Sources and transports of polycyclic aromatic hydrocarbons in the Nanshan Underground River,China

Karst areas have much higher ecological vulnerability and are easy to be contaminated by polycyclic aromatic hydrocarbons (PAHs), which are introduced as health risk pollutants. PAHs ratios were used to understand the sources and transport behavior of PAHs conducted in the karst Nanshan Underground River, China. Water, sediments from the underground river and water, sediments, soil from the surface were collected monthly in 2011 and 2012. Abundant PAHs were found both in the underground river and in the surface system. The detected ΣPAHs concentrations varied from 353 to 13,203 ng L^?1 in the groundwaters and content from 169 to 12,038 ng g^?1 in the sediments of the underground river. The ratios of anthracene to anthracene, plus phenanthrene and fluoranthene to fluoranthene, plus pyrene indicated that PAHs were delivered in the groundwaters from combusted grass, wood, and coal, while in the sediments were a mixture of non-combusted petroleum, grass, wood, coal and combusted grass, wood, coal. The similarities in sources between an underground river and surface system indicated that farmlands play a major role for the transport of PAHs and contamination in the underground river. Karst features are liable for the transport behavior.     

Survey of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons in Jiaxing city, China

Polycyclic aromatic hydrocarbon (PAH) and nitrated PAH (NPAH) products are toxic. Thus, determination of their concentrations is of great interest to researchers of soil and water pollution control. In this work, soil samples, surface water samples, and groundwater samples were collected, and the concentrations of 16 priority PAHs and 15 NPAHs were determined using an HPLC-ultraviolet detector. Results showed that the total PAH concentrations ranged within 489.69–1,670.11 ng/g (average = 905.89 ng/g) in soil samples, 4.00–23.4 μg/l (average = 9.84 μg/l) in surface water samples, and 2.14–22.3 μg/l (average = 8.37 μg/l) in groundwater samples. The NPAH concentrations were one to two orders of magnitude lower than the PAH concentrations and ranged within 22.72–128.70 ng/g (average = 63.88 ng/g) in soil samples. 2-Nitropyrene and 6-nitrochrysene were the most abundant compounds, accounting for about 14.3 and 26.5 %, respectively. Source analysis revealed that most PAHs originated from coal combustion around the study area, whereas NPAH studies suggested that the primary emission of gasoline engines and daytime OH reactions were the dominant sources of these compounds.     

Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments in the Yellow River Estuary, China

Concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments of the Yellow River Estuary (YRE). The isobath-parallel tidal and residual currents play important roles in the variation of PAH distribution, such that the contamination level of PAHs in fine-grained sediments is significantly higher than in the relatively coarse grain size sediments. Both diagnostic ratios and principal component analysis (PCA) with multivariate linear regression (MLR) were used to apportion sources of PAHs. The results revealed that pyrogenic sources are important sources of PAHs. Further analysis indicated that the contributions of coal combustion, traffic-related pollution and mixed sources (spills of oil products and vegetation combustion) were 35, 29 and 36 %, respectively, using PCA/MLR. Pyrogenic sources (coal combustion and traffic-related pollution) contribute 64 % of anthropogenic PAHs in sediments, which indicates that energy consumption could be a predominant factor in PAH pollution of YRE. Acenaphthylene and acenaphthene are the two main species of PAHs with more ecotoxicological concern in YRE.     

The global distribution of polycyclic aromatic hydrocarbons in recent sediments

Polycyclic aromatic hydrocarbons (PAH) and their alkyl homologs are distributed in sediments throughout the world. The qualitative PAH pattern is remarkably constant for most of the locations studied, and the quantitative PAH abundance increases with proximity to urban centers. These findings are consistent with anthropogenic combustion's being the major source of these compounds. Two non-combustion sources of PAH have also been noted: retene coming from abietic acid and perylene probably coming from various extended quinone pigments.     

广州市空气颗粒物中烃类物质的粒径分布

用 Andersen六段分级大流量采样器 (粒径为 : 10～ 7.2 μ m, 7.2～ 3.0 μ m, 3.0～ 1.5 μ m, 1.5～ 0.95 μ m, 0.95～ 0.49 μ m, ≤ 0.49 μ m)采集了广州市荔湾区 4个季度的大气颗粒物样品 , 用气相色谱 (GC)定量分析了其中的正构烷烃 (n-alkanes)组分,用气相色谱-质谱 (GC-MS)定量分析了其中的多环芳烃 (PAHs)组分. CPI2(代表石油成因的碳优势指数 )、 CPI3(代表生物成因的碳优势指数 ) 和 Wax(植物蜡含量 )表明了石油成因的烷烃倾向于富集在细颗粒物上,而生物成因的烷烃倾向于富集在粗颗粒物上.正构烷烃和低相对分子质量多环芳烃表现出双峰模型分布,高相对分子质量多环芳烃呈现单峰模型分布,仅在细颗粒段有一峰值.烷烃和芳烃秋冬季的 MMDs(质量中值直径 )比春夏季的大.在高温季节化合物优先富集在细颗粒物上,而在低温季节则向粗的颗粒物方向偏移.     

Spatial and temporal distribution of polycyclic aromatic hydrocarbons in finegrained sediments of the East China Sea

The nearshore mud area along the Changjiang （Yangtze River） estuary and the coast of Zhejiang and Fujian provinces, and the distal mud area to the southeast of Cheju Island, Korea are the modem accumulative centers, thus, being the ＂sinks＂ of pollutants such as Polycyclic Aromatic Hydrocarbons （PAHs） in the East China Sea （ECS）. PAHs of surface sediment samples from the mud areas of the ECS and a ^210Pb dating sediment core collected using a gravity core from the coastal mud area in the ECS were quantified by GC/MSD with the internal standard materials.     

Spatial distribution and source diagnosis of polycyclic aromatic hydrocarbons in soils from Chengdu Economic Region,Sichuan Province,western China

Surface soils from the Chengdu Economic Region (CER) were analyzed for sixteen United States Environment Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) to study the spatial distribution and to identify the sources of PAHs. Relatively high concentrations (more than 1500 ngg^− 1) of high molecular weight PAHs were found in Chengdu Plain, in the middle of CER, while high concentrations (more than 500 ng g^− 1) of low molecular weight PAHs were detected in the surrounding mountains. The concentrations of ∑₁₆-PAHs in topsoil samples from CER (12.52–75,431.47 ngg^− 1, average value was 3233.92 ngg^− 1) were higher than that from the southern China (21.91–3077 ngg^− 1, average value was less than 500 ngg^− 1), and they were comparable to concentrations in soils from the northern China (366–254,080 ngg^− 1, mean value was more than 3000 ngg^− 1). The concentrations from CER were also much higher than the concentrations of some world clean regions such as Antarctic (34.9–171 ngg^− 1), European high mountains (9–11,000 ngg^− 1, mean value was 158 ngg^− 1) and some Europe residential (736 ngg^− 1) and arable soils (60–145 ngg^− 1, mean value was 66 ngg^− 1). The ratio of tracer compounds (BaA/(BaA + Chr), Flo/(Flo + Pyr), and IcdP/(IcdP + BghiP)) indicated that the high concentrations of PAHs in soils were mainly derived from fossil fuels combustion in mountain region and from the incomplete combustion of petroleum in developed plain area (such as Chengdu and Deyang). From the above distribution characteristics and ratios of tracer compounds, we inferred the reasons for the distribution pattern of PAHs in CER were the domestic heating, emissions, and the physicochemical properties of PAHs.     

珠江广州河段重污染沉积物中多环芳烃赋存状态初步研究

对珠江广州河段重污染沉积物进行粒度分级 (>500 μm、500～ 220 μm、220～ 63 μm、63～ 22 μm和 < 22 μm),每个粒级的样品进行重液分离,收集轻组分 (有机质 )和重组分 (主要为无机矿物及无定型有机质 ).在显微镜下对沉积物中不同粒径轻重组分的吸附剂进行鉴定,对其中的多环芳烃进行定量分析,结果表明,白鹅潭样品中有机质占总质量的 9.10%,富集了 81.55%的多环芳烃,无机矿物和无定型有机质占 90.92%,富集了 18.45%的多环芳烃;黄埔样品中有机质占总质量的 8.95%,富集了 56.50%的多环芳烃,无机矿物和无定型有机质占 91.15%,富集了 43.50%的多环芳烃.轻组分中的有机吸附剂对多环芳烃的富集能力比重组分无机矿物和无定型有机质高 1～ 2个数量级,轻组分有机吸附剂中焦碳和碳黑富集能力较高,植物碎屑较低.总有机碳和碳黑的含量与多环芳烃的富集能力没有明显的相关性.     

Natural and anthropogenic hazards in the Yellow River Delta,China

Natural Hazards - In China, the Yellow River Delta is a unique region with vulnerable ecosystems, and it is under the largest pressure from various risk sources. In recent years, this region has...     

Novel aryl polycyclic aromatic hydrocarbons: Phenylphenanthrene and phenylanthracene identification, occurrence and distribution in sedimentary rocks

Numerous reports have recognised the presence of compounds with molecular weight 254 a.m.u. in aromatic fractions. However, their unequivocal identification has not been achieved due to a lack of reference substances. In geological samples, such m/z 254 compounds could potentially be represented by a number of structural isomers of binaphthyl, phenylphenanthrene, phenylanthracene and indenofluorene with each compound type possessing several positional isomers. In this work, all these m/z 254 compounds, with the exception of the tentatively recognised indenofluorenes, have been unequivocally identified in sedimentary rocks for the first time. Comparison of the mass spectra and the gas chromatography (GC) retention times of synthesised standards with the natural compounds in rocks shows that the major components of aromatic fractions are phenylphenanthrene isomers and, to a lesser extent, binaphthyls and 9-phenylanthracene. The elution sequence expressed as standard retention indices of all these m/z 254 isomers were determined by using high resolution capillary GC with three stationary phases: 5%, 35% and 50% (mole fraction) phenyl substituted methylpolysiloxane on HP-5MS, DB-35MS and DB-17MS columns, respectively. A survey of more than 350 sedimentary rock samples of varying origins and maturity (R_r 0.3–1.4%) reveals that relative abundances of the m/z 254 isomers depend on the maturity of the organic matter. The isomers initially appear at the onset of oil generation (R_r > 0.5%) exclusively in diagenetically/catagenetically oxidised samples containing varying proportions of Types II and III kerogen. Interestingly, all five possible positional phenylphenanthrene isomers (including the most sterically hindered isomer 4-phenylphenanthrene) are present from the beginning of the oil generation window. Such a distribution suggests that low-regioselectivity reactions are likely to be involved in the formation. Interaction, during maturation, of phenyl radicals from primary cracking with aromatic moieties of more resistant terrigenic components of kerogen in an oxidising diagenetic realm is postulated to be responsible for the neoformation of phenylated aromatics in geological samples. Up to the final stages of oil generation, the evolution of the phenyl PAH distributions presumably involve 1,2-phenyl shift reactions and cyclisation, if allowed by the molecular geometry. A near thermodynamically-controlled distribution, with only 3- and 2-phenylphenanthrene and minor 2,2′-binaphthyl remaining, is approached when vitrinite reflectance reaches 1.2% (R_r). The three compounds seem to be persistent beyond the oil window as is suggested by their presence in hydrothermal oil formed at T > 300 °C.     

太原市区土壤中多环芳烃污染特征研究

采用1个样/km2的密度,1个分析组合样/25km2的方法,对太原市区土壤中多环芳烃进行了调查。结果表明,太原市区土壤中多环芳烃的平均含量为8.65μg/g;空间分布上北高南低,高值点主要位于工业区及交通要道地段;组成上以四环及四环以上的多环芳烃为主。通过与国内外城市土壤的对比可知,太原市土壤PAHs污染已相当严重,其来源主要是煤炭的燃烧。太原市工业布局、能耗类型和地理位置是造成土壤PAHs污染的主要原因。     

Alkylation of polycyclic aromatic hydrocarbons in carbonaceous chondrites

Using microprobe laser-desorption, laser-ionization mass spectrometry (μL²MS), we measured the distributions of alkylated and unalkylated polycyclic aromatic hydrocarbons (PAHs) in the free organic material of 20 carbonaceous chondrites. These meteorites represent a variety of meteorite classes and alteration histories, including CI, CK, CM, CO, CR, CV, and Tagish Lake. This work provides information on free organic compounds that is complementary to studies of the structure and composition of meteoritic macromolecular content.For the nine CM2 meteorites analyzed, we observe that higher relative abundances of alkylated PAHs correlate with more intense aqueous activity. We attribute this correlation to the differences in solubility and volatility between unalkylated and alkylated PAHs. Naphthalene and its alkylation series are more susceptible to the effects of aqueous exposure than the less-soluble PAH phenanthrene and its alkylated derivatives. These observations are consistent with the possibility of chromatographic separations on the meteorite parent bodies. We identify six CM2 meteorites with similar PAH distributions that may represent the original, unaltered organic composition of the parent body.Increased metamorphic intensity reduces the abundance of all PAHs. The thermally metamorphosed CK chondrites had no detectable levels of typical meteoritic PAHs. This observation might be explained either by a loss of PAHs caused by volatilization or by a significantly different organic content of the CK parent body.     

Relationship between heavy metals and polycyclic aromatic hydrocarbons in the multi-phases of Nanhu Lake, China

Heavy metals （HMs） and polycyclic aromatic hydrocarbons （PAHs） are two sorts of important pollutants, which were frequently detected in natural aquatic environments at the same time. Surfacial sediments （SSs）, suspended particulates （SPs） and natural surface coatings （NSCs） are recognized as the key solid sinks and sources of heavy metals （HMs） and organic materials （OMs） in natural water systems, playing critical roles in the cycling and transformation of pollutants. The behaviors of HMs in the multi-phases （SSs, SPs and NSCs） have been well investigated, but less reports on those of PAHs, especially on those of HMs and PAHs simultaneously in the multi-phases. Hence, the relationship between HMs （Pb, Cd and Cu） and PAHs （fluorene, phenanthrene, anthracene and pyrene） in the multi-phases of Nanhu Lake in Changchun, China, was studied in this study using methods of acid digestion and extraction, in order to reveal the combined pollution of HMs and PAHs in Nanhu Lake. The information indicated that HMs and PAHs have the similar distribution patterns in the multi-phases of Nanhu Lake, with increasing levels of riMs and PAHs in the SSs, SPs and NSCs. And the enrichment capacities of SPs and NSCs for HMs and PAHs in the water were similar to each other and much greater than that of SSs, implying that SPs and NSCs contributed more to the transference and transformation of HMs and PAHs in the aquatic environments. The relationship between HMs and PAHs has been analyzed by SPSS statistical analysis, and the results showed that the significant correlation of riMs and PAHs was found in the SSs at the confidence level of p = 0.05, but Pb, Cd or Cu had no correlation with any monomer of PAHs in the SPs or NSCs, highlighting the existence of combined pollution of HMs and PAHs in SSs. This was partly due to the relative lability of SPs or NSCs compared to SSs resulting from the water quality of being varied.     

The distribution, sources and toxicity risks of polycyclic aromatic hydrocarbons and n-alkanes in riverine and estuarine core sediments from the Daliao River watershed

The burial characteristics and toxicity risks associated with n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in the riverine and estuarine sediments of the Daliao River watershed were investigated based on three sediment cores. The sum of the n-alkane and PAH concentrations, normalized to organic carbon (OC), ranged from 0.27 to 63.09 μg g^?1OC^?1 and 6.60 to 366.20 μg g^?1OC^?1, respectively. The features and the history of industrial activities, such as the oil and chemical industries and port activities near the river and estuary, resulted in different distributions and sources of hydrocarbons. The sources of pollution were identified based on n-alkane indexes and on diagnostic ratios of PAHs. The diagnostic ratios indicated that the n-alkanes were derived from both biogenic and petrogenic sources in different proportions and that the PAHs were derived primarily from petrogenic combustion sources. A hierarchical cluster analysis grouped the core samples into two clusters. The first cluster, river sediments, corresponded to industrial activities; the second cluster, estuarine sediments, corresponded to port shipping activities. The toxic potency of the PAHs in the cores was assessed in terms of toxic equivalents (TEQs) of dibenzo[a,h]anthracene and benzo[a]pyrene. The top layer of the sediment in the cores had a relatively high toxicity. The TEQ values for benzo(a)pyrene (TEQ_BaP) and dioxins (TEQ_TCDD) furnished a consistent assessment of the PAHs in the sediment cores.     

珠江三角洲经济区主要城市不同功能区大气气溶胶中优控多环芳烃污染评价

以ＷＨＯ的苯并（ａ）芘标准和珠江三角洲经济区大气气溶胶中优控多环芳烃春季区域性背景为依据。对区内主要城市中不同功能区大气气溶胶中优控多环芳烃的污染程度进行了评价。结果表明,在相同的功能区,冬春季节大气气深胶中多环芳烃含量及污染程度较夏季的高;同为冬春季节,商业、居民集中和交通复合功能区的ＰＡＨｓ污染最为严重,交通或居民集中单一功能区次之,工业区较轻;同为夏季,工业区的ＰＡＨｓ污染程度较大,而商业或     

N-Alkanes and polycyclic aromatic hydrocarbons (PAHs) profile of soil from some polluted sites in Niger Delta, Nigeria

Soil samples were collected at different locations from Etche and Obio Akpor local government area (LGA) of River State in Niger Delta. The n-alkane and polycyclic aromatic hydrocarbons were determined qualitatively and quantitatively using GC-FID. The concentration of PAHs in the soil samples ranged from 7.40 to 78.3 ng/g. The highest concentration of PAHs was recorded in Agbada 1 flow station, while the lowest concentration was recorded in Agbada 2 flow station. A significant level of pollution was also observed in the soil of Bomu pipeline at Obio Akpor LGA. Also, the distribution of n-alkanes in the samples was also used to assess the level of pollution in the studied area. Various n-alkanes and PAHs ratios were obtained to know the major source of pollution in the area under study. The main source of pollution was pyrolytic, which might be due to the gas flaring activities going on in the study area. Also, the results showed that n-alkanes could also be a complementary tool in assessing pollution and source apportionment.     

Historical records and the sources of polycyclic aromatic hydrocarbons in the East China Sea

The coastal cities are the most advanced regions in China. In the past few decades, the environment changed very significantly due to large scale human activities in the coastal regions. Polycyclic aromatic hydrocarbons (PAHs) in three dated sediment cores from the west coast of the Yellow Sea (core A01), the Yangtze River estuary (YRE; core A02) and the Oujiang River estuary (ORE; core A03) were analyzed to reconstruct the environmental evolutionary process of the east China coastal region over the past century. In the three cores, PAHs concentrations were increased rapidly. Lower concentrations of PAHs were measured in core A02 than in cores A01 and A03. The vertical variation of PAHs in the YRE was dominated by the petrogenic sources. Historical records of PAHs in the ORE were controlled by pyrolytic sources. PAHs on the west coast of the Yellow Sea were contributed by the two sources.