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1.
Background, aim, and scope Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. They are formed during pyrogenic and diagenetic
processes and are components of petrogenic materials such as oils and coals. To identify PAH sources, several studies have
employed forensic methods, which may be costly to execute. Although a large number of possible forensic methods are available
(e.g., total ion chromatograms, PAH ratios, PAH alkyl homologue series, isoalkanes and isoprenoids, steranes and terpanes,
stable isotope ratios, n-alkanes), one has to decide which method is the appropriate cost effective screening approach. In this study, three approaches
were tested and compared by measuring (1) an extended PAH spectrum (i.e., 45 instead of the common 16 EPA-PAHs), (2) PAH ratios
and (3) n-alkanes to determine if point sources are distinguishable from non-point sources, and if an individual source can be distinguished
from a multiple source contaminated site in the study area. In addition, the study evaluated whether these methods are sufficient
for source identification of selected samples, and if they constitute a sound strategy for source identification prior to
the selection of more cost intensive methods.
Materials and methods Eighteen samples with previously characterized PAH point sources (previously characterized point sources in the Mosel and
Saar region) were analyzed. Additionally, three river bank soils of Mosel and Saar rivers with known non-point PAH sources
were investigated. The point sources were two gasworks, a tar impregnation facility, a creosoted timber, an acid tar, a tank
farm, and a diesel contaminated site. Non-point sources were hard coal particles and atmospheric inputs in river bank soils.
All samples were extracted with hexane and acetone, analyzed with a gas chromatograph coupled to a mass spectrometer for PAH
distribution patterns and ratios. n-Alkanes were measured by a gas chromatograph equipped with a flame ionization detector.
Results Samples collected from point sources and non-point sources were analyzed by the use of three forensic methods, i.e., PAH patterns
of an extended PAH spectrum, PAH ratios and n-alkanes. Identification by PAH patterns alone was insufficient for the non-point sources and some point sources, since the
n-alkanes must be measured, as well. The use of PAH ratios with only 16 EPA-PAHs is less indicative in determining multiple
sources because source assignments (or categories) change depending on the ratio used.
Discussion This study showed that by employing an extended PAH spectrum it is possible to fingerprint and distinguish sources. The use
of alkylated PAHs is essential for identifying petrogenic sources. It is insufficient to rely exclusively on either the common
16 EPA-PAHs or the ratios to the parent PAHs when identifying non-point sources. Source identification using PAH ratios is
only reliable if both parent and alkylated PAHs are measured. n-Alkane analyses provide more detailed information about petrogenic sources by verifying the presence of oils, diesel, gasoline,
or coal in non-point sources.
Conclusions The three methods tested were deemed sufficient to distinguish between point and non-point PAH sources in the samples investigated.
The use of an extended PAH spectrum provides the first step toward identifying possible sources. It simplifies the decision
whether additional forensic methods should be necessary for more detailed source identification.
Recommendations and perspectives The determination of PAH alkyl homologue series, biomarkers, and isotopes is often advised (Kaplan et al., Environ Forensics 2:231–248, 2001; Oros and Simoneit, Fuel 79:515–536, 2000; Wang and Fingas, Mar Pollut Bull 47:423–452, 2003). The methods involved are complex and often expensive. We recommend a relatively uncomplicated and cost-effective method
(i.e., extended PAH spectrum) before further and more expensive forensic investigations are to be conducted. Additional research
with an extended sample set should be carried out to validate these findings for other sources and sites.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Background, Aims, and Scope More frequent occurrence of stronger floods in Europe as well as in other parts of the world in recent years raises major
concern about the material damages, but also an important issue of contamination of the affected areas through flooding. The
effects of major floods on levels and distribution of contamination with hydrophobic organic pollutants were examined from
the continuous set of data for floodplain soils and sediments from a model industrial area in the Czech Republic where a 100-year
flood occurred in 1997. The goal of this study was to evaluate the risk related to contamination associated with such extensive
natural events and characterize the spatial and temporal distribution and dynamics of pollutants related to a major flooding
shortly after the floods and also in the time period several years after floods.
Methods Sediments and alluvial soils from fourteen sites each were repeatedly sampled during the period from 1996 until 2005. The
sampling sites represented five regions. Collected top-layer sediment and soil samples were characterized and analyzed for
hydrophobic organic pollutants PCBs, OCPs and HCB using GC-ECD and PAHs using a GC-MS instrument. Spatial and temporal differences
as well as the relative distribution of the pollutants were examined in detail by statistical analysis including multivariate
methods with special emphases placed on the changes related to floods.
Results The organic pollutants levels in both alluvial soils and sediments exceeded the safe environmental limits at numerous sites.
Pollutants concentrations and relative distribution as well as organic carbon content in both sediment and floodplain soils
were significantly affected by the flooding, which resulted in a decrease of all studied contaminants in sediments and significant
rise of the PAH pollution in the flooded soils. There was a unique and highly conserved PAH pattern in soils regardless of
the floods and greater changes in PAH pattern in sediments related to floods. The relative distribution of individual PAHs
reflected a combustion generated PAH profile. PAH levels in the river sediments rose again at the sites with continuous sources
several years after floods.
Discussion The results showed different dynamics of PAHs and PCBs during the floods when PAHs were redistributed from the sediments to
alluvial soils while PCBs have been washed out of the study regions. The data reveal longer contamination memory and consistent
contamination pattern in soils, whereas sediments showed more dynamic changes responding strongly to the actual situation.
The stable PAH pattern within the regions also indicates that a relative amount of all compounds is comparable across the
samples and, thus, that the sources at different sites have similar character.
Conclusions Sediments have the potential to function as a secondary source of contamination for the aquatic ecosystem, but also for the
floodplain soils and other flooded areas. The floods served as a vector of PAHs contamination from sediments to soils. The
reloading of river sediments in time, namely with PAHs, due to present sources increases their risk as a potential source
in the next bigger flood event both to the downstream river basin and affected alluvial soils.
Recommendations and Perspectives The results stress the importance of including the floodplain soil contamination in the risk assessment focused on flood effects.
Floodplain soils have stable long-term environmental memory related to contamination levels, pattern and distribution, whereby
they can provide relevant information on the overall contamination of the area. The sediments will continue to serve as a
potential source of contaminants and alluvial soils as the catchment media reflecting the major flood events, especially until
effective measures are taken to limit contamination sources.
ESS-Submission Editor: Dr. Henner Hollert (Hollert@uni-heidelberg.de)
This article is openly accessible! 相似文献
3.
PurposeThe study was conducted to quantify the polycyclic aromatic hydrocarbons (PAHs) accumulation in urban soils from different functional areas via atmospheric inputs with particulate matter. Materials and methodsPAH concentration and pattern were measured in the particulate matter of snow depositions, in the upper layers of artificial soils from densely built-up areas and in the undisturbed natural soils (Umbric Retisols) from green park area. Samples were collected in 2011–2013 at 58 sites with different traffic activities located at the territory of the Eastern Administrative Okrug of Moscow. The soil samples and filters with particulate matter were extracted by pressurized liquid extraction using Dionex ASE200. Clean-up analyses were performed on SPE cartridges filled with silica gel. Concentrations of PAHs were determined by high-performance liquid chromatography using an Agilent 1100 System equipped with fluorescent detector. Results and discussionMean values of PAH input with snow particles were 45–57 μg/m2 for recreational and residential zones, and 140–264 μg/m2 for traffic zones. The samples of depositions from different functional areas showed a similar PAH pattern and consisted primarily of 3–4-ring PAHs. Total PAH concentrations in upper layers of artificial soils showed similar mean values of 1.43–2.21 μg/g for all functional zones. The PAH content in soils from the park area was twofold lower than that from the built-up area (0.34–0.63 μg/g), despite equal levels of atmosphere contamination on these territories. The upper layers of natural soils from recreational and traffic zones showed slight differences in PAH content, though PAH input with snow was fivefold higher in the traffic zone. Compared with airborne depositions, soils contained significant amounts of 5–6-ring PAHs. ConclusionsA high level of soil PAH contamination in urban areas of Moscow, several orders of magnitude higher than the current PAH input to them from the atmosphere, indicates a lack of direct connection of the PAH pool in soils with this source. The high PAH content in the upper layer of constructed soils can be the result of repeated use of materials subjected to a constant technogenic impact for the production of artificial soils. 相似文献
4.
Background, Aim and Scope
Polycyclic aromatic hydrocarbons (PAHs) are formed as a result of incomplete combustion and are among the most frequently
occurring contaminants in soils and sediments. PAHs are of great environmental concern due to their ubiquitous nature and
toxicological properties. Consequently, extensive research has been conducted into the development of methods to remediate
soils contaminated with PAHs. Fenton's reagent or ozone is the most commonly studied chemical oxidation methods. However,
the majority of remediation studies use soils that have been artificially contaminated with either one or a limited number
of PAH compounds in the laboratory. Hence, it is essential to extend such studies to soils contaminated with multiple PAHs
under field conditions.
Objectives The objective of this study is to investigate the capacity of Fenton's reagent and ozone to degrade PAHs in soils. The soils
have been collected from a number of different industrial sites and, therefore, will have been exposed to different PAH compounds
in varying concentrations over a range of time periods. The capacity of Fenton's reagent and ozone to degrade PAHs in industrially
contaminated soils is compared to results obtained in studies using soils artificially contaminated with PAHs in the laboratory.
Materials and Methods:
Nine soil samples, contaminated with PAHs, were collected from five different industrial sites in Sweden. For the Fenton's
reagent procedure, the pH of the soil slurry samples was adjusted to pH 3 and they were kept at a constant temperature of
70oC whilst H2O2 was added. For the ozone procedure, soil samples were mixed with 50% water and 50% ethanol and kept at a
constant temperature of 45 oC. Ozone was then continually introduced to each soil sample over a period of four hours. Following
the Fenton's reagent and ozone oxidation procedures, the samples were filtered to isolate the solid phase, which was then
extracted using pressurized liquid extraction (PLE). The sample extracts were cleaned up using open columns and then analysed
by gas chromatography-mass spectrometry (GC-MS).
Results:
The relative abundance of the detected PAHs varied between soils, associated with different industries. For example, low molecular
weight (LMW) PAHs were more abundant in soil samples collected from wood impregnation sites and high overall PAH degradation
efficiencies were observed in soils originating from these sites. In the contaminated soils studied, PAHs were more effectively
degraded using Fenton's reagent (PAH degradation efficiency of 40-86%) as opposed to ozone (PAH degradation efficiency of
10-70%). LMW PAHs were more efficiently degraded, using ozone as the oxidizing agent, whereas the use of Fenton's reagent
resulted in a more even degradation pattern for PAHs with two through six fused aromatic rings.
Discussion:
The degradation efficiency for both methods was largely dependent on the initial PAH concentration in the soil sample, with
higher degradation observed in highly polluted soils. LMW PAHs are more susceptible to degradation than high molecular weight
(HMW) PAHs. As a result of this the relative abundance of large (often carcinogenic) PAHs increased after chemical oxidation
treatment, particularly after ozone treatment. Repeated Fenton's reagent treatment did not result in any further degradation
of soil PAHs, indicating that residual soil PAHs are strongly sorbed. The effectiveness of the two oxidation treatment approaches
differed between industrial sites, thus highlighting the importance of further research into the influence of soil properties
on the sorption capacity of PAHs.
Conclusions:
This study demonstrates that the degree to which chemical oxidation techniques can degrade soil bound PAHs chemical degradation
is highly dependent on both the concentration of PAHs in the soils and the compounds present, i.e. the various PAH profiles.
Therefore, similarities in the PAH degradation efficiencies in the nine soil samples studied were observed with the two chemical
oxidation methods used. However, the degradation performance of Fenton's reagent and ozone differed between the two methods.
Overall, Fenton's reagent achieved the highest total PAH degradation due to stronger oxidation conditions. LMW PAHs showed
higher susceptibility to oxidation, whereas high molecular weight (HMW) PAHs appear to be strongly sorbed to the soils and
therefore less chemically available for oxidation. This study highlights the importance of including soils collected from
a range of contaminated sites in remediation studies. Such soil samples will contain PAH contaminants of varying concentrations,
chemical and physical properties, and have been aged under field conditions. In addition to the chemical and physical properties
of the soils, these factors will all influence the chemical availability of PAHs to oxidation.
Recommendations and Perspectives:
We recommend including aged contaminated soils in chemical degradation studies. In future chemical remediation work, we intend
to investigate the potential influence of the chemical and physical properties of PAHs and soil parameters potential influence
on the chemical oxidation efficiency in aged contaminated soils.
Due to the vast number of contaminated sites there is a great need of efficient remediation methods throughout the world.
This study shows the difficulties which may be experienced when applying remediation methods to a variation of contaminated
sites. 相似文献
5.
PurposeThe purpose of this study is to study the major sources, concentrations, and distributions of polycyclic aromatic hydrocarbons (PAHs) in three different types of green space in Shanghai. In addition, we will quantitatively assess the burden of PAHs in the soil, as well as the potential carcinogenic risk of PAHs in humans. These results will provide valuable information for soil remediation and human health risk management. Materials and methodsA total of 166 surface soil samples were collected in parks, greenbelts, and woodlands. Soils were extracted using accelerated solvent extraction (ASE). PAHs were analyzed by gas chromatography-mass spectrometry (GC-MS). The positive matrix factorization (PMF) model was used to identify major PAH emission sources and quantitatively assess their contributions to PAHs. The incremental lifetime cancer risk (ILCR) was used to quantify the potential health risk of PAHs. Results and discussionThe average concentrations of ∑15 PAHs are 227?±?95 ng g?1, 1632?±?251 ng g?1, and 1888?±?552 ng g?1 in the woodland, park, and greenbelt soils, respectively. The PMF results show that biomass (33%), coal (21%), vehicles (17%), natural gas (14%), oil (9%), and coke (7%) are the dominant sources of PAHs in the park soils. Diesel (40%), tire debris (30%), biomass (15%), gasoline (9%), and oil (5%) are the main sources in the greenbelt soils. Biomass (48%), vehicles (37%), and coal (15%) are the main sources in the woodland soils. The ILCRs of adults and children who are exposed to PAHs in soils range from 9.53?×?10?8~1.42?×?10?5. ConclusionIn three types of green space in Shanghai, the dominant PAHs are high–molecular weight (HMW) compounds (≥?4 rings). This may be due to the proximity of the sampling site to emission sources. In addition, low–molecular weight (LMW) PAHs (with 2–3 rings) are relatively unstable, and these compounds are prone to volatilization and degradation. Source identification indicates that biomass combustion is the most dominant PAH source in the park and woodland soils, while vehicles are the dominant PAH source in the greenbelt soils. The ILCRs of adults and children indicate potential health risks, and children have a greater health risk than adults. 相似文献
6.
Aim and Background Little data are available on the levels of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Mediterranean Sea
Coast of Egypt in general and the Alexandria coastal zone in particular. It was therefore deemed necessary to set up a monitoring
programme to determine the current concentrations of PAHs in bottom sediments, and to identify any area where high concentrations
of these potential hazardous contaminants were present in the Western Harbour of Alexandria.
Methods The composition, distribution and the source of PAHs in surficial sediments of the harbour were investigated. To document
the spatial PAH input, surficial sediment samples from 23 locations throughout the harbour were analysed. as]Results and Discussion
The total PAH load determined in the surficial sediment samples ranged from 8 to 131150 ng g 1 dry wt, generally with most of the samples having total concentrations of PAHs greater than 5000 ng g 1 dry weight. The highest concentration of total PAHs was recorded in sediments of the inner harbour. Ratio values of specific
compounds such as phenanthrene to anthracene, fluoranthrene to pyrene, methyl-phen-anthrene to phenanthrene, methyl-dibenzothiophenes
to dibenzothiophenes, alkylated to non-alkylated and high molecular weight to low molecular weight PAH, were calculated to
evaluate the possible source of PAH contamination in the harbour sediments.
Conclusions Two main sources of PAH in the study area have been found: pyrolytic and petrogenic. Interferences of rather petrogenic and
pyrolytic PAH contaminations were noticed for most samples. The dominant sources of PAH appear to be the combustion processes
through run-off, industrial and sewage discharges, and atmospheric input. The concentrations of PAHs were generally above
levels expected to cause adverse biological effects.
Recommendations and outlook Information from this study and any other relevant studies should be useful in designing future strategies for environmental
protection and management of the harbour. 相似文献
7.
Purpose Polycyclic aromatic hydrocarbons (PAH) are persistent, toxic, and carcinogenic contaminants present in soil ecosystem globally.
These pollutants are gradually accumulating in wastewater-irrigated soils and lead to the contamination of vegetables. Food
chain contamination with PAH is considered as one of the major pathways for human exposure. This study was aimed to investigate
the concentrations of PAH in soils and vegetables collected from wastewater-irrigated fields from metropolitan areas of Beijing,
China. Origin of PAH, daily intake, and health risks of PAH through consumption of contaminated vegetables were studied. 相似文献
8.
Actual information on the level of accumulation of PAHs in soils, their inputs/outputs and fate is still unsatisfactory. The regional scale of data collection is important from practical point of view, since decisions regarding environment protection often require proper assessment of soil information aggregated on this level. The objective of the study was to define the regional levels of PAHs in soils and to examine the relationship with the parameters related to their inputs (emission factors) and to natural conditions (soil properties, geographical localisation). The territory of Poland, comprising 16 regions, was chosen as a model area representing the Central/East European countries. The concentrations of 16 PAH compounds were determined in 266 soil samples collected from 0 to 30-cm upper soil layer from agricultural lands. The data were supplemented with basic soil properties. The regional concentrations of Σ16PAHs were within the limits of 125–756 μg kg ?1 (geometric means) and did not exceed the limit values specified in Polish regulations. They complied also with European soil screening values for intermediate or negligible risk. The key variable affecting the accumulation of PAHs in soils was the regional emission of those contaminants, which described soil concentrations of PAHs in at least 50%; the results suggest time-dependent (delayed) reaction of soil environment to the emission changes. The effect was sensitive to PAH compositions in soils and was most pronounced in the case of higher molecular weight compounds (≥4 rings) transported predominantly with atmospheric particles. The regression models, comprising actual regional emission data, did not indicated on the increasing risk of PAHs accumulation in soils. The evaluations based on the regional content of benzo(a)pyrene in soils implied significant discrepancies between Polish and other internationally accepted criteria in soil contamination. The natural factors (soil characteristics and climate) affected the regional PAH concentrations in very small extent. 相似文献
9.
PurposeWithout precaution to deal with gas emissions and leachate generation, dumpsites have become a severe environmental problem in many developing countries. The objectives of this study were to investigate the pollution status of polycyclic aromatic hydrocarbons (PAHs) in dumpsite soil in rural areas of China and to verify phytoremediation effectiveness with Sedum alfredii Hance and alfalfa (Medicago sativa L.) under complex pollution conditions in PAH-contaminated soil. Materials and methodsIn this study, we collected soil cores from four dumpsites in rural areas of North China (Hebei Province) for analysis, and correspondingly conducted an in situ phytoremediation experiment using Sedum alfredii Hance and alfalfa (Medicago sativa L.) at one of these sites, monitoring the total PAH concentration in soil. Results and discussionResults showed generally moderate pollution by PAHs in soil samples from dumpsites with pockets of heavy pollution. PAH concentrations in dumpsite soil ranged from 827 to 1101 ng/g (dry weight). High-molecular-weight PAHs were present in higher proportions at oldest dumpsite in operation. Certain molecular ratios of PAHs can be used to diagnose the source of PAHs in soil, and it indicated that the main sources were combustion of domestic coal and biomass, as well as the automobile exhaust and kitchen exhaust. A 17-month in situ phytoremediation experiment resulted in the effective removal of PAHs in the Sedum alfredii and alfalfa plots, with total PAH concentrations decreasing by 82.4% and 81.3%, respectively. Furthermore, PAH concentrations in plants correlated to plant growth conditions. ConclusionsThis study indicated that the soils of the dumpsites were generally moderately polluted by PAHs, and some parts of the area were heavily polluted. Both Sedum alfredii and alfalfa absorbed PAHs from soil, and PAH concentrations in these two plants correlated to the growth conditions of the plants. Phytoremediation can effectively be used for PAH removal in open dumpsites. 相似文献
10.
PurposeThis study investigated the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and polycyclic aromatic hydrocarbons (PAHs) in sediments collected from gully pots for road drainage in Hong Kong. The presence and intensity of anthropogenic contamination of road gully sediments were assessed. Identifications of potential sources of trace elements and PAHs were performed to help understand the situation for future control of pollution to the land and aquatic environments. Materials and methodsGully sediment samples were collected from gully pots of 18 roads that are potentially exposed to different pollution sources in Hong Kong. The selection of roads considered different road features, adjacent land uses, and traffic volumes. Composite samples were collected for the analysis of trace elements (Cd, Cr, Cu, Pb, Ni, and Zn) and PAHs by an accredited environmental testing laboratory. Geo-accumulation index (Igeo), contamination factor (Cf), modified degree of contamination (mCd), ecological risk factor (Er), and pollution load index (PLI) were used to assess the level of ecological risk of trace element contamination. Positive matrix factorization (PMF) and PAH diagnostic ratios were applied to identify the sources of trace elements and PAHs. Results and discussionElevated trace element concentrations were commonly found in gully sediments. The concentrations of Zn (267–3700 mg kg?1) were the highest compared to the other trace elements. Noticeable high concentrations of Cu (27–1020 mg kg?1), Pb (21–332 mg kg?1), and Cr (14–439 mg kg?1) were found in all samples. The PAH contents were moderate to high (0.6 to 24.7 mg kg?1). Commercial/industrial emissions and road features that cause frequent acceleration-deceleration and turning events showed important influences on the contaminant levels. Strong correlations between the concentrations of Cd, Cr, Pb, and Zn were identified, implying that these trace elements are likely from common sources. The contamination assessment indices reflect significant sediment pollution. The ecological risk ranges from the considerable/moderate-risk class to over the high-risk class. ConclusionsThe collected gully sediments are identified as highly contaminated and need to be isolated from the environment upon final disposal. Through the comprehensive analysis of the collected data, this study provides a detailed insight into the contaminant levels of road gully sediments and potential sources of contamination. Disposal of gully sediments and potential impacts due to release of contaminants into the downstream aquatic environment during rainstorm events should receive attention and need further investigation. 相似文献
11.
Purpose A comprehensive study was conducted to investigate the presence of polycyclic aromatic hydrocarbons (PAHs) in Dongjiang River Basin (DRB) soils and to evaluate their sources and ecological and health risk. In addition, factors affecting the distribution and fate of PAHs in the soils such as emission density, soil organic matter, degradation, etc. were studied. Materials and methods Surface soil (0–20 cm) samples from 30 sampling sites in the rural areas of DRB were collected and analyzed for 17 polycyclic aromatic hydrocarbons (16 EPA priority PAHs and perylene). Positive matrix factorization model was used to investigate the source apportionment of these PAHs, and an incremental lifetime cancer risk (ILCR) was used to estimate the integrated lifetime risks of exposure to soil-borne PAHs through direct ingestion, dermal contact, and inhalation collectively. Results and discussion The total PAH concentrations in the rural soils in DRB range from 23.5 to 231 μg/kg with a mean concentration of 116 μg/kg. The predominant PAHs in the rural soils were naphthalene, fluoranthene, phenanthrene, and benzo( b)fluoranthene. Cluster analysis was performed to classify the soil PAHs into three clusters, which could be indicative of the soil PAHs with different origins and different properties. Source apportionment results showed that coal, biomass, oil, commercial creosotes, and vehicle contributed 24 %, 24 %, 17 %, 17 %, and 18 % of the total soil PAH burden, respectively. The ILCR results indicated that exposure to these soil-borne PAHs through direct ingestion, dermal contact, and inhalation collectively produces some risk. Conclusions PAHs in the soils of the DRB will produce long-term influences on rivers and oceans via soil erosion and river transport. Therefore, PAHs in rural soils of DRB have potential impacts on the water supply and human health risk. 相似文献
12.
PurposeThe purpose of this paper is to study the responses of soil biological parameters as indicator of ecological status on PAH-contaminated soil. Materials and methodsStudies are conducted on the soils and natural grassy vegetation of monitoring plots subjected to Novocherkassk power station (NPS) emissions. Monitoring plots were established at different distances from the NPS (1.0–20.0 km). Results and discussionThe level of polycyclic aromatic hydrocarbons (PAHs) around NPS is the highest at the monitoring plot located at distance 1.6 km to the northwest through the prevailing wind direction. Gradually, decrease of PAHs was observed while increasing the distance from the NPS through the prevailing wind direction. Calculation of correlations between PAH level and biological activity parameters of soils showed lack of dependence with total and every PAH content in all 12 studied monitoring plots. The most significant correlations were found between PAH content and enzyme activity in the monitoring plots situated through the prevailing wind direction from NPS. ConclusionsThe main pollution source in the studied area is NPS. It was found that contamination of soil by PAHs has a direct dependence on the activity of all biological communities in chernozems, as well as the activities of dehydrogenase and the phytotoxicity of soils. Inverse correlations have been revealed between the PAH contamination and abundance of soil bacteria. 相似文献
13.
Forests of the Northern Czech mountains decline due to industrial emissions. To examine the state of soil contamination with PAHs we analyzed the concentrations of 20 PAHs in the O and A horizons of 4 lower and 4 upper slope sites under beech ( Fagus sylvatica L.) in the Western (WE) and the Eastern Erzgebirge (EE, Kru?né Hory), the Isergebirge (IS, Jizerské Hory), and the Riesengebirge (RI, Krkono?e) at microsites affected and not affected by stem flow. Average PAH sum concentrations in the organic layers ranged between 2000 and 30000 μg kg ?1 increasing in the line WE <RI<EE<IS. PAH concentrations were significantly higher at upper than at lower slope sites indicating long-distance transport. Microsites affected by stem flow had significantly higher PAH concentrations but lower percentages of lower molecular PAHs than microsites not affected by stem flow. This was due to the water collecting effect of the beech bark. Lower molecular PAHs preferentially were sorbed to the bark or leached from the organic layers. PAH concentrations increased from Oi to Oa horizons but decreased in the mineral soil. This was the more pronounced the higher the molecular weight was. The slope of the regression line between the enrichment factors (concentration of a single PAH in the Oa divided by that in the Oi horizon) and the octanol-water partition coefficient decreased as the PAH concentration of the soils increased. This indicates that the microbial activity of organic layers may be reduced by soil contamination. Cluster analysis suggested that the sources of the PAH contamination in the WE were different from the other sites. 相似文献
14.
The content of polycyclic aromatic hydrocarbons (PAHs) in the soils of urbanized areas, including the impact zones of Belarus, were studied. The concentrations of 16 PAHs in the soils were determined for individual and high-rise building zones, forests, and forest parks of Belarus. The levels of the PAH accumulation in the soils of different industrial enterprises and boiler stations were analyzed. Possible sources of soil contamination with PAHs were considered, and the structure of the PAHs in the soils was shown. The levels of the soil contamination were determined from the regulated parameters for individual compounds and the sum of 16 PAHs. 相似文献
15.
During the intensive flood in May–June 2010, the floodplains in Little Poland Vistula Gap, used mostly for agriculture, were
waterlogged for a period of over 1 month. The aim of the study was to assess the effect of the flood on the level of contamination
of the soils in this region. The analysis included basic physicochemical soil properties, contents of ten metals, and concentrations
of 16 polycyclic aromatic hydrocarbons (PAHs). The studies cover two territories on opposite sites of the river Vistula (Wilkow
and Janowiec) differing in their areas (70 and 4.6 km 2) and time of water logging (30 and 10 days). Forty soil samples were collected from both areas immediately after the flood
event from the upper (0–30 cm) soil layer together with four samples from the 30–60-cm depth layer. This was supplemented
by eight samples from the flood-deposited sediment layer (thickness, 2 cm). The concentrations of identified metals (As, Ba,
Cr, Sn, Zn, Cd, Co, Cu, Ni, Pb) at all the sampling points were below the Polish legal limits for the upper layer of soils
for agriculture use. The same regarded the median contents of nine PAHs compounds specified in the Polish regulations. In
both areas, the median contents of Σ16 PAHs (0.21–0.35 mg kg −1), Zn (10.3–10.6 mg kg −1), Pb (9.2–10.7 mg kg −1), and Cd (0.03 mg kg −1) were much below the mean concentrations of those contaminants in arable soils on the national and European levels. The results
show that this severe flooding episode in “clean” agricultural area had no immediate negative impact on the soils as regards
the basic physicochemical properties (organic matter content, acidity, nitrogen content) and did not result in excessive soil
contamination. 相似文献
16.
Samples of treated wastewater drawn from the effluent of the Montreal Urban Community (MUC), Canada, and surface water samples from the St. Lawrence River were collected in 1993 and 1994 and analysed for PCBs and PAHs. The average concentrations of Σ13 PCBs and Σ14 PAHs in the effluent were 1.34 ± 0.71 ng L-1 and 326 ± 229 ng L-1, respectively. PCB concentrations in the effluent did not show any clear seasonal pattern in the effluent but PAH concentrations increased during the winter period. In the effluent plume, both PCB and PAH concentrations increased significantly between the upstream control site and the effluent outfall, and subsequently decreased. The profiles of PCB congeners were similar within the effluent plume and also among water masses of the St. Lawrence River. PAH profiles were also similar within the effluent plume, but were different across the two water masses of the St. Lawrence River. Based on the composition of PCB congeners, atmospheric inputs appear to represent the major source of PCBs in the St. Lawrence River. The sources of PAHs in the MUC effluent and in the St. Lawrence River water would appear to be, respectively, petroleum products and combustion-derived products. 相似文献
17.
Sample preparation affects the results of the determination of persistent organic pollutant (POP) concentrations in soils. We compared the extraction results of POPs from air‐ and freeze‐dried with field‐fresh samples. We determined the concentrations of 21 polycyclic aromatic hydrocarbons (PAHs) and 14 polychlorinated biphenyls (PCBs) in 35 horizons of forest soils (Lithosols and Cambisols) along a deposition gradient caused by a chemical factory in Strá?ske (eastern Slovakia). The organic C (C org) concentrations of the studied samples ranged 14‐477 g kg ‐1, the sum of 21 PAH (Σ 21PAHs) concentrations 53‐6870 μg kg ‐1, and that of 14 PCBs (Σ 14PCBs) 0.12 96 μg kg ‐1. The benzofluoranthenes were the most abundant PAHs, and the hexa‐chlorinated PCBs 138 and 153 were the most abundant PCBs. The deposition gradient was reflected by decreasing PAH and PCB storages in the organic layer with increasing distance from the chemical factory (Σ 21PAHs: 82‐238, Σ 14PCBs: 0.34‐2.3 g ha ‐1). The PAH concentrations in air‐ and freeze‐dried samples were consistently lower than those in field‐fresh extracted samples. For naphthalene, this was mainly attributable to volatilization losses during drying. Naphthalene losses decreased with increasing C org concentrations. For all other PAHs, drying reduced the extractability; the latter was correlated with the water content of the samples. The differences in most PCB concentrations among the sample preparation methods were small (within the determination error of ±15 %) and inconsistent. However, PCBs 8, 28, 52, and 209 had markedly higher concentrations in dried than in fieldfresh extracted samples. The increased recovery of low‐chlorinated PCBs in dried samples may be explained by redistribution of PCBs from higher to lower contaminated samples via the drying room atmosphere because there were no PCBs in analytical blanks. This assumption is supported by a close correlation between the octanol‐air distribution coefficient and the up to hexa‐chlorinated PCB concentrations (normalized to those in field‐fresh extracted samples) in air‐ (r = ‐0.90) and freeze‐dried (r = ‐0.86) samples. Our study shows that each sample preparation method has its specific advantages and disadvantages. Sample drying results in a standardization to a well‐defined water content and facilitates homogenization; therefore it increases the reproducibility of POP determinations. Extraction of field‐fresh samples reduces volatilization losses and contamination risks. 相似文献
18.
The purpose of this study was to determine the degree of PAH contamination and the association of PAHs with metals in urban soil samples from Sevilla (Spain). Fifteen polycyclic aromatic hydrocarbons-PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) and seven metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) have been evaluated in representative urban soil samples. Forty-one top soils (0–10 cm) under different land use (garden, roadside, riverbank and agricultural allotment) were selected. PAHs from soil samples were extracted by sonication using dichloromethane. The simultaneous quantification of 15 different PAH compounds were carried out by HPLC using multiple wavelength shift in the fluorescence detector. For qualitative analysis a photo diode-array detector was used. Metal (pseudo-total) analysis was carried out by digestion of the soils with aqua regia in microwave oven. The mean concentration of each PAH in urban soils of Sevilla showed a wide range, they are not considered highly contaminated. The results of the sum of 15 PAHs in Sevilla soils are in the range 89.5–4004.2 μg kg ?1, but there seems not to be a correlation between the concentration of PAHs and the land use. Of the 15 PAHs examined, phenanthrene, fluoranthene and pyrene were present at the highest concentrations, being the sum of these PAHs about 40% of the total content. Although metal content were not especially high in most soils, there are significant hints of moderate pollution in some particular spots. Such spots are mainly related with some gardens within the historic quarters of the city. The associations among metals and PAHs content in the soil samples was checked by principal components analysis (PCA). The largest values both for ‘urban’ metals (Pb, Cu and Zn) and for PAHs were mainly found in sites close to the historic quarters of the city in which a heavy traffic of motor vehicles is suffered from years. 相似文献
19.
The concentration of polycyclic aromatic hydrocarbons (PAHs) was determined in seawater, sediment, and Rock oyster Saccostrea cucullata collected from four sampling sites in the inter-tidal areas of Bushehr province. The total concentrations of 14 PAHs varied
from 1.5 to 3.6 ng/L in seawater, 41.7 to 227.5 ng/g dry weight in surface sediment, and 126 to 226.1 ng/g dry weight in oyster
tissue. In comparing PAH concentrations among the three matrices in Bushehr province, data showed that the pattern of individual
PAHs in seawater, oyster, and sediment were different. The oysters tended to accumulate the lower molecular weight and the
more water-soluble PAHs. Sediment samples were distinguished from the sea water and oyster samples by the presence of high
molecular weight PAHs, especially six-ring PAHs. Three- and four-ring PAHs were the most abundant compounds among the 14 PAHs
investigated in surface seawater, sediment, and oyster samples. As expected, differences in octanol/water partition coefficient
among individual PAHs and the greater persistence of the higher molecular weight PAHs contributed to the accumulation patterns
in oyster and sediment. The results of the study suggested that the main sources of PAHs in the seawater and sediment in the
region were mixed pyrolitic and petrogenic inputs. 相似文献
20.
Polycyclic aromatic hydrocarbons (PAHs), mainly formed by incomplete anthropogenic organic matter combustion, are ubiquitous in the environment. To assess milk PAH contamination sources, milk samples were collected from the tank milk at farms located near potential contaminating emission sources such as cementworks, steelworks, and motorways. PAH analyses were carried out by gas chromatography coupled to mass spectrometry. Eight PAHs were identified in milk: naphthalene, acenaphthylene, acenaphthene, fluorene, anthracene, fluoranthene, pyrene, and benzo[a]anthracene. For all potential contaminating sources, these eight PAHs were detected with similar profiles and at low concentrations except for fluorene and naphthalene, for which source-molecule interaction is pointed out. 相似文献
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