全文获取类型
收费全文 | 77篇 |
免费 | 3篇 |
国内免费 | 19篇 |
专业分类
废物处理 | 1篇 |
环保管理 | 9篇 |
综合类 | 42篇 |
基础理论 | 13篇 |
污染及防治 | 27篇 |
评价与监测 | 6篇 |
社会与环境 | 1篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 11篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 15 毫秒
91.
Heavy metal removal from synthetic wastewaters in an anaerobic bioreactor using stillage from ethanol distilleries as a carbon source 总被引:1,自引:0,他引:1
This work was conducted to investigate the possibility of using stillage from ethanol distilleries as substrate for sulfate reducing bacteria (SRB) growth and to evaluate the removal efficiency of heavy metals present in wastewaters containing sulfates. The experiments were carried out in a continuous bench-scale Upflow Anaerobic Sludge Blanket reactor (13 l) operated with a hydraulic retention time of 18 h. The bioreactor was inoculated with 7 l of anaerobic sludge. Afterwards, an enrichment procedure to increase SRB numbers was started. After this, cadmium and zinc were added to the synthetic wastewater, and their removal as metal sulfide was evaluated. The synthetic wastewater used represented the drainage from a dam of a metallurgical industry to which a carbon source (stillage) was added. The results showed that high percentages of removal (>99%) of Cd and Zn were attained in the bioreactor, and that the removal as sulfide precipitates was not the only form of metal removal occurring in the bioreactor environment. 相似文献
92.
Xin Zhou Xiaoya Ren Yu Chen Haopeng Feng Jiangfang Yu Kang Peng Yuying Zhang Wenhao Chen Jing Tang Jiajia Wang Lin Tang 《Frontiers of Environmental Science & Engineering》2023,17(3):29
93.
K. Wyat Appel Prakash V. Bhave Alice B. Gilliland Golam Sarwar Shawn J. Roselle 《Atmospheric environment (Oxford, England : 1994)》2008,42(24):6057-6066
This paper is Part II in a pair of papers that examines the results of the Community Multiscale Air Quality (CMAQ) model version 4.5 (v4.5) and discusses the potential explanations for the model performance characteristics seen. The focus of this paper is on fine particulate matter (PM2.5) and its chemical composition. Improvements made to the dry deposition velocity and cloud treatment in CMAQ v4.5 addressing compensating errors in 36-km simulations improved particulate sulfate (SO42−) predictions. Large overpredictions of particulate nitrate (NO3−) and ammonium (NH4+) in the fall are likely due to a gross overestimation of seasonal ammonia (NH3) emissions. Carbonaceous aerosol concentrations are substantially underpredicted during the late spring and summer months, most likely due, in part, to a lack of some secondary organic aerosol (SOA) formation pathways in the model. Comparisons of CMAQ PM2.5 predictions with observed PM2.5 mass show mixed seasonal performance. Spring and summer show the best overall performance, while performance in the winter and fall is relatively poor, with significant overpredictions of total PM2.5 mass in those seasons. The model biases in PM2.5 mass cannot be explained by summing the model biases for the major inorganic ions plus carbon. Errors in the prediction of other unspeciated PM2.5 (PMOther) are largely to blame for the errors in total PM2.5 mass predictions, and efforts are underway to identify the cause of these errors. 相似文献
94.
95.
Izumi Noguchi Kentaro Hayashi Masahide Aikawa Tsuyoshi Ohizumi Yukiya Minami Moritsugu Kitamura Akira Takahashi Hiroshi Tanimoto Kazuhide Matsuda Hiroshi Hara 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):67-75
Temporal trends of non-sea salt (nss-) sulfate and nitrate were analyzed from nationwide precipitation chemistry measurements
provided by the Ministry of the Environment (MOE) for the 1988–2002 fiscal years (April–March). The concentrations and deposition
of nss-sulfate were found to be decreasing, and those of nitrate were stable or slightly increasing at most sites. These deposition
trends were discussed from the viewpoint of emissions of SO2 and NOX during the period of interest. Because monitoring techniques have changed in the number of active sites, samplers, and analytical
methods during the operation period, the median of all annual depositions measured in Japan in a specific year was selected
as the annual representative. The contribution of specific emission sources was also calculated for 1990 on the basis of the
nss-sulfate and nitrate deposition in Japan obtained with a model simulation in which the model did not include volcanic emissions
from Mt. Oyama, Miyakejima Island, which began to erupt suddenly and violently in 2000. For nss-sulfate, the calculated deposition
agrees well with the intensity and trends of the median up to 1999. After 2000, a higher deposition than calculated in the
preceding years was evident, which is attributable to the volcanic SO2 from Mt. Oyama. For nitrate, both the calculated and observed depositions were slightly increasing; however, the calculation
was found to exceed the observation. 相似文献
96.
Xuejun Liu Yangyang Zhang Aohan Tang Chen Wang Xin M Yunzhe Li Wen Xu Xiaoping Xi Aihua Zheng Wenqing Li Zengguo Fang Xiufen Zhao Xianlong Peng Yuping Zhang Jian Han Lijuan Zhang Jeffrey L. Collett 《环境科学学报(英文版)》2022,34(12):83-91
We investigated variations of PM2.5 and water-soluble inorganic ions chemical characteristics at nine urban and rural sites in China using ground-based observations. From 2015 to 2019, mean PM2.5 concentration across all sites decreased by 41.9 µg/m3 with a decline of 46% at urban sites and 28% at rural sites, where secondary inorganic aerosol (SIAs) contributed to 21% (urban sites) and 17% (rural sites) of the decreased PM2.5. SIAs concentrations underwent a decline at urban locations, while sulfate (SO42–), nitrate (NO3–), and ammonium (NH4+) decreased by 49.5%, 31.3% and 31.6%, respectively. However, only SO42– decreased at rural sites, NO3– increased by 21% and NH4+ decreased slightly. Those changes contributed to an overall SIAs increase in 2019. Higher molar ratios of NO3– to SO42– and NH4+ to SO42– were observed at urban sites than rural sites, being highest in the heavily polluted days. Mean molar ratios of NH3/NHx were higher in 2019 than 2015 at both urban and rural sites, implying increasing NHx remained as free NH3. Our observations indicated a slower transition from sulfate-driven to nitrate-driven aerosol pollution and less efficient control of NOx than SO2 related aerosol formation in rural regions than urban regions. Moreover, the common factor at urban and rural sites appears to be a combination of lower SO42– levels and an increasing fraction of NO3– to PM2.5 under NH4+-rich conditions. Our findings imply that synchronous reduction in NOx and NH3 emissions especially rural areas would be effective to mitigate NO3–-driven aerosol pollution. 相似文献
97.
Lingyan Wu Xiaoye Zhang Junying Sun Yu Wang Junting Zhong Zhaoyang Meng 《环境科学学报(英文版)》2022,34(4):503-513
Air pollution in China is complex, and the formation mechanism of chemical components in particulate matter is still unclear. This study selected three consecutive heavy haze pollution episodes (HPEs) during winter in Beijing for continuous field observation, including an episode with heavy air pollution under red alert. Clean days during the observation period were selected for comparison. The HPE characteristics of Beijing in winter were: under the influence of adverse meteorological conditions such as high relative humidity, temperature inversion and low wind speed; and strengthening of secondary transformation reactions, which further intensified the accumulation of secondary aerosols and other pollutants, promoting the explosive growth of PM2.5. PM2.5/CO values, as indicators of the contribution of secondary transformation in PM2.5, were approximately 2 times higher in the HPEs than the average PM2.5/CO during the clean period. The secondary inorganic aerosols (sulfate nitrate and ammonium salt) were significantly enhanced during the HPEs, and the conversion coefficients were remarkably improved. In addition, it is interesting to observe that the production of sulfate tended to exceed that of nitrate in the late stage of all three HPEs. The existence of aqueous phase reactions led to the explosive growth sulfur oxidation ratio (SOR) and rapid generation of sulfate under high relative humidity (RH>70%). 相似文献
98.
The long-range transport of oxidized sulfur(sulfur dioxide(SO_2) and sulfate) and oxidized nitrogen(nitrogen oxides(NO_x ) and nitrate) in East Asia is an area of increasing scientific interest and political concern. This paper reviews various published papers, including ground- and satellite-based observations and numerical simulations. The aim is to assess the status of the anthropogenic emissions of SO_2 and NO_x and the long-range transport of oxidized S and N pollutants over source and downwind region. China has dominated the emissions of SO_2 and NO_x in East Asia and urgently needs to strengthen the control of their emissions, especially NO_x emissions. Oxidized S and N pollutants emitted from China are transported to Korea and Japan, due to persistent westerly winds, in winter and spring.However, the total contributions of China to S and N pollutants across Korea and Japan were not found to be dominant over longer time scales(e.g., a year). The source–receptor relationships for oxidized S and N pollutants in East Asia varied widely among the different studies. This is because:(1) the nonlinear effects of atmospheric chemistry and deposition processes were not well considered, when calculating the source–receptor relationships;(2) different meteorological and emission data inputs and solution schemes for key physical and chemical processes were used; and(3) different temporal and spatial scales were employed. Therefore, simulations using the same input fields and similar model configurations would be of benefit, to further evaluate the source–receptor relationships of the oxidized S and N pollutants. 相似文献
99.
Reactive transport modeling of a permeable reactive barrier for the treatment of mine drainage was used to integrate a comprehensive data set including pore water chemistry and solid phase data from several sampling events over a >3-year time period. The simulations consider the reduction of sulfate by the organic carbon-based treatment material and the removal of sulfate and iron by precipitation of reduced mineral phases including iron monosulfides and siderite. Additional parameters constraining the model include dissolved H2S, alkalinity and pH, as well as a suite of solid phase S-fractions identified by extractions. Influences of spatial heterogeneity necessitated the use of a 2-dimensional modeling approach. Simulating observed seasonal fluctuations and long-term changes in barrier reactivity required the use of temperature dependent rate coefficients and a multimodal Monod-type rate expression accounting for the variable reactivity of different organic carbon fractions. Simulated dissolved concentrations of SO4, Fe, H2S, alkalinity and pH, as well as solid phase accumulations of reduced sulfur phases generally compare well to observed trends over 23 months. Spatial variations, seasonal fluctuations and the time-dependent decline in reactivity were also captured. The modeling results generally confirm, and further strengthen, the existing conceptual model for the site. Overall sulfate reduction and S-accumulation rates are constrained with confidence within a factor of 1.5. 相似文献