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61.
Dynamic model simulations of the future climate and projections of future lifestyles within the Baltic Sea Drainage Basin (BSDB) were considered in this study to estimate potential trends in future nutrient loads to the Baltic Sea. Total nitrogen and total phosphorus loads were estimated using a simple proxy based only on human population (to account for nutrient sources) and stream discharges (to account for nutrient transport). This population-discharge proxy provided a good estimate for nutrient loads across the seven sub-basins of the BSDB considered. All climate scenarios considered here produced increased nutrient loads to the Baltic Sea over the next 100 years. There was variation between the climate scenarios such that sub-basin and regional differences were seen in future nutrient runoff depending on the climate model and scenario considered. Regardless, the results of this study indicate that changes in lifestyle brought about through shifts in consumption and population potentially overshadow the climate effects on future nutrient runoff for the entire BSDB. Regionally, however, lifestyle changes appear relatively more important in the southern regions of the BSDB while climatic changes appear more important in the northern regions with regards to future increases in nutrient loads. From a whole-ecosystem management perspective of the BSDB, this implies that implementation of improved and targeted management practices can still bring about improved conditions in the Baltic Sea in the face of a warmer and wetter future climate.  相似文献   
62.
Zibret G 《Ambio》2012,41(3):292-301
This article presents the impact of the ecological investment in ironworks (dust filter installation) and construction works at a highly contaminated brownfield site on the chemical composition of household dust (HD) and street sediment (SS) in Celje, Slovenia. The evaluation is based on two sampling campaigns: the first was undertaken 1 month before the ecological investment became operational and the second 3 years later. The results show that dust filter installations reduced the content of Co, Cr, Fe, Mn, Mo, W and Zn on average by 58% in HD and by 51% in SS. No reduction was observed at sampling points in the upwind direction from the ironworks. By contrast, the impact of the construction works on the highly contaminated brownfield site was detected by a significant increase (on average by 37%) of elements connected to the brownfield contamination in SS. Such increase was not detected in HD.  相似文献   
63.
Usman M  Faure P  Ruby C  Hanna K 《Chemosphere》2012,87(3):234-240
In this study, feasibility of magnetite-activated persulfate oxidation (AP) was evaluated for the degradation of polycyclic aromatic hydrocarbons (PAHs) in batch slurry system. Persulfate oxidation activated with soluble Fe(II) (FP) or without activation (SP) was also tested. Kinetic oxidation of PAHs was tracked in spiked sand and in aged PAH contaminated soils at circumneutral pH. Quartz sand was spiked with: (i) single model pollutant (fluorenone) and (ii) organic extract isolated from two PAH contaminated soils (H and NM sampled from ancient coking plants) and was subjected to oxidation. Oxidation was also performed on real H and NM soils with and without an extraction pretreatment. Results indicate that oxidation of fluorenone resulted in its complete degradation by AP while abatement was very low (<20%) by SP or FP. In soil extracts spiked on sand, significant degradation of 16 PAHs was observed by AP (70-80%) in 1 week as compared to only 15% by SP or FP systems. But no PAH abatement was observed in real soils whatever the treatment used (AP, FP or SP). Then soils were subjected to an extraction pretreatment but without isolation of organic extract from soil. Oxidation of this pretreated soil showed significant abatement of PAHs by AP. On the other hand, very low degradation was achieved by FP or SP. Selective degradation of PAHs was observed by AP with lower degradation efficiency towards high molecular weight PAHs. Analyses revealed that no by-products were formed during oxidation. The results of this study demonstrate that magnetite can activate persulfate at circumneutral pH for an effective degradation of PAHs in soils. However, availability of PAHs and soil matrix were found to be the most critical factors for degradation efficiency.  相似文献   
64.

Background, aim, and scope  

In literature, the environmental applications of green rust (GR) have mainly been pointed out through the reduction of inorganic contaminants and the reductive dechlorination of chlorinated organics. However, reactions involving GR for the oxidation and mineralization of organic pollutants remain very scantly described. In this study, the ability of three synthetic Fe(II)–Fe(III) green rusts, GR(CO32−), GR(SO42−), and GR(Cl), to promote Fenton-like reaction was examined by employing phenol as a model pollutant. Unlike the traditional Fenton’s reagent (dissolved Fe(II) + H2O2), where the pH values have to be lowered to less than 4, the proposed reaction can effectively oxidize the organic molecules at neutral pH and could avoid the initial acidification which may be costly and destructive for the in situ remediation of contaminated groundwater and soils. The green rust reactivity towards the oxidative transformation of phenol was thoroughly evaluated by performing a large kinetic study, chemical analyses, and spectroscopic investigations.  相似文献   
65.
We developed for the first time a catchment model simulating simultaneously the nutrient land-sea fluxes from all 105 major watersheds within the Baltic Sea drainage area. A consistent modeling approach to all these major watersheds, i.e., a consistent handling of water fluxes (hydrological simulations) and loading functions (emission data), will facilitate a comparison of riverine nutrient transport between Baltic Sea subbasins that differ substantially. Hot spots of riverine emissions, such as from the rivers Vistula, Oder, and Daugava or from the Danish coast, can be easily demonstrated and the comparison between these hot spots, and the relatively unperturbed rivers in the northern catchments show decisionmakers where remedial actions are most effective to improve the environmental state of the Baltic Sea, and, secondly, what percentage reduction of riverine nutrient loads is possible. The relative difference between measured and simulated fluxes during the validation period was generally small. The cumulative deviation (i.e., relative bias) [Sigma(Simulated - Measured)/Sigma Measured x 100 (%)] from monitored water and nutrient fluxes amounted to +8.2% for runoff, to -2.4% for dissolved inorganic nitrogen, to +5.1% for total nitrogen, to +13% for dissolved inorganic phosphorus and to +19% for total phosphorus. Moreover, the model suggests that point sources for total phosphorus compiled by existing pollution load compilations are underestimated because of inconsistencies in calculating effluent loads from municipalities.  相似文献   
66.
67.
Intracerebral tumours of the fetus are very rare conditions, most often presenting clinically as polyhydramnios and hydrocephalus. These conditions can be diagnosed with ultrasound and clearly differentiated from hydrocephalus and other intracranial lesions. The following report is of a case of an intracerebral tumour (glioblastoma multiforme) diagnosed at 33 weeks in utero using ultrasound. The prognosis for this condition is universally poor.  相似文献   
68.
Bias toward legally protecting and prioritizing charismatic taxonomic groups, such as mammals and birds, and against others, such as insects and plants, is well documented. However, the relative costs of conserving various taxonomic groups and the potential of these costs to interact with existing biases have been much less explored. We analyzed conservation programs across more than 2,000 species in 3 countries to investigate the costs of conserving species within taxonomic groups and how these costs might affect conservation planning. For each data set, we tested for differences in mean annual cost among taxonomic groups. For the data set from the United States, recovery plans differed in duration, so we also tested for differences in total costs among taxonomic groups. Although the costs for individual species varied widely, there were strong international consistencies. For example, mammals cost 8–26 times more on average to conserve than plants and 13–19 times more to conserve than aquatic invertebrates. On average, bird species cost 5–30 times more to conserve than plants and 6–14 times more to conserve than aquatic invertebrates. These cost differences could exacerbate unequal resource allocation among taxonomic groups such that more charismatic groups both receive more attention and require more resources, leading to neglect of other taxonomic groups.  相似文献   
69.
Environmental Science and Pollution Research - Naturally occurring layered double hydroxide mineral, brucite (BRU), was compared with hydromagnesite (HYD) and a commercial Mg-rich mineral adsorbent...  相似文献   
70.
The rate of oxygen transport from atmospheric air into water and perfluorocarbon compound (PFC) was investigated. Static and dynamic systems with and without the presence of the lung surfactant monolayer were considered. For the case of water used as an oxygen absorbent, the monolayer activity allowed a simulation of the gas uptake into the lung hypophase. In the second case, a two-phase liquid system with water as a hypophase and PFC as the blood substitute simulated oxygen transport in the alveolus-blood system. Original experimental measurement devices gave the opportunity of determining the gas transport rate with the possibilities of indicating the role of the lung surfactant in the process and evaluating the influence of environmental conditions on the transport phenomena. Results of that work suggest a possible enhancing role of the lung surfactant in the oxygen transfer rate.  相似文献   
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