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A Web-based dredge plume simulation software has been developed for estimating sediment transport and contaminant release from dredging operations. This application software comprises a near-field source model and far-field sediment transport model, combined with the settling analysis of flocculent particles. It is designed to run on all computing platforms with a standard Web browser and is accessible over the Internet. This paper describes its internal software structures and the major features of the application software. In addition, an example application of sediment transport in the Savannah River, GA, is included to illustrate typical input and output screens and to demonstrate the accuracy of the model. The water quality assessment software developed herein will greatly enhance the ability of the predictive tool for estimating sediment transport and resuspension during dredging operations. 相似文献
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Ramos-Gómez J Martins M Raimundo J Vale C Martín-Díaz ML DelValls TA 《Marine pollution bulletin》2011,62(7):1538-1549
Sediment toxicity assessments using caged organisms present advantages over using laboratory and native community studies. The use of caged Arenicola marina in sediment toxicity assessments was evaluated. Lugworms were exposed in situ to sediments from coastal and port areas in Spain for seven days, and the activities of the biotransformation enzymes ethoxyresorufin O-deethylase, dibenzylfluorescein dealkylase and glutathione S-transferase, the activities of the antioxidant enzymes glutathione reductase and glutathione peroxidase and lipid peroxidation were then analyzed as biomarkers. Biomarker results and sediment physicochemical data were integrated. Cádiz Bay (SW Spain) sediments presented metal contamination that was not linked to a biochemical response. In LPGC Port (SW Spain), Pb contamination exhibited a moderate toxic potential, while PAHs, and presumably pharmaceuticals, provoked biochemical responses that efficiently prevented lipid peroxidation. In Santander Bay (N Spain), exposure to PAHs and, presumably, pharmaceuticals induced biomarker responses, but lipid peroxidation occurred nevertheless. These results indicated that caged A. marina were effective for the assessment of sediment quality and that the selected biomarkers were sufficiently sensitive to identify chemical exposure and toxicity. 相似文献
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This paper discusses the imperatives of sand search and describes two case histories of sand search in the Niger Delta. These case histories highlight the project cycle of sand search operations and circumstances in which environmental peculiarities can influence procedures and strategies. Field and laboratory procedures emphasise the applications of particle-size distribution and compaction tests to field construction control. The need to integrate mitigative measures of potential impacts into the planning and execution of projects has been emphasised. Some environmental consequences of sand dredging have also been highlighted. 相似文献
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Due to acidity and metals from acid sulfate soils (a.s. soils), many watercourses in midwestern Finland have since 1960s regularly experienced short but intensive periods of poor water quality during high water flow. This has led to occasional massive fish kills and a significant decline in fish populations. 相似文献
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生石灰和水泥混合处理吹填土的试验研究 总被引：9，自引：0，他引：9
随着中国东南沿海地区经济的迅速发展,土地资源不足的问题显得日益突出,人工吹填造地技术为解决这一问题提供了新的思路。吹填造地关键问题之一是要缩短吹填泥浆的固结的时间,为此在室内进行了沉降柱模拟试验,试图寻找一种在吹填的同时进行加固的方法。在沉降柱试验中发现,用水泥作为添加剂对吹填泥浆进行加固处理,其加固效果不如用水泥和石灰混合材料添加剂的加固效果。通过对两种添加方式的土样进行工程地质性质对比和结构性分析及其他一些物理化学试验结果分析,初步找出了加固效果差异的原因。 相似文献
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A bucket wheel dredge (BWD) for offshore tin mining is part of the long term plan of PT Timah Tbk to identify new dredging technologies for mining in greater than 50 m water depths. Measured tin-ore physical properties are used in a new BWD computer model to investigate deep water tin mining. The model simulates the cutting and hydraulic transport of submerged tin-ore. The results show that hydraulic tin mining beyond water depths of 50 m is feasible. It is best to employ hydraulic transport for lifting the tin-ore from the ocean floor to the surface and to use barges to transport the tin-ore to land processing plants. 相似文献
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Management of coastal ecosystems necessitates the evaluation of pollutant loading based on adequate source discrimination. Monitoring of sediments and fish on the shelf off San Diego has shown that some areas on the shelf are contaminated with polychlorinated biphenyls (PCBs). Here, we present an analysis of PCB contamination in fish on the shelf off San Diego designed to discriminate possible sources. The analysis was complicated by the variability of species available for analysis across the shelf, variable affinities of PCBs among species, and non-detects in the data. We utilized survival regression analysis to account for these complications. We also examined spatial patterns of PCBs in bay and offshore sediments and reviewed more than 20 years of influent and effluent data for local wastewater treatment facilities. We conclude that most PCB contamination in shelf sediments and fish is due to the ongoing practice of dumping contaminated sediments dredged from San Diego Bay. 相似文献
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W.?R.?KellyEmail author H.?A.?Wehrmann T.?R.?Holm J.?L.?Talbott L.?M.?Skowron 《Environmental Geology》2003,45(1):23-34
In 1982, sediments contaminated with zinc, cadmium, and copper were dredged from Lake DePue in Illinois and deposited in a diked sediment disposal area (DSDA) that is flooded annually for at least three months. Data from soil and groundwater samples collected at multiple depths within and adjacent to the DSDA indicate vertical movement of the metals in the subsurface, although groundwater outside of the DSDA was not contaminated with any of the metals. Zinc was elevated in almost all of the wells inside the DSDA. Cadmium concentrations were elevated in shallow wells inside the DSDA, while copper was rarely detected in the groundwater. Comparisons of groundwater samples taken within the DSDA under flooded and unflooded conditions suggest that pH and redox conditions controlled metal solubilities. A comparison between soil cores and sediment cores from Lake DePue suggest that zinc was more mobile than cadmium or copper within the DSDA. 相似文献
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杭州西湖底泥疏浚工程的生态效应 总被引：22，自引：3，他引：19
杭州西湖一直被富营养化问题所困扰。迄今为止,先后采用了多种工程措施进行治理。通过对杭州市政府1999-2002年对西湖实施的底泥疏浚工程前后沉积物中营养物质含量、水质以及水生生物群落各主要类群等方面的研究,评价了此次工程对减轻西湖的营养盐内负荷、控制湖泊富营养化的效果,探讨该工程的生态风险及对西湖水生生态系统重建的影响。研究结果表明：疏浚工程降低了西湖各层沉积物中的有机物、氮和磷含量,尤其是沉积物表层10cm中的有机质、总氮和有机磷含量均有明显的下降;疏浚后西湖水体与富营养化相关的主要指标均有不同程度的改善;水体中浮游植物密度、生物量有不同程度的降低,群落中蓝藻比例下降;浮游动物群落的种类有所增加;疏浚后底栖大型无脊椎动物群落快速恢复;疏浚后的水生生物群落指示水体富营养化程度有所减轻。 相似文献
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