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411.
含高浓度有机物及重金属的废水处理方法研究 总被引:2,自引:0,他引:2
采用铁屑综合处理含高浓度有机物及重金属的废水。经处理后的废水,重金属和COD均达到国家排放标准,研究了铁屑用量,作用时间等的最佳值,并对作用机理作了解释。 相似文献
412.
Marine pollution has received considerable attention during the past few years as the news media has focused on such topics as contaminated seafoods, algae blooms, fish and mammal kills, and dirty beaches. The source of these pollution problems are many and include: sewage outfalls, industrial discharges, storm runoff from agricultural lands and metropolitan areas, waste sludges, dredge materials, and highly concentrated chemical and radioactive wastes. Although the United Nations has banned marine dumping, there is still the problem of legacy wastes and low level discharges into the coastal zone. Disposal of these wastes in the marine environment typically involves either: their placement directly on or within the seabed or dilution in the water column. If wastes are diluted in the water column, they have the potential to be adsorbed onto the surface of sediment particles which are settling to the seabed. As particles settle through the water column they are subjected to extensive dispersal and may eventually be injested by bottom-feeding organisms or bio-accumulation by plankton and, thus, enter the food chain. Geotechnical engineers working as members of multidisciplinary teams apply quantitative knowledge about the behavior and physical performance of earth materials toward designing systems for disposing of these wastes in the oceans and aid in monitoring waste disposal sites. In dredged material disposal geotechnical engineers assist in selecting disposal equipment, predict stable characteristics of dredged material mounds, design mound caps, and predict erodibility of the material. With sewage outfalls, geotechnical engineers design foundation and anchor elements, estimate scour potential around the outfalls, and determine the stability of deposits made up of discharged materials. Geotechnical engineers also consider the influence that pollutants have on the engineering behavior of marine sediment and the extent to which changes in behavior affect the performance of structures founded on the sediment. In each of these roles, careful application of geotechnical engineering principles can contribute toward more efficient and environmentally safe disposal operations. 相似文献
413.
河口泥沙运动有其独特的规律,需要采用高分辨率的观测手段进行系统的现场观测,以此发现河口流速和泥沙分布结构,进而探讨其形成机制,应用声学多普勒流速剖面仪和声学悬浮泥沙观测系统,通过定点和走航式观测长江河口不同潮型和流态下流速和悬浮泥沙浓度时空分布发现:(1)不同潮型出现高浓度“事件”的次数和成因存在差异,中潮型出现高浓度“事件”的可能性最大;(2)抛泥泥沙浓度垂向分布至少有3种结构类型,即上小下大的“L”型、指数型和上大下小的“漂浮”型;(3)受抛泥泥沙输移的影响,断面流场形成低流速区,它们的强度随落潮流的扩散逐渐减弱;(4)不同潮型的落潮流表现出不同的输移行为,大、小潮型落潮流偏北,中潮型落潮流偏南;(5)在落潮流和颗粒重力共同作用下抛泥泥沙同时存在输移扩散和沉降过程,小潮型抛泥泥沙主要就近扩散和沉降,中潮和大潮型抛泥泥沙输移扩散范围较远。 相似文献
414.
415.
We used ‘Voltammetry of MicroParticles’ to investigate electrochemically samples from the Boda Albitic Claystone, a potential site for deep underground disposal of nuclear waste in Hungary. The samples were collected near the surface and at a depth of 1050 m. The electrochemical characterization in acidic media allowed the identification of Fe2+ and Fe3+ ions associated with clays, hematite and pyrite. The cathodic detection of pyrite does not raise special difficulties, but the anodic one is complex and depends on the time of the samples exposure to the atmosphere. This work completes a previous Mössbauer spectroscopy study by clarifying the presence, or absence, of extremely small amounts of pyrite in some samples. 相似文献
416.
Leaching of rock-concrete interfaces 总被引:1,自引:1,他引:0
Summary It has been shown that contacts between host rock and engineered barriers may be critical in the design of deep radioactive
waste repositories. Water is expected to reach the interface zone after the resaturation of the geological massive and its
presence may lead to concrete leaching. Such a phenomenon could increase the interface transmissivity and compromise the confinement
of radioactive waste. This paper intends to investigate the influence of concrete leaching on the hydromechanical behaviour
of host rock-concrete interfaces. Some concrete specimens have been subjected to an accelerated leaching process using ammonium
nitrate. The hydromechanical response of degraded concrete-rock interfaces has been studied under shearing and compared to
that of sound interfaces. Consistent with the results available in the literature on bulk concrete, a loss of mechanical strength
has been observed for the degraded interface. Unlike the sound specimens, the degraded interfaces do not dilate when sheared
and they tend to be closed, thereby preventing water from flowing.
Correspondence: O. Buzzi, Centre for Geotechnical and Materials Modelling, School of Engineering, University of Newcastle,
2308 Callaghan NSW, Australia 相似文献
417.
418.
Effect of soil disturbance on recharging fluxes: case study on the Snake River Plain,Idaho National Laboratory,USA 总被引:1,自引:1,他引:0
Soil structural disturbance influences the downward flow of water that percolates deep enough to become aquifer recharge. Data from identical experiments in an undisturbed silt-loam soil and in an adjacent simulated waste trench composed of the same soil material, but disturbed, included (1) laboratory- and field-measured unsaturated hydraulic properties and (2) field-measured transient water content profiles through 24 h of ponded infiltration and 75 d of redistribution. In undisturbed soil, wetting fronts were highly diffuse above 2 m depth, and did not go much deeper than 2 m. Darcian analysis suggests an average recharge rate less than 2 mm/year. In disturbed soil, wetting fronts were sharp and initial infiltration slower; water moved slowly below 2 m without obvious impediment. Richards’ equation simulations with realistic conditions predicted sharp wetting fronts, as observed for disturbed soil. Such simulations were adequate for undisturbed soil only if started from a post-initial moisture distribution that included about 3 h of infiltration. These late-started simulations remained good, however, through the 76 d of data. Overall results suggest the net effect of soil disturbance, although it reduces preferential flow, may be to increase recharge by disrupting layer contrasts. 相似文献
419.
对城市固废治理系统规划管理是有效进行治理决策的根本方法,由此提出了GIS支持的城市固废规划管理智能决策方法。该方法用规划管理的思想将"城市固废治理系统"的决策划分为操作性、战术性、战略性三个层次。在此基础上,构建系统的总体规划。同时,将KBS与总体规划中的半结构化?非结构化模型相结合,提高决策的智能化水平;将GIS与模型整体集成,增强决策的直观性和全面性。给出了该方法的一般性决策模型及决策过程与主要创新,并以该方法为指导,初步建立了GIS支持的城市固废规划管理智能决策系统。 相似文献
420.
高放废物处置库新疆雅满苏和天湖预选地段地下水同位素特征及其指示意义 总被引:1,自引:0,他引:1
高放废物地质处置是将高放废物与人类环境安全隔离的有效途径。高放废物处置库的围岩通常为低渗透的岩体,其安全性在很大程度上取决于围岩对核废物的屏障功能和作为核素迁移载体的裂隙水运动特征。因此,开展处置库场址水文地质评价工作尤为重要。新疆雅满苏和天湖预选地段是我国高放废物处置库预选地段之一。花岗岩是选定的围岩。在过去的3年里,为了认识该地段地下水的形成机制和更新能力,提供该区处置库场址筛选和评价的依据,在该区开展了区域水文地质调查和地下水样品采集。根据调查结果和样品测试数据,本文主要讨论了该地段地下水同位素特征及其水文地质意义,结果表明,地下水δ~2H值主要分布在10.6‰至-82.5‰之间,平均值-46.1‰;δ~(18)O值主要分布在10.2‰至-9.8‰‰之间,平均值-2.06‰;地下水氚含量在1TU~46.1TU之间。地下水δ~2H和δ~(18)O散点图显示,二者主要落在大气降水线的附近和下方,表明区内地下水主要源自当地现代降水的补给,并经受了强烈的蒸发作用,且深部地下水交替能力明显弱于浅部地下水。这一认识为该区处置库选址和场址评价提供了重要水文地质依据。 相似文献