Fant 9855 publikasjoner. Viser side 278 av 395:
2018
CO2-rensing Klemetsrud. Beregning av nitros- og nitraminer.
Beregning av spredning og dannelse av nitros- og nitramin er gjennomført for et potensielt aminbasert CO2-fangst-anlegg på Klemetsrud. Det er utført beregninger for tre ulike aminer. Beregningene viser makismal utslippskonsentrasjon for de ulike aminene for å sikre overholdelse av anbefalte grenseverdier for nitros- og nitraminer i luft og vann. Høyeste utslippskonsentrasjon som ikke gir overskridelser av grenseverdiene, er mellom 1,1 ppmV og 11 ppmV avhengig av hvilket amin som benyttes.
NILU
2018
2018
Environmental pollutants in the terrestrial and urban environment 2017
Abiotic and biotic samples from the terrestrial and urban environment were analysed for inorganic and various organic contaminants in the Oslo area. The species analysed were earthworms, fieldfare, sparrowhawk, brown rat, tawny owl, red fox and badger. Air and soil samples were also included in the study to increase the understanding on sources and uptake of pollutants. A foodchain approach was used, in order to detect trophic magnification of the different compounds.
NILU
2018
The 1783–1784 Laki eruption provides a natural experiment to evaluate the performance of chemistry-transport models in predicting the health impact of air particulate pollution. There are few existing daily meteorological observations during the second part of the 18th century. Hence, creating reasonable climatological conditions for such events constitutes a major challenge. We reconstructed meteorological fields for the period 1783–1784 based on a technique of analogues described in the Methods. Using these fields and including detailed chemistry we describe the concentrations of sulphur (SO2/SO4) that prevail over the North Atlantic, the adjoining seas and Western Europe during these 2 years. To evaluate the model, we analyse these results through the prism of two datasets contemporary to the Laki period: • The date of the first appearance of ‘dry fogs’ over Europe, • The excess mortality recorded in French parishes over the period June–September 1783. The sequence of appearances of the dry fogs is reproduced with a very-high degree of agreement to the first dataset. High concentrations of SO2/SO4 are simulated in June 1783 that coincide with a rapid rise of the number of deceased in French parishes records. We show that only a small part of the deceased of the summer of 1783 can be explained by the present-day relationships between PM2.5 and relative risk. The implication of this result is that other external factors such as the particularly warm summer of 1783, and the lack of health care at the time, must have contributed to the sharp increase in mortality over France recorded from June to September 1783.
2018
Science Press
2018
2018
2018
2018
2018
2018
This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(0)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast subjected to seasonal anoxia. The first scenario represents the conditions in the lagoon that are compared with experimental data. The four other scenarios were produced by varying the biological productivity, using low and high nutrient (N and P) concentrations, and by varying the redox conditions using different intensity of vertical mixing in the water column. The results of the simulation show that both oxidized and reduced sediments can accumulate Hg, but any shifts in redox conditions in bottom water and upper sediment layer lead to the release of Hg species into the water column. Eutrophication and/or restricted vertical mixing lead to reducing conditions and intensify MeHg formation in the sediment with periodic release to the water column. Oxygenation of an anoxic water body can lead to the appearance of Hg species in the water column and uptake by organisms, whereby Hg may enter into the food web. The comparison of studied scenarios shows that a well-oxygenated eutrophic system favors the conditions for Hg species bioaccumulation with a potential adverse effect on the ecosystem. The research is relevant to the UN Minimata convention, EU policies on water, environmental quality standards and Mercury in particular.
Frontiers Media S.A.
2018
2018