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421.
‘Naphthenic acids’ (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted.  相似文献   
422.
In an unequal society, undesirable wastes often end up in the poorest and least powerful communities, becoming part of the economic and environmental milieu of the inner city. Two contradictory responses to waste reflect contrasting theoretical paradigms. Some wastes can become assets in local economic development, creating incomes through scavenging, industrial jobs in recycling plants or new businesses using locally available materials. Other wastes are an assault on the community that receives them; toxic wastes, polluting facilities and industrial by-products often create local health hazards rather than development. Waste as an asset is consistent with the free market model of economics. The inner city, 'endowed' with waste materials and low-wage labour, has a comparative advantage in labour-intensive processing of materials that the rest of society has discarded. Waste as an assault on the community is consistent with a different model of environmental risk. Some by-products of industry are so hazardous that they should not be produced, or should be tightly regulated. Each model has a realm of validity; the balance between the two depends on which wastes are hazardous, and which are just ugly resources waiting to be discovered.  相似文献   
423.
Integrated pest risk maps and their underlying assessments provide broad guidance for establishing surveillance programs for invasive species, but they rarely account for knowledge gaps regarding the pest of interest or how these can be reduced. In this study we demonstrate how the somewhat competing notions of robustness to uncertainty and potential knowledge gains could be used in prioritizing large-scale surveillance activities. We illustrate this approach with the example of an invasive pest recently detected in North America, Sirex noctilio Fabricius. First, we formulate existing knowledge about the pest into a stochastic model and use the model to estimate the expected utility of surveillance efforts across the landscape. The expected utility accounts for the distribution, abundance and susceptibility of the host resource as well as the value of timely S. noctilio detections. Next, we make use of the info-gap decision theory framework to explore two alternative pest surveillance strategies. The first strategy aims for timely, certain detections and attempts to maximize the robustness to uncertainty about S. noctilio behavior; the second strategy aims to maximize the potential knowledge gain about the pest via unanticipated (i.e., opportune) detections. The results include a set of spatial outputs for each strategy that can be used independently to prioritize surveillance efforts. However, we demonstrate an alternative approach in which these outputs are combined via the Pareto ranking technique into a single priority map that outlines the survey regions with the best trade-offs between both surveillance strategies.  相似文献   
424.
For an integrated assessment of the vulnerability of societies to drought it is necessary to set the benchmark at a level where the impacts of droughts lead to a state of affairs that departs from normal conditions, i.e. a crisis event. This article aims to improve the understanding of drought-related crisis events on the basis of a twofold media content analysis. This approach enables us to test when increased vulnerability in fact leads to a crisis situation and offers an improved understanding of the intensity and the extent of crisis events. To this end, we first outline our perspective on crisis and give an overview on existing approaches to identify crisis events. We then outline our two-step approach of media content analysis aimed at developing a crisis data set for the case study regions Andhra Pradesh (India), Southern Portugal and the Volga region (Russia). Using the Factiva news database and information by regional newspapers, a crisis data set is generated enabling us to define the occurrence and extent of drought-related crisis events in the case study regions. Moreover, based on attributes of drought impacts reported by news sources, we categorize the extensiveness of a specific drought. As a key result, our findings suggest that Southern Portugal, the case study region which is expected to be less susceptible to drought events than the other case study regions, faced the most extended crisis events.  相似文献   
425.
Results of a laboratory study indicate that the rate of solution of atmospheric sulfur dioxide in distilled water, over the range of atmospheric concentrations of 0.81?8.73 mg SO2/M3, is a function of the concentration of SO2 in the atmosphere, with saturation being reached more rapidly at the higher concentrations. This would indicate that rain water, with constantly renewed surfaces, can be very effective in the removal of atmospheric SO2. The pH of the exposed water samples reached values of 4.0 or less, comparable to values observed in fog and cloud water near large industrial areas. Overall solubility of sulfur dioxide in distilled water did not follow the law of partial pressure. At the atmospheric concentrations used it was found that over 98.5% of the sulfite in solution was in the form of the bisulfite ion with, the remainder present as unionized sulfurous acid. Computations using the concentration of unionized sulfurous acid in the solution showed that the solubility of this portion of dissolved sulfite did follow the law of partial pressure.  相似文献   
426.
In the early Fifties, sanitary engineering professional development activities were being undertaken principally by the Joint Committee for the Advancement of Sanitary Engineering. This Committee had representation from a number of organizations whose membership included sanitary engineers. Over the years, this group had been giving thought to expanding its activities to include greater recognition for the sanitary engineer. The result was the creation of the American Sanitary Engineering Intersociety Board in 1955, with the societies supporting the Joint Committee becoming the initial sponsoring organizations: American Public Health Association; American Society for Engineering Education; American Society of Civil Engineers; American Water Works Association; Water Pollution Control Federation.  相似文献   
427.
428.

In an unequal society, undesirable wastes often end up in the poorest and least powerful communities, becoming part of the economic and environmental milieu of the inner city. Two contradictory responses to waste reflect contrasting theoretical paradigms. Some wastes can become assets in local economic development, creating incomes through scavenging, industrial jobs in recycling plants or new businesses using locally available materials. Other wastes are an assault on the community that receives them; toxic wastes, polluting facilities and industrial by-products often create local health hazards rather than development. Waste as an asset is consistent with the free market model of economics. The inner city, 'endowed' with waste materials and low-wage labour, has a comparative advantage in labour-intensive processing of materials that the rest of society has discarded. Waste as an assault on the community is consistent with a different model of environmental risk. Some by-products of industry are so hazardous that they should not be produced, or should be tightly regulated. Each model has a realm of validity; the balance between the two depends on which wastes are hazardous, and which are just ugly resources waiting to be discovered.  相似文献   
429.
The thermal destruction of benzene in methane/air flue gas is studied experimentally using an atmospheric laminar flow reactor in laboratory scale. The reactor is operated at four different fuel equivalent ratios (phi = 0.06, 0.1,0.5, 3.7), and temperatures in the range from 850 to 973 K and realises a residence time of 5 s. Stable-species concentrations are measured by gas chromatography (GC) and high-pressure liquid chromatography (HPLC), where phenol, acetylene, formaldehyde, acrolein, methane and acetaldehyde are the major hydrocarbon products besides CO and CO2. The augmentation of the temperature from 850 to 973 K increases the benzene conversion rate from 55% to 99%. The experimental results for one fuel equivalent ratio (phi = 0.5) are compared to the benzene model proposed by Emdee et al. (J. Phys. Chem. 92 (1992) 2151-2161). A fair agreement is observed for the benzene consumption and the CO production throughout the temperature range considered here. The small hydrocarbons are not very well matched, which requires further research on the sub-models. Our experimental results on laboratory scale provide a database for the modelling of benzene oxidation in waste incinerators.  相似文献   
430.
Material balance of fine particulate matter (PM2.5) measured with the Federal Reference Method (FRM) is developed for one rural and five urban locations in the eastern half of the United States using routine Speciation Trends Network (STN) and FRM chemical measurements and thermodynamic models. The Aerosol Inorganics Model is used to estimate retained particle bound water, and an ammonium nitrate evaporation model is used to estimate nitrate concentrations retained on the Teflon-membrane filter of the FRM. To address large uncertainties in carbonaceous mass calculated from STN carbon measurements, retained carbonaceous mass is derived by material balance between PM2.5 FRM mass and estimates of its non-carbon constituents. The resulting sulfate, adjusted nitrate, derived water, inferred carbonaceous material balance approach (SANDWICH) is compared with reconstructed fine mass (RCFM) using the Interagency Monitoring of Protected Visual Environments monitoring program equation. For this study, the SANDWICH method resulted in approximately 21-27% higher sulfate mass and approximately 24-85% lower nitrate mass. The combined mass associated with sulfates and nitrates, however, are well within +/- 10% of the proportion derived using the more traditional RCFM method. The discrepancies between SANDWICH and measurement-derived carbonaceous mass vary from -21% to +56% on an annual basis and are attributed in part to urban-rural source influences and uncertainties in estimating FRM-retained carbonaceous mass.  相似文献   
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