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41.
Abstract

The São Paulo Metropolitan area (SPMA) is characterized as having one of the worst air pollution problems in Brazil,with frequent violations of air quality standards for particulate matter. This paper presents the results of a eceptor model source apportionment study carried out to develop a quantitative database on which a control strategy could be developed. The study was conducted in four sites with distinct land uses. Fine, coarse (CP), and total suspended particles (TSP) samples were collected on Teflon and glass filters and analyzed by x-ray fluorescence XRF), ion chromatography, and thermal evolution. The sources were characterized by similar methodology. Chemical mass balance (CMB) receptor modeling indicated that carbonaceous material plays an important role in the aerosol composition; that the three major source categories contributing to the fine particles are vehicles, secondary carbon, and sulfates; and that the main contributors to CP and TSP are road dust and vehicles. All sampling sites presented the same general pattern in terms of source contribution, although this contribution varied from site to site.  相似文献   
42.
In the last decade, the development of novel analytical methodologies enabled the identification of several environmental pollutants responsible for health problems associated with indoor exposure. Polycyclic aromatic hydrocarbons (PAHs) are among the potential hazardous chemicals present in ambient air. Due to their bioaccumulation potential and carcinogenic/mutagenic effects, 16 PAHs are currently listed as priority air pollutants. The main goal of this work was to implement a new and simple method for sampling and determination of PAHs in air by using a thermal desorption (TD) technique followed by gas chromatography coupled with mass spectrometry analysis. A detailed study was carried out to optimise the experimental method in each of its phases, including (active) sampling, TD and chromatographic analysis. The results demonstrate that this approach allowed the detection and quantification of the six more volatile PAHs, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, and anthracene. Acceptable precision and good linearity over the explored range were obtained. No carry-over was observed during experimental tests and the method provided a reproducible answer. The applicability of the novel methodology was tested in real environment, namely, on the roof of a building in an urban area, in a domestic kitchen and in a collective car garage. The method enabled the identification of two PAHs in the field samples, specifically, naphthalene (two rings) and phenanthrene (three rings). With regard to PAHs sample composition, the most abundant PAH found, in the three different locations, was naphthalene, accounting for about 84–100 % of the total PAH mass detected.  相似文献   
43.
Portugal is strongly vulnerable to sea hazards due to intense vessel traffic and sea conditions. The southwest region off the Iberian Peninsula lies in the main route from the Mediterranean and Southern Hemisphere to the Northern Europe, causing a ship concentration in a narrow band off Cape S?o Vicente. Tankers represent a significant part of the vessel traffic and the occurrence of oil spills cannot be disregarded. Cape S?o Vicente region is part of a Natural Park with 110 Km of coastline, integrated in the European Natura 2000 network and its socio-economic context is closely related with sea resources exploitation, particularly fishing and tourism. Recognizing the importance of accurate information systems for the decision making process in an oil spill situation, this work presents the development of an integrated tool to support the process in the Algarve coast. The system relies in a regional operational mathematical model based on the MOHID modelling system. The system core is composed by three models (3D hydrodynamics, wave and Lagrangian transport) all linked in the same system and exchanging information in real time. Oil advection and weathering processes are coupled to the Lagragian transport model. The overall operational system includes external operational data products as inputs, to ensure a successful validation of the results. The system is linked to stakeholders and response authorities using a geographic referenced database based on Mapserver technology that will include relevant information for oil spill management.  相似文献   
44.
Factorial design plan was experimented in Perna perna in order to find out the contribution of day exposure, Cd and Cu concentrations in water, and their interactions on metallothioneins (MT), Cd, and Cu (the dependent measured variables) in the gills. The picture obtained is more adequate than by studying the factor effect separately. Compared with the control group, the MT concentration after 22?days exposure period in the mixture of 100?μg/mL Cu and Cd is increased almost two times, showing that P. perna might be used as a biomonitor. Cd showed stronger effect than Cu on MT inducing.  相似文献   
45.
Journal of Material Cycles and Waste Management - Biofilters have been recognized as a key technology in the mitigation of greenhouse gases (GHG) emitted by landfills. This study aimed to evaluate...  相似文献   
46.
Journal of Polymers and the Environment - Polymers used as raw materials for synthetic packaging, i.e., those obtained from petroleum-derived sources, are resistant to degradation. Because of this,...  相似文献   
47.
Behavioral Ecology and Sociobiology - Social complexity has been one of the recent emerging topics in the study of animal and human societies, but the concept remains both poorly defined and...  相似文献   
48.
This paper is focused on novel utilizations of raw materials and technologies for manufacturing lightweight metallic reservoirs. The objective is to develop an environmental friendly technology for producing gas and liquid storage reservoirs that ensures a more efficient utilization of raw materials and a better end-of-life management of products than other technologies currently used to fabricate metallic reservoirs.The proposed technology utilizes previously engineered single-stage nosing of thin-walled tubes using sacrificial (expendable) mandrels to develop a multi-stage process that makes use of recyclable mandrels for producing lightweight, axisymmetric, seamless reservoirs. Recyclable mandrels are cast from low melting point alloys, possess the ability to continuously adapt its shape to that of the preforms and are easily removed by melting, while leaving the reservoir intact, at the end of the process.The prospects for eliminating the welding routes commonly used in the fabrication of reservoirs and for remelting and recycling the mandrels, results in significant economic and time savings and offers potential for opening new markets for the production of low-cost seamless reservoirs.The presentation is supported by experimentation and numerical modelling based on independently determined mechanical properties of the materials with the purpose of understanding the deformation mechanics and identifying the major operating parameters of the proposed technology.  相似文献   
49.
This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by 137Cs. Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide. LAB concentrations increased towards the surface, indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis. Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels. Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area.  相似文献   
50.
Water quality monitoring in reservoirs used for human water consumption, carried out by the Alentejo Regional Authorities of the Environment (south Portugal), revealed seasonal peaks of phenolic compounds above the water-quality legislation. The main objectives of this work were to identify the main phenolic compounds present in water and soil leachates, and to determine the sources of the seasonal concentrations of phenolic compounds in two catchments with different land use patterns: Roxo and Santa Clara catchments. The main phenolic compound detected was 2,4-dinitrophenol (2,4-DNP), both in stream water and soil leachates, with concentrations higher in Roxo catchment. Roxo catchment represents a larger agricultural area than Santa Clara, and it is likely that the origin of the 2,4-DNP is associated with the use of pesticides. A peak of 2,4-DNP concentrations was observed in stream water of both catchments during February, when farmers plough their fields and apply pesticides. The 2,4-DNP peak was probably caused by a precipitation event shortly after the application of pesticides, increasing their transfer from land surfaces to adjacent streams. The leaching behaviour of 2,4-DNP was strongly dependent on the type of soil and pH. In soils with high clay content and low pH, 2,4-DNP was easily adsorbed, and its runoff from the soil to adjacent streams was reduced. Ribeira de Santa Vitória, from Roxo catchment, was the only stream showing a high abundance of vegetation, and the lowest concentrations of 2,4-DNP in water. Plants may play a role in removing contaminants from stream water.  相似文献   
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