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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
Tatiana Simonetto Colla Robson Andreazza Francielle Bücker Marcela Moreira de Souza Letícia Tramontini Gerônimo Rodrigues Prado Ana Paula Guedes Frazzon Flávio Anastácio de Oliveira Camargo Fátima Menezes Bento 《Environmental science and pollution research international》2014,21(4):2592-2602
This study investigated the effectiveness of successive bioaugmentation, conventional bioaugmentation, and biostimulation of biodegradation of B10 in soil. In addition, the structure of the soil microbial community was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis. The consortium was inoculated on the initial and the 11th day of incubation for successive bioaugmentation and only on the initial day for bioaugmentation and conventional bioaugmentation. The experiment was conducted for 32 days. The microbial consortium was identified based on sequencing of 16S rRNA gene and consisted as Pseudomonas aeruginosa, Achromobacter xylosoxidans, and Ochrobactrum intermedium. Nutrient introduction (biostimulation) promoted a positive effect on microbial populations. The results indicate that the edaphic community structure and dynamics were different according to the treatments employed. CO2 evolution demonstrated no significant difference in soil microbial activity between biostimulation and bioaugmentation treatments. The total petroleum hydrocarbon (TPH) analysis indicated a biodegradation level of 35.7 and 32.2 % for the biostimulation and successive bioaugmentation treatments, respectively. Successive bioaugmentation displayed positive effects on biodegradation, with a substantial reduction in TPH levels. 相似文献
942.
There is much discussion within the sustainable development community regarding climate stabilization and particularly, finding
environmentally equitable ways to address emission reductions. Knowing the current level of emission is only one variable
in this complex picture. While the rate of emissions is clearly a problem, the overall increase in GHG concentration in the
atmosphere is ultimately the main driver of anthropogenic warming. Therefore, it is also important to understand the cumulative
emissions, those which have taken us to the current condition. This research presents a case study of six countries to compare
the emissions per capita and cumulative emissions during the past 200 years. It is known that carbon emissions are closely
related to economic activities, but here we show that some countries have reached per capita emissions plateaus at different
levels while others are still rising. Specifically, one approach toward socioeconomic development, in terms of energy–economy,
reaches a plateau at 10 Mt carbon per person, which the United Kingdom and South Korea have attained. The US occupies another
emission regime at 20 Mt carbon per person. Developing economies such as India and China are considerably below these levels,
and unless they follow other integrated economic/environmental solutions, they will continue to increase their per capita
emissions during development. 相似文献
943.
Keigo Akimoto Fuminori Sano Takashi Homma Kenichi Wada Miyuki Nagashima Junichiro Oda 《Sustainability Science》2012,7(2):157-168
This study focuses on analyses of greenhouse gas (GHG) emission reductions, from the perspective of interrelationships among
time points and countries, in order to seek effective reductions. We assessed GHG emission reduction potentials and costs
in 2020 and 2030 by country and sector, using a GHG emission reduction-assessment model of high resolution regarding region
and technology, and of high consistency with intertemporal, interregional, and intersectoral relationships. Global GHG emission
reduction potentials relative to baseline emissions in 2020 are 8.4, 14.7, and 18.9 GtCO2eq. at costs below 20, 50, and 100 $/tCO2eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater
than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the
current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and
26.6 GtCO2eq. at costs below 20, 50, and 100 $/tCO2eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater
than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the
current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and
26.6 GtCO2eq. at costs below 20, 50, and 100 /tCO2eq., corresponding to +33, +8, and −3 %, respectively, relative to 2005. Global emission reduction potentials at a cost below
50 $/tCO2eq. for nuclear power and carbon capture and storage are 2.3 and 2.2 GtCO2eq., respectively, relative to baseline emissions in 2030. Longer-term perspectives on GHG emission reductions toward 2030
will yield more cost-effective reduction scenarios for 2020 as well. 相似文献
944.
Pinus roxburghii (chir-pine) and Quercus leucothchophora (banj-oak) are dominant forests of mountainous part of the Uttarakhand Himalaya. The continued anthropogenic disturbance
is opening the canopy, forming canopy gaps and as a result forest fragments are developing. Thus, the present study aims to
analyze variations in species richness and vegetational parameters in relation to canopy gaps in forests. Total species richness
was greater in open canopied forest compared to moderate and close canopied forests. In comparison between oak and pine forest,
it was greater in oak forest while the proportion of common species was low between oak—pine forests. Mean species richness
did not significantly vary from one canopy gap to another as well as in oak and pine dominated forest. This indicated that
dominant forest types played an important role to form the community structure. The shrubs richness were greater in closed
canopy and between the forests it was greater in pine forest. Tree and shrub density was low in open canopy while herb density
was high in moderate canopy. Thus, this study indicated that the dominant canopy species play an important role in deciding
the community structures especially the distribution of under canopy species. These parameters should be considered for conservation
and maintenance of plant biodiversity of a region. 相似文献
945.
Hans-Jürgen jáger Hartmut Klein 《Journal of the Air & Waste Management Association (1995)》2013,63(5):464-466
Biochemical and physiological experiments were conducted on pea plants (Pisum sativum) continuously exposed in growth chambers to SO2 gas for 18 days. S02 gas concentrations were 0.1, 0.15, and 0.25 ppm. In plants exposed to 0.1 and 0.15 ppm it was clearly demonstrated that there was a greater accumulation of inorganic sulfur, a reduced buffer capacity of the cells relative to H-ions, and a stimulation of glutamate dehydrogenase activity. The only macroscopic symptom seen was slight chlorosis of the older leaves. There was only a slight decrease in fresh and dry weights of these plants compared to the control plants whereas in the group of plants exposed to 0.25 ppm SO2 foliage necrosis was considerable. In addition, there was a marked reduction in the fresh and dry weights of the latter plants. However, the relationship among accumulated inorganic sulfur, reduced buffer capacity, and increased glutamate dehydrogenase activity as seen for the lower S02 concentrations was close. Accordingly, if might be possible to use these three parameters to diagnose S02 injury before any significant symptoms appear. In the case of severe SO2 injury there was a marked increase in glutamine and ammonia concentrations suggesting that these factors in addition to the above could be used in diagnosing severe SO2 injury. There was no significant difference between plants treated with 0.1 or 0.15 ppm SO2 and control plants in the contents of K, Ca, P, and N fractions. Therefore, these factors would not be useful in the early detection of SO2 injury. 相似文献
946.
947.
Höss S Claus E Von der Ohe PC Brinke M Güde H Heininger P Traunspurger W 《Environment international》2011,37(5):940-949
Soft sediments are often highly polluted as many of the toxic chemicals introduced into surface waters bind to settling particles. The resulting accumulation of pollutants in the sediments poses a risk for benthic communities. However, pollution induced changes in benthic communities have been difficult to determine when using macro-invertebrates as bioindicators, as these organisms are often absent in soft sediment. The present study therefore examined the ability of meiofaunal organisms, specifically, nematodes, to assess the ecological status of soft sediments. Over a 9-year period, nematode communities present in sediments collected from large rivers and lake Constance in Germany were studied. These sediments showed a large range of physico-chemical properties and anthropogenic contamination. After the degree of metal and organic contamination was translated into ecotoxicologically more relevant toxic units (TUs), multivariate methods were used to classify nematode taxa in species at risk (NemaSPEAR) or not at risk (NemaSPE(not)AR). This approach clearly distinguished the influence of sediment texture from that of the toxic potential of the samples and thus allowed classification of the nematode species according to their sensitivity to or tolerance of toxic stress. Two indices, expressing the proportion of species at risk within a sample (NemaSPEAR[%](metal), NemaSPEAR[%](organic)), were calculated from independent data sets obtained in field and experimental studies and showed good correlations with the toxic potential (field data) or chemical concentrations (microcosm data). NemaSPEAR[%] indices for metal and organic pollution were therefore judged to be suitable for assessing the impact of chemical contamination of freshwater soft sediments. 相似文献
948.
949.
van Wezel AP Morinière V Emke E ter Laak T Hogenboom AC 《Environment international》2011,37(6):1063-1067
The application of engineered nanomaterials increases strongly. Development of analytical techniques and their application to environmental samples is essential for human and environmental risk assessment of the nanoparticles. The objective of this study was to develop a sensitive analytical method to quantify nC(60) in water, using accurate mass screening liquid chromatography-hybrid linear ion trap Orbitrap mass spectrometry. nC(60) can be transformed by oxidation, reduction and photochemical reaction. Therefore, the formation of some transformation products of nC(60) was studied as well. Finally, the developed analytical method was applied to surface water samples from several locations in the Netherlands. The developed method enabled to detect and quantify aqueous concentrations of the summed nC(60) and its transformation products as low as 5 ng/L. It was observed that nC(60) transformation products exceed quantities of the parent C(60). Despite the high sensitivity of the developed method, no nC(60) or transformation products were detected in an array of Dutch surface waters. This might be due to low emissions, losses in the aqueous phase by sedimentation, sorption or further transformation processes. 相似文献
950.
Silvana Kuhtz 《Environment, Development and Sustainability》2011,13(1):79-85
Climate is one of the more complex physical systems in nature, its behaviour being fundamentally non-linear and chaotic. In
assessing the potential risks from climate change and the costs of averting it, researchers and policymakers encounter pervasive
uncertainty. Sceptics demand to get rid of the inherent uncertainties, and some experts, on the other end, keep sending out
messages of catastrophic scenarios hoping that this will increase people’s awareness of the danger we face. The recent admission
of a mistake in IPCC’s Climate change 2007 report (promptly broadcast by all the major media groups and newspapers from Jan. 20th 2010 onwards) made by the head of
the Intergovernmental Panel on Climate Change—that Himalayan glaciers could melt away by 2035 (the IPCC claim of 2035 is wrong
by over 300 years.)—has already brought a damage to the IPCC’s reputation that is likely to be considerable. But in this paper,
perhaps risking being provocative and paradoxical, instead of looking for the right answers to what we think are inevitable uncertainties, we intend to search for new questions that may lead to a new way of
thinking and may bring about new lifestyles and behaviour for citizens and firms. 相似文献