排序方式: 共有67条查询结果,搜索用时 62 毫秒
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Daniele Fabbri Cristian Torri Bernd R.T. Simoneit Leszek Marynowski Ahmed I. Rushdi Monika J. Fabiańska 《Atmospheric environment (Oxford, England : 1994)》2009,43(14):2286-2295
Levoglucosan (L), mannosan (M), galactosan (G) and other cellulose and lignin markers from burn tests of Miocene lignites of Poland were determined by gas chromatography–mass spectrometry (GC–MS) to assess their distributions and concentrations in the smoke. Their distributions were compared to those in the pyrolysis products of the lignites. Levoglucosan and other anhydrosaccharides are products from the thermal degradation of cellulose and hemicellulose and are commonly used as tracers for wood smoke in the atmosphere. Here we report emission factors of levoglucosan in smoke particulate matter from burning of lignite varying from 713 to 2154 mg kg?1, which are similar to those from burning of extant plant biomass. Solvent extracts of the lignites revealed trace concentrations of native levoglucosan (0.52–3.7 mg kg?1), while pyrolysis yielded much higher levels (1.6–3.5 × 104 mg kg?1), indicating that essentially all levoglucosan in particulate matter of lignite smoke is derived from cellulose degradation. The results demonstrate that burning of lignites is an additional input of levoglucosan to the atmosphere in regions where brown coal is utilized as a domestic fuel. Interestingly, galactosan, another tracer from biomass burning, is not emitted in lignite smoke and mannosan is emitted at relatively low concentrations, ranging from 7.8 to 70.5 mg kg?1. Thus, we propose L/M and L/(M + G) ratios as discriminators between products from combustion of lignites and extant biomass. In addition, other compounds, such as shonanin, belonging to lignans, and some saccharides, e.g., α- and β-glucose and cellobiose, are reported for the first time in extracts of bulk lignites and of smoke particulate matter from burning these lignites. 相似文献
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Marlies J Kampschreur Cristian Picioreanu Nico Tan Robbert Kleerebezem Mike S M Jetten Mark C M van Loosdrecht 《Water environment research》2007,79(13):2499-2509
Nitric oxide production was measured during nitrification in a laboratory-scale bioreactor, operated at conditions relevant to municipal nitrifying wastewater treatment plants. This study aims to determine which type of microorganism and which metabolic pathway is responsible for nitric oxide emission during nitrification. Simulation studies were used to identify which pathway is the main source of nitric oxide emission, based on the following three hypothetical pathways for nitric oxide emission: (a) nitrification, (b) denitrification by ammonia-oxidizing bacteria with ammonium as electron donor, and (c) heterotrophic denitrification. The results of the study suggest that, in a nitrifying reactor treating wastewater containing solely ammonium and nutrients, denitrification by ammonia-oxidizing bacteria is the main nitric-oxide-producing pathway. During the experiments, 0.025% of the treated ammonium is emitted as nitric oxide, independent of the aeration rate imposed. Nitrite presence and oxygen limitation were found to increase the nitric oxide emission. 相似文献
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Beatriz Rivela Ranón Méndez Cristian Bornhardt Gladys Vidal 《Waste management & research》2004,22(3):131-141
A Chilean leather tanning industry (tannery) was studied in terms of input/output (I/O) analysis of beamhouse, tanyard and retanning processes. The physical-chemical characterization of 19 streams were investigated. Streams from the beamhouse process and some streams from the retanning process were found to have high organic contents ranging from 2.5 to 18.1 g COD L(-1). The pH ranged between 3.45 and 12.28. Sulphur was found in most of the streams whereas chromium was detected in two wastewaters from the tanyard and in seven streams from the retanning process. Pollution prevention opportunities were evaluated and an appropriate treatment strategy was proposed. The main emphasis was on determining waste reduction measures that can be easily implemented and are not particularly expensive. Measures for reduction at source were proposed to reduce water and chemicals consumption and wastewater pollution. A so-called S(index) strategy was used to evaluate proposals on segregation and specific treatment of the main chromium- and sulphur-containing wastewaters. It was suggested that some streams may be re-used, but it is necessary to apply anaerobic or aerobic treatment first, depending on their organic load. Solid wastes were also evaluated and a proposal for their reduction and disposal was made. 相似文献
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This study uses an environmental extension of the Leontief price model to analyse various tax rates on the carbon dioxide (CO2) and other greenhouse gases (GHGs) emissions that are generated by the most polluting sectors of the Chilean economy. By using this methodology, it is possible to obtain a counterfactual scenario for the prices, levels of production and emissions of each economic sector, as well as, for tax collection, consumer spending and the consumer price index. This analysis is important because Chile is internationally committed to reducing its emissions by 30% by 2030. According to the results, to meet the target CO2 emissions only using tax policies, tax should be approximately 20 times higher than their current levels in the electricity sector. Alternatively, a lower tax of US $30/ton of CO2 and other GHGs applied to all sectors of the economy could reduce CO2 and other GHGs emissions by up to 25.7% with less of a negative impact on the economy. 相似文献
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Joshua E. Cinner Michele L. Barnes Georgina G. Gurney Stewart Lockie Cristian Rojas 《Conservation biology》2021,35(3):816-823
Markets are increasingly being incorporated into many aspects of daily life and are becoming an important part of the conservation solution space. Although market-based solutions to environmental problems can result in improvements to conservation, a body of social science research highlights how markets may also have unforeseen consequences by crowding out or displacing 3 key types of behaviors potentially relevant to conservation, including people's willingness to engage in collective action and civic duty; tolerance for inflicting harm on others (third-party externalities); and desire for equity. Better understanding of the contexts and mechanisms through which this crowding out occurs and whether specific market-based instruments are more prone to different types of crowding out will be crucial to developing novel conservation initiatives that can reduce or prevent crowding out. 相似文献
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Cristian Parker Mario Letelier Juan Muñoz 《Environment, Development and Sustainability》2013,15(5):1337-1363
Faced with global climate change, local elites are confronted with the main dilemma of a developing country: development requires economic growth, but this effort also requires consideration of environmental factors and sustainable patterns of production and consumption. Based on empirical evidence from qualitative research on businesses and political elites in Chile—a paradigmatic South American middle-income country—this paper explores the extent to which local elites are aware of the severity of challenges posed by global climate change and identify main climate change concerns in their discourse. The degree to which domestic elites are aware of the paradigm shift they must assume toward clean industrial production is a key issue of environmental governance that involves private non-governmental actors. This paper gives clues to a better understanding of what is happening with strategic actors in developing nations and their understanding of their decision-making capacity concerning environmental policy and investments for facing global climate change. The main conclusion of the research is that awareness of climate change in local elites’ discourse is relative. It is not accompanied by a full acceptance of their agency and is not leading to a paradigm shift toward a clean model of development because of domestic elites’ position within globalization processes. 相似文献
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Having an adequate and extensively recognized resource governance system is essential for the conservation and sustainable use of crop genetic resources in a highly populated planet. Despite the widely accepted importance of agrobiodiversity for future plant breeding and thus food security, there is still pervasive disagreement at the individual level on who should own genetic resources. The aim of the article is to provide conceptual clarification on the following concepts and their relation to agrobiodiversity stewardship: open access, commons, private property, state property and common heritage of humankind. After presenting each property regime, we will examine whether and how these incentivize the conservation, improvement and sharing of crop genetic resources, and conclude by defending a mixed property regime. 相似文献