全文获取类型
收费全文 | 4065篇 |
免费 | 364篇 |
国内免费 | 2345篇 |
专业分类
安全科学 | 251篇 |
废物处理 | 211篇 |
环保管理 | 625篇 |
综合类 | 3997篇 |
基础理论 | 435篇 |
污染及防治 | 1141篇 |
评价与监测 | 88篇 |
社会与环境 | 22篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 4篇 |
2023年 | 29篇 |
2022年 | 116篇 |
2021年 | 137篇 |
2020年 | 156篇 |
2019年 | 156篇 |
2018年 | 150篇 |
2017年 | 163篇 |
2016年 | 241篇 |
2015年 | 307篇 |
2014年 | 380篇 |
2013年 | 403篇 |
2012年 | 519篇 |
2011年 | 464篇 |
2010年 | 371篇 |
2009年 | 372篇 |
2008年 | 313篇 |
2007年 | 372篇 |
2006年 | 444篇 |
2005年 | 303篇 |
2004年 | 236篇 |
2003年 | 201篇 |
2002年 | 137篇 |
2001年 | 125篇 |
2000年 | 139篇 |
1999年 | 123篇 |
1998年 | 79篇 |
1997年 | 76篇 |
1996年 | 59篇 |
1995年 | 47篇 |
1994年 | 35篇 |
1993年 | 29篇 |
1992年 | 26篇 |
1991年 | 26篇 |
1990年 | 13篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有6774条查询结果,搜索用时 15 毫秒
941.
概述了蚯蚓生态滤池的研究进展,介绍了蚯蚓生态滤池化学除磷的工艺流程和设备参数;由试验得出氯化铁(FeCl3·6H2O)是蚯蚓生态滤池化学除磷的合适药剂,并确定最经济投加量为50mg/L;在此条件下,研究了化学除磷小试滤池产生的污泥性质,包括污泥产率的变化、重金属含量、污泥的脱水性能、污泥的稳定化程度以及污泥的最终处置方法。 相似文献
942.
Nonylphenol in the environment: a critical review on occurrence, fate, toxicity and treatment in wastewaters 总被引:16,自引:0,他引:16
Soares A Guieysse B Jefferson B Cartmell E Lester JN 《Environment international》2008,34(7):1033-1049
Nonylphenol is a toxic xenobiotic compound classified as an endocrine disrupter capable of interfering with the hormonal system of numerous organisms. It originates principally from the degradation of nonylphenol ethoxylates which are widely used as industrial surfactants. Nonylphenol ethoxylates reach sewage treatment works in substantial quantities where they biodegrade into several by-products including nonylphenol. Due to its physical-chemical characteristics, such as low solubility and high hydrophobicity, nonylphenol accumulates in environmental compartments that are characterised by high organic content, typically sewage sludge and river sediments, where it persists. The occurrence of nonylphenol in the environment is clearly correlated with anthropogenic activities such as wastewater treatment, landfilling and sewage sludge recycling. Nonylphenol is found often in matrices such as sewage sludge, effluents from sewage treatment works, river water and sediments, soil and groundwater. The impacts of nonylphenol in the environment include feminization of aquatic organisms, decrease in male fertility and the survival of juveniles at concentrations as low as 8.2 mug/l. Due to the harmful effects of the degradation products of nonylphenol ethoxylates in the environment, the use and production of such compounds have been banned in EU countries and strictly monitored in many other countries such as Canada and Japan. Although it has been shown that the concentration of nonylphenol in the environment is decreasing, it is still found at concentrations of 4.1 mug/l in river waters and 1 mg/kg in sediments. Nonylphenol has been referred to in the list of priority substances in the Water Frame Directive and in the 3rd draft Working Document on Sludge of the EU. Consequently there is currently a concern within some industries about the possibility of future regulations that may impose the removal of trace contaminants from contaminated effluents. The significance of upgrading sewage treatment works with advanced treatment technologies for removal of trace contaminants is discussed. 相似文献
943.
《International Journal of Sustainable Engineering》2013,6(3):228-234
Disposal of sewage sludge from waste water treatment plants is a serious environmental problem of increasing magnitude. Waste water treatment generates as much as 70 g of dry solids per capita per day. Although one of the disposal solutions for this waste is through incineration, still almost 30% of sludge solids remain as ash. This paper presents results related to reuse of sewage sludge ash in concrete. The sludge was characterised for chemical composition (X-ray flourescence analysis), crystalline phases (X-ray diffraction analysis) and pozzolanic activity. The effects of incineration on crystal phases of the dry sludge were investigated. Two water/cement (W/C) ratios (0.55 and 0.45) and three sludge ash percentages (5%, 10% and 20%) per cement mass were used as filler. The mechanical performance of sewage sludge ash concrete (SSAC) at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests and capillary water absorption. Results show that sewage sludge ash leads to a reduction in density and mechanical strength and to an increase in capillary water absorption. Results also show that SSAC with 20% of sewage sludge ash and W/C = 0.45 has a 28 day compressive strength of almost 30 MPa. SSAC with a sludge ash contents of 5% and 10% has the same capillary water absorption coefficient as the control concrete; as for the concrete mixtures with 20% sludge ash content, the capillary water absorption is higher but in line with C20/25 strength class concretes performance. 相似文献
944.
人工湿地技术处理生活污水 总被引:1,自引:0,他引:1
本文评估了一级强化预处理+人工湿地在处理生活污水方面的使用范围,提出当进水中氨氮达到35mg/L,通过一级强化预处理以及人工湿地的出水难以达到一级B标准;同时由于人工湿地大部分为厌氧环境,对硝态氮去除效果良好,本文提出在进水氨氮浓度较高的情况下,将硝化加入人工湿地的预处理,利用人工湿地的一部分硝化能力和良好的反硝化能力使出水达标排放。 相似文献
945.
针对工业废水采用普通活性污泥法处理易出现的丝状菌型污泥膨胀,分析和总结出五种主要膨胀类型:低负荷型、低溶解氧型、营养缺乏型、高硫化物型、pH值不平衡型。对污泥负荷、溶解氧、污水种类、营养成分及pH值和温度的变化等因素对污泥膨胀中菌胶团和丝状菌生长的相互影响进行阐述,给出污泥膨胀理论,并对不同类型的污泥膨胀提出相应的控制方法。 相似文献
946.
关于农村污水治理项目供给主体的探讨 总被引:2,自引:0,他引:2
从农村污水治理项目的社区性公共物品属性出发,说明农村污水治理项目不应完全由政府供给。通过梳理以日本为代表的发达国家的具体做法,提出了多元化供给的观点,并初步探讨了各供给主体的责任和义务。 相似文献
947.
随着乌昌经济的发展,城市人口快速增长,生活污水的排放量剧增,对环境造成直接和潜在威胁。通过对乌昌地区城镇污水处理现状,昌吉州人工防护林建设状况分析,结合防护林用水量及地下水资源现状分析。探讨城镇污水处理的全新模式,从其生态效益、环境效益、社会效益和经济效益做了分析阐述。 相似文献
948.
为进一步提高循环式活性污泥工艺(CASS)的脱氮除磷效果,改变其运行方式,采用好氧脉冲曝气,提出频繁硝化-反硝化循环式活性污泥工艺(FND-CASS).结果表明,FND-CASS工艺与CASS工艺相比,在去除污水中有机物方面能力略有下降,但在脱氮除磷方面具有明显的优势.在同样的进水流量且DO浓度控制较低的运行条件下,F... 相似文献
949.
950.