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   875篇
  免费   9篇
  国内免费   70篇
安全科学   20篇
废物处理   4篇
环保管理   96篇
综合类   574篇
基础理论   51篇
污染及防治   148篇
评价与监测   55篇
社会与环境   6篇
  2024年   5篇
  2023年   9篇
  2022年   10篇
  2021年   14篇
  2020年   22篇
  2019年   24篇
  2018年   16篇
  2017年   11篇
  2016年   16篇
  2015年   17篇
  2014年   23篇
  2013年   24篇
  2012年   28篇
  2011年   61篇
  2010年   27篇
  2009年   53篇
  2008年   45篇
  2007年   58篇
  2006年   41篇
  2005年   45篇
  2004年   42篇
  2003年   44篇
  2002年   40篇
  2001年   46篇
  2000年   38篇
  1999年   47篇
  1998年   37篇
  1997年   41篇
  1996年   15篇
  1995年   15篇
  1994年   15篇
  1993年   14篇
  1992年   4篇
  1991年   5篇
  1983年   1篇
  1981年   1篇
排序方式: 共有954条查询结果,搜索用时 15 毫秒
1.
A batch recycle removal of copper ions from an industrial effluent by means of copper foam cathodes was tested. A constant current of 750 A was applied to the cell in order to perform the reduction. Copper depletion was investigated at different solution flow rates and a removal greater than 98% was obtained with a flow rate of 1000 l/h. The influence of initial metal concentration on copper deposition and current efficiency is also discussed.  相似文献   
2.
Heterogeneous water phase catalysis as an environmental application: a review   总被引:15,自引:0,他引:15  
Catalytic water phase processes as an environmental application is a relatively novel subject with tremendous potential in the near future. This review of 120 references presents the wide scale of heterogeneous water phase applications studied mainly within past five years. Both oxidation and hydrogenation processes are included as well as TiO2 assisted photocatalysis. According to the references, heterogeneous catalysis is developing rapidly. New bimetallic catalysts and supports with higher surface area have improved catalytic efficiency in both oxidation and hydrogenation processes. It also seems that study on use of some waste materials such as red mud as catalyst is a very progressive field. On the whole, the chemical aspects are pretty well known, but the catalyst durability, and in many cases activity as well, has to be improved.  相似文献   
3.
详细、全面地阐述了废水监测工作系统应具备的基本条件和设施及各个环节之间的协调配合关系,指出了该系统管理中应注意的主要问题。  相似文献   
4.
Treated wastewater from a food-processing plant, together with intermittent outflow from a hypereutrophic pond, were discharged over a 20-year period to a cattail-dominated wetland and hence to a small stream. Organics and nutriet levels in the effluent were comparable to levels in domestic wastewater. Fifteen variables were monitored upstream and downstream from the plant over 18 months. Means for most variables were slightly higher downstream, but differences between stations were not statistically significant. Wetland processing of nitrogen was markedly affected by a change from drought to flood conditions. After accounting for dilution, the overall effect of the wetland on the effluent was to reduce biological oxygen demand 43.7%, ammonia N 46.3%, nitrate/nitrite N 17.4%, and conductivity 15.6%. However, total suspended solids were increased 41.4%, total organic nitrogen 28.8%, and total phosphorus 24.7%. It was concluded that the wetland effectively renovated the effluent but the removal efficiency would be improved if the effluent were pretreated to reduce phosphorus and dispersed to increase residence time in the wetland.  相似文献   
5.
This article documents the general need to reuse water reclaimed from sewage effluents for beneficial purposes and then considers in detail which specific uses will be most beneficial. The analysis begins by describing five levels of wastewater treatment: primary, secondary, tertiary, advanced, and advanced plus complete treatment. Next, five major uses for reclaimed water are identified: groundwater recharge, industrial use, irrigation, recreational lakes, and direct municipal reuse. Subcategories of reuse falling under each of the five major reuse categories are also identified and discussed. The analysis then proceeds to review significant literature available on health and environmental effects, treatment and distribution costs, and public opinion concerns in relation to each of the five major uses and their related subcategories. The paper concludes with a cumulative numerical analysis of the disbenefits associated with each specific type of reuse summed over the health effects, environmental effects, treatment costs, distribution costs, and public opinion concerns. Uses of reclaimed water for industrial purposes and for irrigation of fodder and fiber crops are found to be most beneficial by the analysis here employed, and use for aquifer recharge and direct municipal reuse are found to be least beneficial.  相似文献   
6.
Abundance of fecal caliform bacteria is a weak index of the presence of human pathogens in wastewater entering coastal waters. In spite of this, use of fecal caliform indices for management purposes is widespread. To gain insight into interpretation of fecal coliform data, we evaluated size of stocks of fecal coliforms in water, sediments, and sea wrack, in Buttermilk Bay, a coastal embayment in Massachusetts. Sediments contained most of the fecal coliforms. Fecal coliforms in sediments were as much as one order of magnitude more abundant than in the water column or in sea wrack. The fecal coliforms in sediments of Buttermilk Bay were so abundant that resuspension of fecal coliforms from just the top 2 cm of muddy sediments could add sufficient cells to the water column to have the whole bay exceed the federal limit of fecal coliforms for shellfishing. The major sources of fecal coliforms to the bay were water-fowls, surface runoff, groundwater, and streams. Waterfowl were the largest source of fecal coliforms during cold months; surface runoff, streams, and groundwater were most important during warm months. Redirection of surface runoff pipes is unlikely to be a very successful management action since contributions via this source are insufficient to account for the measured increases in concentrations of fecal coliforms in water. Removal of waterfowl is also unlikely to be useful, since fecal coliform concentrations leading to closures of shellfish beds and swimming areas are most frequent during warm months when waterfowl are rarest. Rates of loss of fecal caliform cells from the water column by death and tidal exchange were high. Mortality of cells was about an order of magnitude larger than losses by tidal exchange. The amounts of fecal coliforms brought into the bay by waterfowl, surface runoff, groundwater, and streams are an order of magnitude smaller than the losses by mortality and tidal removal. This implies that there is an additional source of fecal coliforms within the bay. We suggest that resuspension of the upper layers of sediments can easily account for the fecal coliforms present in the water. Fecal coliform content of water and shellfish were not correlated. In contrast, sediment and shellfish fecal coliform abundances were significantly related. Monitoring of fecal coliforms in sediments may provide a better assessment of shellfish than sampling of water. The large fecal coliform stock in sediments should be the first priority for management. Efforts ought to be directed toward the reduction of sediment fecal coliform stocks. Lowering nutrient additions to coastal water bodies may be one practical approach.  相似文献   
7.
Phosphorus (P) inputs to sewage treatment works (STW) come from a variety of sources and filtration of treated wastewater prior to discharge into receiving waters is a common practice. This means P in treated wastewaters may be present in forms that are potentially more bioavailable and mobile. We conducted a 2-year study to determine P species up and downstream of two STW outfalls into two tributaries of the River Thames. Downstream of the outfalls, P concentrations in both rivers were frequently greater by an order of magnitude for all species of P. A high proportion of total P (TP) in the downstream waters was determined as dissolved, which was largely comprised of soluble reactive P (SRP) - considered as the most bioavailable P species. Furthermore no significant difference in SRP was found in receiving waters passed through 0.45 and 0.10 μm filters. This means that P from STWs occurs in <0.1 μm fraction size, which will not readily settle to the channel bed and is more easily assimilated by biota. This distinguishes STW inputs from agricultural runoff where a high proportion of P occurs as particulate P which is both less bioavailable and more likely to settle to the channel bed. This implies that STWs derived P is likely to have a greater adverse impact on the receiving river than agricultural runoff.  相似文献   
8.
A daily model was used to quantify the components of the total urban water balance of the Curtin catchment, Canberra, Australia. For this catchment, the mean annual rainfall was found to be three times greater than imported potable water, and the sum of the output from the separate stormwater and wastewater systems exceeded the input of imported potable water by some 50%. Seasonal and annual variations in climate exert a very strong influence over the relative magnitude of the water balance components; this needs to be accounted for when assessing the potential for utilizing stormwater and wastewater within an urban catchment.  相似文献   
9.
磷矿数量减少与含磷污水造成的水体富营养化问题对磷资源的可持续利用提出了迫切要求。从污水处理的不同环节回收磷并重新利用,是实现磷资源循环利用的有效途径。本文讨论了国内外磷回收技术的研究进展和应用实例,包括从含磷污泥和富磷污水中回收磷的工艺,并对磷回收的技术经济性进行了分析。  相似文献   
10.
Recycling wastewater seems to have become a highly useful technique for meeting the shortage of fresh water in all parts of the world. It seems all the more important for Muslim countries because a large number of these countries face acute fresh water shortage. This paper views the problem from an Islamic viewpoint, that is, in the light of the Qur'n, theSunnah, andFiqh works.In Islamic law, water is classified into three categories oftahr,thir, andmutanajjis. The last two categories can be transmuted intotahr water and thus may be used for all mundane as well as religious purposes if they are assimilated into the overall supply oftahr water. This would be lawful from the Islamic viewpoint even without treating the water. To make use of modern technology in order to recycle wastewater effluents after treatment seems quite in keeping with the spirit and letter of the Islamic teachings.  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