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Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media – A study on zinc, copper and nickel Texto completo
2011
Hedberg, Yolanda | Herting, Gunilla | Odnevall Wallinder, Inger
Membrane filtration is commonly performed for solid–liquid separation of aqueous solutions prior to trace metal analysis and when assessing “dissolved” metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples. Filtration using both non-cleaned and pre-cleaned filters revealed contamination and adsorption effects, in particular pronounced for zinc, evident for copper but non-significant for nickel. The results clearly show these artifacts to be non-systematic both for non-cleaned and pre-cleaned membranes. The applied pressure was of minor importance. Measurements of the labile fraction by means of stripping voltammetry clearly elucidate that membrane filtration followed by total metal analysis cannot accurately assess the labile or the dissolved metal fraction.
Mostrar más [+] Menos [-]Influence of arbuscular mycorrhizal fungi on the growth and nutrient status of bermudagrass grown in alkaline bauxite processing residue Texto completo
2011
Giridhar Babu, A. | Sudhakara Reddy, M.
A nursery experiment was conducted to evaluate the potential role of arbuscular mycorrhizal (AM) fungi in encouraging the vegetation cover on bauxite residue (red mud) sites. An alkali tolerant bermudagrass (Cynodon dactylon) adapted to local conditions were grown in red mud with different amendments with and without AM fungi to assess mycorrhizal effects on plant growth, mineral nutrition, metal uptake and neutralization of bauxite residue. Inoculation of AM fungi significantly increased the plant growth, nutrient uptake and reduced Fe, Al accumulation in plant tissue and also improved the soil physico-chemical and biochemical properties. Gypsum and sludge amended treatments inoculated with AM fungi had maximum biomass, nutrient uptake and reduced accumulation of metals. The neutralization of red mud was significant in presence of AM fungi than control. The experiment provided evidence for the potential use of bermudagrass in combination with AM fungi for ecological restoration of bauxite residue sites.
Mostrar más [+] Menos [-]Nitrogen concentrations in mosses indicate the spatial distribution of atmospheric nitrogen deposition in Europe Texto completo
2011
Harmens, H. | Norris, D.A. | Cooper, D.M. | Mills, G. | Steinnes, E. | Kubin, E. | Thöni, L. | Aboal, J.R. | Alber R., | Carballeira, A. | Coşkun, M. | De Temmerman, L. | Frolova, M. | González-Miqueo, L. | Jeran, Z. | Leblond, S. | Liiv, S. | Maňkovská, B. | Pesch, R. | Poikolainen, J. | Rühling, Å | Santamaria, J.M. | Simonèiè, P. | Schröder, W. | Suchara, I. | Yurukova, L. | Zechmeister, H.G.
In 2005/6, nearly 3000 moss samples from (semi-)natural location across 16 European countries were collected for nitrogen analysis. The lowest total nitrogen concentrations in mosses (<0.8%) were observed in northern Finland and northern UK. The highest concentrations (≥1.6%) were found in parts of Belgium, France, Germany, Slovakia, Slovenia and Bulgaria. The asymptotic relationship between the nitrogen concentrations in mosses and EMEP modelled nitrogen deposition (averaged per 50 km × 50 km grid) across Europe showed less scatter when there were at least five moss sampling sites per grid. Factors potentially contributing to the scatter are discussed. In Switzerland, a strong (r² = 0.91) linear relationship was found between the total nitrogen concentration in mosses and measured site-specific bulk nitrogen deposition rates. The total nitrogen concentrations in mosses complement deposition measurements, helping to identify areas in Europe at risk from high nitrogen deposition at a high spatial resolution.
Mostrar más [+] Menos [-]Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan Texto completo
2011
Hirata, Sawako Horai | Hayase, Daisuke | Eguchi, Akifumi | Itai, Takaaki | Nomiyama, Kei | Isobe, Tomohiko | Agusa, Tetsuro | Ishikawa, Toshiyuki | Kumagai, Michio | Tanabe, Shinsuke
The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza.
Mostrar más [+] Menos [-]Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Texto completo
2011
Ochoa-Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz Mínguez, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M Esther | Sheppard, Lucy J. | Stock, William D.
Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Texto completo
2011
Ochoa-Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz Mínguez, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M Esther | Sheppard, Lucy J. | Stock, William D.
We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling.
Mostrar más [+] Menos [-]Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment Texto completo
2011
Ochoa Hueso, Raúl | Allen, Edith B. | Branquinho, Cristina | Cruz, Cristina | Dias, Teresa | Fenn, Mark E. | Manrique, Esteban | Pérez-Corona, M. Esther | Sheppard, Lucy J. | Stock, William D. | Biología
Revisamos las consecuencias ecológicas de la deposición de N en las cinco regiones mediterráneas del mundo. La estacionalidad de las precipitaciones y los incendios regulan el ciclo del N en estos ecosistemas con escasez de agua, donde domina la deposición seca de N. La acumulación de nitrógeno en los suelos y en las superficies de las plantas produce picos de disponibilidad con las primeras lluvias invernales. El desacoplamiento entre los flujos de N y la demanda de la planta promueve pérdidas por lixiviación y emisiones de gases. Las diferencias en la disponibilidad de P pueden controlar la respuesta a los aportes de N y la susceptibilidad a la invasión de plantas exóticas. Los pastos invasores se acumulan como combustible durante la estación seca, alterando los regímenes de incendios. California y la cuenca mediterránea son las más amenazadas por la deposición de N; sin embargo, existe evidencia limitada de los impactos de la deposición de N fuera de California. En consecuencia, se necesita más investigación para determinar las cargas críticas para cada región y tipo de vegetación en función de los elementos más sensibles, como los cambios en la composición de las especies de líquenes y el ciclo del N.
Mostrar más [+] Menos [-]Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea Texto completo
2011
van Franeker, Jan A. | Blaize, Christine | Danielsen, Johannis | Fairclough, Keith | Gollan, Jane | Guse, Nils | Hansen, Poul Lindhard | Heubeck, Martin | Jensen, Jens-Kjeld | Le Guillou, Gilles | Olsen, Bergur | Olsen, Kåre-Olav | Pedersen, John | Stienen, Eric W.M. | Turner, Daniel M.
The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003–2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive.
Mostrar más [+] Menos [-]Arsenic distribution in soils and plants of an arsenic impacted former mining area Texto completo
2011
Otones, V. | Álvarez-Ayuso, E. | García-Sánchez, A. | Santa Regina, I. | Murciego, A.
A mining area affected by the abandoned exploitation of an arsenical tungsten deposit was studied in order to assess its arsenic pollution level and the feasibility of native plants for being used in phytoremediation approaches. Soil and plant samples were collected at different distances from the polluting sources and analysed for their As content and distribution. Critical soil total concentrations of As were found, with values in the range 70–5330mgkg⁻¹ in the uppermost layer. The plant community develops As tolerance by exclusion strategies. Of the plant species growing in the most polluted site, the shrubs Salix atrocinerea Brot. and Genista scorpius (L.) DC. exhibit the lowest bioaccumulation factor (BF) values for their aerial parts, suggesting their suitability to be used with revegetation purposes. The species Scirpus holoschoenus L. highlights for its important potential to stabilise As at root level, accumulating As contents up to 3164mgkg⁻¹.
Mostrar más [+] Menos [-]The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Texto completo
2011
Stevens, Carly J. | Duprè, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B.
The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Texto completo
2011
Stevens, Carly J. | Duprè, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B.
A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2–44 kg N ha⁻¹ yr⁻¹) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.
Mostrar más [+] Menos [-]The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe Texto completo
2011
Stevens, Carly J. | Dupre, Cecilia | Dorland, Edu | Gaudnik, Cassandre | Gowing, David J.G. | Bleeker, Albert | Diekmann, Martin | Alard, Didier | Bobbink, Roland | Fowler, David | Corcket, Emmanuel | Mountford, J. Owen | Vandvik, Vigdis | Aarrestad, Per Arild | Muller, Serge | Dise, Nancy B. | Open University | Lancaster Environment Centre ; Lancaster University | Universität Bremen [Deutschland] = University of Bremen [Germany] = Université de Brême [Allemagne] | Universiteit Utrecht / Utrecht University [Utrecht] | Biodiversité, Gènes & Communautés (BioGeCo) ; Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB) | Energy Research Centre of the Netherlands (ECN) | Radboud University [Nijmegen] | Natural Environment Research Council (NERC) | Department of Biology ; University of Washington [Seattle] | Norwegian Institute for Nature Research (NINA) | Université Paul Verlaine - Metz (UPVM) | Manchester Metropolitan University (MMU) | European Science Foundation; DfG (Germany); NERC (United Kingdom); NWO (The Netherlands); INRA; ADEME; Aquitaine Region (France)
International audience | A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2–44 kg N ha−1 yr−1) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.
Mostrar más [+] Menos [-]The efficiency of tobacco Bel-W3 and native species for ozone biomonitoring in subtropical climate, as revealed by histo-cytochemical techniques Texto completo
2011
Alves, Edenise S. | Moura, Bárbara B. | Pedroso, Andrea N.V. | Tresmondi, Fernanda | Domingos, Marisa
We aimed to verify whether hydrogen peroxide (H₂O₂) accumulation and cell death are detected early in three bioindicators of ozone (O₃), Nicotiana tabacum ‘Bel-W3’, Ipomoea nil ‘Scarlet O’Hara’ and Psidium guajava ‘Paluma’, and whether environmental factors also affect those microscopic markers. The three species were exposed to chronic levels of O₃ in a subtropical area and a histo-cytochemical technique that combines 3,3′-diaminobenzidine (DAB) with Evans blue staining was used in the assessments. The three species accumulated H₂O₂, but a positive correlation with O₃ concentration was only observed in N. tabacum. A positive correlation between O₃ and cellular death was also observed in N. tabacum. In I. nil and P. guajava, environmental factors were responsible for symptoms at the microscopic level, especially in P. guajava. We conclude that the most appropriate and least appropriate bioindicator plant for O₃ monitoring in the subtropics are N. tabacum ‘Bel-W3’ and P. guajava ‘Paluma’, respectively.
Mostrar más [+] Menos [-]Organophosphorus flame retardants and plasticizers in the atmosphere of the North Sea Texto completo
2011
Möller, Axel | Xie, Zhiyong | Caba, Armando | Sturm, Renate | Ebinghaus, Ralf
Air samples collected in the German part of the North Sea from March to July 2010 were investigated for organophosphorus compounds (OPs) being applied as flame retardants and plasticizers. The ∑₈OPs concentration ranged from 110 to 1400 pg m⁻³ while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m⁻³. The highest concentrations were observed in continental air masses showing the high influence of industrialized regions including production sites on atmospheric emissions and concentrations. The occurrence of OPs even in oceanic/Arctic air masses shows that OPs can undergo long-range atmospheric transport. Dry particle-bound deposition fluxes from 9 to 240 ng m⁻² d⁻¹ for ∑₈OPs were estimated leading to a minimum annual flux of 710 ± 580 kg y⁻¹ OPs into the German North Sea. This study presents the first occurrence of OPs in the marine atmosphere together with important information on their long-range transport potential.
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