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81.
At the onset of the 2010 statutory deadline for the respect of the European National Emission Ceiling directive, two questions arise. Will the engaged regulations for the respect of ozone air quality thresholds be fully efficient on the most polluted regions? How can we design the continuation of ozone control in those areas? This study is based on refined 3D modelling studies over a French Mediterranean region. It compares 2001 and 2003 situations with several prospective 2010 emission scenarios with, for the first time, the evaluation of local action plans. The degree of compliance with air quality regulation is investigated and the impact of emission control on the local potential for ozone formation is discussed. The results show that current efforts on emissions, although substantial and efficient, are not sufficient yet to abrogate all the ozone threshold exceedances. They also highlight the gap between regulatory and effective emission control, as well as the need for regional regulations to complete national efforts. Finally, the simulations indicate that large-scale emission control significantly helps reducing rural ozone (?20 ppbv) but affects much fewer (?2 to ?10 ppbv) the highest peaks. The continuation and the strengthening of ozone policies under their current form in such regions are considered.  相似文献   
82.
INTRODUCTION: Flowing of the acid mine drainage may contaminate the adjacent water bodies causing substantial changes in the aquatic ecosystem. This aspect is the most relevant problem in the southern of Santa Catarina once the contaminated areas are inserted in the watershed of the Araranguá, Urussanga, and Tubar?o rivers, increasing the need for recovery studies. These areas are between Criciúma, I?ara, Urussanga, Siderópolis, Lauro Müller, Orleans, and Alfredo Wagner towns where a conservation unit exist called the Environmental Preservation Area of Baleia Franca. Aiming to compare the kinetics of the ash derived from burning coal and to neutralize acid mine drainage, different neutralizer, limestone, fly, and bottom ash, was mounted on a pilot scale experiment. DISCUSSION: The transport parameters showed the same order of infiltration and dispersion: fly ash < bottom ash < limestone. The order of measured alkalinity was: limestone < fly ash < bottom ash, with pH values of 9.34, 12.07, and 12.25, respectively. The limestone kinetics of acidic drainage neutralization was first order with reaction rate constant k?=?0.0963 min(-1), bottom ash was 3/4 with k?=?0.0723 mol(1/4) L(-1/4) min(-1), and the fly ash had higher order kinetics, 4/3, with reaction rate constant k?=?27.122 L(1/3) mol(-1/3) min(-1). However, by mathematical modeling, it was found that due to a combination of transport and kinetics, only limestone treatment reached a pH above 6 within 5 years, corresponding to the ideal as planned.  相似文献   
83.
An important alternative for sustainable use of tucunaré stocks and improvement in fishermen welfare in Balbina reservoir, Central Amazon, would be to train commercial fisherman to also become tourist guides for sport fishing. In this study, we modeled fishermen response to this question, in order to evaluate the acceptance of such an idea. Thus, we surveyed 47 fishermen, who currently comprise approximately 75% of the total fishermen population. This survey was implemented during December of 2001 and January of 2002. We used a probity analysis to run two models. The first model includes the variables: family size, school level, fishing time, residence time and boat ownership. On the other hand, the second model includes the number of children under and above eight years old but not the family size. Both models are significant and the most relevant variables are: fishing time (years of participation of fisherman is in the activity) and residence time (length of residency of particular fishermen live at the village nearby the reservoir).  相似文献   
84.
Climate change poses an existential threat to Small Island Developing States (SIDS). They have played a leading role in raising awareness of climate change on the international stage and advocating for strong climate action, notably through the Alliance of Small Island States (AOSIS). Despite their heterogeneity, they succeeded in building a common diplomatic discourse and influencing strategy, and mobilized political leaders as well as talented negotiators and advisors.Small Island States were a crucial group in the negotiating period up to, during the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21), and for the entry into force of the Paris Agreement. SIDS succeeded to secure their special circumstances as vulnerable countries, demonstrated leadership in raising ambition to reduce greenhouse gas emissions to help secure an ambitious long-term temperature goal of limiting global warming to below 1.5 °C, and advanced the complex debate on loss and damage.Small Island States face major challenges to advance their leadership on climate change moving forward: securing immediate actions for those particularly vulnerable countries and increasing their influence within and outside the climate change negotiations. For Small Island states, the 1.5 °C goal should be considered “the visible part of the iceberg” for their diplomacy in a post-Paris context.  相似文献   
85.
Cattle activity greatly influences plant species composition and biomass production of grassland ecosystems. Dung deposition by cattle together with grazing and trampling can be considered as one of the important factors driving vegetation dynamics in pastures. The objective of this study was to investigate at 10-cm and 1-month resolution the plant community dynamics induced by dung deposition in two plant communities (a mesotrophic and an oligotrophic grassland) in a pasture of the Swiss Jura Mountains. Vegetation was sampled four or three times during the vegetation period in contiguous 10 cm × 10 cm quadrats from the centre of the dung pat to a distance of 60 cm. A lower grazing intensity near the dung pat was recorded for all observation periods. In the mesotrophic grassland the canopy was higher near the dung pat already one week after dung deposition. Vegetation around dung pats was submitted to two opposite fertilizing and grazing gradients, which induced changes in vegetation texture and structure at fine scale and short term. We observed a positive rank correlation between species turnover and distance to the dung for both communities, suggesting a seasonal stabilizing effect of dung on the plant composition of their direct surroundings (0–10 cm) likely due to cattle avoidance. Since dung pats are dropped every year in different locations, they create in the pasture a shifting mosaic of nutrient availability and grazing intensity inducing at seasonal scale micro-successions in plant communities.  相似文献   
86.
87.
An ensemble-trajectory analysis technique known as Quantitative Transport Bias Analysis was applied to determine which geographic areas systematically contributed to above- and below-average fine particle mass (PM2.5) over eastern North America. Six-hour average measurements from 12 rural or suburban locations in eastern North America collected using a tapered element oscillating microbalance were individually associated with corresponding 3-day back-trajectories for the warm seasons (May-September) of 2000 and 2001. Much of the populated areas of northeastern North America were implicated in the build-up of PM2.5 to above-average concentrations. The finer structure of the Quantitative Transport Bias Analysis pattern indicated that transport from the Ohio River Valley, particularly the eastern portion of this area, was most often associated with the highest PM2.5 concentrations. In addition, air masses originating over a relatively large area from southeast Ohio to the western part of Virginia and the western Kentucky to central Tennessee area tended to result in relatively high PM2.5 concentrations over northeastern North America. These observation-based findings were consistent with the spatial distribution of the main sulfur dioxide emissions sources and the major oxides of nitrogen point sources.  相似文献   
88.
Environmental Science and Pollution Research - This work aims to integrate several hydrogen peroxide (H2O2) activation mechanisms, photolysis (UVC irradiation), chemical electron transfer (TiO2-P25...  相似文献   
89.
The objective of this research is to characterize the variability of trace metals in the Rio Santa watershed based on synoptic sampling applied at a large scale. To that end, we propose a combination of methods based on the collection of water, suspended sediments, and riverbed sediments at different points of the watershed within a very limited period. Forty points within the Rio Santa watershed were sampled between June 21 and July 8, 2013. Forty water samples, 36 suspended sediments, and 34 riverbed sediments were analyzed for seven trace metals. The results, which were normalized using the USEPA guideline for water and sediments, show that the Rio Santa water exhibits Mn concentrations higher than the guideline at more than 50% of the sampling points. As is the second highest contaminating element in the water, with approximately 10% of the samples containing concentrations above the guideline. Sediments collected in the Rio Santa riverbed were heavily contaminated by at least four of the tested elements at nearly 85% of the sample points, with As presenting the highest normalized concentration, at more than ten times the guideline. As, Cd, Fe, Pb, and Zn present similar concentration trends in the sediment all along the Rio Santa.The findings indicate that care should be taken in using the Rio Santa water and sediments for purposes that could affect the health of humans or the ecosystem. The situation is worse in some tributaries in the southern part of the watershed that host both active and abandoned mines and ore-processing plants.  相似文献   
90.
The present study investigates the application of a noncommercial peroxidase enzyme, which was extracted from rice bran, to decolorize wastewater that was simulating effluent from a textile manufacturer using a red dye in its coloration process.  相似文献   
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