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   7877篇
  免费   1506篇
  国内免费   392篇
安全科学   462篇
废物处理   789篇
环保管理   1072篇
综合类   4930篇
基础理论   671篇
环境理论   1篇
污染及防治   1630篇
评价与监测   142篇
社会与环境   54篇
灾害及防治   24篇
  2025年   19篇
  2024年   120篇
  2023年   155篇
  2022年   164篇
  2021年   226篇
  2020年   199篇
  2019年   181篇
  2018年   168篇
  2017年   211篇
  2016年   258篇
  2015年   258篇
  2014年   385篇
  2013年   436篇
  2012年   509篇
  2011年   508篇
  2010年   404篇
  2009年   449篇
  2008年   373篇
  2007年   573篇
  2006年   688篇
  2005年   527篇
  2004年   452篇
  2003年   444篇
  2002年   374篇
  2001年   317篇
  2000年   284篇
  1999年   266篇
  1998年   191篇
  1997年   148篇
  1996年   113篇
  1995年   101篇
  1994年   83篇
  1993年   64篇
  1992年   33篇
  1991年   30篇
  1990年   10篇
  1989年   4篇
  1988年   4篇
  1986年   7篇
  1982年   3篇
  1981年   4篇
  1980年   3篇
  1978年   2篇
  1977年   2篇
  1975年   2篇
  1974年   3篇
  1973年   4篇
  1972年   3篇
  1971年   3篇
  1970年   2篇
排序方式: 共有9775条查询结果,搜索用时 107 毫秒
441.
随着染料工业的发展,其生产废水已成为主要的水体污染源。目前染料已有成千上万种之多,它们不但具有特定的颜色,而且结构复杂,以高分子络合物为多。且生物降解性较低,大多具有潜在毒性,在环境中的归趋依赖于很多未知因子。这些特点致使染料废水难以找到行之有效的处理方法。介绍了几种染料废水的处理技术及其发展趋势,这些研究对染料废水的治理具有一定的指导意义。  相似文献   
442.
通过对国内外再生造纸废水处理工艺的归纳与总结,结合再生造纸的工艺特点,提出再生造纸废水低成本治理工艺。采用锅炉烟气处理脱墨黑夜,漂白废水用于废水脱色,采用絮凝沉淀、过滤等物化+生化处理相结合的方法处理综合废水。实现废水多级回用,循环水使用率达80%~90%,少量废水达标排放,投资和运行费用可节省近50%。  相似文献   
443.
文章对南山隧道K4+374-+381段塌方进行了地质上的成因分析,并说明了相应的处理措施。  相似文献   
444.
塔河油田一号联合站(塔一联)稠油污水具有粘度大、油水密度差小、乳化严重等特点,它的回用与外排具有一定的难度.通过实验室和现场试验研制开发的破乳剂和混凝剂,强化了除油效果,减轻了过滤系统的负荷,处理污水达到了注水水质指标.  相似文献   
445.
    
A three-dimensional electrochemical oxidation(3D-EC) reactor with introduction of activated carbon(AC) as particle micro-electrodes was applied for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions(current density of 500 A/m~2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L), the average removal efficiencies of chemical oxygen demand(COD_(cr)), NH3–N, total organic carbon(TOC), and ultraviolet absorption at 254 nm(UV_(254)) of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of COD_(cr), NH_3–N, TOC, and UV_(254) were 76.6, 20.1, and42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of COD_(cr) was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard(GB 8978-1996). The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for COD_(cr), NH_3–N, TOC, and UV_(254) during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation(2D-EC) reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry(GC–MS) analysis revealed that electrochemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.  相似文献   
446.
以库区天然水培养的二形栅藻(Scenedesmus dimorphus)为研究对象,利用大气压强电场电离放电产生羟基自由基(·OH),结合压力溶气气浮前处理工艺处理高藻水.实验结果表明,对于藻密度为65.6×10~4 cells/mL,浊度为10.8NTU,COD_(Mn)为6.74mg/L的高藻水,在总氧化剂TRO浓度为1.03 mg/L时,藻类去除效率达到100%;总细菌,总大肠菌群和大肠埃希氏菌均未检出;出水COD_(Mn)由1.43 mg/L降至1.25mg/L,降低了10%;浊度由0.66NTU降至0.54NTU,降低了12.59在排放高藻水的主管路中·OH杀藻的接触反应时间仅为6s.因此汽浮-·OH强氧化组合工艺可高效快速地处理高藻水,为保障水源水的供水安全探索了一种新的思路.  相似文献   
447.
    
A fungal consortium including Aspergillus niger, Mucor hiemalis and Galactomyces geotrichum was tested for the treatment of dairy wastewater. The bio-augmentation method was tested at lab-scale (4 L), at pilot scale (110 L) and at an industrial scale in Wastewater Treatment Plants (WWTP). The positive impact of fungal addition was confirmed when fungi was beforehand accelerated by pre-culture on whey (5 g/L lactose) or on the dairy effluent. Indeed, chemical oxygen demand (COD) removal yields increased from 55% to 75% for model medium, diluted milk. While after inoculation of an industrial biological tank from a dairy factory with the fungal consortium accelerated by pre-cultivation in a 1000 L pilot plant, the outlet COD values decreased from values above the standard one (100 mg/L) to values in the range of 50-70 mg/L. In addition, there was a clear impact of fungal addition on the ’hard’ or non-biodegradable COD owing to the significant reduction of the increase of the COD on BOD 5 ratio between the inlet and the outlet of the biological tank of WWTP. It was in the range of 451%-1111% before adding fungal consortium, and in the range of 257%-153% after bio-augmentation with fungi. An inoculated bioreactor with fungal consortium was developed at lab-scale and demonstrated successfully at pilot scale in WWTP.  相似文献   
448.
  总被引:5,自引:0,他引:5  
The mixture of five yeast strains obtained from soil could remove about 85% TOC of oil-rich wastewater in batch test.While the highest MLSS was obtained at an N:C of 1:5,the oil removal decreased with the increase of N:C during yeast sludge cultivation.Ammonium chloride was the best nitrogen source for yeast cultivation from the viewpoint of yeast growth and oil utilizxation.An ammonia concentration of over 1300 mg/L led to mass death of yeast at a pH of 5.The ammonia concentration should be controlled at a level of 1000 mg/L or lower.  相似文献   
449.
Heavy metals in water bodies purified by suspended substrate of rivers   总被引:2,自引:0,他引:2  
IntroductionHeavymetalsinwaterbodiesaresignificantlydifferentfromorganicpollutantsthatcanbemicrobiologicallydegradedordecomposed .Generally ,theyarepurifiedthroughtheiradsorptionontosuspendedsubstratesinrivers.Adsorptionofheavymetalsonriversuspendedsub…  相似文献   
450.
Experiment on microbial degradation with two kinds of biological process, hydrolytic acidification-aerobic process and aerobic process was conducted to treat the anthraquinone dye wastewater with CODc, concentration of 400 mg/L and chroma 800. The experimental result demonstrated that the hydrolytic-aerobic process could raise the biodegradability of anthraquinone dye wastewater effectively. The effluent CODc, can reach 120-170 mg/L and chroma 150 which is superior to that from simple aerobic process.  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