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101.
102.
零价铁与厌氧微生物协同还原地下水中的硝基苯 总被引:1,自引:0,他引:1
通过间歇式实验,考察了零价铁与厌氧微生物协同还原地下水中硝基苯的效果。实验结果表明,由零价铁腐蚀为厌氧微生物提供H2电子供体还原硝基苯的效果明显优于零价铁和微生物单独作用,硝基苯去除率分别提高21.8%和57.0%。弱酸性条件有利于协同反应进行,当初始pH为5.0和6.0时,4 d后硝基苯去除率比初始pH为7.0时的提高74.4%和35.2%。增加零价铁投加量可提高协同还原的效果,零价铁最佳投加量为250 mg/L。零价铁腐蚀产生的Fe2+无法作为电子供体被微生物利用,但可作为无机营养元素促进协同过程。由于零价铁产H2速率受表面覆盖物影响不明显,在地下水修复过程中可保证协同效果并延长零价铁的使用寿命。 相似文献
103.
The radon isotope 222Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes. 相似文献
104.
大连市中心城区地下水“三氮”污染分析 总被引:1,自引:1,他引:0
依据《地下水质量标准》(GB/T 14848-1993),对大连市中心城区2006-2010年地下水"三氮"监测资料进行分析。结果表明,"三氮"的检出率(最高为100%)和超标率(最高为58.8%)都较高,其中亚硝酸盐氮超标显著。氨氮浓度各年均值均超标,呈波动变化;亚硝酸盐氮浓度各年均值均超标,并呈上升趋势;硝酸盐氮各年均值波动变化,总体呈上升趋势。除2009年以外,其他4年中丰水期的硝酸盐氮浓度都比枯水期高;除2007年外,其他4年中的丰水期氨氮浓度都比枯水期低。"三氮"最高浓度值主要出现在中心城区周边区域。 相似文献
105.
Kevin G. Boggs Robert W. Van Kirk Gary S. Johnson Jerry P. Fairley P. Steve Porter 《Journal of the American Water Resources Association》2010,46(6):1116-1132
Boggs, Kevin G., Robert W. Van Kirk, Gary S. Johnson, Jerry P. Fairley, and P. Steve Porter, 2010. Analytical Solutions to the Linearized Boussinesq Equation for Assessing the Effects of Recharge on Aquifer Discharge. Journal of the American Water Resources Association (JAWRA) 46(6):1116–1132. DOI: 10.1111/j.1752-1688.2010.00479.x Abstract: There is a need to develop a general understanding of how variations in aquifer recharge are reflected in discharge. Analytical solutions to the linearized Boussinesq equation governing flow in an unconfined aquifer provide a unified mathematical framework to quantify relationships among lag time, attenuation and distance between aquifer recharge and discharge and the effect of an up-gradient no-flow boundary. We applied this framework to three types of recharge: (1) instantaneous, (2) periodic, and (3) constant rate for a finite duration. When the temporal scale of recharge exceeds the diffusive aquifer time scale, recharge will be reflected in discharge quickly and with little attenuation. When aquifer time scale is large, most recharge events are shorter in scale than that of the aquifer, resulting in large attenuation. Attenuation is more sensitive to boundary effects than lag time, and boundary effects increase as recharge time scale increases. Boundary effects can often be ignored when the recharge source is farther than 1/3 of the domain length away from the no-flow boundary. We illustrate analytical results with application to the economically critical Eastern Snake River Plain Aquifer in Idaho. In this aquifer, detectable annual and decadal cycles in discharge can result from recharge no farther than 20 and 60 km away from the discharge point, respectively. The effects of more distant, long-term recharge can be detected only after a time lag of several decades. 相似文献
106.
107.
某矿区土壤和地下水重金属污染调查与评价 总被引:3,自引:0,他引:3
为了解湘南某矿区土壤和地下水重金属污染状况,对该矿区东河流域附近重金属污染源进行了调查,同时,对地下水和土壤样品进行了采样分析,结果表明:(1)该矿区东河流域附近的主要污染源有18个,其中有色金属选厂、尾矿库、采矿场和冶炼厂是排放重金属较多的污染源;(2)20个采样点中土壤重金属Pb、Cd、Zn、As和Hg大部分超过国家土壤环境质量标准(GB15618-1995),综合污染指数P综〉1,该矿区主要的重金属污染元素为Cd、As和Hg,且土壤中Cd、Zn和As的含量两两之间存在着极显著的正线性相关关系;(3)重金属元素在土壤中的纵向迁移不明显,该矿区附近20个采样点的地下水并未受到污染,综合污染指数P综〈1。20个采样点地下水Pb、Cd、Zn、As、Hg浓度均能达到地下水质量标准(GB/T14848.9)中的Ⅲ类标准。 相似文献
108.
Randall J. Schaetzl L. Keith Hendrie Scott W. Kirsch 《Journal of the American Water Resources Association》1989,25(5):1023-1030
ABSTRACT: Soil water was monitored by neutron scattering in six soils, three each within two drainage catenas in east-central Illinois, over a 15-month time span. The prairie soils have formed in: (1) 76–152 cm of silt loam, eolian sediments (bess) over glacial till (Catlin-Flanagan-Drummer catena), and (2) bess greater than 152 cm in thickness (Tama-Ipava-Sable catena). We characterized the water content of these soils over the total time span and for wet and dry climatic subsets, as an aid to potential irrigation decisions. Soils of the thin bess, C-F-D catena dried out to lower water contents and had greater soil water variability than did the thick bess soils. Under wet conditions, soil water contents in the two catenas were quite similar. Alleviation of surface and subsurface drying via irrigation would thus be more advantageous to yields on the C-F-D soils than on the T-I-S soils. 相似文献
109.
110.
Thomas V. Belanger Donald F. Mikutel 《Journal of the American Water Resources Association》1985,21(2):265-272
Data from a study on East Lake Tohopekaliga, Florida, indicate that the seepage meter measurement method may often overestimate nutrient contributions to lakes. Nutrient loading data from this method and a method employing lakeside piezometer nutrient data and seepage meter flows were not comparable. Seepage nutrient loading from the meter and piezometer methods comprised 39 and 18 percent of the nitrogen budget and 38 and 9 percent of the phosphorus budget, respectively, for East Lake Tohopekaliga. In terms of water, groundwater seepage accounted for only 14 percent of the total input to the lake. It is felt that some of the past studies using the seepage meter method to estimate nutrient loading may be in error due to reasons related to the enclosure of lake sediments by the meter and the accompanying anaerobic conditions which quickly result. 相似文献