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A probabilistic model for accidental cargo oil outflow from product tankers in a ship–ship collision 全文
2014
Goerlandt, Floris | Montewka, Jakub
In risk assessment of maritime transportation, estimation of accidental oil outflow from tankers is important for assessing environmental impacts. However, there typically is limited data concerning the specific structural design and tank arrangement of ships operating in a given area. Moreover, there is uncertainty about the accident scenarios potentially emerging from ship encounters. This paper proposes a Bayesian network (BN) model for reasoning under uncertainty for the assessment of accidental cargo oil outflow in a ship–ship collision where a product tanker is struck. The BN combines a model linking impact scenarios to damage extent with a model for estimating the tank layouts based on limited information regarding the ship. The methodology for constructing the model is presented and output for two accident scenarios is shown. The discussion elaborates on the issue of model validation, both in terms of the BN and in light of the adopted uncertainty/bias-based risk perspective.
显示更多 [+] 显示较少 [-]Evaluation of the levels of alcohol sulfates and ethoxysulfates in marine sediments near wastewater discharge points along the coast of Tenerife Island 全文
2014
Fernández-Ramos, C. | Ballesteros, O. | Zafra-Gómez, A. | Camino-Sánchez, F.J. | Blanc, R. | Navalón, A. | Pérez-Trujillo, J.P. | Vílchez, J.L.
Alcohol sulfates (AS) and alcohol ethoxysulfates (AES) are all High Production Volume and ‘down-the-drain’ chemicals used globally in detergent and personal care products, resulting in low levels ultimately released to the environment via wastewater treatment plant effluents. They have a strong affinity for sorption to sediments. Almost 50% of Tenerife Island surface area is environmentally protected. Therefore, determination of concentration levels of AS/AES in marine sediments near wastewater discharge points along the coast of the Island is of interest. These data were obtained after pressurized liquid extraction and liquid chromatography–tandem mass spectrometry analysis. Short chains of AES and especially of AS dominated the homologue distribution for AES. The Principal Components Analysis was used. The results showed that the sources of AS and AES were the same and that both compounds exhibit similar behavior. Three different patterns in the distribution for homologues and ethoxymers were found.
显示更多 [+] 显示较少 [-]Size distribution of water-soluble inorganic ions in urban aerosols in Shanghai 全文
2014
Tao, Ye | Yin, Zi | Ye, Xingnan | Ma, Zhen | Chen, Jianmin
The size distribution of water-soluble inorganic components of urban aerosols in Shanghai was studied. The size-resolved aerosol samples collected by an 8-stage cascade sampler between April and May of 2012 were analyzed by ion chromatography. The ion mass concentrations followed the sequence of SO42−>NO3−~NH4+>Ca2+>Na+ ~Cl−>K+>Mg2+>F− for each size fraction below 2.1μm, while the sequence was NO3−>SO4−2>Ca2+>NH4+>Na+>Cl−>K+>Mg2+>F− for coarse mode particles larger than 3.3μm. The size distribution in 5 fractions showed that SO42−, NO3−, and NH4+ were generally in the fine mode peaking below 1μm while Ca2+, Mg2+, Na+, and Cl− were bimodally distributed with a second peak larger than 2.1μm. Back trajectory analyses revealed that the air masses could be classified into three main groups. The total ion concentrations were comparable between the terrestrial and mixing regimes. In the terrestrial regime, fine mode sulfate and nitrate were predominantly associated with ammonium. The excessive sulfate and nitrate over the whole size range might exist in the forms of Ca(NO3)2 and CaSO4. In the maritime regime, the decrease in SO42−, NO3−, and NH4+ contributed to the improvement in air quality. Besides marine aerosols, local emissions from soil dust and coal combustion were also important sources of sea-salt type ions (i.e., Na+ and Cl−).
显示更多 [+] 显示较少 [-]Diversity of bacterial community and detection of nirS- and nirK-encoding denitrifying bacteria in sandy intertidal sediments along Laizhou Bay of Bohai Sea, China 全文
2014
Wang, Liping | Zheng, Binghui | Nan, Bingxu | Hu, Peilong
The microbial community and the nirS- and nirK-encoding denitrifiers in the intertidal sediments along Laizhou Bay in China were studied using pyrosequencing and real-time quantitative PCR (qPCR), respectively. There were three primary intertidal zones: Laizhou (La), Weifang Harbor (We), and Dongying (Do). Significant differences in composition and abundances at the different taxonomic levels were observed among the three bacterial communities. The qPCR results indicated that the nirS gene abundance varied from 8.67×105 to 5.68×106copies/gwet weight (ww), whereas the nirK gene abundance varied from 1.26×105 to 1.89×106copies/gww. The canonical correlation analysis (CCA) indicated that the sand percentage was the most important factor in shaping the bacterial community followed by silt percentage, NO2−, TOC, DO, pH, and clay percentage, whereas the clay percentage, pH, NO3−, DO, NO2−, TOC, silt percentage, and sand percentage were the most important factors associated with regulating the abundance of nirS- and nirK-encoding denitrifiers.
显示更多 [+] 显示较少 [-]A reassessment of the use of Posidonia oceanica and Mytilus galloprovincialis to biomonitor the coastal pollution of trace elements: New tools and tips 全文
2014
Richir, J. | Gobert, S.
The present study gives a summary using state-of-the-art technology to monitor Posidonia oceanica and Mytilus galloprovincialis as bioindicators of the pollution of the Mediterranean littoral with trace elements (TEs), and discusses their complementarity and specificities in terms of TE bioaccumulation. Furthermore, this study presents two complementary indices, the Trace Element Spatial Variation Index (TESVI) and the Trace Element Pollution Index (TEPI): these indices were shown to be relevant monitoring tools since they led to the ordering of TEs according to the overall spatial variability of their environmental levels (TESVI) and to the relevant comparison of the global TE pollution between monitored sites (TEPI). In addition, this study also discusses some underestimated aspects of P. oceanica and M. galloprovincialis bioaccumulation behaviour, with regard to their life style and ecophysiology. It finally points out the necessity of developing consensual protocols between monitoring surveys in order to publish reliable and comparable results.
显示更多 [+] 显示较少 [-]Regional distribution of halogenated organophosphate flame retardants in seawater samples from three coastal cities in China 全文
2014
Hu, Mengyang | Li, Jun | Zhang, Beibei | Cui, Qinglan | Wei, Si | Yu, Hongxia
Thirteen samples of seawater were collected from Yellow Sea and East China Sea near Qingdao, Lianyungang, and Xiamen, China. They were analyzed for halogenated organophosphorus flame retardants (OPFRs). The compounds selected for detection were Tris(2-chloroethyl) phosphate (TCEP), Tris(2-chloroisopropyl) phosphate (TCPP), Tris (1,3-dichloro-2-propyl) phosphate (TDCPP), and Tris(2,3-dibromopropyl) phosphate (TDBPP). The total concentrations ranged from 91.87 to 1392ng/L and the mean concentrations of these four chemicals were 134.44, 84.12, 109.28, and 96.70ng/L, respectively. TCEP exhibited the highest concentrations, although concentrations of TCPP and TDCPP were also fairly high in Lianyungang and Xiamen. Generally, Lianyungang was the most heavily polluted district, with very high concentrations of TCEP at LYG-2 (550.54ng/L) and LYG-4 (617.92ng/L). The main sources of halogenated OPFRs were municipal and industrial effluents of wastewater treatment plants in the nearby economic and industrial zones.
显示更多 [+] 显示较少 [-]Interannual changes in δ15N values in Fucus vesiculosus L 全文
2014
Carballeira, Carlos | Rey-Asensio, Ana | Carballeira, Alejo
The natural abundance of 15N (δ15N) has been widely used to detect anthropogenically derived N loads in environmental impact studies. The present study involved retrospective analysis of subsamples of Fucus vesiculosus L. collected during a period of three years (2008–2010) from two sites: a control site, within a coastal reference area, and an area affected by the effluents of a marine land-based fish farm. The isotopic signal in different subsamples of the macroalgae thalli (tissue that has grown during the same period) varied depending on the age of the tissue. Moreover, the isotopic signal decreased significantly with the age of the frond to within a certain range. The δ15N of F. vesiculosus is temporally unstable; therefore, measurement of the δ15N of macroalgal tissues does not allow reliable retrospective biomonitoring of environmental pollution. Further knowledge about the growth and other biological aspects of this species is required.
显示更多 [+] 显示较少 [-]Bioconcentration of the anionic surfactant linear alkylbenzene sulfonate (LAS) in the marine shrimp Palaemonetes varians: A radiotracer study 全文
2014
Renaud, Florent | Warnau, Michel | Oberhänsli, François | Teyssié, Jean-Louis | Temara, Ali | Rouleau, Claude | Metian, Marc
Uptake and depuration kinetics of dissolved [14C]C12-6-linear alkylbenzene sulfonate (LAS) were determined in the shrimp Palaemonetes varians using environmentally relevant exposure concentration. The shrimp concentrated LAS from seawater with a mean BCF value of 120Lkg−1 after a 7-day exposure. Uptake biokinetics were best described by a saturation model, with an estimated BCFss, of 159±34Lkg−1, reached after 11.5days. Shrimp weight influenced significantly BCF value with smaller individuals presenting higher affinity to LAS. To the light of a whole body autoradiography, major accumulation of LAS occurred in the cephalothorax circulatory system (gills, heart, hepatopancreas) and ocular peduncle, but not in the flesh, limiting potential transfer to human consumers. LAS depuration rate constant value of the shrimp was 1.18±0.08d−1 leading to less than 1% of remaining LAS in its tissues after 8days of depuration.
显示更多 [+] 显示较少 [-]210Po, Cd and Pb distribution and biomagnification in the yellowfin tuna Thunnus albacares and skipjack tuna Katsuwonus pelamis from the Eastern Pacific 全文
2014
Ruelas-Inzunza, J. | Soto-Jiménez, M.F. | Ruiz-Fernández, A.C. | Ramos-Osuna, M. | Mones-Saucedo, J. | Páez-Osuna, F.
We measured Cd and Pb in the muscle and stomach contents of Thunnus albacares and Katsuwonus pelamis to define the distribution of the elements in the tissues and their degrees of biomagnification. 210Po was measured in the livers of both species and compared to the results of similar studies. The trophic position of the tuna species was determined by N isotope measurements. The average activity of 210Po in the liver ranged from 119 to 157 (Bqkg−1 wet weight) in K. pelamis and T. albacares. The trophic position of T. albacares (4.60) was higher than that of K. pelamis (3.94). The Cd content of the muscle increased significantly with the trophic position of the tuna. δ13C in T. albacares and K. pelamis varied, with values of 3.13 and 1.88‰, respectively. The δ15N values in yellowfin tuna were higher than in skipjack tuna. The trophic position of T. albacares (4.60±0.67) was therefore more elevated than that of K. pelamis (3.94±1.06). Pb was biomagnified in T. albacares (transfer factor=1.46).
显示更多 [+] 显示较少 [-]ALien Biotic IndEX (ALEX) – A new index for assessing impacts of alien species on benthic communities 全文
2014
Çinar, Melih Ertan | Bakir, Kerem
Biotic indices are mainly aimed at assessing levels of deterioration caused by chemical or organic pollution. However, no biotic index to date has been developed to detect impacts of alien species on benthic communities. In this paper, a new biotic index, namely ALEX, is proposed to address the objectives of the Water Framework Directive and was tested in Mersin Bay (Levantine Sea, Turkey). Species were divided into four biogeographic groups, namely native species, casual species, established species and invasive species, and the metric considers the relative importance of these groups in samples. The index classified the ecological status of some stations which are shallow, and close to harbor and river mouths as bad or poor in February and October. The ALEX values were positively and significantly correlated with total nitrogen, silicate and silt percentage in sediment, and negatively correlated with depth and the distance from the harbor.
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