共查询到20条相似文献，搜索用时 15 毫秒
1.
Sediments collected from the Elizabeth River, VA, a highly contaminated subestu-ary of the James River, were analyzed for polycyclic aromatic hydrocarbons (PAHs). Select isomer ratios (BbF/BkF, BaA/chrysene, and IP/BghiP) and molecular weight fractions (ΣPAH202/202-276 and ΣPAH252/202-276) were identified as source indicators for two former wood-treatment facilities (Atlantic Wood and Eppinger & Russell) located on the southern branch of the Elizabeth River. These facilities are suspected as probable contributors to the high PAH contamination in sediments. Plots of the wood-treatment source indicators, along with those for coal, wood, and automotives, revealed a likely contribution from only one of the former wood-treatment facilities, in addition to the possible contribution of coal/coal gasification to PAH contamination in sediments of the main stem and southern branch of the Elizabeth River. By examining PAH isomer ratios from known or suspected sources, it is possible to distinguish multiple sources of PAHs to an ecosystem. 相似文献
2.
In this study the volatile components of four Inula species (Inula germanica L., I. bifrons (L.) L., I. ensifolia L., and I. salicina L.) were analysed by GC-FID/MS. A total of 141 chemical compounds were identified. A distinct volatile chemical profiles with high variation in the type of compounds was observed. Inula germanica was rich in oxygenated monoterpenes (54.7%), with cis-carvyl acetate (20.7%) and 1,8-cineole (14.6%) as main components. Sesquiterpenoids dominated in I. bifrons (60.3%), while the relatively high percentage of fatty acids characterized the other two species I. ensifolia and I. salicina (44.1 and 39.8%, respectively). Principal component analysis (PCA) and cluster analysis (CA) were used to investigate the variations in the volatiles of different Inula species. 相似文献
3.
Assem O. Barakat Alaa Mostafa Nadia B. El-Sayed Terry L. Wade Stephen T. Sweet 《Soil & Sediment Contamination》2013,22(3):315-331
This investigation represents the first extensive study of the spatial distribution, sources, and potential effects of polycyclic aromatic hydrocarbons (PAHs) in sediments from Lake Manzala, the largest of Egypt's Mediterranean coastal lakes. The concentrations of PAHs (Σ39 components) ranged from 246 to 9910 ng g?1 dry wt., the highest values corresponding to urban hotspots with high anthropogenic input coming from wastewater discharges and combustion activities and decreasing offshore. The levels of PAHs were significantly lower compared to values reported in several coastal/estuarine areas (e.g., in Spain, Italy, USA, and Egypt) receiving substantial anthropogenic inputs from urban and industrial activities. Source ratios indicated that the PAHs were mainly from petrogenic sources in near-shore urban hotspots, with higher contributions of pyrolytic sources in coastal and offshore areas which are little influenced by human activities. Sediment quality guidelines (SQGs) showed that except at one station heavily impacted by sewage discharge, the total and individual PAH concentrations were below effect range low (ERL) concentrations that are not likely to adversely affect benthic biota. 相似文献
4.
为深入了解湖泊环境生态系统的变化规律,为湖泊渔业和湖泊管理提供基础数据,于2007年夏季测定了武汉市梁子湖、斧头湖、柴泊湖、南湖和野芷湖5个养殖湖泊的浮游生物的数量和生物量。利用SPSS软件,对5个湖泊浮游植物6个门和浮游动物4个类的数量和生物量进行了主成分分析和因子分析。主成分分析和因子分析的结果是不相同的,其原因是两种方法的差异所致。两种方法结合使用,将有效地提高分析结果的准确度。分析结果表明,影响5个湖浮游生物的第1至第6个主成分分别为枝角类桡足类数量和重量因子、轮虫数量重量和绿藻门数量因子、隐藻门数量和重量因子、原生动物数量和重量因子、蓝藻门数量因子、硅藻门数量和绿藻门重量因子。使用SPSS软件,对5个湖泊13个点的浮游生物的数量和生物量予以了层次聚类法,并将5个湖泊的13个点分为5类,即梁子湖和斧头湖敞水区的3号和5号点为一类;梁子湖和斧头湖围拦养殖区的1号和4号点,以及梁子岛附近的2号点为一类;柴泊湖的6、7、8号3个点为一类;南湖原排污口附近的10号点为一类;南湖与野芷湖的其他9、11、12和13号4个点为一类。经分析认为,形成这个结果是由城市废水、生活污水和养殖生产所致。 相似文献
5.
Sediment samples collected over a 3-year period from Brisbane River, Australia, were analysed for fifteen (15) polycyclic aromatic hydrocarbons (PAHs). The total PAH concentrations varied from 148 to 3079 ng/g with a mean concentration of 849 ± 646 ng/g. The study revealed that PAH input into the river was primarily dominated by pyrogenic sources as evidenced by the predominance of the high molecular weight (HMW) PAHs. Temporal variations of PAHs can be linked to the level of urbanization, with continuous input of combustion related PAHs in the commercial area of the river. Inherent deficiencies in using a single source identification/apportionment approach were overcome by using diagnostic ratios, principal component analysis/absolute principal component scores (PCA/APCS) and positive matrix factorization (PMF). Both, PCA/APCS and PMF resolved four (4) identical factors or sources of PAHs, namely: gasoline emissions, diesel emissions, biomass burning and natural gas combustion. Diagnostic ratios, PCA/APCS and PMF analysis indicated that vehicular emissions were the principal sources especially within the lower section of the river while biomass burning had moderate contribution. The distribution, temporal trend and source apportionment suggest the containment of industrial-derived sources of PAHs in the river. From an ecological point of view, the risk posed by PAHs in the Brisbane River sediment appears to be low. Nevertheless, when the investigated sites were ranked using multi-criteria decision making methods(MCDM) the commercial stratum was the most contaminated. Assessment of potential risks posed by incidental dermal exposure to PAHs revealed some degree of cancer risk, especially to children. 相似文献
6.
7.
Phenanthrene biodegradation was investigated at different soil water contents [0.11, 0.22, 0.33, 0.44 g H2O (g soil)?1] to determine the effects of water availability on biodegradation rate. A subsurface horizon of Kennebec silty loam soil was used in this study. [9-14C] phenanthrene was dissolved in a mixture of organic contaminants that consisted of 76% decane, 6% ρ-xylene, 6% phenanthrene, 6% pristane, and 6% naphthalene, and then added to the soil. The highest rate of mineralization, in which 0.23% of the [9-14C] phenanthrene degraded to 14CO2 after 66 days of incubation, was observed at the soil water content of 0.44 g H2O/g dry soil. Most of the 14C remained in the soil as the parent compound or as nonextractable compounds by acetonitrile at the highest water content. Concentrations of nonextractable compounds increased with water content, but residual extractable phenanthrene decreased significantly with increasing water content, which presumably indicates that bio-transformation occurred. The mineralization analysis of radiolabeled 9th carbon in phenanthrene underestimated phenanthrene biodegradation. The strong adsorption and low solubility of phenanthrene contributed to the low mineralization of phenanthrene 9th carbon. The other components were subject to higher biological and abiotic dissipation processes with increasing soil water content. 相似文献
8.
《Phytochemistry》2013
Cryptic speciation refers to cases where species are clearly genetically differentiated, but show little or no morphological differences. This study investigated whether volatile components can be used to distinguish the cryptic species within the Conocephalum conicum complex. Thirteen samples were included in this study representing four cryptic species (A, F, J, L) and the recently described Conocephalum salebrosum (formerly cryptic species S) detected in a worldwide collection. Results received from GC–MS analyses showed some differences between samples, indicating the existence of chemical polymorphism. It is evident from both statistical analyses (CA and PCA), that cryptic species L appears to be the most differentiated species, with the volatile components not significantly shared with the rest of the types. The most characteristic compound of this type is the sesquiterpene alcohol, conocephalenol. Distinction between other examined cryptic species were also indicated. However species F and J, as well as species A and C. salebrosum, share a great similarity in their volatile composition and are grouped together in both CA and PCA. Despite their similarities, we were able to find chemical markers which can describe each species. Cubebol is characteristic for C. salebrosum, while cryptic species A produces (E)-methylcinnamate. The presence of a large amount of the monoterpene hydrocarbon, sabinene, is characteristic for cryptic species J. In one of the analyzed specimens belonging to the cryptic species F, a large amount of cyclocolorenone was detected. Chemical differentiation was correlated with the geographical distribution of the analyzed samples. 相似文献
9.
Representative soil samples (n = 60) collected from suburban agricultural land in Tianjin were analyzed to determine 16 PAHs in this study. Accelerated solvent extraction, GPC (Gel Permeation Chromatography), and SPE (Solid Phase Extraction) clean-up procedures were employed for PAH preparation prior to analysis with gas chromatography–mass spectrometry. The concentrations of the total PAHs (T-PAHs) ranged from 228.6 ng/g to 14722.1 ng/g with the mean value of 613.1 ng/g. Bap concentrations in many sites exceeded the suggested standards. Spatial variation of PAHs in soil was illustrated; the pollution status and comparison to other cities were also investigated. Severe PAH soil pollution was observed in some sites near urban areas. Higher PAH concentrations were detected at the downwind side of the urban areas, indicating the influence of human activities. Two indicative ratios (Fl/(Fl+Pyr, Baa/(Baa+Chr)) and principal component analysis were used to identify the possible sources of PAHs. These suggested that coal combustion was still the most important source of PAHs in Tianjin, which coincided well with the previous studies. These data can be further used to assess the health risk associated with soils polluted by PAHs and can help local government find proper ways to reduce PAHs’ pollution in soils. 相似文献
10.
贵阳市表层土壤中多环芳烃的分布特征及来源解析 总被引：3，自引：0，他引：3
运用高效液相色谱仪对贵阳市区及近郊的表层土壤中16种多环芳烃(PAHs)进行了定量分析,对其分布特征、污染水平以及来源进行了探讨.结果表明:土壤中PAHs含量为61～ 1560 μg·kg-1,城区土壤样品中PAHs含量为247～1560 μg·kg-1,郊区土壤样品中PAHs含量为61 ～339 μg· kg-1,土壤中4环、5环PAHs含量较高,在土壤PAHs含量中占有绝对优势;参照国外环境标准,对区域表层土壤PAHs的污染现状进行了评价,结果显示,贵阳市表层土壤受到一定程度的PAHs污染.利用相关系数法和典型源三角图法对PAHs的可能来源进行了解析,发现贵阳市的土壤主要受到燃煤排放以及混合污染源——燃煤与汽车尾气排放PAHs的联合污染. 相似文献
11.
Antoaneta Trendafilova Milka Todorova Victoria Ivanova Petar Zhelev Ina Aneva 《化学与生物多样性》2021,18(10):e2100498
In this study, the essential oil composition of five Thymus species, belonging to Sect. Hyphodromi (A. Kerner) Halácsy – Thymus atticus Čelak., T. leucotrichus Halácsy, T. striatus Vahl, T. zygioides Griseb. and T. perinicus (Velen.) Jalas. was studied by GC/MS/FID. T. atticus, T. leucotrichus, and T. striatus were characterized by high amounts of sesquiterpenoids (57.7, 78.9 and 79.7 %, respectively) with β-caryophyllene and caryophyllene oxide as the main constituents. Aromatic compounds (61.2 %) were the most abundant group in T. zygioides essential oil, with thymol (51.2 %) as the principal component. The essential oil from the endemic species T. perinicus contained almost equal amounts of monoterpenoids (37.8 %) and aromatic compounds (36.0 %) with borneol (17.9 %) and thymol (20.9 %) as the major components. The obtained results revealed the existence of new chemotypes of T. atticus (caryophyllene oxide/β-caryophyllene), T. leucotrichus (β-caryophyllene/elemol/germacrene D) and T. striatus (β-caryophyllene/germacrene D/caryophyllene oxide). The essential oil content of endemic T. perinicus is reported for the first time. Principal component analysis (PCA) and cluster analysis (CA) were used to investigate the variations in the essential oils of different Thymus species from Sect. Hyphodromi (A. Kerner) Halácsy. 相似文献
12.
Esra Üçüncü Tunca Tolga T. Ölmez Alper D. Özkan Ahmet Altındağ Evren Tunca Turgay Tekinay 《International journal of phytoremediation》2016,18(8):785-793
Following the rapid uptake of contaminants in the first few hours of exposure, plants typically attempt to cope with the toxic burden by releasing part of the sorbed material back into the environment. The present study investigates the general trends in the release profiles of different metal(loid)s in the aquatic macrophyte Lemna minor and details the correlations that exist between the release of metal(loid) species. Water samples with distinct contamination profiles were taken from Nilüfer River (Bursa, Turkey), Yeniça?a Lake (Bolu, Turkey), and Bey?ehir Lake (Konya, Turkey) and used for release studies; 36 samples were tested in total. Accumulation and release profiles were monitored over five days for 11 metals and a metalloid (208Pb, 111Cd, 52Cr,53Cr,60Ni,63Cu,65Cu,75As,55Mn, 137Ba, 27Al, 57Fe, 66Zn,68Zn) and correlation, cluster and principal component analyses were employed to determine the factors that affect the release of these elements. Release profiles of the tested metal(loid)s were largely observed to be distinct; however, strong correlations have been observed between certain metal pairs (Cr/Ni, Cr/Cu, Zn/Ni) and principal component analysis was able to separate the metal(loid)s into three well-resolved groups based on their release. 相似文献
13.
Melittis melissophyllum L., a medicinal plant currently used in the folk medicine, was analyzed for the content of flavonoid compounds. The plants were collected in two locations in Poland in May and September. MeOH Extracts from the leaves and flowers (separately) were analyzed by HPLC‐DAD. Eight compounds were identified in all the samples and quantitatively analyzed as cinaroside (=luteolin 7‐O‐glucoside), rutin, myricetin, quercitrin, quercetin, luteolin, kaempferol, and apigenin. M. melissophyllum accumulated the highest total amounts of flavonoids in May (flowers: from 258 to 271 mg/100 g dry weight (dw); leaves: from 143 to 155 mg/100 g dw) and significantly lower ones in September (leaves: from 83 to 92 mg/100 g dw). The main compound was cinaroside (May: up to 249 mg/100 g dw; September: up to 43 mg/100 g dw). Advanced multivariate statistical techniques (cluster analysis (CA) and principal component analysis (PCA)) were used to characterize the sample populations and to analyze the data. We report, for the first time, the results of the quantitative analysis of M. melissophyllum flavonoids and seasonal changes in their accumulation. Our results show that the time of harvesting has a significant influence on the flavonoid content in M. melissophyllum, while the geographical location does not have such an effect. 相似文献
14.
15.
辽宁省盘锦地区滨海盐渍土在发展生态农业条件下土壤肥力的变化 总被引：2，自引：0，他引：2
土壤是农业生产实践中最基本的生产资料,在某种意义上讲是不可替代的。合理的开垦利用土壤资源,特别是采取最佳优化的生产方式,则起着提高土壤肥力,夺取农业高产、高效与稳产及保护整个地区的资源环境,特别是保护土壤资源的永续利用的作用。盘锦地区已在较长时期的生产实践中,总结出了调整产业结构,培肥土壤,提高土地生产率以及改善地区生态环境的良好经验。本文通过以原来滨海土壤盐渍化严重的大洼县荣兴农场新开分场农户范丰明发展生态农业为研究对象,考察滨海氯化物盐渍土在不同利用方式下其不同地类土壤肥力指标的变化,并采用总体间协方… 相似文献
16.
AbstractAn explanatory study was carried out to divulge the sources, contamination level of different classes of Polycyclic Aromatic Hydrocarbons (PAHs) distribution and the impact of vehicular traffic on the roadside soil by assessing incremental lifetime cancer risk at each site to understand the potential health risk of nearby residents along the National Highway-2 Delhi–Kolkata India. Comparison of the cancer risk assessment was performed using Monte Carlo simulation for the entire study area. The results revealed 90% cancer risk value of 6.40?×?10?5 and 6.5?×?10?5 for children and adults, respectively, whereas, without simulation the Total Cancer Risk (TCR) for adults was 6.925?×?10?5 and 6.220?×?10?5 for children, observed maximum at the location (S5). The dilemma of risk assessment indicating profoundly contaminated soil. Comparison of PAHs concentration with the background values of PAHs ranged from 1.478 to 27.493?mg kg?1. The (IP/BgP) ratio specified that the PAHs content of the highway roadside sample is preponderate by diesel vehicle emission, biomass combustion and coal combustion. The study clearly revealed and advocated the influence of organic and inorganic pollution, which aggravates and causes health issues to the nearby inhabitants. This study could also be advantageous to similar consequences seen elsewhere in the world. 相似文献
17.
Alexander Genshaft Joe‐Ann S. Moser Edward L. D'Antonio Christine M. Bowman David W. Christianson 《Proteins》2013,81(6):1051-1057
The reversible acetylation of lysine to form N6‐acetyllysine in the regulation of protein function is a hallmark of epigenetics. Acetylation of the positively charged amino group of the lysine side chain generates a neutral N‐alkylacetamide moiety that serves as a molecular “switch” for the modulation of protein function and protein–protein interactions. We now report the analysis of 381 N6‐acetyllysine side chain amide conformations as found in 79 protein crystal structures and 11 protein NMR structures deposited in the Protein Data Bank (PDB) of the Research Collaboratory for Structural Bioinformatics. We find that only 74.3% of N6‐acetyllysine residues in protein crystal structures and 46.5% in protein NMR structures contain amide groups with energetically preferred trans or generously trans conformations. Surprisingly, 17.6% of N6‐acetyllysine residues in protein crystal structures and 5.3% in protein NMR structures contain amide groups with energetically unfavorable cis or generously cis conformations. Even more surprisingly, 8.1% of N6‐acetyllysine residues in protein crystal structures and 48.2% in NMR structures contain amide groups with energetically prohibitive twisted conformations that approach the transition state structure for cis‐trans isomerization. In contrast, 109 unique N‐alkylacetamide groups contained in 84 highly accurate small molecule crystal structures retrieved from the Cambridge Structural Database exclusively adopt energetically preferred trans conformations. Therefore, we conclude that cis and twisted N6‐acetyllysine amides in protein structures deposited in the PDB are erroneously modeled due to their energetically unfavorable or prohibitive conformations. Proteins 2013; © 2012 Wiley Periodicals, Inc. 相似文献
18.
Atagana HI 《Letters in applied microbiology》2004,39(2):163-168
AIMS: To investigate the effects of co-composting poultry manure with soil contaminated with different concentrations of polycyclic aromatic hydrocarbons (PAHs), on the degradation of selected PAHs in a static-pile compost system. METHODS: Mispah form (Food & Agricultural Organisation, FAO : lithosol) soil contaminated with PAHs was co-composted with poultry manure for 19 months. The soil was mixed with wood chips in a ratio of 1:1 to improve aeration and then mixed with poultry manure in a ratio of 4:1. A data logger measured temperature monthly. Residual concentrations of selected PAHs in the compost were determined monthly by gas chromatography/flame ionisation detection (GC/FID). Moisture, pH, ash content and C:N ratios were also monitored monthly. Microbial activity was measured by measuring CO(2) evolution. CONCLUSIONS: The results obtained in this experiment have shown that co-composting poultry manure with PAH-contaminated soil is capable of removing large concentrations of high molecular weight PAH from contaminated soil to levels below 1 mg kg(-1) in 19 months. SIGNIFICANCE AND IMPACT OF THE STUDY: The paper adds to the body of knowledge necessary for the development of a cost effective technology for the remediation of soil contaminated with high molecular weight PAHs by providing information on the behaviour of selected PAHs and factors such as nutrient ratio, temperature and pH during composting. 相似文献
19.
【目的】以多环芳烃(PAHs)污染盐碱土壤为对象,分析比较翅碱蓬根际与非根际土壤细菌群落多样性,为植物-微生物联合修复PAHs污染盐碱土壤提供依据。【方法】在胜利油田油井附近采集翅碱蓬根际土壤和无翅碱蓬生长区域的裸地表层土壤,基于高通量测序技术分析样品中微生物群落结构,并进一步运用Real-time PCR解析土壤中PAHs双加氧酶基因丰度。【结果】翅碱蓬根际土壤盐含量为22.51 g/kg,明显低于裸地土壤的40.03 g/kg,土壤pH值差别不大,分别为8.20和8.22;根际土壤有机质和总氮含量分别为24.41 g/kg和1.59 g/kg,C/N值为15,裸地土壤有机质和总氮含量分别为18.80 g/kg和0.71 g/kg,C/N值为26;高通量测序得到根际和裸地土壤样品优质序列分别为53 854条和30 312条,在97%相似水平下,根际土壤样品所得OTU数、Chao 1指数和ACE指数分别为5 934、11 461和15 555,分别高于裸地土壤对应指数的值(4 262、8 262、11 186),序列分析结果显示,根际土壤包含细菌32门758属,多于裸地土样28门676属,翅碱蓬根际土壤群落结构多样性均高于裸地土壤;PAHs污染盐碱土壤中存在丰富的微生物资源,有Thioalkalispira、Halothiobacillus、Thiohalophilus等多种嗜盐碱或耐盐碱微生物,并在根际土壤中检测到了PAHs双加氧酶基因(PAH-RHDα)。【结论】Thioalkalispira、Halothiobacillus、Thiohalophilus等嗜盐碱或耐盐碱微生物是胜利油田PAHs污染盐碱土壤中的优势菌属;翅碱蓬能有效降低根际土壤盐含量并改善C/N值,增加微生物群落结构多样性,提高PAHs关键功能基因的丰度,有助于促进嗜盐碱PAHs降解微生物在PAHs污染盐碱土壤的生物修复中发挥作用。 相似文献