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301.
Contemporary human activities such as tropical deforestation, land clearing for agriculture, pest control and grassland management lead to biomass burning, which in turn leads to land-cover changes. However, biomass burning emissions are not correctly measured and the methods to assess these emissions form a part of current research area. The traditional methods for estimating aerosols and trace gases released into the atmosphere generally use emission factors associated with fuel loading and moisture characteristics and other parameters that are hard to estimate in near real-time applications. In this paper, fire radiative power (FRP) products were extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) and from the Geostationary Operational Environmental Satellites (GOES) fire products and new South America generic biomes FRE-based smoke aerosol emission coefficients were derived and applied in 2002 South America fire season. The inventory estimated by MODIS and GOES FRP measurements were included in Coupled Aerosol-Tracer Transport model coupled to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) and evaluated with ground truth collected in Large Scale Biosphere–Atmosphere Smoke, Aerosols, Clouds, rainfall, and Climate (SMOCC) and Radiation, Cloud, and Climate Interactions (RaCCI). Although the linear regression showed that GOES FRP overestimates MODIS FRP observations, the use of a common external parameter such as MODIS aerosol optical depth product could minimize the difference between sensors. The relationship between the PM2.5μm (Particulate Matter with diameter less than 2.5 μm) and CO (Carbon Monoxide) model shows a good agreement with SMOCC/RaCCI data in the general pattern of temporal evolution. The results showed high correlations, with values between 0.80 and 0.95 (significant at 0.5 level by student t test), for the CATT-BRAMS simulations with PM2.5μm and CO.  相似文献   
302.
This study addresses the means local administrators and legislators in emerging economies dispose of to implement directives passed down to them by international environmental agreements. Specific reference is made to agreements and policies dealing with fresh water supply and waste management. Although the Johannesburg Summit asked that the proportion of people without access to drinking water and basic sanitation be halved by 2015, actions need to be developed on a local scale to reach the target. They need to consider the existence of supply limits for water and the subtle difference between sanitation and waste collection. The concepts of reactive and proactive legislation are confronted. Proactive legislation, already used in the industrialized World, is proposed to introduce new patterns of behavior into emerging economy communities. The proposed legal texts have the capacity to be self-fulfilling in the quest for local compliance with international targets.  相似文献   
303.
To assess environmental risks related to contaminants in soil it is essential to predict the available pool of inorganic contaminants at regional scales, accounting for differences between soils from variable geologic and climatic origins. An approach composed of a well-accepted soil extraction procedure (0.01 M CaCl(2)) and empirical Freundlich-type models in combination with mechanistically based models which to date have been used only in temperate regions was applied to 136 soils from a South European area and evaluated for its possible general use in risk assessment. Empirical models based on reactive element pools and soil properties (pH, organic carbon, clay, total Al, Fe and Mn) provided good estimations of available concentrations for a broad range of contaminants including As, Ba, Cd, Co, Cu, Hg, Mo, Ni, Pb, Sb, Se and Zn (r(2): 0.46-0.89). The variation of the pools of total Al in soils expressed the sorptive capacity of aluminosilicates and Al oxides at the surfaces and edges of clay minerals better than the actual variability of clay contents. The approach has led to recommendations for further research with particular emphasis on the impact of clay on the solubility of As and Sb, on the mechanisms controlling Cr and U availability and on differences in binding properties of soil organic matter from different climatic regions. This study showed that such approach may be included with a good degree of certainty for first step risk assessment procedures to identify potential risk areas for leaching and uptake of inorganic contaminants in different environmental settings.  相似文献   
304.

Background, aim, and scope  

Olive oil mill wastewater (OOMW) environmental impacts minimization have been attempted by developing more effective processes, but no chemical or biological treatments were found to be totally effective to mitigate their impact on receiving systems. This work is the first that reports simultaneously the efficiency of three different approaches: biological treatment by two fungal species (Trametes versicolor or Pleurotus sajor caju), enzymatic treatment by laccase, and chemical treatment by photo-Fenton oxidation on phenols removal.  相似文献   
305.
Monitoring of ambient air PCDD/F levels in Portugal   总被引:3,自引:0,他引:3  
Coutinho M  Pereira M  Borrego C 《Chemosphere》2007,67(9):1715-1721
As part of a monitoring program conducted by IDAD--Institute for Environment and Development and supported by regional municipal solid waste (MSW) management authorities, dioxin concentrations in ambient air were measured in three regions of Portugal: Porto, Lisbon and Madeira. These independent studies were performed with the intention of providing data as a basis for the evaluation of potential impacts of the operation of recently built MSW incinerators. Thus, 170 samples were collected in nine different sites from January 1999 till present. The measured levels revealed an extremely variable content of PCDDs/PCDFs depending both on the area and the season of the year. Samples taken in Porto and Lisbon reveal a similar homologue structure even if concentrations measured in the Porto region are significantly greater. Data from Madeira is characteristic of a remote site with some of the congeners concentrations below the detection limit.  相似文献   
306.
The influence of the colonization of salt marsh sediments with Halimione portulacoides was evaluated by analysing the fluorescent dissolved organic matter (FDOM) in sediment pore waters from a salt marsh at different depths. Cores of sediments at colonized and non-colonized sites were collected from a coastal lagoon (Ria de Aveiro, Portugal). The DOC content of extracted pore waters was determined and characterized by synchronous molecular fluorescence (Deltalambda=60nm) and UV-visible spectroscopies. The common practice of freezing sediment cores for further and later chemical investigation was shown not to be an appropriate methodology of sample preservation. On the contrary, freezing of extracted and filtered pore water seemed not to affect either the DOC content or the fluorescence properties of pore waters. Two types of fluorescent substances were found in the pore waters spectra; one corresponding to humic-like substances and another one resembling proteins. However, major differences were found in the spectra of pore waters depending on both depth and the presence/absence of vegetation colonization.  相似文献   
307.
The exploration and production of oil and gas reserves often result to drill cutting accumulations on the seafloor adjacent to drill locations. In this study, the detection of drilling influence on marine sediments was performed by meta-analytical comparison between data from pre- and post-drilling surveys undertaken in offshore Campos Basin, southeast of Brazil. Besides this overall appraisal on the geochemical variables, a multivariate assessment, considering only the post-drilling data, was performed. Among the variables, fines content, carbonates, total organic carbon, barium, chromium, copper, iron, manganese, nickel, lead, vanadium, zinc, and total petroleum hydrocarbons, only barium, copper, and hydrocarbons were related to drilling impacts. In relation to the point of discharge, relative elevated levels in the post-drilling campaigns were observed preferentially up to 500 m in the northeast and southwest directions, associated to the Brazil Current-predominant direction. Other distributed concentrations in the surroundings seem to indicate the dilution and dispersion of drilling waste promoted by meteoceanographic factors.  相似文献   
308.
Large dam construction in water deficient areas is a management decision often controversial. Besides providing water storage, economical benefits, and a source of renewable energy, the construction and flooding caused by large dams cause disruptions in natural systems. We monitored the pre- and post-Alqueva dam impacts on the threatened carnivore species (polecat, otter, wildcat and Iberian lynx) populations in SE Portugal, and assessed which factors mostly contribute to post-dam distribution. Major short term impacts of large dams are: (1) increase in accessibility and human presence; (2) movement of heavy machinery and dam-workers; (3) deforestation with habitat loss and fragmentation; (4) change from lotic to lentic system; (5) lower prey availability and harsher capture; and (6) changes in land use adjacent to the reservoir. Thus, the response to those impacts can be predicted as a decline of polecat, wildcat and lynx distribution ranges, and a recovery of the otter from the severe short term impacts. Our results corroborate this hypothesis for all the species, especially during deforestation/early flooding. Otter's distribution range increased in the phase of greater impact, with a subsequent decrease with flooding. Our results suggest carnivores used "escape" areas with favourable habitat and prey conditions, however, the areas with higher probability of species presence decreased by two fold showing a drastic range reduction. To ensure populations' survival of these charismatic threatened carnivore populations of Mediterranean landscapes of south-east Portugal, we propose continuing the monitoring program and the development of a conservation program for the subsisting areas of optimal and suboptimal habitats.  相似文献   
309.
A major concern for the cork and wine industry is ‘cork taint’ which is associated with chloroanisoles, the microbial degradation metabolites of chlorophenols. The use of chlorophenolic compounds as pesticides within cork forests was prohibited in 1993 in the European Union (EU) following the introduction of industry guidance. However, cork produced outside the EU is still thought to be affected and simple, robust methods for chlorophenol analysis are required for wider environmental assessment by industry and local environmental regulators. Soil samples were collected from three common-use forests in Tunisia and from one privately owned forest in Sardinia, providing examples of varied management practice and degree of human intervention. These provided challenge samples for the optimisation of a HPLC-UV detection method. It produced recoveries consistently >75 % against a soil CRM (ERM-CC008) for pentachlorophenol. The optimised method, with ultraviolet (diode array) detection is able to separate and quantify 16 different chlorophenols at field concentrations greater than the limits of detection ranging from 6.5 to 191.3 μg/kg (dry weight). Application to a range of field samples demonstrated the absence of widespread contamination in forest soils at sites sampled in Sardinia and Tunisia.  相似文献   
310.
This study describes the first attempt to validate a Portuguese natural soil (PTRS1) to be used as reference soil for ecotoxicological purposes, aimed to both: (i) obtain ecotoxicological data for the derivation of Soil Screening Values (SSVs) with regional relevance, acting as a substrate to be spiked with ranges of concentrations of the chemicals under evaluation and (ii) act as control and as substrate for the dilution of contaminated soils in ecotoxicological assays performed to evaluate the ecotoxicity of contaminated soils, in tier 2 of risk assessment frameworks, applied to contaminated lands. The PTRS1 is a cambisol from a granitic area integrated in the Central Iberian Zone. After chemical characterization of the soil in terms of pseudo-total metals, PAHs, PCBs and pesticide contents, it was possible to perceive that some metals (Ba, Be, Co, Cr and V) surpass the Dutch Target Values (Dtvs) corrected for the percentage of organic matter and clay of the PTRS1. Nevertheless, these metals displayed total concentrations below the background total concentrations described for Portuguese soils in general. The same was observed for aldrin, endosulfan I, endosulfan II, heptachlor epoxide, and heptachlor; however the Dtvs corrected become negligible. The performance of invertebrate and plant species, commonly used in standard ecotoxicological assays, was not compromised by both soil properties and soil metal contents. The results obtained suggest that the PTRS1 can be used as a natural reference soil in ecotoxicological assays carried out under the scope of ecological risk assessment.  相似文献   
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