?rische Verbreitung und der atmosph?rische Eintrag von Pflanzenschutzmitteln
mit einer geringen Flüchtigkeit aufgezeigt. Immissions-Konzentrationen lagen zwischen weniger als 0.005 ng·m−3 und maximal 0.32 ng·m−3 Atrazin wird fast ausschlie?lich in der Partikelphase, offensichtlich im Ungleichgewicht mit der Gasphase, verfrachtet. Dies
verz?gert wahrscheinlich den photochemischen Abbau in der Atmosph?re. Die Konzentrationen im Flüssigwasser aufliegender Wolken
erreichten zu den Applikationsterminen nahezu 1.6 μg·1−1. Die Eintr?ge über die Atmosph?re betrugen in exponierter Lage im Fichtelgebirge mit 0.13 mg·m−2·a−1 ca. 0.4% der Aufwandmengen in 3j?hrigen Maisfruchtfolgen. Im Alpenraum wurden mit 0.012 mg·m−2·a−1 deutlich niedrigere Frachten gemessen als im Fichtelgebirge.Das Umweltrisiko durch die atmosph?rische Verbreitung und Deposition von Atrazin und anderen Pflanzenschutzmitteln mit vergleichbaren
physikalisch-chemischen Eigenschaften ist als ?u?erst gering einzustufen.
Atmospheric occurrence and deposition of atrazine are measured. During the application of atrazine, highest concentrations
reached 1.6 μg·1−1 in liquid water of lowlying clouds touching mountain tops. Atmospheric deposition, however, hardly amounts to 0.4% of the
flux on crop land by direct spraying. Airborne concentrations ranged from less than 0.005 ng·m−3 to 0.32 ng·m−3. Contrary to theoretical expectations, almost all atrazine was found in the particulate matter, indicating nonequilibrium
with the gas phase. This may inhibit a rapid photochemical decomposition. Human health concerns and environmental risks due
to the atmospheric occurrence and deposition of atrazine are judged as minor. This conclusion can be applied to many other,
physicochemically related pesticides. 相似文献
4.
Sorption, desorption, and degradation of (4-chloro-2-methylphenoxy)acetic acid in representative soils of the Danubian Lowland, Slovakia 总被引:1,自引:0,他引:1
Herbicide leaching through soil into groundwater greatly depends upon sorption-desorption and degradation phenomena. Batch adsorption, desorption and degradation experiments were performed with acidic herbicide MCPA and three soil types collected from their respective soil horizons. MCPA was found to be weakly sorbed by the soils with Freundlich coefficient values ranging from 0.37 to 1.03 mg1−1/n kg−1 L1/n. It was shown that MCPA sorption positively correlated with soil organic carbon content, humic and fulvic acid carbon contents, and negatively with soil pH. The importance of soil organic matter in MCPA sorption by soils was also confirmed by performing sorption experiments after soil organic matter removal. MCPA sorption in these treated soils decreased by 37-100% compared to the original soils. A relatively large part of the sorbed MCPA was released from soils into aqueous solution after four successive desorption steps, although some hysteresis occurred during desorption of MCPA from all soils. Both sorption and desorption were depth-dependent, the A soil horizons exhibited higher retention capacity of the herbicide than B or C soil horizons. Generally, MCPA sorption decreased in the presence of phosphate and low molecular weight organic acids. Degradation of MCPA was faster in the A soil horizons than the corresponding B or C soil horizons with half-life values ranging from 4.9 to 9.6 d in topsoils and from 11.6 to 23.4 d in subsoils. 相似文献
5.
Eija K. Saski Raimo Mikkola Jussi V. K. Kukkonen Mirja S. Salkinoja-Salonen 《Environmental science and pollution research international》1997,4(4):194-202
Environmental properties of organic matter contained halogen and sulfur were studied in sediments of bleached kraft pulp mill
effluent (BKME) recipient lakes and 2 m3 outdoor enclosures (mesocosms). The BKME contributed to 1% (v/v) of the total water flow in the lake downstream of the pulp
mill where the sediments contained 1.7 to 4 mg of tetrahydrofuran extractable organic halogen (EOX-Cl) and 0.6 to 0.8 mg of
tetrahydrofuran extractable organic sulfur (EOS-S) g−1 of organic matter. Upstream sediment contained 0.03 mg of EOXCl and 0.7 mg of EOS-S g−1 of organic matter. EOX was a better indicator for the influence of BKME in the recipient sediment than EOS. The polarity
of BKME contained EOX corresponded to log Kow of < 1, and that of the downstream sediment contained EOX to > 4.5. HP-SEC analysis of the molecular weight distribution
(MWD) of the EOX showed a peak between 300 to 600 g mol−1 for the BKME and between 1000 to 2000 g mol−1 for the downstream sediment. The MWD of the BKME contained EOS peaked at 300 to 1000 g mol−1, and that of the downstream sediment contained EOS at 1000 to 5000 g mol−1. These results indicate that BKME contained organic halogen and sulfur undergo major structural transformations when incorporated
into sediment. The biota-to-sediment accumulation factor (BSAF) of EOX from sediments formed downstream of the mill and in
the mesocosms to the lipids ofLumbriculus variegatus was 0.4 to 0.7. This is of a similar order of magnitude to the BSAF reported for 2,3,7,8-tetrachlorodibenzop-dioxin and 2,3,7,8-tetrachlorodibenzofuran. 相似文献
6.
Hickman ZA Swindell AL Allan IJ Rhodes AH Hare R Semple KT Reid BJ 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1041-1045
This study sought to extend validation of a cyclodextrin based extraction method for the assessment of PAH-biodegradation potential to complex multi-contaminant matrices. To this end, four reference materials (RMs) were produced by blending, in different proportions, soils impacted with diesel, lubricating oil and spent oxide. These reference materials had modest ∑PAH (16 US EPA) concentrations that ranged from 5.6 ± 0.5 to 44.4 ± 4.5 mg kg−1. However, extractable petroleum hydrocarbon (EPH) concentrations were comparatively high (up to 2520 ± 204 mg kg−1). To complement these RMs, two further soils from a municipal gas plant (MGP) with highly elevated concentration of PAHs ranging from 877 ± 52 to 2620 ± 344 mg kg−1 were also tested. Results showed, regardless of matrix complexity, that PAH biodegradation within the four RM substrates, and two MGP soils correlated well with biodegradation predicted by hydroxypropyl-β-cyclodextrin (HPCD) extraction. 相似文献
7.
Paz-Alberto AM Sigua GC Baui BG Prudente JA 《Environmental science and pollution research international》2007,14(7):498-504
Background, Aims and Scope The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of
the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment
makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive
and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation.
Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were:
(1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass
and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass
species as potential phytoremediators in terms of Pb accumulation by plants.
Methods The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg−1 (37.5 kg ha−1) and 150 mg kg−1 (75 kg ha−1) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments
using an atomic absorption spectrophotometer. This study was laid out following a 3 × 2 factorial experiment in a completely
randomized design.
Results On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85–39.39
Mg ha−1). Carabaograss had the lowest herbage mass production of 4.12 Mg ha−1 and 5.72 Mg ha−1 from soils added with 75 and 150 mg Pb kg−1, respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination
in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 ± 2.81 mg kg−1). This was followed by cogongrass (2.34 ± 0.52 mg kg−1) and carabaograss with a mean Pb level of 0.49 ± 0.56 mg kg−1. Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150
mg kg−1) to the soil.
Discussion Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed
to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root
system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency
of plants as phytoremediators could be correlated with the plants’ total biomass. This implies that the higher the biomass,
the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what
they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport
of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most
metal removal from the soil.
Conclusions The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil.
It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also
potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated
soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction
on sites contaminated with high levels of heavy metals; particularly Pb.
Recommendations and Perspectives High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters,
battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly
vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and
public parks.
ESS-Submission Editor: Dr. Willie Peijnenburg (wjgm.peijnenburg@rivm.nl) 相似文献
8.
Marek Roszko Marta Kamińska Krystyna Szymczyk Renata Jędrzejczak 《Journal of environmental science and health. Part. B》2018,53(1):25-34
The aim of this work was to assess dietary risk resulting from consumption of polycyclic aromatic hydrocarbons (PAHs) with tea infusions. To this end, levels of 28 PAHs in black, green, red and white teas available on the Polish retail market have been assessed. Profiles and correlation between concentrations of individual PAHs have been identified. A model study on transfer of PAHs from tea leaves into tea preparations has been conducted. Relatively high concentrations of 28 evaluated PAHs have been found in 58 tested samples of black, green, red and white teas sampled on the Polish retail market. Total concentration ∑28PAH ranged from 57 to 696 µg kg?1 with mean 258 µg kg?1 (dry tea leaves). The most mature tea leaves fermented to a small degree contained relatively the highest PAH levels among all four tested tea types. Relatively low PAH transfer rates into tea infusions and limited volumes of the consumed tea keep the risks associated with PAH dietary intake at a safely low level.The worst-case scenario dietary intake values were 7.62/0.82/0.097 ng kg?1 b.w. day?1 (estimated on the basis of the maximum found concentrations 696/113/23 µg kg?1 and maximum observed transfer rates 24/16/9%) for ∑28PAH/∑PAH4/B[a]P, respectively. MOE values calculated using the above worst case estimates exceeded 700,000 and 400,000 (BMDL10 0.07 and 0.34 mg kg?1 b.w. day?1) for B[a]P and PAH4, respectively. Both B[a]P and PAH4 concentrations may be used as indicators of total PAH concentration in tea leaves; PAH4 slightly better fits low molecular weight PAHs. Several correlations between various PAHs/groups of PAHs have been identified, the strongest one (R2 = 0.92) between PAH4 and EU PAH 15+1. 相似文献
9.
Adsorption of lambda-cyhalothrin and cypermethrin on two typical Chinese soils as affected by copper
Jun Liu Xiaomeng Lü Jimin Xie Yafei Chu Cheng Sun Qian Wang 《Environmental science and pollution research international》2009,16(4):414-422
Background, aim, and scope Pesticides and heavy metals pollution in soil environment has become a serious problem in many countries including China.
Repeated applications of bordeaux mixture (a blend of copper sulfate and calcium hydroxide) and pyrethroid (Pys) insecticides
have led to elevated copper (Cu) and Pys concentrations in vineyard surface soils. However, few studies focused on the interaction
of Pys and heavy metals in the soil environment. Our previous studies had indicated the combined effect of cypermethrin (CPM)
and Cu on soil catalase activity. Also, we had suggested that the addition of Cu could catalyze photo-degradation of CPM and
lambda-cyhalothrin (λ-CHT) in aqueous solution and restrain their degradation in soil. To better understand the potential
influence of Cu on the fate of Pys in the soil environment, the aim of the present work was to examine the effect of Cu on
the adsorption of λ-CHT and CPM on two typical Chinese soils with different soil characteristics, which was one of the key
processes controlling the fate of Pys, and to provide more information about the potential ecological risk of chemicals on
the soil ecosystem. Fourier transform infrared and point charges analysis using the MOPAC program of the Gaussian system were
also used to reveal the probable adsorption mechanism of λ-CHT and CPM on soils.
Materials and methods Two vineyard soils with different properties were chosen as experimental samples. They were sampled from 0 to 10 cm, dried,
and sieved to 2 mm. Each soil was spiked with copper sulfate solution to obtain the following total soil Cu concentrations:
100, 200, 400, 800, and 1,600 mg·kg−1. The treated soils were incubated for 2 weeks and then dried at 20°C. For each soil sample and at each soil Cu concentration,
the adsorption of λ-CHT and CPM was measured using a batch equilibrium method. The concentration of λ-CHT was determined by
HPLC, and the amount of λ-CHT and CPM adsorbed by the soil sample at equilibrium was determined by the difference between
the initial and equilibrium concentrations in solution corrected by the blank adsorption measurement.
Results Without the addition of Cu, the adsorption of λ-CHT and CPM on Black soil is greater than that on Red soil, while the adsorption
of λ-CHT on both soils is significantly stronger than that of CPM. As the soil Cu concentration increased from 19 (or 18;
background) to 1,600 mg·kg−1, the adsorption coefficient (K
d) of λ-CHT decreased from 12.2 to 5.9 L·kg−1 for Red soil, and from 26.1 to 16.8 L·kg−1 for Black soil, whereas the CPM adsorption coefficient in both soils decreased nearly by 100% (K
d decreased from 9.4 to 0.2 L·kg−1 for Red soil and from 16.2 to 0.5 L·kg−1 for Black soil).
Discussion Pys adsorption is a surface phenomenon which depends on the surface area and the organic matter content. Thus, the Black soil,
having higher organic matter and greater surface area than that of the Red soil, show greater adsorption affinity to λ-CHT
and CPM. In our study, the different adsorption affinity of the two Pys was obtained, which was probably attributed to differences
with respect to their physical–chemical properties. Further comparison upon the two Pys was conducted. The point charges of
halogen atoms in the λ-CHT and CPM were calculated, the differences of which probably lead to the fact that λ-CHT has a stronger
binding capacity to soils than CPM. Also, FTIR spectra show that competitive adsorption occurs between CPM and Cu for the
same adsorption sites, which is responsible for the obtained suppression of CPM adsorption affected by Cu.
Conclusions Lambda-cyhalothrin shows a significantly stronger adsorption than cypermethrin on both soils. This phenomenon may be due to
several reasons: (1) λ-CHT has lower solubility and a higher octanol–water partition coefficient value than CPM; (2) λ-CHT
consists of specific isomers, whereas CPM is mixtures of eight different isomers; (3) the chlorine and fluorine atoms in the
λ-CHT have a negative point charge, whereas the chlorine atoms in the CPM have a positive point charge. As the soil Cu concentrations
increased from 19 (or 18) mg·kg−1 to 1,600 mg·kg−1, the adsorption coefficient of λ-CHT and CPM decreased on both soils. This is mainly due to a competition between Cu and
Pys for occupying the adsorption sites on soils. The information from this study have important implications for vineyard
and orchard soils, which often contain elevated levels of Cu and Pys. These results are also useful in assessing the environmental
fate and health effect of λ-CHT and CPM.
Recommendations and perspectives It is important for environmental scientists and engineers to get a better understanding of soil–metal–organic contaminant
interactions. However, pesticide adsorption involves complex processes, and shortcomings in understanding them still restrict
the ability to predict the fate and behavior of pesticide. Therefore, considerable research should be carried out to understand
the mechanism of interaction between Pys and heavy metal on soils clearly. 相似文献
10.
Hybholt TK Aamand J Johnsen AR 《Environmental pollution (Barking, Essex : 1987)》2011,159(5):1085-1091
The aim of the study was to determine centimeter-scale spatial variation in mineralization potential in diffusely polluted soil. To this end we employed a 96-well microplate method to measure the mineralization of 14C-labeled organic compounds in deep-well microplates and thereby compile mineralization curves for 348 soil samples of 0.2-cm3. Centimeter-scale spatial variation in organic matter and the mineralization of glucose, benzoic acid, and PAHs (phenanthrene and pyrene) was determined for urban road-side soil sampled as arrays (7 × 11 cm) of 96 subsamples. The spatial variation in mineralization was visualized by means of 2-D contour maps and quantified by means of semivariograms. The geostatistical analysis showed that the easily degradable compounds (glucose and benzoic acid) exhibited little spatial variation in mineralization potential, whereas the mineralization was highly heterogeneous for the PAH compounds that require specialized degraders. The spatial heterogeneity should be taken into account when estimating natural attenuation rates. 相似文献
11.
Oxidation of a PAH polluted soil using modified Fenton reaction in unsaturated condition affects biological and physico-chemical properties 总被引:3,自引:0,他引:3
A batch experiment was conducted to assess the impact of chemical oxidation using modified Fenton reaction on PAH content and on physico-chemical and biological parameters of an industrial PAH contaminated soil in unsaturated condition. Two levels of oxidant (H2O2, 6 and 65 g kg−1) and FeSO4 were applied. Agronomic parameters, bacterial and fungal density, microbial activity, seed germination and ryegrass growth were assessed. Partial removal of PAHs (14% and 22%) was obtained with the addition of oxidant. The impact of chemical oxidation on PAH removal and soil physico-chemical and biological parameters differed depending on the level of reagent. The treatment with the highest concentration of oxidant decreased soil pH, cation exchange capacity and extractable phosphorus content. Bacterial, fungal, and PAH degrading bacteria densities were also lower in oxidized soil. However a rebound of microbial populations and an increased microbial activity in oxidized soil were measured after 5 weeks of incubation. Plant growth on soil treated by the highest level of oxidant was negatively affected. 相似文献
12.
Effect of Pb toxicity on leaf growth, antioxidant enzyme activities, and photosynthesis in cuttings and seedlings of Jatropha curcas L 总被引:3,自引:0,他引:3
Shu X Yin L Zhang Q Wang W 《Environmental science and pollution research international》2012,19(3):893-902
Background
Cuttings and seedlings of Jatropha curcas L. were exposed to different regimes of lead (Pb) stress as Pb(NO3)2 at 0 (CK), 0.5, 1, 2, 3, and 4 mM kg−1 soil. 相似文献13.
Necati Kayaalp Mustafa Evren Ersahin Hale Ozgun Ismail Koyuncu Cumali Kinaci 《Environmental science and pollution research international》2010,17(9):1547-1552
Background, aim, and scope
Chemical oxygen demand (COD) is used as a discharge standard parameter in wastewater treatment plant design, environmental modelling and many other applications. Chloride interference is an important problem of COD measurement for wastewaters containing low organic matter and high chloride concentrations. In case of chloride concentrations up to 2,000 mg/L, mercury sulphate addition at a ratio of 10:1 (HgSO4:Cl−) can adequately mask the interference. When chloride concentration exceeds 2,000 mg/L, this ratio becomes ineffective to hinder the interference. At this point, it is proposed to use a greater and constant ratio of mercury sulphate addition. However, this application sometimes results in extra mercury sulphate addition which is not necessary. Even in some cases, greater addition of mercury sulphate alone is not a solution to erroneous measurement results. The purpose of the study is to determine optimum HgSO4:Cl− ratios according to the chloride concentrations of the samples and to show the importance of the strength of the digestion solution for the correct determination of the COD parameter. 相似文献14.
《Atmospheric environment (Oxford, England : 1994)》2007,41(13):2729-2739
Burning of agricultural waste residue is a common method of disposal when preparing land following crop harvest. This practice introduces volatile organic compounds, including polycyclic aromatic hydrocarbons (PAHs), into the atmosphere. This study examines the particle size distribution in the smoke emissions of two common agricultural waste residues (biofuels) in California, almond prunings and rice straw. The residues were burned in a combustion chamber designed specifically for this purpose, and the smoke emissions were collected on 10-stage MOUDI impactors for analysis of PAH and total particle mass. The results, in units of emission factors, show that combustion temperature is an important factor in determining the smoke particle PAH composition. Total PAH emissions from rice straw burns were 18.6 mg kg−1 of fuel, while the emissions from almond prunings were lower at 8.03 mg kg−1. The less volatile five- and six-ring PAH was predominately on smaller particles where it condensed in the early stages of combustion while the more volatile three- and four-ring PAH formed on larger particles as the smoke cooled. 相似文献
15.
Selenium fractions in organic matter from Se-rich soils and weathered stone coal in selenosis areas of China 总被引:5,自引:0,他引:5
A high degree of association between Selenium (Se) and organic matter has been demonstrated in natural environments, but Se fractions and speciation in organic matter is unclear. In this study, a method for quantifying organic matter associated with Se (OM-Se) was developed to investigate Se fractions in organic matter in Se-rich soils and weathered stone coal from Enshi, China, where Se poisoning of humans and livestock has been documented. Initially, Se was extracted using water and a phosphate buffer. Subsequently, OM-Se was extracted using NaOH, and then speciated into Se associated with fulvic acids (FA-Se) and humic acids (HA-Se). Both FA-Se and HA-Se were further speciated into the weakly bound and strongly bound fractions using a customized hydride generation reactor. The results show that FA-Se (1.91-479 mg kg−1) is the predominant form of Se in all Se-rich soils and the weathered stone coal samples, accounting for more than 62% of OM-Se (3.07-484 mg kg−1). Weakly bound FA-Se (1.33-450 mg kg−1) was prevalent in the total FA-Se, while weakly bound HA-Se (0.62-26.2 mg kg−1) was variable in the total HA-Se (1.15-32.5 mg kg−1). These data indicate that OM-Se could play a significant source and sink role in the biogeochemical cycling of Se in the supergene environment. Weakly bound FA-Se seems to act as a potential source for bioavailable Se, whereas strongly bound HA-Se is a possible OM-Se sink which is not readily transformed into bioavailable Se. 相似文献
16.
Liu J Yan C Macnair MR Hu J Li Y 《Environmental science and pollution research international》2007,14(5):345-349
Background Acid-volatile sulfide (AVS) is operationally defined as sulfides in sediment, which are soluble in cold acid, and is reported
as the most active part of the total sulfur in aquatic sediments. It is a key partitioning phase controlling the activities
of divalent cationic heavy metals in sediment.
Methods In order to examine this in mangrove environments, six sites were selected along the Jiulong River Estuary in Fujian, China,
which had previously been reported to be polluted by heavy metals. Sediments were sampled from 0–60 cm depth at each site,
and the spatial distribution of AVS and SEM (simultaneously extracted metals: copper, cadmium, zinc, and lead) were determined.
Results and Discussion The results indicate that the AVS concentrations had a spatial variation, ranging from 0.24 to 16.10 μmol g−1 sediment dry weight. The AVS concentration in the surface layer is lower than that of the deeper sediment, with peak values
in the 15–30 cm horizon. There was no correlation between the AVS value and organic matter content or total dissolved salts,
but a significant positive correlation of AVS with surface sediment (0–5 cm) moisture content was found. This indicates that
water logged sediments tend to have a high AVS value. The amount of SEM was within the range of 0.33–2.80 μmol g−1 sediment dry weight and decreased with sediment depth.
Conclusions There was a marked variation in AVS and SEM among different sites studied. AVS concentrations were generally lower in the
surface sediments, while SEM concentrations slightly decreased with the depth. Higher concentrations of SEM found in the upper
layers of the sediments confirm the earlier suggestions that this study area may suffer from increasing heavy metal pollution.
Recommendations and Perspectives When monitoring environmental impacts by using AVS, the micro and large-scale spatial variation as well as vertical distribution
need to be estimated to avoid misleading results. Both AVS and SEM concentrations in different sediment layers should be taken
into account in assessing the potential impact of heavy metals on the biotic environment. 相似文献
17.
《国际环境与污染杂志》2011,36(4):411-417
This study was conducted to investigate the influence of vehicle emissions on zinc and lead content of cow's milk, grazing at 15 different locations near to roadsides in Sakarya, Turkey. The results obtained for zinc were between 1262 μg kg−1 and 6566 μg kg−1. An acceptable range of zinc content from various sides confirmed the absence of possible toxicological risks in this region. The lead levels ranged from 3.24 μg kg−1 to 80.69 μg kg−1. The levels of lead in milk samples collected from roadside pastures were higher than the regulatory limits and pose a health risk. 相似文献
18.
Cecilia Flores Vernica Morgante Myriam Gonzlez Rodrigo Navia Michael Seeger 《Chemosphere》2009,74(11):1544-1549
Simazine is a s-triazine herbicide that has been applied worldwide for agriculture. This herbicide is the second most commonly detected pesticide in surface and groundwater in the United States, Europe and Australia. In this study, simazine adsorption behaviour was studied in two agricultural soils of the Aconcagua valley, central Chile. The two studied soils were soil A (loam, 8.5% organic matter content) and soil B (clay-loam, 3.5% organic matter content). Three times higher simazine adsorption capacity was observed in soil A (68.03 mg kg−1) compared to soil B (22.03 mg kg−1). The simazine adsorption distribution coefficients (Kd) were 9.32 L kg−1 for soil A and 7.74 L kg−1 for soil B. The simazine adsorption enthalpy in soil A was −21.0 kJ mol−1 while in soil B the adsorption enthalpy value was −11.5 kJ mol−1. These results indicate that simazine adsorption process in these soils is exothermic, governing H bonds the adsorption process of simazine in both the loam and clay-loam soils. These results and the potentiometric profiles of both soils, suggest that simazine adsorption in soil A is mainly governed by simazine–organic matter interactions and in soil B by simazine–clay interactions. The understanding of simazine sorption–desorption processes is essential to determine the pesticide fate and availability in soil for pest control, biodegradation, runoff and leaching. 相似文献
19.
The analysis of material used in this study demonstrated that the amount of polycyclic aromatic hydrocarbons (PAHs) in smoked sprats varies from the level below the lowest detection limit in muscles up to 9.99 µg kg?1 of benzo[a]pyrene (BaP) in fish skin. Such a high level of PAHs in skin was reported only in one of six batches of sprats, while mean BaP level was at 1.69 µg kg?1. Regardless such a high BaP level in skin, its concentration in muscles did not exceed the maximum acceptable level. The study objective was to assess to what extent packaging materials adsorb PAH compounds from food. Changes in the PAH levels were monitored in fish during their storage in packages made of various materials. The storage time was from 0 to 168 hours. The obtained results varied considerably, therefore their scatter did not allow to confirm unequivocally the preliminary hypothesis about the reduction of PAHs due to their migration to packaging material. However, analysis of the packaging used in this study demonstrated a significant increase in the level of total 16 PAHs. When high-density polyethylene (HDPE) packaging was analysed, a six-fold increase in the total 16 PAHs was observed comparing to the blank sample. 相似文献
20.
《Atmospheric environment (Oxford, England : 1994)》2007,41(12):2660-2669
Emission factors (EFs) of pollutants from post-harvest agricultural burning are required for predicting downwind impacts of smoke and inventorying emissions. EFs of polycyclic aromatic hydrocarbons (PAH), methoxyphenols (MP), levoglucosan (LG), elemental carbon (EC) and organic carbon (OC) from wheat and Kentucky bluegrass (KBG) stubble burning were quantified in a US EPA test burn facility. The PAH and MP EFs for combined solid+gas phases are 17±8.2 mg kg−1 and 79±36 mg kg−1, respectively, for wheat and 21±15 mg kg−1 and 35±24 mg kg−1, respectively, for KBG. LG, particulate EC and artifact-corrected OC EFs are 150±130 mg kg−1, 0.35±0.16 g kg−1 and 1.9±1.1 g kg−1, respectively, for wheat and 350±510 mg kg−1, 0.63±0.056 g kg−1 and 6.9±0.85 g kg−1, respectively, for KBG. Positive artifacts associated with OC sampling were evaluated and remedied with a two-filter system. EC and OC accounted for almost two-thirds of PM2.5 mass, while LG accounted for just under 3% of the PM2.5 mass. Since EFs of these pollutants generally decreased with increasing combustion efficiency (CE), identifying and implementing methods of increasing the CEs of burns would help reduce their emissions from agricultural field burning. PAH, OC and EC EFs are comparable to other similar studies reported in literature. MP EFs appear dependent on the stubble type and are lower than the EFs for hard and softwoods reported in literature, possibly due to the lower lignin content in wheat and KBG. 相似文献