摘要:
A natural gradient, single well, tracer dilution non-continuous mixing apparatus and method for measuring flow of liquids through porous media are described. The method has been applied to concentrations of Light Nonaqueous Phase Liquid (LNAPL) in monitoring wells to measure the rate of LNAPL flow through the wells and through the adjacent formation. Similar measurements were made for concentrations of water in other formations. A LNAPL-soluble fluorescing tracer was added to LNAPL in the wells, and a water-soluble fluorescing tracer was added to water in the wells. The tracer is initially uniformly-mixed into the LNAPL or water in the well, and the tracer concentration is measured using a fiber optic cable and a spectrometer. The LNAPL or water with dissolved tracer is then allowed to flow from the well without any mixing. At a later time, the LNAPL or water and tracer in the well are mixed to a uniform tracer concentration, and the tracer concentration is remeasured. Using the initial tracer concentration, the subsequently mixed tracer concentration, the elapsed time, and the well diameter, a LNAPL flow rate is calculated.
摘要:
A passive sampling apparatus and method for measuring the cumulative mass of a selected gas being transported through a known cross-sectional area, for example, a soil surface, during a chosen period of time, using absorbent material, are described. Two quantities of absorbent material are disposed in a hollow container, such as a pipe section, and spaced apart such that they may be readily separated for analysis. The absorbent material closest to the soil captures the gas leaving the soil. Under reversed flow conditions, for example when the ambient air enters the ground because of fluctuations in atmospheric pressure, the upper absorbent material captures the component of interest entering the apparatus, thereby preventing this gas from entering the lower material and disturbing the measurement. The apparatus can therefore sequester the component of interest without being affected by the direction of gas transport.
摘要:
A method and apparatus for measuring in situ flow of non-aqueous phase liquids (NAPLs) through a porous medium is described. A tracer is introduced into a well or boring located in the medium and the tracer concentration in the well kept uniform by mixing. The rate at which the tracer is depleted from the well has been determined to be proportional to the flow rate of the NAPL through the well or boring and surrounding formation.
摘要:
A method and apparatus for measuring in situ flow of non-aqueous phase liquids (NAPLs) through a porous medium is described. A tracer is introduced into a well or boring located in the medium and the tracer concentration in the well kept uniform by mixing. The rate at which the tracer is depleted from the well has been determined to be proportional to the flow rate of the NAPL through the well or boring and surrounding formation.
摘要:
A passive sampling apparatus and method for measuring the cumulative mass of a selected gas being transported through a known cross-sectional area, for example, a soil surface, during a chosen period of time, using absorbent material, are described. Two quantities of absorbent material are disposed in a hollow container, such as a pipe section, and spaced apart such that they may be readily separated for analysis. The absorbent material closest to the soil captures the gas leaving the soil. Under reversed flow conditions, for example when the ambient air enters the ground because of fluctuations in atmospheric pressure, the upper absorbent material captures the component of interest entering the apparatus, thereby preventing this gas from entering the lower material and disturbing the measurement. The apparatus can therefore sequester the component of interest without being affected by the direction of gas transport.
摘要:
A natural gradient, single well, tracer dilution non-continuous mixing apparatus and method for measuring flow of liquids through porous media are described. The method has been applied to concentrations of Light Nonaqueous Phase Liquid (LNAPL) in monitoring wells to measure the rate of LNAPL flow through the wells and through the adjacent formation. Similar measurements were made for concentrations of water in other formations. A LNAPL-soluble fluorescing tracer was added to LNAPL in the wells, and a water-soluble fluorescing tracer was added to water in the wells. The tracer is initially uniformly-mixed into the LNAPL or water in the well, and the tracer concentration is measured using a fiber optic cable and a spectrometer. The LNAPL or water with dissolved tracer is then allowed to flow from the well without any mixing. At a later time, the LNAPL or water and tracer in the well are mixed to a uniform tracer concentration, and the tracer concentration is remeasured. Using the initial tracer concentration, the subsequently mixed tracer concentration, the elapsed time, and the well diameter, a LNAPL flow rate is calculated.