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1.
The present study evaluates the potential of Hymeniacidon heliophila as bioindicator of PAH contamination. For this, concentration of 33 PAH was determined in organisms from sites with different contamination level including the heavily polluted Guanabara Bay, Rio de Janeiro, and less impacted coastal areas. PAH concentration and typology were determined in sponges collected from different depths and in two different seasons. The brown mussel broadly studied as bioindicator was also sampled from the same sites for comparison. Both species provided similar information on total PAH concentration which is related to site contamination level. Sponges, however, revealed slight tendency to accumulation of combustion-derived PAH in relation to petrogenic compounds. Differences in PAH typology between species may derive from the interspecific variation in particle size ingestion. Different hydrocarbon typologies were observed in sponges from dry and wet season and PAH concentration varied with depth. H. heliophila may be used as an alternative approach to investigate the presence and sources of PAH in estuarine areas.  相似文献   

2.
Seven stations were established in the Quanzhou Bay (24.73°-24.96°N, 118.50°-118.70°E) in China on three cruises to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation poten- tial of indigenous microorganisms by measuring the respiratory intensity with the addition of PAHs in sediment samples was also one of the aims of this study. The results show that the total PAH concentrations of the sedimen...  相似文献   

3.
Organic contaminants from several different chemical classes were analyzed in surface sediments along a transect from the head to the mouth of Narragansett Bay. The chemical classes included total hydrocarbons, polycyclic aromatic hydrocarbons, substituted benzotriazoles and phthalic acid esters. Sediment concentrations of all compounds were highest in the Providence River and decreased with distance downbay. The observed decreases were approximately exponential for all compounds; however, the distances at which the concentrations decreased to one-half of their initial concentrations (half-distances) were different.The depth distributions of these compounds in sediment cores from three locations were also investigated. A sediment core collected near the head of the bay (Conimicut Point) showed a well defined historical record of contaminant input to the bay. At a mid-bay location (North Jamestown), however, the record was smeared because of extensive bioturbation.A sediment core collected near the mouth of the bay (Rhode Island Sound) showed a subsurface increase for all of the measured compounds. The results of detailed analyses suggest that this horizon may have been influenced by dredge spoil material originally from the head of the bay.  相似文献   

4.
Coastal marine sediment, air and seawater samples were collected at six sampling stations in the Eastern Mediterranean Sea distant from pollutant point sources. All sediment samples were analyzed to determine polycyclic aromatic hydrocarbon (PAH), black carbon (BC) and organic carbon (OC) contents. The PAH contents of gaseous and seawater samples of the study were determined in order to evaluate the role of air–sea exchange as PAH nonpoint source to the marine sediments. The average concentration of the total PAHs (∑PAHs) in the sediments varied from 2.2 to 1056.2 ng g−1 dry weight. The average BC and OC contents varied from 0.3 to 5.6 and from 2.9 to 21.4 mg g−1 dry weight, respectively. ∑PAH concentration in the marine atmosphere varied from 20.0 to 83.2 ng m−3. Air–water exchange flux (FA–W) estimation has indicated air transport as a significant source of PAHs to pristine marine sediments of Eastern Mediterranean. In addition, the significant correlation between the PAHs and the organic and soot carbon content further suggests the importance of atmospheric input of PAHs to the sediments.  相似文献   

5.
长江口外沉积物中多环芳烃结构类型的分布   总被引:5,自引:0,他引:5  
本文采用色谱—质谱—质谱—计算机系统技术,分析了长江口外两个表层沉积物中多环芳烃组分,并探讨了其有机质的来源和地球化学特征。  相似文献   

6.
Photodegradation of PAHs in the water-soluble fraction of Kuwait crude oil in seawater was investigated under various environmental factors (temperature, light intensity, oxygen levels and presence of a sensitizer) in laboratory conditions. All factors investigated had significant effect on the degradation rates of PAHs. At 15 °C almost all PAHs optimally degraded at an oxygen level of 4 ppm. For lower molecular weight PAHs a light intensity of 500 W/m2 in the presence of the sensitizer worked well. Higher molecular weight PAHs degraded at faster rates at a light intensity 750 W/m2. At 30 °C, most of the PAHs degraded optimally at an oxygen level of 0 ppm and light intensity of 500 or 750 W/m2 in presence of the sensitizer. At 40 °C, most of PAHs degraded optimally at low oxygen concentrations (0 and 4 ppm) and a light intensity of 500 W/m2 in the presence of the sensitizer. Linear regression indicated that for most of the compounds, light intensity had the greatest effect on degradation rates.  相似文献   

7.
为研究广西珍珠湾红树林湿地表层沉积物有机质中烃类化合物的分布特征及来源,于2021年9月采集珍珠湾红树林湿地表层沉积物样品13件,对沉积物中的正构烷烃和多环芳烃(PAHs)进行测试分析。分析结果表明:珍珠湾红树林湿地表层沉积物中正构烷烃的含量(干重)为362.17~10 390.72 ng/g,PAHs含量(干重)为7.76~28.06 ng/g,总体处于含量较低的水平;特征参数比值法分析结果显示,正构烷烃主要来源于陆源非浮水草本植物,未受石油及其衍生品的污染;PAHs具有大分子化合物占优势的特征,同分异构体比值法分析结果表明PAHs的潜在来源有石油、石油燃烧和煤炭草木燃烧,主成分分析-多元线性回归分析结果表明,其来源主要为混合燃烧源(>52%),其次为石油污染源;应用效应区间低/中值法对PAHs进行生态风险评价,结果表明PAHs生态风险处于较低水平。  相似文献   

8.
Salt-water inflows into the Baltic Sea are important events for renewing the deep and bottom waters of the deep basins of the Baltic Sea. These events occur only at irregular intervals. The last strong event was in January 1993 followed by minor inflows in winter 1993/1994. As a result of these inflows, the deep water of the central Baltic basins was completely renewed.Based on extensive observations of polycyclic aromatic hydrocarbons (PAHs) in water, fluffy layer material and surface sediments between 1992 and 1998, the transformation of PAHs and the modification of their distribution in the Baltic deep water is discussed in connection with the spreading of the inflowing highly saline and oxygen-rich water along its pathway from the sills into the central basins. In the course of the inflows in 1993/1994, the PAH concentration in the deep water of the different basins increased significantly. The concentrations were elevated, at least by a factor of 2 and as much as seven to eight times (for the four-ring PAHs) compared to the previous and the following years. Two hypotheses for the causes were discussed: the inflowing salt water may have entrained more highly polluted surface water in the western Baltic Sea, or it may have entrained contaminated fluffy layer material or sediment particles along the route of transport.  相似文献   

9.
Hydrocarbons have been investigated in the sediments of Port Valdez, Alaska after three to five years of oil terminal operation with a routine daily discharge of 170 kg of petroleum residue in an otherwise undeveloped area. Surficial benthic sediments (0–5 cm) and core segments down to 30 cm have been analyzed. Information about total hydrocarbons, unresolved complex mixture, normal alkanes, pristane, phytane, hopanes and polycyclic aromatic hydrocarbons indicates that petroleum, biogenic hydrocarbons, and combustion-derived aromatic hydrocarbons are present in sediments around the terminal at concentrations up to 218 μg g?1 dry sediment. The vertical, horizontal and temporal distributions of anthropogenic hydrocarbons indicate that most of the sedimentary hydrocarbon accumulation has occurred within 1 km of the terminal. A simple calculation suggests that less than 3% of the total oil discharged during routine operations of the terminal has entered the sediments of Port Valdez. For comparison sediment hydrocarbon accumulation associated with a nearby small boat harbor was also examined.  相似文献   

10.
This study examined the concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface sediments collected in July 2004 from eight stations in the Zhelin Bay, one of the most important bays for large-scale mariculture in Guangdong Province. Thirteen individual parent PAH compounds were identified using high performance liquid chromatography with UV detection. The overall average concentration of total PAHs was 477.0 ng/g, ranging from 146.1 to 928.8 ng/g. Low molecular mass PAHs with two to three rings (e.g., acenaphthene) were dominant in each sample. The PAH concentration varied among sampling stations, with the highest concentration observed at bay outlets and the lowest found at stations outside the bay. Ratios of low to high molecular mass PAHs and fluoranthene to pyrene were used to determine the origin of PAHs, and results indicated mainly petroleum-derived contamination. Compared with other bays and harbors around the world, the total concentrations of PAHs in surface sediments at the Zhelin Bay are moderate, but this does not exclude the possibility of potential impact on human consumers because some strong carcinogenic PAHs with high molecular mass were found at the station with a nearby caged-fish and oyster farm. Long-term monitoring of PAH contamination in the Zhelin Bay is recommended to reduce the potential toxicological effects on aquatic organisms and humans.  相似文献   

11.
As part of a geochemical study of C25 and C30 biogenic alkenes in estuarine environments, distributions of these compounds in detritus and sediments collected from a New England salt marsh (Round Swamp on Conanicut Island in Narragansett Bay, Rhode Island) have been determined. The alkene assemblages detected, consisting primarily of four acyclic C25 dienes and trienes and a C30 bicyclic diene, qualitatively resemble those previously reported for other sediments in which anoxic conditions were prevalent. These similarities exist despite significant differences in the principal sources of sedimentary organic matter, suggesting that the occurrence of these specific alkenes is more likely associated with an in situ process common to anoxic environments than with a direct input from a specific source. Size fractionation (> 840 μm and < 840 μm to 1·2 μm) of marsh detritus revealed that the larger size fraction, consisting primarily of decaying Spartina debris, contains significant amounts of alkenes. This result, together with alkene subsurface profiles which show high surface concentrations decreasing to near-background levels by 20 cm, suggest that anaerobic bacteria are mediating in situ production of these compounds. Previous studies of bacterial hydrocarbons have not reported the presence of these C25 and C30 alkenes, although similar compounds have been isolated from several species of methanogenic bacteria. However, attempts to induce alkene synthesis by decomposing Spartina anaerobically in the laboratory were unsuccessful. In light of this result, the exact source of alkenes in marsh sediments remains uncertain. The absence from marsh sediments of other C25 alkenes whose sedimentary distributions had been previously correlated with the presence of marine (planktonic) organic matter implies the existence of different origins for structurally related constituents of this hydrocarbon series.  相似文献   

12.
13.
中国北部辽东湾表层沉积物中PAHs源解析和生态风险评价   总被引:1,自引:0,他引:1  
研究于2014年和2015年对辽东湾表层沉积物中16种多环芳烃(PAHs)的来源和生态风险状况进行了调查和评估。辽东湾表层沉积物中16种PAHs的含量范围为88.5-347 ng/g,高值区主要分布在辽东湾中部海域。对辽东湾各站位沉积物中多环芳烃的含量进行中聚类分析结果表明,辽东湾的采样站位可分为两类,一类站位主要分布在辽东湾沉积物中部海域,另一类站位主要分布在受陆源污染较为严重的近岸海域。辽东湾表层沉积物中PAHs的来源为燃烧源和石油源的混合来源,其中燃烧源为主要来源。萘、苊、苊烯、菲、二苯并[a,h]蒽可能偶尔会引发有害生物效应;辽东湾表层沉积物为低致癌风险;辽东湾中部海域表层沉积物中PAHs的生态风险和毒性污染水平高于辽东湾近岸海域。  相似文献   

14.
Surface sediment samples from a matrix of fifty-five sites covering virtually the entire Bohai Sea (Bohai), China were analyzed for total organic carbon (TOC), total nitrogen (TN), n-alkanes, unresolved complex mixture (UCM), biomarkers and stable carbon isotopic composition (δ13C), and principal component analysis was performed for source identification of organic matter (OM). The distribution of organic carbon correlated well with sediment grain size with the finest sediments having the highest concentration, suggesting the influence of hydrodynamics on the accumulation of sedimentary organic matter (SOM). The corrected TOC/ON (organic nitrogen) ratios and δ13C indicated mixed marine and terrestrial sources of SOM. Results suggested that δ13C could be used as a potential indicator to observe the dispersion of Huanghe-derived sediments in Bohai. Total n-alkane concentrations varied over 10-fold from 0.39 to 4.94 μg g− 1 (dry weight) with the maximum terrigenous/aquatic alkane ratio observed at the Huanghe River Estuary (HRE) due to more higher plant OM from riverine inputs. C12–C22 n-alkanes with even-to-odd predominance were observed in several central-eastern Bohai sites. The HRE and its adjacent area is the main sink for the Huanghe river-derived OC. The ubiquitous presence of UCM, biomarkers (hopanes and steranes) and PCA results indicated the presence of petroleum contamination in Bohai, mainly from offshore oil exploration, discharge of pollutants from rivers, shipping activities and atmospheric deposition.  相似文献   

15.
Polycyclic aromatic hydrocarbons (PAHs) were identified and measured in surface seawater and in the tissues (gills and mantle) of indigenous black mussels, Mytilus galloprovincialis, collected from three coastal sites of Saronikos Gulf (Greece), a gulf that exhibits high levels of pollution. The total PAHs measured by spectrofluorometry in the surface seawater were found in the range of 425–459 ng L−1 at the most polluted sites 1 and 2 (Elefsis Bay–Salamis Island) and in the range of 103–124 ng L−1 at site 3 (Aegina Island). PAHs' sources in seawater were identified by application of specific PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene. Levels of PAHs in soft tissues (gills and mantle) of indigenous mussels were much higher than those reported for seawater. Total PAH concentrations in mantle tissues were in the range of 1300–1800 ng g−1 dry weight (dw) tissue at sites 1 and 2 and approximately 380 ng g−1 dw at site 3. In gill tissues total PAH concentrations were in the range of 1480–2400 ng g−1 dw at sites 1 and 2 and approximately 430 ng g−1 dw at site 3. PAHs composition was dominated by two-, three- and four-ring compounds in seawater, where 17 different PAH compounds were identified and measured in mussel tissues. Mussels can be used as sentinel organisms to monitoring PAHs' contamination, since they concentrate PAHs from the surrounding water media and therefore making the chemical analysis simpler and less prone to error than that for water. In surface seawater possible weathering and photodegradation due to hot climates contribute to reduced PAHs concentrations.  相似文献   

16.
In 1993 collections of marine mussels (Mytilus galloprovincialis) were deployed 1 m from the water surface at six sites in San Diego Bay for 88 days. A similar mussel deployment was conducted in 1995, except the animals were deployed 1 m off the bottom and only for 32 days. After recovery from the sites, tissue was extracted with dichloromethane and the solvent extracts analyzed for chemical contaminant content and the ability to produce CYP1A1 induction in a transgenic cell line (TV101L cells). The cells used in the assay (P450 RGS) are stably transfected with a plasmid containing firefly luciferase linked to human CYP1A1 promoter sequences. Induction (fold increase compared to control) was determined by luminometry 16 h after application of small volumes (2–10 μl) of solvent extracts to cultured cells. Small mussels deployed in the Naval Station (NAV) in 1993 exhibited very high bioaccumulation of polycyclic aromatic hydrocarbons (PAHs; 52 μg/g) and polychlorinated biphenyls (PCBs), in addition to very strong induction of CYP1A1 measured by reporter gene system (RGS) responses. Large mussels deployed at the NAV station in 1993 and intermediate-sized animals placed at three stations within the NAV station in 1995 accumulated 13–29 μg PAH/g and exhibited relatively high RGS responses. Correlation of RGS responses for all mussel samples to the measured PAH concentrations was 0.85 (r2). When the concentrations of seven specific PAHs found in the samples are converted to benzo[a]pyrene equivalents, from previously derived toxic equivalency factors (TEFs) for this test system, and compared to measured RGS responses, the correlations are approximately 0.9. The results of these studies indicate that the RGS biomarker can be used as a screening tool for detection of CYP1A1-inducing compounds in tissues, and an estimate of potential human health or ecological risk from ingestion of contaminated organisms. Positive RGS responses can be followed by detailed chemical analyses of PAHs and coplanar PCBs using the same extract.  相似文献   

17.
基于对胶州湾表层沉积物中总可水解氨基酸(THAA)的含量、组成、构型及分布特征的系统研究,通过氨基酸碳氮归一化产率(THAA-C%,THAA-N%)、降解因子DI、反应活性指数RI以及D型氨基酸占比(D-AA%,摩尔百分比)等指标结合碳氮比(TOC/TN)、碳稳定同位素(δ13C)探析了胶州湾沉积物中有机质的来源与降解状态,利用细菌源有机质及胞外肽酶活性(EEA)探讨了微生物在有机质迁移转化过程中的作用与贡献。结果表明,胶州湾表层沉积物中氨基酸平均含量为(7.60±3.64)μmol/g,在陆源与海源混合影响下,其水平分布呈现湾内高于湾外、湾内东部高于西部的特点,表明湾内东部陆源输入对沉积物THAA具有较高贡献。THAA-C%、THAA-N%、DI、RI以及D-AA%等指示因子均显示胶州湾表层沉积物中有机质的降解程度呈现湾外高于湾内、湾内东部高于西部的变化趋势,有机质来源、微生物活性与上覆水水深共同影响了有机质的降解程度。胶州湾表层沉积物中细菌源有机碳的贡献率为(29.35±18.73)%,其水平分布显示出湾内西部与湾外相近且高于湾内东部的特点。细菌胞外肽酶活性(EEA)平均为(0.81±1.31)nmol/(g·h)(以MCA计),整体分布趋势与细菌贡献率相反,呈现湾内东部高于湾内西部和湾外的特性。沉积物中有机质的不同海源、陆源占比决定了有机质的可降解性,而有机质的降解程度进一步影响了细菌源有机质的贡献与胞外肽酶活性。  相似文献   

18.
2015年10月采集长江口及废黄河口51个沉积物样品,对沉积物中的多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)的含量进行测定,探讨长江口及废黄河口海域表层沉积物中PAHs的分布组成、来源及潜在的生态风险评价。总PAHs的含量范围为4.23~292.39 ng/g,平均值含量为67.40 ng/g。研究区样品的PAHs含量呈现"北部低南部高"的空间分布特征,舟山群岛东部区域PAHs含量普遍偏高,长江口次之,废黄河口最低。与国内其他海区相比,研究区域PAHs总体处于中低等污染水平。运用统计分析和特征比值法对来源进行分析,研究区域沉积物中PAHs主要是以4环、5环为主,来源分析显示PAHs的主要来源为各类燃烧源及石油源的混合来源。根据效应区间低/中值法(ERL/ERM)评价结果显示,长江口及废黄河口海域的潜在生态风险很小,但对生态有一定的潜在威胁,也应该引起重视。  相似文献   

19.
There is a need for sensitive biological effect methods by which to detect impacts of chronic exposure to low concentrations of contaminants. Two methods shown to be potentially useful for monitoring purposes in fish include lysosomal membrane stability and peroxisome proliferation. These biological endpoints were assessed in Atlantic cod (Gadus morhua) head kidney following exposure to a mixture of produced water components including polycyclic aromatic hydrocarbons, phenol, and alkylphenols. Lysosomal damage of head kidney cells occurred within the first two weeks and did not recover during the entire exposure period (32 weeks). Lysosomal membrane stability was not affected by gender and was responsive at low concentrations of contamination, indicating that lysosomal membrane stability measured in the head kidney could be a useful biomarker for effects of offshore pollution. Peroxisome proliferation, measured as acyl-CoA oxidase activity in the head kidney, appeared to be a potential biomarker in male cod exposed less than 16 weeks.  相似文献   

20.
Detailed organic geochemical analyses were performed on surface water particulate samples of the lower Kalix River and northern Bothnian Bay collected during the spring flood of 2005. Both bulk geochemical and molecular biomarker analyses indicated a predominance of terrestrially-derived particulate organic matter (POM), both of higher plant and Sphagnum origin in the low salinity zone (LSZ) of the Kalix River estuary, with an increasing contribution of marine-derived POM in the offshore Bothnian Bay basin.Two-dimensional box modeling of the mixed surface layer in the LSZ indicated that 65% of the particulate organic carbon (POC) and between 73 and 93% of the terrestrial biomarker classes analyzed (high molecular weight n-alkanes, n-alkanoic acids and n-alkanols as well as sitosterol) were degraded in the course of their weeklong transit through the inner LSZ during the spring flood. This corresponds to field-based degradation rate constants for the biomarkers of 0.5 and 2.5 day− 1, which are similar to results reported from mesocosm experiments for related compounds. The degradation rate constant for terrestrial POC of 0.38 day− 1 was about 20 times larger than for DOC and suggests that POC mineralization stands for 44% of the total mineralization, which is much larger than previously considered.This sub-arctic river-export regime has a geochemistry resembling that of neighboring western Russian Arctic Rivers, suggesting that a large part of the OM coastally exported from northernmost Eurasian soils may be degraded within the vicinity of the river mouths and putatively be released as carbon dioxide. The 65% degradation of terrestrial POC in the coastal surface water of this sub-arctic recipient is substantially larger than a global-average of 35% used in recent budget estimates of the fate of terrestrially-exported POC on the pan-arctic shelves. Considering ongoing and predicted changes in the Arctic Region due to global warming a more efficient degradation of river-exported terrestrial POC may have far-reaching consequences for the large-scale biogeochemical cycling of carbon in the pan-arctic region and beyond.  相似文献   

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