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Bioaugmentation strategy employing a microbial consortium immobilized in chitosan beads for oil degradation in mesocosm scale Texto completo
2016
Dellagnezze, B.M. | Vasconcellos, S.P. | Angelim, A.L. | Melo, V.M.M. | Santisi, S. | Cappello, S. | Oliveira, V.M.
A bacterial consortium composed by four metagenomic clones and Bacillus subtilis strain CBMAI 707, all derived from petroleum reservoirs, was entrapped in chitosan beads and evaluated regarding hydrocarbon degradation capability. Experiments were carried out in mesocosm scale (3000L) with seawater artificially polluted with crude oil. At different time intervals, mesocosms were sampled and subjected to GC-FID and microbiological analyses, as total and heterotrophic culturable bacterial abundance (DAPI and CFU count), biological oxygen demand (BOD) and taxonomic diversity (massive sequencing of 16S rRNA genes). The results obtained showed that degradation of n-alkane hydrocarbons was similar between both treatments. However, aromatic compound degradation was more efficient in bioaugmentation treatment, with biodegradation percentages reaching up to 99% in 30days. Community dynamics was different between treatments and the consortium used in the bioaugmentation treatment contributed to a significant increase in aromatic hydrocarbon degradation.
Mostrar más [+] Menos [-]Heavy metal accumulation in surface sediments at the port of Cagliari (Sardinia, western Mediterranean): Environmental assessment using sequential extractions and benthic foraminifera Texto completo
2016
Schintu, Marco | Marrucci, Alessandro | Marras, Barbara | Galgani, François | Buosi, Carla | Ibba, Angelo | Cherchi, A. (Antonietta)
Superficial sediments were taken at the port of Cagliari (Sardinia, Italy), which includes the oil terminal of one of the largest oil refineries in the Mediterranean. Significant trace metal concentrations were found in the whole port area. Sequential extraction of metals from the different sediment fractions (BCR method) showed a higher risk of remobilisation for Cd, which is mostly bound to the exchangeable fraction. Foraminiferal density and richness of species were variable across the study area. The living assemblages were characterized by low diversity in samples collected close to the port areas. Ammonia tepida and bolivinids, which were positively correlated with concentrations of heavy metals and organic matter content, appeared to show tolerance to the environmental disturbance. The sampling sites characterized by the highest values of biotic indices were located far from the port areas and present an epiphytic and epifaunal biocoenosis.
Mostrar más [+] Menos [-]Application of novel image base estimation of invisible leaf injuries in relation to morphological and photosynthetic changes of Phaseolus vulgaris L. exposed to tropospheric ozone Texto completo
2016
Drapikowska, M. | Drapikowski, P. | Borowiak, K. | Hayes, F. | Harmens, H. | Dziewiątka, T. | Byczkowska, K.
This study aimed to evaluate the degree of Phaseolus vulgaris L. (bean) leaf tissue injury caused by tropospheric ozone. To validate O3 symptoms at the microscopic level, Evans blue staining together with an image processing method for the removal of distortions and calculation of dead leaf areas was applied. Net photosynthetic rate (PN), stomatal conductance (gs) and intercellular CO2 concentration (Ci) were determined to evaluate leaf physiological responses to ozone. It was found that both resistant and sensitive varieties of bean were damaged by ozone; however, the size of necrotic and partially destroyed leaf area in the sensitive genotype (S156) was bigger (1.18%, 2.18%) than in the resistant genotype (R123), i.e. 0.02% and 0.50%. Values of net photosynthetic rates were lower in the sensitive genotype in ambient air conditions, than in the resistant genotype in ambient air conditions. We further found that there was a correlation between physiological and anatomical injuries; net photosynthetic rate (PN) was negatively correlated with percentage of necrotic area of both genotypes, while stomatal conductance (gs), intercellular CO2 concentration (Ci) were positively correlated with percentage of necrotic tissue of both genotypes. Moreover, visible injures in both genotypes were positively correlated with percentage of anatomical injures. In conclusion, the presented combinations of morphological, anatomical and physiological markers allowed differential diagnosis of ozone injury.
Mostrar más [+] Menos [-]Nutrient distribution and structure affect the acidification of eutrophic ocean margins: A case study in southwestern coast of the Laizhou Bay, China Texto completo
2016
Zhang, Jinfeng | Gao, Xuelu
The effects of nutrient distribution and structure on the acidity of coastal waters were analyzed based on the data of 48 surface water samples collected in the southwestern coast of the Laizhou Bay and its adjacent rivers (SWLZB) which are heavily influenced by nutrient-laden discharges. The concentration and structure of nutrients varied considerably along the coast owing to different contributors. The studied inshore waters exhibited a sign of acidification. The pH was significantly negatively correlated with the concentration of NO3-N, NO2-N, NH4-N and DSi, but showed no obvious correlation with the concentration of PO4-P and the ratio of TDN/TDP, DSi/DIN and DSi/PO4-P, respectively. The results indicated that the distribution of nutrients might well be an important environmental factor affecting the acidification of the SWLZB in warmer months.
Mostrar más [+] Menos [-]Anthropogenic microfibres pollution in marine biota. A new and simple methodology to minimize airborne contamination Texto completo
2016
Torre, Michele | Digka, Nikoletta | Anastasopoulou, Aikaterini | Tsangaris, Catherine | Mytilineou, Chryssi
Research studies on the effects of microlitter on marine biota have become more and more frequent the last few years. However, there is strong evidence that scientific results based on microlitter analyses can be biased by contamination from air transported fibres. This study demonstrates a low cost and easy to apply methodology to minimize the background contamination and thus to increase results validity. The contamination during the gastrointestinal content analysis of 400 fishes was tested for several sample processing steps of high risk airborne contamination (e.g. dissection, stereomicroscopic analysis, and chemical digestion treatment for microlitter extraction). It was demonstrated that, using our methodology based on hermetic enclosure devices, isolating the working areas during the various processing steps, airborne contamination reduced by 95.3%. The simplicity and low cost of this methodology provide the benefit that it could be applied not only to laboratory but also to field or on board work.
Mostrar más [+] Menos [-]Plastic debris in great skua (Stercorarius skua) pellets corresponds to seabird prey species Texto completo
2016
Hammer, S. | Nager, R.G. | Johnson, P.C.D. | Furness, R.W. | Provencher, J.F.
Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua). We examined 1034 regurgitated pellets from a great skua colony in the Faroe Islands for plastics and found approximately 6% contained plastics. Pellets containing remains of Northern fulmars (Fulmarus glacialis) had the highest prevalence of plastic. Our findings support previous work showing that Northern fulmars have higher loads of plastics than other sympatric species. This study demonstrates that marine plastic debris is transferred from surface feeding seabird species to predatory great skuas. Examination of plastic ingestion in species that do not ingest plastics directly can provide insights into how plastic particles transfer vertically within the food web.
Mostrar más [+] Menos [-]Transcriptomic response to water accommodated fraction of crude oil exposure in the gill of Japanese flounder, Paralichthys olivaceus Texto completo
2016
Zhu, Lin | Qu, Keming | Xia, Bin | Sun, Xuemei | Chen, Bijuan
Illumina-based RNA-seq was used to determine the short-term transcriptomic responses of Paralichthys olivaceus gill to an environmentally relevant level of water accommodated fraction (WAF) of crude oil. 213,979 transcripts and 128,482 unigenes were obtained. Differential expression analysis revealed that 1641 and 2142 genes were significantly up- and down-regulated. Enrichment analysis identified a set of GO terms and putative pathways involved in the response of P. olivaceus to WAF exposure. Analysis of the transcripts revealed the effective protective mechanisms of P. olivaceus to reduce the toxic effects of WAF. Moreover, WAF exposure induced the metabolism of energy substrates, and downstream pathway genes were modified to provide protection against toxic damage. Transcripts analysis demonstrated that the genes involved in circadian rhythm signaling were regulated in gills of P. olivaceus exposed to WAF. These results provide insights into the mechanisms of WAF-induced toxicity in fishes and into the WAF-sensitive biomarkers in P. olivaceus.
Mostrar más [+] Menos [-]Urban dew formation efficiency and chemistry in Poland Texto completo
2016
Gałek, G. | Sobik, M. | Błaś, M. | Polkowska, Ż | Cichała-Kamrowska, K.
The measurements of dew formation efficiency and chemistry were performed in Poland in September 2009, as a part of a longer, two-year sampling campaign. Pairs of sites, representing centers of major Polish cities and rural conditions in three different regions, were compared. With the aim to get more detailed landuse-oriented characteristics of dew, two additional sites were set close to Wroclaw. Collection of dew at each site was made by means of flat, insulated, passive radiative condenser, 1 m2 in area. The analysis has included a number of physico-chemical variables, i.e.: dew water volume, pH, conductivity (σ), concentration of some major anions: F−, Cl−, NO2−, NO3−, SO42−, PO43− and cations: Na+, K+, Mg2+, Ca2+, NH4+. The dew formation efficiency at the rural stations is about two times higher than in the nearby city centres and such regularity is complex in its origin. The results show generally low contamination of dew (16.8–132.6 μS cm−1) in comparison to literature examples, but definitely more acidic (pH ∼5.0). The urban dew is characterized about two times higher contamination than nearby rural and independently of the place of collection the dominant ions are NO3−, SO42− and Ca2+, all anthropogenic in origin. The sources of dew pollution have mostly regional character or alternatively urban emissions effectively contaminate dew even several tens of kilometers away. The urban dew pH is higher than rural, but dew is potentially acidic and corrosive at the level of urban canopy.
Mostrar más [+] Menos [-]Indoor air quality investigation of the school environment and estimated health risks: Two-season measurements in primary schools in Kozani, Greece Texto completo
2016
Kalimeri, Krystallia K. | Saraga, Dikaia E. | Lazaridis, Vasileios D. | Legkas, Nikolaos A. | Missia, Dafni A. | Tolis, Evangelos I. | Bartzis, John G.
Two primary schools and one kindergarten were selected in the city of Kozani, Greece in order to investigate the school environment, the indoor air pollutants that children are exposed to and possible health risks at school. In each school three classrooms and one outdoor position were monitored from Monday to Friday, in both non-heating (26/09/2011–14/10/2011) and heating (23/01/2012–10/02/2012) period. Temperature, relative humidity and CO2, were continuously monitored. Formaldehyde, benzene, trichloroethylene, pinene, limonene, NO2 and O3 were measured with diffusive samplers. CO was monitored every day (30 min/day). Radon was measured for four weeks with short term radon detectors. PM2.5 was gravimetrically determined while PM2.5 and PM10 fractions were measured using the optical light scattering technique. Building material emission testing for VOCs was performed using the Field and Laboratory Emission Cell (FLEC). The ventilation rate for each classroom was calculated based on the CO2 measurements.Results indicated that indoor air concentrations of the measured pollutants were within accepted limits with indicative ranges 1.5–9.4 μg/m3 for benzene, 2.3–28.5 μg/m3 for formaldehyde, 4.6–43 μg/m3 for NO2 and 0.1–15.6 μg/m3 for O3. Emissions from building materials seem to have a significant contribution to the indoor air quality. Very low ventilation rates (0.1–3.7 L/s per person) were observed, indicating inadequate ventilation and possible indoor air quality problems requiring intervention measures. The estimated average lifetime cancer risks for benzene, formaldehyde and trichloroethylene were very low.
Mostrar más [+] Menos [-]Pollution characteristics of atmospheric particulate mercury near a coal-fired power plant on the southeast coast of China Texto completo
2016
Gao, Jinyu | Wang, Hao | Cai, Wu | Wu, Jingting | He, Yunfeng
PM2.5 and PM10 samples were collected in a rural area from December 2014 to August 2015 near a coal-fired power plant on the southeast coast of China. The total mercury concentrations in PM2.5 ranged from 116.2 to 1070.9 pg/m3 and in PM10 from 173.4 to 1456.8 pg/m3, with averages of 309.5 ± 94.9 and 387.5 ± 133.5 pg/m3, respectively. These were much higher than those found in many foreign cities. The concentrations of mercury in PM2.5 and PM10 varied seasonally, with the highest average concentration in winter. This was probably due to the seasonal variation of meteorological conditions and concentration of particulates. The highest mass-based concentration of mercury in PM2.5 and PM10 was observed in spring. This result might be related to the prevailing sea winds in spring. The spatial variation of particulate mercury conformed to the concentration distribution characteristics of pollutant discharged from coal-fired power plant elevated source at the downwind area. The seasonal variation in the concentrations of the four mercury species (including exchangeable particulate mercury: EXPM, HCl-soluble particulate mercury: HPM, elemental particulate mercury: EPM, and residual particulate mercury: RPM) were all identical to the seasonal variation of total particulate mercury (TPM) in PM2.5 and PM10 (winter > spring > summer). Owing to the variation of meteorological conditions, the proportion of different mercury species in TPM followed different seasonal trends. In contrast to RPM, the percentage of both HPM and EPM in PM2.5 was higher than in PM10.
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