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   386篇
  免费   28篇
  国内免费   186篇
安全科学   20篇
废物处理   22篇
环保管理   78篇
综合类   321篇
基础理论   40篇
污染及防治   95篇
评价与监测   20篇
社会与环境   4篇
  2023年   5篇
  2022年   7篇
  2021年   10篇
  2020年   14篇
  2019年   15篇
  2018年   14篇
  2017年   22篇
  2016年   18篇
  2015年   30篇
  2014年   26篇
  2013年   40篇
  2012年   36篇
  2011年   18篇
  2010年   30篇
  2009年   32篇
  2008年   20篇
  2007年   35篇
  2006年   35篇
  2005年   31篇
  2004年   21篇
  2003年   24篇
  2002年   12篇
  2001年   15篇
  2000年   10篇
  1999年   8篇
  1998年   7篇
  1997年   6篇
  1996年   11篇
  1995年   4篇
  1994年   3篇
  1993年   4篇
  1992年   3篇
  1991年   2篇
  1990年   2篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1979年   6篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
  1973年   2篇
  1972年   2篇
排序方式: 共有600条查询结果,搜索用时 62 毫秒
401.
过滤—厌氧—好氧工艺处理酒精废水   总被引:7,自引:0,他引:7  
耿土锁 《环境科技》2001,14(3):11-13
介绍了酒精废水的高效低耗处理工艺,即首先用转鼓滤机去除60%左右的悬浮物并回收作粗饲料;其次,借助原水高温特点,用完全混合式高温厌氧池使废水充分消化;再次,用沉淀池和气浮池实现废水和厌氧污泥的完全分离,使废水的COD降解了92%-94%;最后为好氧处理工段,整个工艺对COD和SS的去除率分别高达99%和99.8%,不仅处理率高,而且能耗很低,还可以回收粗饲料和沼气能源。  相似文献   
402.
对国内外的水污染收费系统进行了比较研究,在借鉴国外经验的基础上,运用ZSM解释结构模型分析了水污染收费系统的问题,并从直辖市排污费和使用者收费,完善使用者收费,及污水集中处理设施的企业化经营管理等几个方面,探讨了系统改进方案。  相似文献   
403.
稠油采油污水回用于热采锅炉用水的研究   总被引:6,自引:0,他引:6  
利用曝气除油、引气气浮、化学除硅、树脂吸附和软化的方法对稠油污水进行处理,出水完全达到热采锅炉用水指标,可用于热采锅炉给水,为解决污水排污染环境和热采生产供水不足的矛盾提供了可行的技术工艺。  相似文献   
404.
The present study demonstrates comparison of Cr accumulatingpotential by the plants of Najas indica Cham. (submerged),Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeatedmetal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulationpotential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions incomparison to N. indica and A. sessilis. The maximumaccumulation of 1378, 458 and 201 g g-1 dw Cr was found in the leaves of V. spiralis, N. indica and A. sessilis, respectively at 8 mg L-1 after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll andprotein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plantswere treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). Theplants of V. spiralis treated with 100% tannery wastewatershowed the maximum accumulation (57.5 g g-1 dw) of Cr in the roots after 10 days of exposure. The plants were foundeffective in removing Cr from solution and tannery effluent.  相似文献   
405.
406.
从含油污泥中回收油技术的研究   总被引:1,自引:4,他引:1  
研究从某炼厂含油污泥中回收油的问题,分析结果表明:此种油污泥含油率46.7%、含水率51.2%、含砂率1.7%。实验中分别研究了离心法、热滤法的回收油效果。最终以热滤法实现了油回收率95%、脱水率99%。确定了以热滤法作为该含油污泥回收油的方法。  相似文献   
407.
ABSTRACT: A stochastic programming framework is developed to evaluate the economic implications of reliability criteria and multiple effluent controls on nonpoint source pollution. An integrated watershed simulation model is used to generate probability distributions for agricultural effluents in surface and ground water resulting from agricultural practices. Results from the planning model indicate that reliability and multiple effluent constraints significantly increase the cost of nonpoint controls but the effects vary by control alternative. The analysis indicates that an evaluation of multiple water quality objectives can be an important planning tool for designing nonpoint source controls for innovative programs to promote cost-effective water quality regulation.  相似文献   
408.
ABSTRACT: Sewage effluent is commonly disposed of on land in arid regions, and the majority usually recharges the groundwater. Few evaluations have been made of the effect of effluent disposal on groundwater quality in the west. Groundwater hydrologists are rarely involved with treatment plant design and operation or effluent disposal in the San Joaquin Valley, California. The author's purpose is to evaluate the effect of regional sewering programs on groundwater quality in this valley. Research was conducted on past studies of sewage effluent disposal. An extensive water sampling program was undertaken near the Fresno Sewage Treatment Plant. Chloride contents were used to trace recharged effluent. The extent of recharged effluent was delineated and traced for about ten miles. Sampling between the plant and the urban Fresno area indicated a high probability of large-scale leakage of raw sewage into the groundwater.  相似文献   
409.
ABSTRACT: A laboratory boat designed to investigate toxic effects on site and its use as a bioassay tool in the study of a refinery effluent discharged into the Schuylkill River, a tributary of the Delaware River, is described. Three-hundred thirty-six-hour continuous-flow bioassay s exposing the bluegill sunfish, the channel catfish, the tadpole snail, the grass shrimp, and the sheephead minnow to concentrations of refinery effluent in Schuylkill, Delaware River, and Delaware Bay water, with and without the addition of sediment were performed. Results indicated that the toxicity (lethality) of fresh samples tested aboard the boat (refinery effluent, dilution water, sediment) were considerably higher (i.e., refinery effluent at full strength was 2.2X as lethal to the bluegill, 1.4X as lethal to the channel catfish, 1.5X as lethal to the sheep-head minnow and 100X as lethal to the grass shrimp) than the same test material collected from the refinery outfall and brought to a central laboratory for testing. Chemical analysis and bioassay data is presented showing the effects of aging and irradiation upon the refinery effluent.  相似文献   
410.
ABSTRACT: Total culturable heterotrophic bacteria in a coal ash basin and drainage system were monitored over a period of two years. In the first year heavy (bottom) ash was sluiced to the basin resulting in a pH of 6.5. During the second year fly ash was precipitated and added to the sluice lowering the basin pH to 4.6. Sulfate concentrations during 1975 ranged from 16–73 ppm (mean 33) and in 1976 from 44–88 ppm (mean 72). Mean annual basin temperatures were 28.8 and 26.0 C, respectively. Approximately 1500 m in the receiving swamp below the basin, mean pH and temperature were 6.8 and 22.2 C for the first year, and 5.4 and 22.1 C for the second. Total culturable bacteria and diversity (colony types) were reduced at all sampling stations by 44 and 30 percent, respectively, whereas the percentage of the population comprised of chromagenic bacteria increased by 51 percent at the lower pH; Data indicated the pH had a greater effect than did water temperature when temperature was within the range of 15–25 C. The predominant genera within the system in the first year were Bacillus, Sarcina, Achromobacter, Flavobacterium, and Pseudomonas. In the second year, at the lower pH, predominant genera were Pseudomonas, Flavobacterium, Chromobacterium, Bacillus, and Brevibacterium.  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