全文获取类型
收费全文 | 660篇 |
免费 | 27篇 |
国内免费 | 257篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 51篇 |
环保管理 | 47篇 |
综合类 | 344篇 |
基础理论 | 142篇 |
污染及防治 | 232篇 |
评价与监测 | 28篇 |
社会与环境 | 26篇 |
灾害及防治 | 29篇 |
出版年
2023年 | 11篇 |
2022年 | 35篇 |
2021年 | 27篇 |
2020年 | 22篇 |
2019年 | 20篇 |
2018年 | 24篇 |
2017年 | 26篇 |
2016年 | 27篇 |
2015年 | 46篇 |
2014年 | 58篇 |
2013年 | 70篇 |
2012年 | 52篇 |
2011年 | 66篇 |
2010年 | 44篇 |
2009年 | 32篇 |
2008年 | 38篇 |
2007年 | 52篇 |
2006年 | 35篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 23篇 |
2002年 | 19篇 |
2001年 | 17篇 |
2000年 | 21篇 |
1999年 | 27篇 |
1998年 | 17篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有944条查询结果,搜索用时 593 毫秒
651.
652.
壬基酚聚氧乙烯醚在印染废水处理工艺中的去除研究 总被引:1,自引:0,他引:1
为减少印染助剂壬基酚聚氧乙烯醚(nonylphenol ethoxylates,NPEO)及其降解产物壬基酚(nonylphenol,NP)随印染废水进入水体造成的不利环境影响,对2种常规印染废水处理净水工艺处理含NPEO的模拟印染废水效率开展了研究。研究发现,结合厌氧水解和曝气氧化的生物处理工艺能迅速地将废水中NPEO去除,去除率达到90%以上,但排水中残余一定含量的NP、短链NPEO和短链壬基酚聚氧乙烯醚酸酯(nonylphenol polyethoxycarboxylate,NPEC),在减少排水中NP、短链NPEO和短链NPEC浓度方面,接触氧化法比活性污泥法效果更好。排水中的NP和短链NPEO来自厌氧水解阶段长链NPEO的降解;减少排水中NP、短链NPEO需要减少厌氧水解阶段产生的短链NPEO。 相似文献
653.
采用光电催化氧化技术对天津市某石化企业反渗透单元浓水进行处理。经光催化、电化学及光电催化氧化处理后浓缩液出水的COD、氨氮及色度去除率进行了对比研究。详细探讨了不同电流密度、反应时间及紫外灯功率对COD、氨氮及色度去除效果的影响。结果表明,在电流密度为2.0 mA/cm2,紫外灯光强度为30μW/cm2的条件下,处理150min后,COD的去除率为92.06%,氨氮浓度从44.61 mg/L下降至2.84 mg/L,色度去除率达到100%。对光电催化氧化法处理不同时间的出水进行了三维荧光光谱及凝胶色谱分析。结果表明,光电催化氧化法可将反渗透浓水中大部分大分子有机物结构破坏,使其分解成小分子有机物。 相似文献
654.
生物墙对地下水中六价铬的去除效果模拟研究 总被引:1,自引:0,他引:1
通过土柱实验模拟地下水环境,研究以发酵树皮为主要反应介质的渗透性生物墙对地下水中六价铬的去除效果,为六价铬污染地下水的修复提供方法和依据。结果表明,模拟生物墙运行数天后,墙内形成弱碱性(pH 7~8)、强还原(Eh<-100 mV)环境,有利于六价铬转化为三价铬并生成沉淀。在进水六价铬浓度为20 mg/L、水流速度为3.7 cm/d的运行条件下,3周期间生物墙对六价铬的去除率稳定在98%左右,生物墙内沿水流方向三价铬的浓度先上升后下降(最高达6.6 mg/L),出水三价铬约为1.0 mg/L。吸附和微生物转化是生物墙对水中六价铬去除的主要反应。 相似文献
655.
采用O3/H2O2高级氧化工艺处理炼油厂反渗透(RO)浓水,用溶气泵加压溶气并产生微气泡强化传质,确定装置运行条件,考察气体中臭氧浓度、H2O2/O3初始摩尔比、pH和温度对O3/H2O2处理RO浓水效果的影响,并对RO浓水处理效能进行研究。结果表明,随着气体中臭氧浓度的增加,COD的去除率基本呈线性增加;加入适当量H2O2能提高臭氧氧化RO浓水的效果,H2O2/O3初始摩尔比在0~0.8范围内,COD的去除率先增加后下降,H2O2/O3初始摩尔比为0.5时COD去除率最大;pH从6.84增加到9.01,COD去除率逐渐增大,pH为10.03时COD去除率反而降低;在14~28℃范围内,温度低时,升高温度COD去除率增加较大,温度较高时,升高温度对COD去除率的影响较小。为考察该工艺的稳定性,在H2O2/O3初始摩尔比为0.5、溶液pH为8~9、臭氧浓度为80~100 mg/L、温度为10~28℃条件下,对COD为90~140 mg/L的RO浓水氧化处理4~10 h,出水COD维持在39.9~49.9 mg/L,达到《城镇污水处理厂污染物排放标准(GB 18918-2002)》中的一级A标准;去除1 g COD消耗O3 1.4~3.3 g,消耗O3与H2O2的总氧量为2.2~4.4 g。 相似文献
656.
Practices and opportunities of ecosystem service studies for ecological restoration in China 总被引:1,自引:0,他引:1
Shiliang Liu Yuhong Dong Fangyan Cheng Ana Coxixo Xiaoyun Hou 《Sustainability Science》2016,11(6):935-944
New approaches have emerged in integrating ecosystem services, their structure and function for ecological restoration. As the concept relating with ecosystem services has become widely accepted in last decade in China, its linking with ecological restoration will provide good opportunities and make substantial progress towards sustainable development. By analyzing the traditional ecological restoration procedure in China, we developed a framework of ecological restoration based on ecosystem services valuation. Relevant researches of ecological restoration based on ecosystem services are also carefully reviewed. China’s ecosystem services studies and payments for ecosystem services (PES) experiences were extensively discussed to show the ecological restoration strategy and its change. Two case studies in China were presented to show the framework for ecological restoration based on PES. We suggested that despite the limitations of valuation uncertainties at present, PES could be an opportunity for ecological restoration by evaluating the trade-offs of different stakeholders. In current state in China, challenges and opportunities coexist and scientists should work together in the integrated research of sustainable ecological management and economic development policies. 相似文献
657.
Kuo-Jen Liao Xiangting Hou Matthew J. Strickland 《Journal of the Air & Waste Management Association (1995)》2016,66(8):748-757
An important issue of regional air quality management is to allocate air quality management funds to maximize environmental and human health benefits. In this study, we use an innovative approach to tackle this air quality management issue. We develop an innovative resource allocation model that allows identification of air pollutant emission control strategies that maximize mortality avoidances subject to a resource constraint. We first present the development of the resource allocation model and then a case study to show how the model can be used to identify resource allocation strategies that maximize mortality avoidances for top five Metropolitan Statistical Areas (MSAs) (i.e., New York, Los Angeles, Chicago, Dallas-Fort Worth, and Philadelphia) in the continental United States collectively. Given budget constraints in the U.S. Environmental Protection Agency’s (EPA) Clean Air Act assessment, the results of the case study suggest that controls of sulfur dioxide (SO2) and primary carbon (PC) emissions from EPA Regions 2, 3, 5, 6, and 9 would have significant health benefits for the five selected cities collectively. Around 30,800 air pollution–related mortalities could be avoided during the selected 2-week summertime episode for the five cities collectively if the budget could be allocated based on the results of the resource allocation model. Although only five U.S. cities during a 2-week episode are considered in the case study, the resource allocation model can be used by decision-makers to plan air pollution mitigation strategies to achieve the most significant health benefits for other seasons and more cities over a region or the continental U.S.Implications: Effective allocations of air quality management resources are challenging and complicated, and it is desired to have a tool that can help decision-makers better allocate the funds to maximize health benefits of air pollution mitigation. An innovative resource allocation model developed in this study can help decision-makers identify the best resource allocation strategies for multiple cities collectively. The results of a case study suggest that controls of primary carbon and sulfur dioxides emissions would achieve the most significant health benefits for five selected cities collectively. 相似文献
658.
659.
Qianyu Hang Haiyan Wang Zhaosheng Chu Bibi Ye Chunmei Li Zeying Hou 《Environmental science and pollution research international》2016,23(9):8260-8274
Water quality standard for nitrate becomes more and more strict, and the plant carbon source is widely used for denitrification by constructed wetland (CW) and bioreactor. However, the nitrate removal efficiency by different types of plant carbon source are not evaluated comprehensively. Denitrification performance of different plant carbon sources, and the influence of dosing method and pretreatment are thoroughly reviewed in this paper, which aims to investigate the accurate utilization of plant carbon source for nitrogen (as nitrate) removal. It is concluded that plant carbon source addition for all types of CWs and bioreactors can improve the nitrate removal efficiency to some extent, and the dosing method of plant carbon source for denitrification should be further studied and optimized in the future. The popular carbon sources for CW and bioreactor denitrification enhancement are woodchip, chopped macrophytes, crop plants, macrophytes litters, etc. The recommended optimum C:N ratios for CW and bioreactor are 4.0:5.0 and 1.8:3.0, respectively. The physical and biological pretreatments are selected to supply organic carbon for long-term denitrification. 相似文献
660.
Adsorption of ammonium on biochar prepared from giant reed 总被引:1,自引:0,他引:1
Jie Hou Lei Huang Zhimin Yang Yaqi Zhao Chaoren Deng Yucheng Chen Xin Li 《Environmental science and pollution research international》2016,23(19):19107-19115
Giant reed was used as precursor for making biochar in order for the adsorption of NH4 +–N from aqueous solution. And the adsorption of the product to NH4 +–N was examined. The surface features of biochar were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), and X-ray diffraction (XRD). XRD patterns showed several peaks and correspond to the high amount of crystalline material. The crystals contain KCl, K2O, CaO, MgO, and SiO and possess high surface area which enhances adsorption. The influence of different parameters such as initial concentration, adsorption time, pH, and ionic strength has been carried out. The adsorption could reach equilibrium through 24 h reaction and had the best adsorption amount at the solution pH values from 7 to 9. The cation has great influence on the adsorption of NH4 +–N, whereas the anion exerted a weaker effect. The adsorption followed pseudo-first-order and pseudo-second-order models. And the intraparticle diffusion and desorption studies further elucidated that the mechanism of adsorption on the product was ion exchange. The product equilibrium data was well described by the Langmuir and Freundlich model. The maximum adsorption capacities were 1.490 mg/g. Biochar derived from giant reed at 500 °C was suggested as a promising adsorbent for the removal of NH4 +–N from slightly polluted wastewater. 相似文献