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101.
The objective of this study is to discuss the role of networks formed of waste-picker cooperatives in ameliorating problems of final disposal of solid waste in the city of Rio de Janeiro, since the city’s main landfill will soon have to close because of exhausted capacity. However, it is estimated that in the city of Rio de Janeiro there are around five thousand waste-pickers working in poor conditions, with lack of physical infrastructure and training, but contributing significantly by diverting solid waste from landfills. According to the Sustainable Development Indicators (IBGE, 2010a, IBGE, 2010b) in Brazil, recycling rates hover between 45% and 55%. In the municipality of Rio de Janeiro, only 1% of the waste produced is collected selectively by the government (COMLURB, 2010), demonstrating that recycling is mainly performed by waste-pickers. Furthermore, since the recycling market is an oligopsony that requires economies of scale to negotiate directly with industries, the idea of working in networks of cooperatives meets the demands for joint marketing of recyclable materials. Thus, this work presents a method for creating and structuring a network of recycling cooperatives, with prior training for working in networks, so that the expected synergies and joint efforts can lead to concrete results. We intend to demonstrate that it is first essential to strengthen the waste-pickers’ cooperatives in terms of infrastructure, governance and training so that solid waste management can be environmentally, socially and economically sustainable in the city of Rio de Janeiro.  相似文献   
102.
A method to measure the emissive concentration of 5-ethylidene-2-norbornene (ENB), a reactive compound used in industrial synthesis of terpolymers, has been developed. The starting points for the development of the presented method are European and Italian reference methods for the quantification of nonreactive volatile organic compounds in industrial emission. In this study, sampling conditions and desorption solvent have been optimized in laboratory and the method was applied in an industrial plant. The laboratory tests showed a good recovery (88–95 %). The concentrations of ENB in industrial emission obtained with the developed method were compared with an online gas chromatography–flame ionization results (R 2?>?0.97). In addition, several manual measurements were performed in parallel, and the resulting %RSD repeatability was <9 %. The developed method provides a discontinuous technique to measure reactive volatile organic compounds using easy-to-use instruments and assures a very good accuracy and precision even with high-humidity gas flows. The method could be extended to other reactive compounds of the same class.  相似文献   
103.
Atmospheric particulate matter is altering climate. For instance marine biogenic particles are cooling climate. Organic markers are major tools to elucidate the sources of atmospheric particulate matter. Formate is commonly used as a marker of continental aerosols, whereas methanesulphonate is used as tracer of biogenic marine aerosols. However, transformation processes during aerosol transport may modify their relative concentrations and, in turn, introduce a bias in the assessment of particle sources. Actually very little is known about the transformation of formate and methanesulphonate in aerosols. Therefore, we irradiated formate and methanesulphonate in the presence of nitrate and haematite. Nitrate and haematite are aerosol photosensitisers, producing reactive species that degrade organic compounds. The time evolution of formate and methanesulphonate was monitored by ion chromatography. Our results show that formate is transformed from 1.6 to 4.1 times faster than methanesulphonate. This trend is partly due to higher reactivity with the hydroxyl radical and partly due to additional reaction with other transients such as nitrogen dioxide. Such results strongly suggest faster formate transformation during particle transport. Therefore, when formate and methanesulphonate are used as particle tracers, an overestimation of marine biogenic versus continental particle sources is expected. This bias has major implications for climate prediction models, because marine biogenic particles have a cooling effect on climate.  相似文献   
104.
This work investigates the ignition of tetrafluoroethylene induced by the adiabatic compression that can arise by activating a high speed valve separating two portions of a pipeline with a high pressure difference. In the tests performed the high pressure zone contained tetrafluoroethylene at pressures between 15 and 30 bar. For the low pressure zone, experiments with nitrogen, air and tetrafluoroethylene were carried out. The pressure range in the low pressure zone was comprised between 0.05 and 1 bar. The pipe diameters analyzed were 15 and 20 mm. For the analyzed geometries, special conditions were required in order to reach reproducible ignitions, namely air at temperatures of at least 105 °C had to be present in the compression pipe. Furthermore, a minimum length of the compression pipe had to be used. The current work describes the experimental setup employed for the tests and discusses the achieved results. Numerical simulations were performed in order to clarify unexpected findings.  相似文献   
105.
Environmental Science and Pollution Research - In this study we propose, a multi-step strategy of selection and characterization of long-term dataset of contaminant concentrations in different...  相似文献   
106.
107.
The present study reports the results of an investigation on occurrence of octylphenols (OPs), nonylphenols (NPs) and their respective ethoxylates (with 1-6 ethoxylic group) in aquatic species of commercial interest from the Tyrrhenian Sea. Samples were collected at Livorno, Fiumicino and Salerno commercial harbors, during September-October 2003. The data obtained showed that almost all of the tested compounds were found in all the samples. NP was generally detected at the highest concentrations. Among the tested species common to the three sampling sites, mullets and seabreams generally showed high values of total alkylphenols (APs) and alkylphenol ethoxylates (APEOs) (44-55 ng g(-1) and 27-525 ng g(-1) fw), yet, the maximum concentrations were found in shrimps from Fiumicino (1255 ng g(-1) fw). On the contrary, the lowest concentrations were observed in hakes and anchovies (34-36 ng g(-1) and 6-37 ng g(-1) fw). Tuna, exhibited very high concentrations of total alkylphenolic compounds (APEs) (889 ng g(-1) fw). Seafood from Fiumicino fishing area, which is under the influence of the River Tiber, showed a degree of contamination of at least one order of magnitude higher than the other two sites. On the basis of the results of this study, the corresponding daily intakes of NPs are much lower than the TDI proposed by the Danish Environmental Agency.  相似文献   
108.
109.
Concentrations of PAHs and PCDD/Fs were measured throughout one year, and PCBs during the second semester, at a rural site in a natural park representative of background pollution in central Italy; results were compared with simultaneous measurements performed at an urban site in Rome 60km away. Twenty-four daily samples were collected at each site by a high-volume PM(10) sampler from February 2000 to January 2001. After ultrasonic extraction and clean-up by TLC, samples were analysed by GC-MS. Mean concentrations of benzo[a]pyrene (BaP, as a marker of carcinogenic PAHs), summation operatorPCDD/Fs and summation operator64 PCBs in Rome were, respectively: 1.1ngm(-3), 65fgWHO-TEQm(-3), 553pgm(-3). The background concentrations were, respectively: 0.016ngm(-3), 3fgWHO-TEQm(-3), and 94pgm(-3). Hence, BaP, and the other PAHs, showed the highest urban-background gradient (two orders of magnitude) and PCBs the lowest. The background pollution levels of BaP and PCDD/Fs were in agreement with the few available background/remote measurements in Europe. In Rome PAHs and PCBs, but not PCDD/Fs, were clearly seasonal; the PCDD/F TEQ was moderately correlated with BaP (P<0.001). At the background site, the seasonality of PAHs was less marked, while it could not be assessed for PCDD/Fs and PCBs. The PCB TEQ accounted for 4% and 15% of total (PCDD/Fs+PCBs) TEQ at the urban and background site, respectively. Mean PM(10) concentration was 54microgm(-3) in Rome and 15microgm(-3) at the background site.  相似文献   
110.
The development of biomonitoring programs based on the macroinvertebrate community requires the understanding of species distribution patterns, as well as of the responses of the community to anthropogenic stressors. In this study, 49 metrics were tested as potential means of assessing the condition of 29 first- and second-order streams located in areas of differing types of land use in São Paulo State, Brazil. Of the sampled streams, 15 were in well-preserved regions in the Atlantic Forest, 5 were among sugarcane cultivations, 5 were in areas of pasture, and 4 were among eucalyptus plantations. The metrics were assessed against the following criteria: (1) predictable response to the impact of human activity; (2) highest taxonomic resolution, and (3) operational and theoretical simplicity. We found that 18 metrics were correlated with the environmental and spatial predictors used, and seven of these satisfied the selection criteria and are thus candidates for inclusion in a multimetric system to assess low-order streams in São Paulo State. These metrics are family richness; Ephemeroptera, Plecoptera and Trichoptera (EPT) richness; proportion of Megaloptera and Hirudinea; proportion of EPT; Shannon diversity index for genus; and adapted Biological Monitoring Work Party biotic index.  相似文献   
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