首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   83篇
  免费   1篇
安全科学   1篇
废物处理   5篇
环保管理   8篇
综合类   5篇
基础理论   7篇
污染及防治   36篇
评价与监测   7篇
社会与环境   15篇
  2022年   2篇
  2021年   4篇
  2020年   2篇
  2019年   1篇
  2018年   8篇
  2017年   1篇
  2016年   1篇
  2015年   3篇
  2014年   4篇
  2013年   7篇
  2012年   1篇
  2011年   5篇
  2010年   4篇
  2009年   4篇
  2008年   2篇
  2007年   8篇
  2006年   7篇
  2005年   2篇
  2003年   6篇
  2002年   2篇
  2001年   1篇
  2000年   3篇
  1997年   2篇
  1995年   2篇
  1992年   1篇
  1986年   1篇
排序方式: 共有84条查询结果,搜索用时 15 毫秒
41.
The efficacy of ozonation and of photocatalysis processing in the treatment of pulp mill ECF (elementary chlorine free) bleaching and textile effluents was evaluated by determining total organic carbon reduction (TOC) and the toxicity. The chronic toxicity of the effluents was evaluated by the ability to inhibit the growth of algae Selenastrum capricornutum. Cultured hamster V79 fibroblasts were used to assess the cytotoxicity of effluents submitted to different detoxification processes. Two endpoints were measured in V79 cells: 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) reduction and neutral red uptake (NRU). Both treatment processes were able to reduce the TOC, although ozonization was less effective for pulp mill ECF bleaching. The pulp mill ECF bleaching and textile effluents reduced the growth of S. capricornutum by 39% and 27%, respectively. However, at the highest concentration tested, the textile effluents treated by photochemical process for 60 min showed increased cytotoxicity in V79 cells compared to the untreated effluent when assessed by the NRU and MTT reduction assays (increases of 30% and 40%, respectively). Pulp mill ECF bleaching effluent treated by ozonization had a similar cytotoxicity to that of untreated effluent in the NRU assay. In contrast, the MTT reduction assay indicated that effluents treated with ozone were around 20% more cytotoxic than untreated effluents. These results show that cultured fibroblasts may be useful for studying cellular responses to pollutants and may be included in tests to monitor the efficiency of effluent detoxification processes.  相似文献   
42.
Activated carbons were prepared from flamboyant pods by NaOH activation at three different NaOH:char ratios: 1:1 (AC-1), 2:1 (AC-2), and 3:1 (AC-3). The properties of these carbons, including BET surface area, pore volume, pore size distribution, and pore diameter, were characterized from N2 adsorption isotherms. The activated carbons obtained were essentially microporous and had BET surface area ranging from 303 to 2463 m2 g−1.13C (CP/MAS and MAS) solid-state NMR shows that the lignocellulosic structures were completely transformed into a polycyclic material after activation process, thermogravimetry shows a high thermal resistance, Boehm titration and Fourier-transform infrared spectroscopy allowed characterizing the presence of functional groups on the surface of activated carbons. Scanning electron microscopy images showed a high pore development. The experimental results indicated the potential use of flamboyant pods as a precursor material in the preparation of activated carbon.  相似文献   
43.
Currently, there is no nationally representative human milk biomonitoring program in the United States (U.S.) and no studies have reported non-persistent pesticides in the milk of U.S. women. In this pilot study we developed a multiresidue laboratory method to measure non-persistent and persistent pesticides and polychlorinated biphenyl (PCB) congeners in human milk samples from women residing in the agricultural region of Salinas, CA (n = 13) and the urban San Francisco Bay Area, CA (n = 21). Samples were collected from 2002-2007. Median concentrations in pg g(-1) milk among urban and agricultural women, respectively were reported for: chlorpyrifos (24.5 and 28.0), cis-permethrin (81.9 and 103), trans-permethrin (93.1 and 176), hexachlorobenzene (191 and 223), β-hexachlorocyclohexane (220 and 443), o,p'-DDT (36.6 and 62.4), p,p'-DDT,(107 and 102), o,p'-DDE (5.65 and 5.17), p,p'-DDE (3170 and 3490), dacthal (2.79 and 3.43), PCB 118 (92.8 and 17.0), PCB 138 (183 and 38.2), PCB 153 (242 and 43.6) and PCB 180 (239 and 683). Among urban women, median concentrations were 4.02 and 4.32 pg g(-1) milk for chlorpyrifos-methyl and propoxur, respectively. These results suggest that neonates and young children may be exposed to persistent and non-persistent pesticides and PCBs via breast milk.  相似文献   
44.

The study addresses in vitro degradation potential of airborne Aspergillus and Penicillium/Talarmyces species originating from cultural heritage conservation premises. A series of rapid, cost effective biodegradation assays were performed to assess production of extracellular pigments, acids, and enzymes. Most of the isolates have demonstrated positive growth in at least one of the preformed tests. Strongest overall degradation potential was demonstrated for Penicillium brevicompactum, P. glabrum, and Talaromyces sayulitensis while Aspergillus domesticus, A. penicillioides, A. pseudoglaucus, and A. ruber did not exhibit positive reaction in any of the employed assays. Majority of isolates exhibited proteolytic and cellulolytic activity while carbonate dissolution was observed for only five tested fungi. Highest alteration of pH value in liquid media was documented for T. sayulitensis while A. niger and P. expansum exhibited strongest acid production on CREA. Certain isolates, mostly Penicillium species, displayed production of extracellular pigments. The results imply that many of the tested fungi have significant biodegradation capacity, indicating their potential to inflict structural and esthetic alterations on cultural heritage objects.

  相似文献   
45.
Ascidian fauna have been intensively studied in the Atlantic Ocean, adjacent subpolar regions and Mediterranean Sea for the last 20 years. Here, we have described current species distribution patterns and identified nested areas of endemism using parsimony analysis of endemicity (PAE). We also identified diversity hotspots, areas in which species occurred exclusively, and gaps in information about distribution patterns. Finally, we compared ascidian distributions among various proposed biogeographic divisions. The comprehensive literature review provided data on the geographic distribution of 627 species of ascidians. In the West Atlantic, there were three peaks in richness: north Caribbean—96 species, São Paulo and Rio de Janeiro—61 species and the subantarctic region—54 species. In the eastern Atlantic, the greatest richness occurred on Spanish and French coasts—91 species and in Senegal—83 species. In the Mediterranean, the greatest richness was in Spain and France—142 species and Italy—127 species. PAE designated 20 areas of endemism nested within eight larger regions that were more or less in agreement with realms or provinces of previous studies: North Atlantic, Caribbean, southeastern Brazil, Magellanic, Subantarctic, Tropical West Africa, South Africa, and Mediterranean. Distribution patterns of the Ascidiacea, in general, followed previously proposed divisions of regions and provinces in the Atlantic and adjacent polar regions, but not subdivisions of these regions.  相似文献   
46.
Journal of Polymers and the Environment - The search for highly productive agriculture has considerably increased the use of fertilizers, becoming a worrying source of environmental and health...  相似文献   
47.
ABSTRACT: The spatial and temporal variability of dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate concentration and total coliform (TC) were investigated at nine sampling stations distributed along the main rivers of the Piracicaba River Basin, a 12,400 km2 catchment located in São Paulo State, one of the most developed regions of Brazil. Spatially, a downstream impoverishment of water quality conditions was observed, as seen by the decrease of DO, and increase of BOD, nitrate, and TC. These changes were probably caused by accumulating downstream discharge of domestic and industrial sewage. Temporal evaluation of 18 years of data showed that DO decreased with time for the majority of the sampling stations, while BOD, nitrate, and TC increased. A law, approved at the end of 1991, proposed a new water tax for river water extraction for industrial and agricultural use. The amount of this tax is determined according to the water quality of the extracted water. Therefore, the evaluation of the water quality status in this basin is a first step to help resources managers to determine the values for this tax.  相似文献   
48.
ABSTRACT: The construction of the Tucurui Hydroelectric Plant on the Tocantins River basin in Brazil requires flood forecasting for ensuring the safety of the cofferdam. The latter has been initially designed for a flood with a return frequency of one in 25 years. Lack of adequate forecasting facilities during the earlier stages of construction has resulted in significant damages and construction delays. Statistical forecasting models were developed by Projeto de Hidrologiay Climatologie da Amazonia (PHCA) for the purpose of preventing further damages at the site. These models are currently in use and are the subject of this paper. The application of these models during the 1980 flood season, when the highest flood on record occurred at the Tucurui site, proved of great assistance in preventing the flooding of the cofferdam. In conjunction with the development of these models a number of data collection platforms using data transmission through the GOES system were installed to provide automatically the data required for forecasting.  相似文献   
49.
To minimize the environmental impact of textile effluents, mainly related to their high coloration and the presence of toxic or carcinogenic reactive dyes, the efficiency of photochemical and ozonation processes, applied in the form of isolated and combined procedures, were evaluated. The investigation was focused on the reduction of total organic carbon content (TOC), color and acute toxicity (monitoring by inhibition of Escherichia coli respiration). For a reaction time of 60 min, the anatase TiO2-assisted photocatalytic process produces color and TOC reduction of about 90% and 50%, respectively. Meanwhile, the ozonation process gives a decolorization of about 60% but negligible TOC reduction. When the processes were applied in a simultaneous form, the decolorization was almost complete and the TOC reduction was higher than 60%. The three treatments studied yield an acute toxicity reduction of around 50%.  相似文献   
50.
In the metropolitan area of S?o Paulo, Brazil, ozone and particulate matter (PM) are the air pollutants that pose the greatest threat to air quality, since the PM and the ozone precursors (nitrogen oxides and volatile organic compounds) are the main source of air pollution from vehicular emissions. Vehicular emissions can be measured inside road tunnels, and those measurements can provide information about emission factors of in-use vehicles. Emission factors are used to estimate vehicular emissions and are described as the amount of species emitted per vehicle distance driven or per volume of fuel consumed. This study presents emission factor data for fine particles, coarse particles, inhalable particulate matter and black carbon, as well as size distribution data for inhalable particulate matter, as measured in March and May of 2004, respectively, in the Janio Quadros and Maria Maluf road tunnels, both located in S?o Paulo. The Janio Quadros tunnel carries mainly light-duty vehicles, whereas the Maria Maluf tunnel carries light-duty and heavy-duty vehicles. In the Janio Quadros tunnel, the estimated light-duty vehicle emission factors for the trace elements copper and bromine were 261 and 220 microg km(-1), respectively, and 16, 197, 127 and 92 mg km(-1), respectively, for black carbon, inhalable particulate matter, coarse particles and fine particles. The mean contribution of heavy-duty vehicles to the emissions of black carbon, inhalable particulate matter, coarse particles and fine particles was, respectively 29, 4, 6 and 6 times higher than that of light-duty vehicles. The inhalable particulate matter emission factor for heavy-duty vehicles was 1.2 times higher than that found during dynamometer testing. In general, the particle emissions in S?o Paulo tunnels are higher than those found in other cities of the world.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号