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331.
Environmental Science and Pollution Research - The side effects from the use of plant protection products and their potential effects on non-target arthropods (NTAs) such as honey bees, other...  相似文献   
332.
A model was developed to simulate the sewage sludge gasification in an atmospheric fluidised bed gasifier using Aspen Plus. The model here presented was based on the Gibbs free energy minimisation and the restricted equilibrium method was used to calibrate it against previously published experimental data obtained in a lab-scale gasification plant. A sensitivity analysis of the model was carried out by modifying parameters such as the temperature, equivalence ratio (ER) and the steam-to-biomass ratio. The modeled results were in good agreement with the experimental data (especially when air was used as gasifying agent) and reproduced satisfactorily the experimental trends found for the gas composition, the carbon conversion (Xc) and the cold gas efficiency (CGE) under different gasification conditions. Operating at higher temperatures increased the production of H2 and CO, as well as the Xc and the CGE. The increase in ER produced higher Xc, yet the CGE experienced slight changes due to a decrease in the lower heating value of the resulting syngas, as well as the oxidation of combustible gases. The use of air+steam as gasifying agent increased the H2 content of the produced gases but decreased the accuracy of the model.

Implications: Gasification is an available alternative to produce energy as well as several raw materials from sewage sludge. The syngas obtained from this technology totally depends on the type of gasifier and the operation conditions, which can be optimized with the help of models. In this work, a relatively simple model was built using ASPEN PLUS. Despite its simplicity, the outputs of the model are in good agreement with experimental results what makes its use interesting for assessing scaling-up possibilities from lab-scale to pilot-scale gasification processes.  相似文献   

333.
Environment Systems and Decisions - Sustainable innovation has gained prominence in recent years, due to the demands imposed by global competition, social pressures and the needs of consumers and...  相似文献   
334.
A monitoring and evaluation program was undertaken, involving six different styles of evaluation to determine whether a low-cost, eight month education campaign that operated within a small commercial district was successful at changing people's behavior and reducing stormwater litter loads. This project also tested newly developed guidelines for monitoring and evaluating all types of non-structural stormwater quality best management practices (BMPs). The project evaluated: the extent and quality of the campaign's implementation; the degree to which it changed the awareness, attitudes, self-reported behavior and actual behavior of merchants and the public; and the nature of changes in stormwater litter loads. Overall, the education campaign produced mixed results, with the net result being modestly positive. Specifically, it was: unsuccessful at significantly influencing the knowledge or attitudes of merchants or the public; modestly successful at influencing the behavior of merchants and the public; and modestly successful at reducing litter loads in stormwater. At a theoretical level, the project highlights how using different 'styles' of BMP evaluation can help to build a more complete picture of a BMP's performance. At a practical level, the project helped to improve the monitoring and evaluation guidelines and produced evidence-based design guidelines for future campaigns that aim to reduce littering in commercial areas.  相似文献   
335.
The urban groundwater of the central Besòs river basin (the La Llagosta aquifer) has become contaminated due to the infiltration of wastewater from septic tanks and sewage networks, and by industrial activities located in urban areas. The groundwater hydrogeochemistry of the La Llagosta aquifer was characterized using isoconcentration maps, hydrogeochemical diagrams (Piper, Schoeller-Berkaloff) and by analyzing hydrogeochemical changes along a flow-path that crosses an urban and peripheral industrial area in the main alluvial aquifer (the La Llagosta unit). The evolution of cations, anions and heavy metals along the flow path and the use of the PHREEQC numerical code indicate a complex set of geochemical processes, which result from the interaction between the sources of pollution, the groundwater flow and the mineral composition of the aquifer materials. The contaminated groundwater below the urban areas shows high contents of NO(3)(-) (90-100 mg/L) and an increase in the concentrations of Ca(2+) and Mg(2+) which coincides with a decrease in pH. The Eh shows greater variation than the pH along the flow line studied, with values ranging between 56 mV in the industrial area and 370 mV in the urban area. The area with the lowest Eh value coincides with the highest concentrations of dissolved Fe (4.7 mg/L) and Mn (0.22 mg/L).  相似文献   
336.
The RAD Laboratory measured annual means of radon activity concentrations in 15 277 first-floor rooms of dwellings and in 325 rooms on upper floors in Hungary (1994-2004). The original purpose of the survey was to find radon-prone area in Hungary. The maximum measured value was 5800 Bq m(-3), while the minimum was 10 Bq m(-3). Due to geological diversity and different structures of buildings, the data set of first-floor rooms did not follow the lognormal distribution. Therefore, strata were chosen so that the measured data fitted the lognormal distribution. The numbers of dwellings above a given radon level were determined in each stratum. The national distribution was then taken as the sum of the individual distributions of all strata. This distribution was not lognormal. The parameters of the best fitting lognormal distribution were GM = 58 Bq m(-3), GSD = 2.2. The weighted averages of strata values GM = 62 Bq m(-3), GSD=2.1 were obtained corresponding to 92% of Hungarian dwellings.  相似文献   
337.
Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former.  相似文献   
338.
Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl-14C] paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 microg paraquat g(-1) substrate. The action of the worms did not influence the loss of 14C from the substrates, as the 14C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.  相似文献   
339.
Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow‐nesting seabirds, and to a lesser extent adults, are attracted to and then grounded (i.e., forced to land) by lights when they fly at night. We reviewed the current state of knowledge of seabird attraction to light to identify information gaps and propose measures to address the problem. Although species in families such as Alcidae and Anatidae can be grounded by artificial light, the most affected seabirds are petrels and shearwaters (Procellariiformes). At least 56 species of Procellariiformes, more than one‐third of them (24) threatened, are subject to grounding by lights. Seabirds grounded by lights have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and employed mitigation to reduce the rate of light‐induced mortality and save thousands of birds every year. These programs also provide useful information for seabird management. However, these data are typically fragmentary, biased, and uncertain and can lead to inaccurate impact estimates and poor understanding of the phenomenon of seabird attraction to lights. We believe the most urgently needed actions to mitigate and understand light‐induced mortality of seabirds are estimation of mortality and effects on populations; determination of threshold light levels and safe distances from light sources; documentation of the fate of rescued birds; improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and research on seabird‐friendly lights to reduce attraction.  相似文献   
340.
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