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Coastal waters environmental monitoring supported by river basin pluviometry and offshore wave data Texto completo
2015
Abramic, Andrej | Martínez-Alzamora, Nieves | González del Rio Rams, Julio | Ferrer Polo, José
Environmental monitoring in the scope of the Water Framework Directive 2000/60/EC (WFD) is usually expensive and requires considerable human effort. In this study, we analyzed data obtained by a WFD coastal waters monitoring network over a three-year period (35 campaigns), with the aim to ascertain is it possible to increase the monitoring efficiency and obtain more accurate results. As the trophic condition of the coastal waters of Valencia is primarily, but not entirely, determined by continental loads and hydrodynamic conditions, additionally we analyzed related river basin pluviometry (daily frequency) and oceanographic (one hour frequency) data. Chlorophyll a, salinity, rain and wave data time series were analyzed separately, to identify any possible pattern. Analyzing coastal water bodies integrating all four parameters, it is found strong interactions between coastal waters trophic conditions, sea hydrodynamics and related basin pluviometry. Eight phytoplankton biomass scenarios associated to environmental conditions are identified and finally developed basis for a new efficient monitoring strategy and more accurate coastal waters assessment.
Mostrar más [+] Menos [-]Evaluation of steelmaking slag as basal media for coastal primary producers Texto completo
2015
Akiyama, Yoshihiro B. | Yano, Hitomi | Koba, Kyohei | Katayama, Takahiro | Asaoka, Satoshi | Okuda, Tetsuji | Nakai, Satoshi | Yamamoto, Tamiji | Nishijima, Wataru
The use of granular steelmaking slag as a substitute for natural sand in the construction of tidal flats was investigated. Using an intertidal flat simulator, we evaluated dephosphorization slag mixed with 8% by dry weight of dredged sediment (DPS+DS) as a basal medium for the growth of benthic macro- and microalgae in comparison with silica sand mixed with 8% dredged sediment (SS+DS). Species compositions of macro- and microalgae were distinctly different between DPS+DS and SS+DS. The mean dry weight of macroalgae on DPS+DS was three orders of magnitude higher than that on SS+DS. Sediment shear strength and pH were higher in DPS+DS than in SS+DS or in the sediment of natural tidal flats. These results suggest that DPS contributes to changing the sediment environment, thereby changing the algal composition compared to the composition on natural tidal flats.
Mostrar más [+] Menos [-]Mapping the Global Dust Storm Records: Review of Dust Data Sources in Supporting Modeling/Climate Study Texto completo
2015
Wang, Julian X. L.
Dust storms, as extreme environmental events, are one of the Earth’s major natural hazards. Their impact on socio-economics can range from local urban to (trans-) continental and from minutes to decades, such as the dust bowl of the 1930s in the United States. Research on dust storms can be traced back for several decades as a meteorological extension. Latest technology developments have enabled comprehensive studies on dust storms, including sampling improvement, analytic studies, and numerical modeling. However, inhomogeneity of the data has hampered and sometimes even misguided research on comprehensive understanding of dust storms and exploring their feedbacks with climate. This review will focus on currently available observations of dust activities, which include routine meteorological records, in situ air chemistry observations, and satellite remote sensing. The aim is to show data sources and the status of their usage in a common framework for global dust regions. Emphasis is placed on data continuity and the spatial and temporal coverage of dust storms, since it is anticipated that this brief summary of dust data will benefit modeling and climate studies. Therefore, it must be noted that field campaign data are outside of the scope of the current review, although they play an important role in research and understanding.
Mostrar más [+] Menos [-]Remediation of DDT and Its Metabolites in Contaminated Sediment Texto completo
2015
Chattopadhyay, Sandip | Chattopadhyay, Devamita
Chlorinated pesticides and chlorinated organics can be transformed or partially degraded in sediments under appropriate environmental conditions. Although 1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane (DDT) is very persistent in the environment, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), a degradation product of DDT, is generally the constituent most widely detected in the environment and DDE is also resistant to further biotransformation. DDT and its degradation products (DDTR) may be transported from one medium to another by sorption, bioaccumulation, dissolution, or volatilization. In sediments, DDT strongly adheres to suspended particles, but once metabolized, DDE, the primary product, is slightly soluble in water. The major migration process for DDTR in sediment-water systems is sorption to sediment or other organic matter and the primary distribution route is the transportation of the particulates to which the compound is bound. Understanding the fate and transport of DDTR in the natural environment based on its specific characteristics is important in determining appropriate remediation option. Common DDT-contaminated sediment remediation options include dredging, capping, and natural attenuation. Sediment washing and phytoremediation have also been used in contaminated sites. Dredging is the most common sediment remediation option to remove the contaminated benthic sediments but often suffers from technical limitations like incomplete removal, unfavorable site conditions, sediment resuspension, and disposal issues. Capping is an in situ, low-cost remediation option for immobilization of DDT in several contaminated sediment sites. Natural or anthropogenic materials containing reactive ingredients, as distinct from a conventional sand or gravel cap, involve placing reactive materials as part of the cap matrix to increase sorption, and to enhance chemical reactivity with DDTR, or accelerate degradation. Natural attenuation can treat the DDT-contaminated sediment, but the time frame for complete remediation may be relatively long. Addition of suitable co-metabolites and acclimatized microorganisms to DDTR-contaminated sediment and alteration of sediment-water micro-environment by manipulating soil pH, moisture content, and other chemical conditions may result in degradation of DDTR associated with sediments at rates faster than the natural attenuation rate.
Mostrar más [+] Menos [-]Applying sediment quality guidelines on soft sediments of the Gulf of Finland, Baltic Sea Texto completo
2015
Vallius, Henry
The Gulf of Finland is known to have been rather largely contaminated by heavy metals during the last half of the 20th century, but indications of recovery have been reported. In order to investigate the recent levels of heavy metals and arsenic in the uppermost soft sediments of the off-shore Gulf of Finland coring of altogether 23 sites were performed. The subsamples of the cores are 605 in total and thus give a good picture of heavy metal levels in the surface sediments during the first decade of this century. In order to evaluate methods and predict sediment toxicity the sediment concentrations are compared to American SQG:s. Majority of the subsamples exceeded the threshold levels of both used SQG:s, but some exceeded also the midrange effects quality guidelines. As, Cd, Hg, and Zn concentrations still occur at unacceptably high levels in sediments of the off-shore Gulf of Finland.
Mostrar más [+] Menos [-]Development of current and future pollutant emissions for Portugal Texto completo
2015
Sa, Elisa | Ferreira, Joana | Carvalho, Anabela | Borrego, C.
Air pollutant emissions are a fundamental input for accurate air quality simulations. Therefore, a detailed estimation of current emissions should be performed, mainly for the activity sectors that have higher contributions to emission totals. In order to estimate air quality under climate change at regional scale, it is extremely important to provide the most accurate emission inventories based on the emission scenarios used as input for the global climate models. The Representative Concentration Pathways (RCPs) are the most recent developed emission scenarios. Emission inventories used in air quality simulations at regional scale for future periods should be based on these recent developments. In this sense, an Emission Projections under RCP scenarios (EmiPro–RCP) model was developed to assist the estimation of future emission inventories for GHG and common air pollutants. This paper describes the methodology developed under EmiPro–RCP model and presents the estimation of current and projected emissions for Portugal for CO, PM2.5, PM10, SOx, NOx, NMVOC and NH3, which will be used as input in air quality modeling systems. A comparison between the inventories was performed and the results indicated that all the RCPs scenarios predict a decrease in most of the air pollutant emissions until 2100, with the exception of NH3 that increases. The main decreases are found in the coastal zone of Portugal, mainly in Porto and Lisbon urban areas, while the NH3 increases are located not only in the coastal zone but also in the southern inland of Portugal.
Mostrar más [+] Menos [-]PAHs in the Ría de Arousa (NW Spain): A consideration of PAHs sources and abundance Texto completo
2015
Pérez-Fernández, Begoña | Viñas, Lucía | Franco, M Ángeles | Bargiela, Jesica
Analysis of 35 parental and alkylated homologues of PAHs (Polycyclic Aromatic Hydrocarbons) was carried out in eleven marine sediment samples collected along a central transect in the biggest Galician ría. The samples were collected using a box-core dredge and, after freeze-drying, were kept frozen until analysis. The sediments were extracted by PLE (Pressurized Liquid Extraction) procedure and the quantification of PAHs was performed using gas chromatography coupled to mass spectrometry (GC–MS) with the aid of deuterated PAH internal standards. The total concentration of studied PAHs (Σ35PAHs) ranged from 44.8 to 7901ngg−1 dry weight (d.w.). The highest PAH concentrations were found in sediments collected near the harbour (7901ngg−1) and the cleanest positions were located in the outer zone of the ría.To date, these results are the first data presented in the area so they could be used for regular monitoring and control of future pollution episodes.
Mostrar más [+] Menos [-]Preliminary assessment of contaminants in the sediment and organisms of the Swartkops Estuary, South Africa Texto completo
2015
Nel, L. | Strydom, N.A. | Bouwman, H.
Urban estuaries are susceptible to metal and organic pollution, yet most remain understudied in South Africa with respect to the presence, concentrations and distribution of contaminants. Metal and organic chemical concentrations were assessed in sediment and organisms from different trophic levels in the lower reaches of the Swartkops Estuary. Species sampled included Upogebia africana (Malacostraca: Upogebiidae), Gilchristella aestuaria (Clupeidae), Psammogobius knysnaensis (Gobiidae), Mugil cephalus (Mugilidae), Lichia amia (Carangidae), Argyrosomus japonicus (Sciaenidae), Pomadasys commersonnii (Haemulidae) and Larus dominicanus (Avis: Laridae). This study is one of the most comprehensive studies to date assessing pollution levels in a food web in estuaries in South Africa. Due to biomagnification, higher concentrations of Arsenic, Lead, Mercury and Cadmium were found in the juveniles stages of popular angling fishes. High concentrations of Cadmium and Arsenic were recorded in the liver of L. amia, A. japonicus and P. commersonnii which exceed international quality food guidelines. Eggs from the gull, L. dominicanus, showed detectable concentrations of PCBs.
Mostrar más [+] Menos [-]Current air quality plans in Europe designed to support air quality management policies Texto completo
2015
Miranda, Ana | Silveira, Carlos | Ferreira, Joana | Monteiro, Alexandra | Lopes, Diogo | Relvas, Helder | Borrego, C. | Roebeling, Peter
The intensification of the human activity in urban areas as a result of the increasing population has contributed to the air pollution worsening in cities. To reverse this trend, the European Commission established a legal framework to improve the air quality. Thereby the Member States need to develop air quality plans (AQP) for zones and agglomerations where air quality limit values are exceeded, in order to implement pollution control strategies and meet the legal requirements. Understanding the reasons for the levels of air quality non–compliance as well as evaluating available and commonly used tools to predict the air quality and their effects, is crucial for the decision–making process on air quality management policies. Based on a compilation of regional and local AQP, a review of assessment capabilities and used modeling tools to evaluate the effects of emission abatement measures on the air quality and health was performed. In most cases, models are applied to estimate emissions and to assess the resulting air quality from both reference and emission abatement scenarios. Air quality’s impacts on the health and environment are rarely quantified. Regarding the air quality assessment, beyond the modeling, monitored data for validation of simulations are also used. Some studies, however, do not include the use of air quality models, considering the monitoring network as spatially representative of the study domain (e.g. Lisbon Region, Riga, Malta). In order to overcome methodological limitations for quantifying the impacts of emission abatement measures, economic evaluation techniques or even Integrated Assessment Methodologies (IAM) have been developed. IAM, already applied in some AQP or case studies, namely for Antwerp and London, are used for assessing how reductions in emissions contribute to improve air quality, reduce exposure and protect human health.
Mostrar más [+] Menos [-]Long-term functional changes in an estuarine fish assemblage Texto completo
2015
Baptista, J. | Martinho, F. | Nyitrai, D. | Pardal, M.A. | Dolbeth, M.
The functional diversity of the fish assemblages of the Mondego estuary was studied for a discontinuous 30-year period (1988–2012). During this time, hydrological changes occurred due to man-induced alterations and weather extremes. These changes led to alterations in the structure and function of the fish community. Species richness and functional richness decreased over time and the fish community started to explore new micro-habitats and food resources. Before severe hydrological changes, the community was dominated by pelagic, detritivorous and species with wider salinity ranges. After, the community became dominated by demersal, benthic, piscivorous and marine species. During a drought, omnivorous became increasingly important, reflecting greater possibilities of using available feeding resources. We have also found an increase in sub-tropical species throughout the years, which might be related to gradual temperature increases at a global scale. This study also confirmed estuaries as extremely important for restocking several commercial species.
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