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71.
Platinum and Rh content in the atmosphere of Rome as released by car catalytic converters was monitored from 1998 to 2000 in six urban sites with different traffic intensities and in one rural area. Samples collected with medium-volume PM10 samplers were analyzed by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS). The Pt content varied from 2.4 to 60.1 pg m(-3) (mean value 17.8 pg m(-3)) at the urban locations whilst that of Rh spanned the range 0.8-9.4 pg m(-3) (average value 4.0 pg m(-3)). The rural area showed metal levels mostly below the limits of detection, pointing to automobile traffic as the main source of those elements in the urban atmosphere. The highest mean concentrations of Pt and Rh, ie. 22.2 and 5.0 pg m(-3), were detected along the ring road where the traffic density is high (>100,000 vehicles per day) and the driving speed between 100 and 120 km h(-1). The lowest Pt and Rh mean concentrations, i.e. 11.4 and 3.4 pg m(-3), were measured downtown, where traffic density is lower (20,000 vehicles per day) and the driving speed is limited (50 km h(-1)). Significant concentrations of Pt and Rh were found in the vicinity of traffic signals, indicating that the "stop-and-go" conditions might also affect their release. The measured Pt/Rh ratio spanned the range 3.3-5.9 in accordance with that present in the more commonly used gasoline car catalytic converters. Seasonal variations between wintertime (with Pt and Rh mean concentrations of 23.8 and 5.1 pg m(-3), respectively) and summertime (with Pt and Rh mean concentrations of 14.1 and 3.3 pg m(-3), respectively) were also observed.  相似文献   
72.
Development projects in tropical forests can impact biodiversity.Assessment and monitoring programs based on the principles of adaptive management assist managers to identify and reduce suchimpacts. The small mammal community is one important component ofa forest ecosystem that may be impacted by development projects. In 1996, a natural gas exploration project was initiated in a Peruvian rainforest. The Smithsonian Institution's Monitoring andAssessment of Biodiversity program cooperated with Shell Prospecting and Development Peru to establish an adaptive management program to protect the region's biodiversity. In thisarticle, we discuss the role of assessing and monitoring small mammals in relation to the natural gas project. We outline theconceptual issues involved in establishing an assessment andmonitoring program, including setting objectives, evaluating the results and making appropriate decisions. We also summarizethe steps taken to implement the small mammal assessment, provideresults from the assessment and discuss protocols to identifyappropriate species for monitoring.  相似文献   
73.
A natural deactivation of chrysotile asbestos occurs on serpentinite rocks where lichens selectively grow on the fibres and secrete metabolites, including oxalic acid, which, in the long term, turn the fibres into a non-toxic amorphous material.  相似文献   
74.
The hydrothermal carbonization of sewage sludge has been studied as an alternative technique for the conversion of sewage sludge into value-added products, such as soil amendments. We tested the toxicity of biosolid hydrochar (Sewchar) to earthworms. Additionally, the toxicity of Sewchar process water filtrate with and without pH adjustment was assessed, using brine shrimps as a model organism. For a Sewchar application of 40 Mg ha?1, the earthworms significantly preferred the side of the vessel with the reference soil (control) over side of the vessel with the Sewchar treatments. There was no acute toxicity of Sewchar to earthworms within the studied concentration range (up to 80 Mg ha?1). Regarding the Sewchar process water filtrate, the median lethal concentration (LC50) to the shrimps was 8.1% for the treatments in which the pH was not adjusted and 54.8% for the treatments in which the pH was adjusted to 8.5. The lethality to the shrimps significantly increased as the amount of Sewchar process water filtrate increased. In the future, specific toxic substances in Sewchar and its process water filtrate, as well as their interactions with soil properties and their impacts on organisms, should be elucidated. Additionally, it should be identified whether the amount of the toxic compounds satisfies the corresponding legal requirements for the safe application of Sewchar and its process water filtrate.  相似文献   
75.

The aim of this study was to obtain information on the presence and levels of hazardous organic pollutants in groundwater located close to solid waste landfills. Eighty-two environmental contaminants, including 16 polycyclic aromatic hydrocarbons (PAHs), 20 volatile organic compounds (VOCs), 29 polychlorinated biphenyls (PCBs), 7 dioxins (polychlorinated dibenzo-p-dioxins, PCDDs) and 10 furans (polychlorinated dibenzofurans, PCDFs) were monitored in areas characterised by different geological environments surrounding three municipal solid waste landfills (Palermo, Siculiana and Ragusa) in Sicily (Italy) in three sampling campaigns. The total concentrations of the 16 PAHs were always below the legal threshold. Overall, the Fl/Fl + Py diagnostic ratio revealed that PAHs had a petrogenic origin. VOC levels, except for two notable exceptions near Palermo landfill, were always below the legal limit. As concerns PCB levels, several samples were found positive with levels exceeding the legal limits. It is worth noting that the % PCB distribution differs from that of commercial compositions. In parallel, some samples of groundwater containing PCDDs and PCDFs exceeding the legal threshold were also found. Among the 17 congeners monitored, the most abundant were the highest molecular weight ones.

  相似文献   
76.
Environment, Development and Sustainability - The use of fossil fuels in modern economies has been a success because of the low cost of fossil resources. However, the depletion of fossil reserves,...  相似文献   
77.
Six hundred and sixty-seven water samples were collected from public drinking water supplies in Sicily and analysed for electric conductivity and for their Cl(-), Br(-) and F(-) contents. The samples were, as far as possible, collected evenly over the entire territory with an average sampling density of about one sample for every 7,600 inhabitants. The contents of Cl(-) and Br(-), ranging between 5.53 and 1,302 mg/l and between <0.025 and 4.76 mg/l respectively, correlated well with the electric conductivity, a parameter used as a proxy for water salinity. The highest values were found both along the NW and SE coasts, which we attributed to seawater contamination, and in the central part of Sicily, which we attributed to evaporitic rock dissolution. The fluoride concentrations ranged from 0.023 to 3.28 mg/l, while the highest values (only three exceeding the maximum admissible concentration of 1.5 mg/l) generally correlated either with the presence in the area of crystalline (volcanic or metamorphic) or evaporitic rocks or with contamination from hydrothermal activity. Apart from these limited cases of exceeding F(-) levels, the waters of public drinking water supplies in Sicily can be considered safe for human consumption for the analysed parameters. Some limited concern could arise from the intake of bromide-rich waters (about 3% exceeding 1 mg/l) because of the potential formation of dangerous disinfection by-products.  相似文献   
78.
First flush in a combined sewer system   总被引:1,自引:0,他引:1  
Pollutant first flush was examined in an urban catchment with area of 12.7 ha and drained by a combined sewer system located in northern Italy. A total of 23 rainfall-runoff events were monitored and 281 samples were analyzed. The selected quality parameters were biochemical oxygen demand, chemical oxygen demand, suspended solids, settleable solids, total phosphorus, total nitrogen, ammonium nitrogen, lead, and zinc, specific conductivity and hydrocarbons. A subset of representative storms was selected for first flush analysis. The catchment presented a strong first flush for almost all storms and most constituents. The analysis shows that treating the maximum amount of the early part of the runoff is a better strategy than treating a constant flow rate. Best management practices that can treat or store the first runoff are favored in this kind of system for these water quality parameters.  相似文献   
79.
80.
This article analyzes diverse aspects of the waste management of electronic and electric equipment. The scope of the study focuses on end-of-life strategies currently implemented in industrialized economies such as Japan, the United States, and the European Union. The objective is a comparative analysis of such strategies in order to identify logistic issues that may contribute to the further improvement of waste management policies. The results indicate that although all strategies follow the extended producer responsibility principle, in practice several logistic differences arise due to particular interpretations of the concept. In general, it was observed that a direct comparison is rather difficult since the strategies consider different legal frameworks, they cover different types and numbers of products, and the resultant mass flows and related operational costs are highly context-dependent variables. Therefore, it is not possible to indicate which strategy presents the highest overall efficiency. The study concludes that a little contribution is feasible if the advantages and weaknesses of the models depicted and discussed here are considered in further regulatory decisions.Extended version of the poster presentation A comparative analysis of end-of-life strategies for home appliances in Japan, America, and the European Union, accepted at the 31st Annual Meeting of Environmental Systems Research, Japan Society of Civil Engineers (JSCE), October 24–25, 2003, Kitakyushu, Japan  相似文献   
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