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41.
悬浮液进样原子荧光光谱法测定海洋沉积物样品中的痕量汞 总被引:2,自引:1,他引:2
研究了一种使用悬浮液进样原子荧光光谱法测定海洋沉积初中痕量汞的快速简便的方法。控制悬浮液的颗粒粒径在200目(d≤0.076mm),用磁力搅拌器搅拌以保证悬浮液分散均匀稳定,以水溶液标准作标准曲线,该法方法的检出限为0.001μg/L,加标回收率为90.5%-103.4%,RSD为4.39%。将此法用于标准物质GBw07314、GBw08301、GSBZ50013—88、GSB50014—88和实验室外控样的分析,得到了满意的结果,证明该方法准确可靠。 相似文献
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为研究南水北调通水后,水源改变及水库调度对底泥盐分释放的影响,2005年7月,取0~60cm深度的北塘水库原状底泥样品,在实验室内模拟分析不同底泥含盐量、不同蓄水水质及水位变动和扰动条件下底泥氯化物释放规律。结果表明,底泥中Cl~-含量为0.043%,释放强度为0.12g/m~2·d,Cl~-含量越高,释放强度越大。在底泥含盐量相同的条件下,蓄去离子水的底泥Cl~-释放强度是蓄水库水的1.87倍。扰动状态下,底泥中的Cl~-有5.0%~9.5%释放出来,高于静止状态的3.2%~5.6%。水库运行水位发生变化,将影响底泥盐分的释放。1.0m水深条件下Cl~-的释放量是1.5m水深的5.8倍。水库四周地下水中Cl~-浓度为8.0×10~3~4.2×10~4mg/L,远高于目前水库水的Cl~-浓度。因此,一定要避免水库在低于设计低水位和周边地下水水位的条件下运行,防止底泥盐分释放及地下水反向补给造成水库水质的成化。 相似文献
45.
重金属在淀山湖沉积物上的吸附研究 总被引:9,自引:1,他引:9
本文以淀山湖沉积物作为研究对象 ,研究了 Cu、Zn、Pb和 Cd在淀山湖沉积物上的等温吸附和沉积物对重金属吸附的影响因素。结果表明 ,重金属 Cu、Zn、Pb和 Cd在淀山湖沉积物上的等温吸附符合 L angmuir模型 ,淀山湖沉积物对重金属饱和吸附量的大小顺序为 Zn>Cu>Pb>Cd。淀山湖沉积物的组成对重金属吸附有较大的影响 ,其中沉积物中粘粒对 Cu、Zn、Pb和 Cd的吸附最强。沉积物中有机质对 4种重金属也有较强的吸附 ,特别对 Zn的吸附最强。碳酸盐对 Zn的吸附较弱 ,而对 Cu、Pb和 Cd有较强的吸附。 p H值对重金属吸附也有较大的影响 ,吸附量随着 p H值的升高而增大。温度对吸附的影响则较小 相似文献
46.
Marty D. Matlock Kevin Ray Kasprzak G. Scott Osborn 《Journal of the American Water Resources Association》2003,39(2):267-275
ABSTRACT: The lower reaches of the Arroyo Colorado have historically failed to meet their use under subsection 303(b) of the U.S. Clean Water Act due to fecal coliform bacteria and low dissolved oxygen (DO). Fish kills, especially at the tidal confluence at the Port of Harlingen, Texas, have been reported. Oxygen demand from sediment (SOD) for a river typically has two states‐diffusion limited SOD (SOD) and potential SOD (pSOD), expressed when sediment is resuspended through increased flow or other disturbances. The objective of this research was to measure SOD in the Arroyo Colorado River in situ, estimate pSOD ex situ, and evaluate the relationship between SOD and the depositional environment. We measured SOD and pSOD in the Arroyo Colorado River at up to eight sites over three sampling events. We identified the sample sites based on a modified Rosgen geomorphic index for streambed stabilization. Sites with high sediment deposition potential had high SOD. The average values of SOD between sites were 0.62 g/m2/day (standard deviation 0.38 g/m2/day) and ranged from 0.13 to 1.2 g/m2/day. Potential SOD values ranged from as low as 19.2 to as high as 2,779 g/m3 sediment/ day. Potential SOD can serve as an indicator of the possible impact of SOD from resuspended sediment in stream systems. 相似文献
47.
Christopher I. Thornton Steven R. Abt Warren P. Clary 《Journal of the American Water Resources Association》1997,33(6):1279-1288
ABSTRACT: A meandering stream channel was simulated in the Hydraulics Laboratory at Colorado State University and a series of tests was conducted using four types of vegetation to evaluate the potential effects of vegetation on sediment deposition and retention in a stream channel. The data collected included average flow velocity, flow depth, length of vegetation, density of vegetation, cross-sectional area of the vegetative stem, wetted perimeter of the vegetative stem, and injection and flushing time. The findings indicated that the vegetation could retain from 30 to 70 percent of the deposited sediments. The ability of vegetation to entrap and retain sediment is related to the length and cross-sectional area of the vegetation. The variables describing the flow and the vegetative properties were combined to form a predictive parameter, the sedimentation factor (Sd) that can be compared with the amount of sediment entrapped by vegetation in a stream system. A relation was developed correlating vegetation length to sediment retention after flushing for flexibility and rigid vegetation. 相似文献
48.
本文介绍了沱江和釜溪河近年来的氨污染现状及危害,认为氨是应治理的首位污染物;简要分析了生物、化学、物理化学三类除氨方法的优缺点;着重介绍了吹脱法除氨技术,提出用吹脱法治理沱江和釜溪河的无机氨污染,并进行了上述各法的经济效益比较 相似文献
49.
Nada Horvatinčić José Luis Briansó Bogomil Obelić Jadranka Barešić Ines Krajcar Bronić 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):475-485
The process of eutrophication in form of intense plant growth has been observed in some lakes and water streams at the Plitvice
Lakes National Park in central Croatia. Here we investigate whether this phenomenon is a consequence of anthropogenic pollution
or due to naturally produced organic matter in the lakes. We applied chemical analysis of water at two springs and four lakes
(nutrients, dissolved organic carbon (DOC), trace elements) and measurements of surface lake sediments (mineral and organic
fraction analyses, trace elements) in four different lakes/five sites. The chemical composition of water does not indicate
recent anthropogenic pollution of water because the concentrations of most trace elements are below detection limits. The
concentrations of DOC and nutrients are slightly higher in the area of increased eutrophication-plant growth. Also the content
of organic matter in the sediment is at the highest level in areas with highest C/N ratio indicating that the organic fraction of this sediment is mainly of terrestrial origin. There is no significant difference
among the trace element concentration in the upper segment of all cores, deposited approximately during last 50 years when
higher anthropogenic influence is expected due to development and touristic activity, and the lower part of the cores, corresponding
to the period approximately 100–200 years before present. The content of trace elements and organic matter in sediments decreases
from the uppermost lake downstream. According to our results there is no indication of recent anthropogenic pollution in water
and sediment. Higher concentrations of DOC in water as well as phosphorus and some other elements in the lake sediment can
be a consequence of input of natural organic matter to the lake water. 相似文献
50.
Aaron I. Packman Andrea Marion Mattia Zaramella Cheng Chen Jean-François Gaillard Denis T. Keane 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):433-442
Hyporheic exchange is known to provide an important control on nutrient and contaminant fluxes across the stream-subsurface
interface. Similar processes also mediate interfacial transport in other permeable sediments. Recent research has focused
on understanding the mechanics of these exchange processes and improving estimation of exchange rates in natural systems.
While the structure of sediment beds obviously influences pore water flow rates and patterns, little is known about the interplay
of typical sedimentary structures, hyporheic exchange, and other transport processes in fluvial/alluvial sediments. Here we
discuss several processes that contribute to local-scale sediment heterogeneity and present results that illustrate the interaction
of overlying flow conditions, the development of sediment structure, pore water transport, and stream-subsurface exchange.
Layered structures are shown to develop at several scales within sediment beds. Surface sampling is used to analyze the development
of an armor layer in a sand-and-gravel bed, while innovative synchrotron-based X-ray microtomography is used to observe patterns
of grain sorting within sand bedforms. We show that layered bed structures involving coarsening of the bed surface increase
interfacial solute flux but produce an effective anisotropy that favors horizontal pore water transport while limiting vertical
penetration. 相似文献