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31.
In multiphase systems capillary pressures play a significant role on fluid movement and retention. The facility to predict
the effect of different thermal remediation strategies requires the knowledge of the effect of temperature on capillary pressure-saturation
relationships in the soils.
The objective of recent study was (a) to develop a technique for routinely measuring the pressure-saturation curves of soil
samples saturated with a nonpolar liquid at different regulated temperatures (b) to build a database using the measured pressure-saturation
curves and the physical, chemical properties of the model soils (c) to establish the dependence of nonaqueous phase liquid
retention on the soil properties and the temperature.
The retention curves (extraction isotherms) with nonaqueous phase liquid were determined using a modified
pressure plate extractor. The wetting phase was a non-aromatic hydrocarbon distillation product. Pressure plates were designed and constructed in
the laboratory of our department. The temperature was held constant at 20, 40 and 60 ∘C.
Statistical analysis was performed involving selected soil parameters and the measured nonaqueous phase liquid retention data.
The results show that knowing some easily measurable soil parameters (bulk density, particle size distribution, humus and
lime content) we can estimate the nonaqueous phase liquid retention of the soils. The measured “extraction isotherms” provide
essential information about the temperature-dependency of pressure-saturation curves. 相似文献
32.
The New Jersey Toxics Reduction Workplan for Ny-Nj Harbor: Distribution of Pcdd/Fs in Ambient Waters
As part of the NJ Toxics Reduction Workplan for NY-NJ Harbor, ambient water samples were collected at fifteen locations along
the tidal portions of the Hackensack, Passaic, Raritan, Rahway and Elizabeth Rivers, and in Newark Bay, the Arthur Kill, and
Kill van Kull. A Trace Organics Platform Sampler was used to collect a total of 75 suspended sediment phase samples between
June 2000 and May 2002. These samples were analyzed for spatial and wet vs. dry weather trends in the 17 polychlorinated dibenzo-p-dioxins
and dibenzofurans (PCDD/Fs; modified USEPA Method 1613b). Mean total PCDD/F (tPCDD/F) concentrations at the sampling locations
ranged between 3.8 and 41.5 ng/g. On average, OCDD accounted for almost 80% of the tPCDD/F concentrations; mean total [PCDD/F
– OCDD] concentrations ranged between 0.84 and 5.20 ng/g at the sampling locations. Mean 2,3,7,8-TCDD concentrations ranged
between 0.003 and 0.28 ng/g, with the highest concentrations (> 0.10 ng/g) along the tidal Passaic and lower Hackensack Rivers,
and in upper Newark Bay. Mean tPCDD/F Toxic Equivalency Quotients (TEQ) ranged between 45 and 344 TEQ pg/g, with the highest
levels found in the lower Passaic River. Toxicity was primarily driven by 2,3,7,8-TCDD concentrations in the Passaic and Hackensack
Rivers, and in Newark Bay. Examples of congener distribution patterns at some of the sampling locations are also presented. 相似文献
33.
34.
矿井井筒提升设备绕流的数值模拟 总被引:2,自引:0,他引:2
基于经典的流体力学理论,建立罐笼绕流的二维RNGκ-ε湍流模型,分析其初始边界条件,并结合工程实际应用FLUENT计算流体动力学软件模拟罐笼运行时井筒内流场及压力场,得出井筒内流场及压力场的变化规律。研究结果表明:在罐笼运行期间,由于空间受限而引发活塞效应,井筒内压力发生瞬态变化,造成通风系统的压力波动,导致气流运动的动态改变,对通风系统稳定性有一定的影响。 相似文献
35.
通过对特种胶塑复合管的抗张强度计算和生产实践,证明了矿用充填管路采用胶塑复合管是可行的。为矿用充填管以胶塑复合管替代铁管提供了依据。 相似文献
36.
基于系统的试验 ,总结已有成果 ,研究了饱和黄土和砂土液化在液化机理、液化判别标准、影响液化的因素、孔压和应变的发展等方面的异同之处。研究表明 ,由于在液化机理上存在差异 ,导致二者动荷载下的孔压和应变发展特点有显著差别 ;同一因素对二者液化性状的影响可能相似 ,也可能不同 ;在动三轴液化试验中 ,黄土和砂土均可采用初始液化作为液化的判别标准。 相似文献
37.
38.
利用多年的环境监测数据,分析南昌市环境空气中主要污染物尘类、二氧化硫和氮氧化物产生的原因,并提出有效控制上述污染物的具体措施。 相似文献
39.
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