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1.
细菌质粒中常带有一些可编码降解特殊有毒物质酶的基因,为了研究质粒对有毒物质CN^-的降解的意义,主要调查了焦化废水中好氧异养菌的质粒分布特点。从山西省焦化企业公司生化站、太原煤气公司焦化厂生化站中筛选出53株细菌,利用琼脂糖凝胶电泳法,采用GDS-8000型凝胶电泳分析仪进行拍照,同时测定各菌株降氰、降酚能力,CN^-采用异烟酸-毗唑啉酮法,酚采用4-氨基安替比林法测定。结果表明,质粒的存在与降氰力有一定的关系,但对降酚力的影响差异不显著。同时,通过对其中11^*号菌株进行了质粒转化和消除实验,证明质粒稳定,不可用十二烷基磺酸钠(SDS)消除掉,用E.cbli DHI作受体菌,用11^#菌株作供体菌。作转化实验,但由于种种原因,没有筛洗到转化子。 相似文献
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Hajabdollahi Hassan Shafiey Dehaj Mohammad 《Environmental science and pollution research international》2021,28(28):37580-37591
Environmental Science and Pollution Research - In this paper, a concept of balance is used to improve the important parameters of the thermal systems. In fact, using this concept give the designer... 相似文献
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Ekici Selçuk Şöhret Yasin 《Environmental science and pollution research international》2021,28(9):10847-10859
Environmental Science and Pollution Research - In the last decade, aircraft-induced environmental issues have attracted much research interest. In addition to studies on performance related... 相似文献
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The Evolution of the Environmental Quality Concept: From the US EPA Red Book to the European Water Framework Directive 总被引:1,自引:0,他引:1
Vighi M Finizio A Villa S 《Environmental science and pollution research international》2006,13(1):9-14
- DOI: http://dx.doi.org/10.1065/espr2006.01.003
Background Water Quality Criteria were firstly defined in the 1970s by the EPA in the USA and the EIFAC in Europe, recognizing the need
for protecting water quality in order to allow the use of water resources by man. In the 1990s, the European Commission emphasized
the importance of safeguarding structure and function of biologic communities. These approaches were chemically-based. The
European Water Framework Directive (WFD) substantially changes the concept of Water Quality, by assuming that a water body
needs to be protected as an environmental good and not as a resource to be exploited. In this frame, the biological-ecological
quality assumes a prevailing role.
Main Features The Water Quality concept introduced by the WFD is a challenge for environmental sciences. Reference conditions should be
defined for different typologies of water bodies and for different European ecoregions. Suitable indicators should be developed
in order to quantify ecological status and to define what a 'good' ecological status is. Procedures should be developed for
correlating the deviation from a good ecological to the effects of multiple stressors on function and structure of the ecosystem.
The protection of biodiversity becomes a key objective. In this frame, the traditional procedures for ecotoxicological risk
assessment, mainly based on laboratory testing, should be overcome by more site-specific approaches, taking into account the
characteristics and the homeostatic capabilities of natural communities. In the paper an overview of the present knowledge
and of the new trends in ecotoxicology to get these objectives will be given. A procedure is suggested based on the concept
of Species Sensitivity Distribution (SSD).
Recommendations and Perspective . The need for more site-specific and ecologically-oriented approaches in ecotoxicology is strongly recommended. The development
of new tools for implementing the concept of 'Stress Ecology' has been recently proposed by van Straalen (2003). In the same
time, more 'cological realism'is needed in practically applicable procedures for regulatory purposes. 相似文献
6.
Fraga Filho Carlos Alberto Dutra 《Environmental science and pollution research international》2021,28(14):17170-17180
Environmental Science and Pollution Research - Negative impacts are caused by oil spills on coastal ecosystems. In the phenomenon of oil spreading, the knowledge of the physical properties of the... 相似文献
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Christodoulos Pilinis Robert J. Farber 《Journal of the Air & Waste Management Association (1995)》2013,63(5):702-709
An Aerosol Trajectory Model (ATM) is applied to the South Coast Air Basin of California for a two-day episode in August 1982 to evaluate proposed control strategies that aim to reduce atmospheric aerosols. Model predictions Indicate that secondary organic aerosols decrease linearly with reactive hydrocarbon emissions. In addition, the model shows that If sulf ate is produced only in the gas phase by oxidation of SO2, then reduction In SO2 emissions yields a nearly proportional decrease In sulfate levels. Reduction in ammonia emissions, combined with reduction of NOx emissions, gives the best results In terms of nitrate control. The order in which the emission controls are implemented Is predicted to have a major impact on the reduction of secondary atmospheric aerosols. 相似文献
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In this article, focusing on the ongoing implementation of the EU Water Framework Directive, we analyze some of the opportunities
and challenges for a sustainable governance of water resources from an ecosystem management perspective. In the face of uncertainty
and change, the ecosystem approach as a holistic and integrated management framework is increasingly recognized. The ongoing
implementation of the Water Framework Directive (WFD) could be viewed as a reorganization phase in the process of change in
institutional arrangements and ecosystems. In this case study from the Northern Baltic Sea River Basin District, Sweden, we
focus in particular on data and information management from a multi-level governance perspective from the local stakeholder
to the River Basin level. We apply a document analysis, hydrological mapping, and GIS models to analyze some of the institutional
framework created for the implementation of the WFD. The study underlines the importance of institutional arrangements that
can handle variability of local situations and trade-offs between solutions and priorities on different hierarchical levels. 相似文献
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In streams and creeks, the aquatic flora is exposed to fluctuating concentrations of herbicides during and following their application. Peak concentrations of herbicides, like the chloroacetanilide S-metolachlor, are usually detected following rain events. In this study, we assessed the effect of S-metolachlor pulse exposure on the algae Scenedesmus vacuolatus. We measured the time-dependency of effects during exposure on algae population and identified the algae development stage most sensitive to S-metolachlor. Furthermore, we assessed the time-to-recovery of the algae following exposure. A 6h pulse exposure at 598mugl(-1) was sufficient to inhibit cell reproduction by 50%. However, the exposure period had to coincide with the cell development stage specifically inhibited by S-metolachlor, which is the end of the cell growth phase. In algae populations composed of cells at all development stages, we initially observed an increase in the size of some algal cells, ultimately leading to an inhibition of the growth rate. In these experimental conditions, effects were observed after 18h of exposure and greatly increased with time. The recovery of algae following exposure to strongly inhibiting S-metolachlor concentrations was delayed and only occurred after 29h. These findings suggest that peak exposure to S-metolachlor may affect the growth of sensitive alga in surface waters, considering that the effects extend beyond the period of exposure. 相似文献
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In this paper, we discuss the classification results of the toxicological responses of 32 in vivo and in vitro test systems to the first 10 MEIC chemicals. In this order we have used different fuzzy clustering algorithms, namely hierarchical fuzzy clustering, hierarchical and horizontal fuzzy characteristics clustering and a new clustering technique, namely fuzzy hierarchical cross-classification. The characteristics clustering technique produces fuzzy partitions of the characteristics (chemicals) involved and thus it is a useful tool for studying the (dis)similarities between different chemicals and for essential chemicals selection. The cross-classification algorithm produces not only a fuzzy partition of the test systems analyzed, but also a fuzzy partition of the considered 10 MEIC (multicentre evaluation of in vitro cytotoxicity) chemicals. In this way it is possible to identify which chemicals are responsible for the similarities or differences observed between different groups of test systems. In another way, there is a specific sensitivity of a chemical for one or more toxicological tests. 相似文献
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Ouda Ahmed S. Gharieb Mahmoud 《Environmental science and pollution research international》2023,30(1):127-144
Environmental Science and Pollution Research - In this study, the effect of K-feldspar on the behavior of alkali-activated slag pastes (AAS) before and after exposure to seawater was evaluated by... 相似文献
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Redox reactions in the Fe-As-O2 system 总被引:1,自引:0,他引:1
We have examined two redox reactions involving arsenic and iron at near-neutral pH: the reduction of As(V) by Fe(II) under anoxic conditions, and the co-oxidation of As(III) during Fe(II) oxygenation. We also considered the impact of goethite, pH buffers, and radical scavengers on these reactions. In a series of anoxic experiments, Fe(II) was found to reduce As(V) in the presence of goethite, but not in homogeneous solution. The reaction rate increased with increasing pH and Fe(II) concentration, but in all cases was relatively slow. In aerobic experiments, the kinetics of Fe(II) oxygenation at neutral pH, and the corresponding oxidation of As(III) were found to depend heavily on pH buffer type and concentration. The classic formulation of Fe(II) oxidation by oxygen, involving four single-electron transfers, was reviewed and found to be inadequate for explaining observed oxidation of Fe(II) and As(III). Widely cited rate constants for Fe(II) oxygenation originate from experiments conducted in carbonate buffer, and do not match observations made in phosphate, MES, or HEPES systems. In phosphate buffer, Fe(II) oxidation is rapid and dependent on phosphate concentration. In MES and HEPES buffers, Fe(II) oxidation is much slower due to the lack of labile ferrous iron species. Oxygenation of Fe(II) appears to proceed through different mechanisms in phosphate and MES or HEPES systems. In both cases, reactive intermediary species are produced which can oxidize As(III). These oxidants are not the hydroxyl radical, but may be Fe(IV) species. 相似文献
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Gorji Shaghayegh Gorji Ali 《Environmental science and pollution research international》2021,28(13):15575-15579
Environmental Science and Pollution Research - In addressing the current COVID-19 pandemic and evaluating the measures taken by global leaders so far, it is crucial to trace back the circumstances... 相似文献
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Effects of the parasiticide ivermectin on the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata 总被引:2,自引:0,他引:2
Although widely used for the treatment of endo- and ectoparasites in livestock and pets, very few data on chronic effects on aquatic organisms are available for the parasiticide ivermectin. In the present study, toxicity of ivermectin to two freshwater organisms, the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata was investigated. For D. magna, a mean LC(50) 48 h of 5.7 ngl(-1) was derived from 10 acute tests. Chronic toxicity of ivermectin to D. magna was extremely high: with 0.001 and 0.0003 ngl(-1), respectively, nominal LOEC and NOEC based on growth and reproduction were far below the analytical limit of detection for this compound. P. subcapitata was considerably less sensitive to ivermectin than D. magna. For both growth rate and yield, EC(50) was >4,000 microgl(-1), LOEC was 1,250 microgl(-1) and NOEC 391microgl(-1). In view of the high toxicity to D. magna, the use of ivermectin might pose a risk to local aquatic ecosystems. Further studies should be carried out to investigate the effects of ivermectin and its degradation products on pelagic and benthic freshwater invertebrates. 相似文献
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Tian Jiandong Lu Longyuan He Guifang 《Environmental science and pollution research international》2021,28(21):26858-26870
Environmental Science and Pollution Research - Optimizing the locations of sewage treatment plants has enormous practical significance. In this study, a large-system mathematical model was... 相似文献
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Xue Z Hao J Chai F Duan N Chen Y Li J Chen F Liu S Pu W 《Journal of the Air & Waste Management Association (1995)》2005,55(12):1816-1826
This paper analyzes the air quality impacts of coal-fired power plants in the northern passageway of the West-East Power Transmission Project in China. A three-layer Lagrangian model called ATMOS, was used to simulate the spatial distribution of incremental sulfur dioxide (SO2) and coarse particulate matter (PM10) concentrations under different emission control scenarios. In the year 2005, the emissions from planned power plants mainly affected the air quality of Shanxi, Shaanxi, the common boundary of Inner Mongolia and Shanxi, and the area around the boundary between Inner Mongolia and Ningxia. In these areas, the annually averaged incremental SO2 and PM10 concentrations exceed 2 and 2.5 microg/m3, respectively. The maximum increases of the annually averaged SO2 and PM10 concentrations are 8.3 and 7.2 microg/m3, respectively, which occur around Hancheng city, near the boundary of the Shaanxi and Shanxi provinces. After integrated control measures are considered, the maximum increases of annually averaged SO2 and PM10 concentrations fall to 4.9 and 4 microg/m3, respectively. In the year 2010, the areas affected by planned power plants are mainly North Shaanxi, North Ningxia, and Northwest Shanxi. The maximum increases of the annually averaged SO2 and PM10, concentrations are, respectively, 6.3 and 5.6 microg/m3, occurring in Northwest Shanxi, which decline to 4.4 and 4.1 microg/m3 after the control measures are implemented. The results showed that the proposed power plants mainly affect the air quality of the region where the power plants are built, with little impact on East China where the electricity will be used. The influences of planned power plants on air quality will be decreased greatly by implementing integrated control measures. 相似文献
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Zhang Yuanjing Wu Yaoguo Sun Jichao Hu Sihai Zhang Yuxi Xiang Xiaoping 《Environmental science and pollution research international》2018,25(17):16702-16709
Environmental Science and Pollution Research - In the Hebei Plain of North China, 70% of the inhabitants depend on groundwater for drinking water. Little is known regarding high-iodine... 相似文献