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Результаты 1831-1840 из 5,151
Occurrence and distribution of perfluoroalkyl substances (PFASs) in sediments of the Dalian Bay, China Полный текст
2018
Ding, Guanghui | Xue, Huanhuan | Zhang, Jing | Cui, Fuxu | He, Xin
In the present study, the spatial distributions and vertical variations of PFASs in the sediments of the Dalian Bay were investigated. The total concentrations of PFASs (∑PFASs) in surface sediments of Dalian Bay ranged from 1.49 to 2.66ngg⁻¹ dw. The predominant PFASs in surface sediments were PFOA, PFBS and PFBA with the concentration ranges of 0.50 to 0.95, 0.21 to 0.94, and 0.035 to 0.32ngg⁻¹ dw, respectively. For the two sediment cores, ∑PFASs ranged from 1.20 to 2.00 and from 1.37 to 2.06ngg⁻¹ dw, respectively. There was a maximum ∑PFASs concentration value near the surface. In general, ∑PFASs gradually decreased with increasing sampling depth after reaching the maximum. PFOA, PFBS and PFBA were also the predominant PFASs in the two sediment cores. It is recommended that the monitoring and risk assessment of short-chain PFAS should be taken into consideration, and further researches are needed to understand the transportation and fate of these chemicals in the aquatic environment.
Показать больше [+] Меньше [-]Assessing the ecological status of Italian lagoons using a biomass-based index Полный текст
2018
Mistri, Michele | Borja, Angel | Aleffi, Ida Floriana | Lardicci, Claudio | Tagliapietra, Davide | Munari, Cristina
We compared the performance of abundance- and biomass-based M-AMBI in the 13 major Italian lagoons, using a benthic dataset constituted by 208 sampling sites. The relative importance of ecological groups changed when using abundance or biomass, sometimes leading to an improved ecological status classification. Being biomass more ecologically relevant than abundance, the adoption of a biomass-based index may better describe the ecological status of lagoons, where the community is naturally disturbed and dominated by tolerant and opportunist species.
Показать больше [+] Меньше [-]Sustainable recycling of mooring ropes from decommissioned offshore platforms Полный текст
2018
Sudaia, David Pascoal | Bastos, Milton Briguet | Fernandes, Elieti Biques | Nascimento, Christine Rabello | Pacheco, Elen B.A.V. | da Silva, Ana Lúcia N.
Decommissioning offshore Floating Production, Storage and Offloading (FPSO) platforms requires extensive technical knowledge, since it generates different post-consumer materials, including mooring lines. These ropes are made from polyester high tenacity yarn, based on polyethylene terephthalate (PET), and their high added value means they should not be discarded as scrap. This paper aims to present a review and technical opportunities, from an economic standpoint, of recycling the mooring lines recovered from decommissioned FPSOs. Studies conducted over the last two years have researched and developed different potential applications for the fibers. These studies include collaborative project initiatives involving technical and management professionals, universities and private enterprises, with a view to achieving a more sustainable destination for these fibers.
Показать больше [+] Меньше [-]Microplastic contents from maricultured and natural mussels Полный текст
2018
Renzi, Monia | Guerranti, Cristiana | Blašković, Andrea
Results of this research focuses on microplastic contents (levels, type, size, colour) in maricultured and natural mussels (Mytilus galloprovincialis) from different Italian stocks. No significant differences were found among maricultured and natural stocks. All recovered MPs are filaments ranging within 750–6000 μm of maximum length (average values 1150–2290 μm). Feeding raw mussel could produce median MP intakes of 6.2–7.2 items/g w.w. Concerning human exposure by diet, both raw and cooked values are important. Some preliminary tests performed in this study evidenced that the cooking process determined lower MPs levels (−14%) in cooked tissues compared to raw ones, MPs were recorded in cooking water and were characterized by a lower size than in raw mussels. Results obtained by this study represent an important baseline on MPs level to evaluate environmental and human exposure risks by diet.
Показать больше [+] Меньше [-]Oil and gas infrastructure decommissioning in marine protected areas: System complexity, analysis and challenges Полный текст
2018
Burdon, D. | Barnard, S. | Boyes, S.J. | Elliott, M.
Many offshore oil and gas production facilities are nearing the end of their operational life, with decommissioning now becoming a global challenge. The compatibility of decommissioning operations to marine protected areas (MPAs) creates further challenges. The recently-developed DAPSI(W)R(M) problem structuring framework (covering Drivers, Activities, Pressures, State changes, Impacts (on Welfare) and Responses (as Measures)) was applied here to interrogate the complexity of decommissioning oil and gas infrastructure within MPAs, with outputs feeding into the development of a novel database tool for Screening Potential Impacts of Decommissioning Activities (SPIDA). In meeting the current requirements of the marine regulatory regime, SPIDA provides a more streamlined, evidence-based process which can be applied by industry, statutory nature conservation bodies and regulators for identifying and evaluating evidence that supports the implications of decommissioning alternatives on the condition of MPAs. SPIDA has been developed to be adapted for other activities and sectors, including offshore renewables.
Показать больше [+] Меньше [-]Mercury contents in relation to biometrics and proximal composition and nutritional levels of fish eaten from the Western Mediterranean Sea (Almería bay) Полный текст
2018
Sánchez-Muros, M.J. | Morote, E. | Gil, C. | Ramos-Miras, J.J. | Torrijos, M. | Rodríguez Martin, J.A.
Mercury contents in relation to biometrics and proximal composition and nutritional levels of fish eaten from the Western Mediterranean Sea (Almería bay) Полный текст
2018
Sánchez-Muros, M.J. | Morote, E. | Gil, C. | Ramos-Miras, J.J. | Torrijos, M. | Rodríguez Martin, J.A.
Total liver and muscle mercury, and muscular composition, biometrics and trophic levels, were determined in four species (Mullus surmuletus, Merluccius merluccius, Auxis rochei and Scomber japonicus) of the Mediterranean Sea (Almería Bay, Spain). Mercury levels did not exceed the maximum residue limit, and M. merluccius obtained the highest level in muscle. Considerable variations in Hg content among individuals were observed in non-gregarious species. A positive correlation between Hg and trophic level or length was found in muscle, but not in liver. Organs (liver or muscle) with major Hg accumulation depend on species; muscle in M. merluccius and liver in S. japonicus. The results indicate that Hg levels in fish depend on intra- and interspecies factors that should be taken into account in systems to monitor Hg levels.
Показать больше [+] Меньше [-]Mercury contents in relation to biometrics and proximal composition and nutritional levels of fish eaten from the Western Mediterranean Sea (Almería bay) Полный текст
2018
Sánchez-Muros, María José | Morote, E. | Gil, Carlos | Ramos-Miras, José Joaquín | Torrijos Garrido, Manuel | Rodríguez Martín, José Antonio | Gil, Carlos [0000-0002-9903-1303] | Ramos-Miras, José Joaquín [0000-0001-6194-7191]
otal liver and muscle mercury, and muscular composition, biometrics and trophic levels, were determined in four species (Mullus surmuletus, Merluccius merluccius, Auxis rochei and Scomber japonicus) of the Mediterranean Sea (Almería Bay, Spain). Mercury levels did not exceed the maximum residue limit, and M. merluccius obtained the highest level in muscle. Considerable variations in Hg content among individuals were observed in non-gregarious species. A positive correlation between Hg and trophic level or length was found in muscle, but not in liver. Organs (liver or muscle) with major Hg accumulation depend on species; muscle in M. merluccius and liver in S. japonicus. The results indicate that Hg levels in fish depend on intra- and interspecies factors that should be taken into account in systems to monitor Hg levels.
Показать больше [+] Меньше [-]Marine litter at the seafloor – Abundance and composition in the North Sea and the Baltic Sea Полный текст
2018
Kammann, Ulrike | Aust, Marc-Oliver | Bahl, Horst | Lang, Thomas
Marine litter at the seafloor – Abundance and composition in the North Sea and the Baltic Sea Полный текст
2018
Kammann, Ulrike | Aust, Marc-Oliver | Bahl, Horst | Lang, Thomas
Litter is present in all marine waters around the globe. It consists of several compound classes of which plastic is of special interest because of its high abundance and possible threat to marine organisms. The regional distribution, composition and abundance of large litter items (LI) at the sea floor of the North Sea and the Baltic Sea were investigated based on 175 bottom trawls between 2013 and 2015. Different types of marine litter >2.5cm were classified according to the protocol of the ICES International Bottom Trawl Survey. The results showed considerable geographical variation: In the North Sea, a mean litter abundance of 16.8LI/km² was found, whereas the litter abundance in the Baltic Sea was significantly lower (5.07LI/km²). In general, plastic represented 80% of the litter items. During the study, some methodical aspects with possible impact on the results were identified that need to be addressed in future sampling campaigns.
Показать больше [+] Меньше [-]Marine litter at the seafloor - abundance and composition in the North Sea and the Baltic Sea Полный текст
2018
Kammann, Ulrike | Aust, Marc-Oliver | Bahl, Horst | Lang, Thomas
Litter is present in all marine waters around the globe. It consists of several compound classes of which plastic is of special interest because of its high abundance and possible threat to marine organisms. The regional distribution, composition and abundance of large litter items (LI) at the sea floor of the North Sea and the Baltic Sea were investigated based on 175 bottom trawls between 2013 and 2015. Different types of marine litter> 2.5 cm were classified according to the protocol of the ICES International Bottom Trawl Survey. The results showed considerable geographical variation: In the North Sea, a mean litter abundance of 16.8 LI/km2 was found, whereas the litter abundance in the Baltic Sea was significantly lower (5.07 LI/km2). In general, plastic represented 80% of the litter items. During the study, some methodical aspects with possible impact on the results were identified that need to be addressed in future sampling campaigns.
Показать больше [+] Меньше [-]Potential microbial consortium involved in the biodegradation of diesel, hexadecane and phenanthrene in mangrove sediment explored by metagenomics analysis Полный текст
2018
Tiralerdpanich, Parichaya | Sonthiphand, Prinpida | Luepromchai, Ekawan | Pinyakong, Onruthai | Pokethitiyook, Prayad
Hydrocarbon contamination is a serious problem that degrades the quality of mangrove ecosystems, and bioremediation using autochthonous bacteria is a promising technology to recover an impacted environment. This research investigates the biodegradation rates of diesel, hexadecane and phenanthrene, by conducting a microcosm study and survey of the autochthonous microbial community in contaminated mangrove sediment, using an Illumina MiSeq platform. The biodegradation rates of diesel, hexadecane and phenanthrene were 82, 86 and 8 mg kg⁻¹ sediment day⁻¹, respectively. The removal efficiencies of hexadecane and phenanthrene were >99%, whereas the removal efficiency of diesel was 88%. A 16S rRNA gene amplicon sequence analysis revealed that the major bacterial assemblages detected were Gammaproteobacteria, Deltaproteobacteria, Alphaproteobacteria. The bacterial compositions were relatively constant, while reductions of the supplemented hydrocarbons were observed. The results imply that the autochthonous microorganisms in the mangrove sediment were responsible for the degradation of the respective hydrocarbons. Diesel-, hexadecane- and phenanthrene-degrading bacteria, namely Bacillus sp., Pseudomonas sp., Acinetobacter sp. and Staphylococcus sp., were also isolated from the mangrove sediment. The mangrove sediment provides a potential resource of effective hydrocarbon-degrading bacteria that can be used as an inoculum or further developed as a ready-to-use microbial consortium for the purpose of bioremediation.
Показать больше [+] Меньше [-]Development of a novel methodology for in vivo quantification of N/O/S-containing polycyclic aromatic hydrocarbons located on the epidermis of mangrove roots using graphene quantum dots as a fluorescence quencher Полный текст
2018
Li, Ruilong | Wang, Shaopeng | Wang, Yinghui | Yu, Kefu
A novel approach for in vivo determination of typical N/O/S-containing PAHs located on the epidermis of mangrove roots was developed using graphene quantum dots (GQDs) as a fluorescence quencher. The decreasing fluorescence intensity from GQDs was attributed to the amount of N/O/S-containing PAHs introduced onto the epidermis of mangrove roots. The linear ranges of the proposed method were 10.3–980ngg⁻¹, 9.5–1350ngg⁻¹ and 7.8–1200ngg⁻¹ for DBF, DBT and CAR located on the epidermis of K. obovata roots, respectively. This method was also shown to be valid for quantifying the N/O/S-containing PAHs on the root epidermis in the presence of heavy metal (10mmolL⁻¹) and dissolved organic matter (1mgL⁻¹ C). Moreover, the death rates of epidermal cells were almost unchanged (p>0.05) after acquiring the fluorescence spectra, which is superior to the previously reported LITRF method with which the cell death rates increased to 42.6%.
Показать больше [+] Меньше [-]Present status of 137Cs in seawaters of the Lombok Strait and the Flores Sea at the Indonesia Through Flow (ITF) following the Fukushima accident Полный текст
2018
Suseno, Heny | Wahono, Ikhsan Budi
Due to thermocline and surface water from the western equatorial Pacific Ocean, which are transported to the Indian Ocean, Indonesian marine waters play an important role in the global ocean circulation. The objective of this study was to assess the spatial distribution of ¹³⁷Cs in the Lombok Strait as part of a national monitoring program concerning the possible impacts of radionuclides released as a result of the Fukushima accident. Sampling was conducted in the Flores sea and Lombok Strait on 15 to 24 November 2013. Measurements for the Lombok strait showed that ¹³⁷Cs concentrations at surface layer, thermocline layer and 1000m depth were 0.27Bqm⁻³; 0.42Bqm⁻³ and <MDA (0.01Bqm⁻³), respectively. The water concentration of ¹³⁴Cs at all monitoring stations were under MDA (0.01Bqm⁻³). The results the study indicate that the radiocesium input was from global fallout.
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