Measurement of LNAPL flow using single-well tracer dilution techniques   总被引：1，自引：0，他引：1  

Sale T  Taylor GR  Iltis G  Lyverse M 《Ground water》2007,45(5):569-578

This paper describes the use of single-well tracer dilution techniques to resolve the rate of light nonaqueous phase liquid (LNAPL) flow through wells and the adjacent geologic formation. Laboratory studies are presented in which a fluorescing tracer is added to LNAPL in wells. An in-well mixer keeps the tracer well mixed in the LNAPL. Tracer concentrations in LNAPL are measured through time using a fiber optic cable and a spectrometer. Results indicate that the rate of tracer depletion is proportional to the rate of LNAPL flow through the well and the adjacent formation. Tracer dilution methods are demonstrated for vertically averaged LNAPL Darcy velocities of 0.00048 to 0.11 m/d and LNAPL thicknesses of 9 to 24 cm. Over the range of conditions studied, results agree closely with steady-state LNAPL flow rates imposed by pumping. A key parameter for estimating LNAPL flow rates in the formation is the flow convergence factor alpha. Measured convergence factors for 0.030-inch wire wrap, 0.030-inch-slotted polyvinyl chloride (PVC), and 0.010-inch-slotted PVC are 1.7, 0.91, and 0.79, respectively. In addition, methods for using tracer dilution data to determine formation transmissivity to LNAPL are presented. Results suggest that single-well tracer dilution techniques are a viable approach for measuring in situ LNAPL flow and formation transmissivity to LNAPL.  相似文献   

Role of Hydrology in the Formation of Co-rich Mn Crusts from the Equatorial N Pacific,Equatorial S Indian Ocean and the NE Atlantic Ocean     

Geoffrey P. Glasby  Bruce Mountain  Theckethottathil C. Vineesh  Virupaxa Banakar  Ramesh Rajani  Xiangwen Ren 《Resource Geology》2010,60(2):165-177

Co-rich Mn crusts from four different locations of the world ocean have been studied to understand the role of dissolved oxygen of the ambient seawater in the formation of Co-rich Mn crusts. WOCE (World Ocean Circulation Experiment) oxygen profiles of modern seawater in the Equatorial North Pacific Ocean, Equatorial South Indian Ocean and the North East Atlantic Ocean have been evaluated with respect to the occurrence of Co-rich Mn crusts at depths ranging from 1500 to 3200 m. The oxygen content at these depths varied from ∼90–240 µmol/kg. The oxygen minimum zone (OMZ), with oxygen contents in the range ∼45–100 µmol/kg, is located in the depth range 800–900 m in these regions. The age of the ocean crust on which seamounts formed is in the range 80.3–180 Ma. Profiles of the oxygen contents of seawater with depth in the oceans are shown to be extremely useful in establishing the optimum conditions for the formation of Co-rich Mn crusts. The use of WOCE oxygen profiles to study geochemical processes in the oceans is highly recommended.  相似文献   

Incorporation of Transition and Platinum Group Elements (PGE) in Co-rich Mn Crusts at Afanasiy-Nikitin Seamount (AFS) in the Equatorial S Indian Ocean     

Geoffrey P. Glasby 《Resource Geology》2010,60(2):212-215

Of the 12 elements enriched in Co-rich Mn crusts from the Afanasiy-Nikitin Seamount in the Equatorial S Indian Ocean, Mn, Fe and Co are enriched by a factor of ~10⁹ compared to their concentrations in seawater whereas Ni and Cu are enriched by a factor of ~10⁷ and the PGE and Au by a factor of ~10⁵ to 10⁷ compared to their concentrations in seawater. The relatively high concentration of Pt in the crusts reflects its occurrence as fine-grained particles in the crusts rather than adsorption of the elements from seawater.  相似文献   

Editorial     

Geoffrey Newall 《Geological Journal》1980,15(1):1-1

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