KR20170105926A - Apparatus for concurrently determining hydraulic conductivity, dispersivity and effective porosity of soils, and method for determining hydraulic conductivity, dispersivity and effective porosity of soils using the same apparatus - Google Patents

Apparatus for concurrently determining hydraulic conductivity, dispersivity and effective porosity of soils, and method for determining hydraulic conductivity, dispersivity and effective porosity of soils using the same apparatus Download PDF

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KR20170105926A
KR20170105926A KR1020160029314A KR20160029314A KR20170105926A KR 20170105926 A KR20170105926 A KR 20170105926A KR 1020160029314 A KR1020160029314 A KR 1020160029314A KR 20160029314 A KR20160029314 A KR 20160029314A KR 20170105926 A KR20170105926 A KR 20170105926A
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sample
tracer
column
soil
concentration
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KR1020160029314A
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KR101804376B1 (en
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정상용
벤카트라마난 세나파티
엘리어벡 카키모프
조준열
강형빈
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부경대학교 산학협력단
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
    • G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
    • G01N15/088—Investigating volume, surface area, size or distribution of pores; Porosimetry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
    • G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
    • G01N15/082—Investigating permeability by forcing a fluid through a sample
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
    • G01N2015/0023—Investigating dispersion of liquids

Abstract

The present invention provides a simultaneous determination apparatus capable of simultaneously determining a permeability coefficient, a dispersion index, and an effective porosity, which are characteristic data of an aquifer important for groundwater development, management, and maintenance by performing a single experiment. The simultaneous determination apparatus can simply determine the permeability coefficient, the dispersion index, and the effective porosity, which are the characteristic data of the aquifer important for groundwater development, management, and maintenance with a single experiment by using the soil sample, thereby ensuring accuracy in data, and significantly reducing the costs and the time required for analyzing characteristics of the aquifer.

Description

TECHNICAL FIELD The present invention relates to an apparatus for simultaneously determining the permeability coefficient, the dispersion index and the effective porosity of a soil, and the method of determining the permeability coefficient, the dispersion index and the effective porosity of the soil using the same. , dispersivity and effective porosity of soils using the same apparatus}

The present invention relates to a device capable of simultaneously determining the permeability coefficient, the dispersion index and the effective porosity of a soil, and a method for determining the permeability coefficient, dispersion index and effective porosity of the soil using the same.

Groundwater is an important source of drinking water, with little change in water temperature due to seasonal changes and little change in quality. In addition, surface water penetrates into the ground to form underground water, and the natural filtering by the soil provides good water quality, and it contains a large amount of various minerals that are beneficial to the human body, resulting in high quality drinking water. In comparison with surface water, maintenance and development costs are low, and developed countries have long been developing and using groundwater for drinking purposes.

In general, the formation of the above-mentioned groundwater plays an important role in the formation of aquifer in the stratum, and the aquifer is permeable among the strata and saturated with water and sufficient to discharge a considerable amount of water Means a stratum that has permeability and numerical continuity. Soil aquifers are well developed with pores in the medium, and groundwater is relatively uniformly present in all pores. However, in the crystalline rock aquifers, the cracks in the groundwater layer must be well developed for the presence and distribution of groundwater. The groundwater productivity of these aquifers is governed by the permeability coefficient, groundwater availability by the effective porosity and diffusion of pollutants in the aquifer by the dispersion index.

Therefore, these permeability factors, effective porosity and dispersion index are very important parameters for the development, conservation and management of groundwater as a peculiar factor that characterize the aquifer. Various methods have been studied for their determination.

For example, in Korean Patent Registration No. 10-1523067, a gas cylinder for injecting nitrogen gas, a water cylinder for discharging water injected by the pressure of nitrogen gas, A penetration rod formed in the bottom of the water cylinder to form a flow passage for the water to flow into the interior of the water cylinder and a plurality of water outlets connected to the lower end of the penetration rod for discharging water from the water cylinder through the penetration rod to the ground for measurement of permeability coefficient And a circulation slope is formed by laminating annular slits on the surface of the soil.

As another example, in order to analyze the aquifer characteristics as described above, in Korean Patent Laid-Open Publication No. 10-2006-0132329 of Document 2, the permittivity constants of the respective media constituting the ground are combined and reacted using a measurement sensor Discloses a dielectric constant measuring system for calculating the porosity or effective porosity of a ground medium in a saturated or unsaturated state.

The apparatus and system as described above have calculated the permeability coefficient, the dispersion index, or the effective porosity, which are characteristic data of the aquifer in the stratum, through different methods. However, since the soil samples are made in nature, the aquifer data collected from each separate test are not accurate because each soil sample used by the method can not be absolutely identical. There is a problem in that it is inevitably required to analyze each characteristic separately, and there is a disadvantage that cost and time are consumed.

Therefore, there is a need for a study on a method that can overcome such shortcomings.

Korean Patent No. 10-1523067 (Published on May 27, 2015) Korean Patent Publication No. 10-2006-0132329 (published on December 21, 2006) Public Utility Model Room 2000-0013204 (Published on July 15, 2000) Korean Patent Publication No. 10-2011-0064914 (published on June 15, 2011)

DISCLOSURE Technical Problem The present invention has been devised to solve the problems of the prior art as described above, and it is an object of the present invention to provide a device capable of simultaneously determining the permeability coefficient, the dispersion index and the effective porosity of the soil, and the permeability coefficient, dispersion index and effective porosity And to provide a technical description of how to determine.

Technical Solution According to an aspect of the present invention, there is provided a tracer apparatus including: a receiving space in which a tracer sample to be supplied through an opening is received; a valve member provided to supply a tracer sample of a predetermined volume at a predetermined speed; A sample supply unit; A column including a discharge space through which a tracer sample supplied from the sample supply unit passes through the soil sample and is connected to the sample supply unit and is connected to the sample supply unit; A plurality of storage tanks for separately storing the tracer samples discharged through the discharge port of the column portion at predetermined time intervals; A permeability coefficient calculator connected to the plurality of reservoirs to calculate a permeability coefficient of the soil sample; A dispersion index calculating unit connected to the plurality of storage tanks to calculate a dispersion index of the soil sample using a change in concentration of the tracer sample; And an effective porosity calculating unit calculating the effective porosity of the soil sample using the change in concentration of the tracer sample calculated by the dispersion index calculating unit.

In order to measure the head of the tracer sample supplied to the sample supply unit and the length of the soil sample filled in the column unit, the sample supply unit and the column unit are made of a transparent material, Wherein a scale is formed.

The outlet may be provided with a membrane.

In addition, the tracer sample is characterized by containing sodium bromide (NaBr) or potassium bromide (KBr).

The sample supply unit may further include a pressure supply unit provided on one side of the sample supply unit.

Also, the permeability coefficient calculation unit may calculate the permeability coefficient based on the cross-sectional area of the sample supply unit and the column unit; A length of the soil sample filled in the column portion; An initial head of the tracer sample supplied to the sample supply unit; After completion of the supply of the tracer sample to the column portion, the final head of the tracer sample remaining in the sample supply portion; And a total time taken for the tracer sample to pass through the column section, to calculate the permeability coefficient of the soil sample.

The dispersion index calculating unit may be connected to the plurality of storage tanks to detect variation in concentration of the tracer samples separated and stored at predetermined time intervals to calculate the dispersion index of the soil samples.

The effective porosity calculating unit may calculate an average flow rate using a change in concentration of the tracer sample and calculate a specific discharge of the tracer sample from the total discharge amount of the tracer sample discharged through the outlet of the column The effective porosity of the soil sample is calculated using the volume of the non-spilled tracer sample and the average flow rate.

(A) collecting a soil sample from the soil and filling the column sample with the soil sample; (b) injecting a tracer sample stored in a sample supply unit into a column portion filled with the soil sample at a predetermined speed; (c) separating and recovering the tracer samples injected into the column portions at predetermined time intervals; (d) after completing the supply of the tracer sample to the column portion, the cross-sectional area of the sample supply portion and the column portion, the length of the soil sample filled in the column portion, the initial head of the tracer sample supplied to the sample supply portion, Calculating a permeability coefficient of the soil sample using a final head of the tracer sample remaining in the tracer sample and a total time required for the tracer sample to pass through the column; (e) generating a concentration hysteresis curve using the concentration of the tracer sample collected at step (c) at a time interval and the initial concentration of the tracer sample injected at step (b), and then calculating a time corresponding to a preset concentration ratio Calculating a dispersion index of the soil sample; And (f) a specific discharge calculated in consideration of a total volume of the sample supplied to the column in the step (c) and a total cross-sectional area of the column, Calculating the effective porosity of the soil sample by using the average flow rate of the soil sample obtained by applying the time corresponding to the concentration ratio calculated in the method of determining the permeability coefficient, the dispersion index, and the effective porosity of the soil .

In addition, the soil sample is characterized by being a Buddhist sample.

In the step (a), the soil sample is collected using a drilling method.

Also, the tracer sample is characterized by containing sodium bromide (NaBr) or potassium bromide (KBr) in a concentration of 400 to 600 mg / L.

In addition, in the step (c), the concentration of the tracer sample recovered separately at predetermined time intervals is measured, and the concentration of the tracer sample collected in the step (b) is compared with the concentration of the tracer sample supplied to the column. And stopping the supply of the tracer sample to the column when the concentration difference of the tracer sample supplied to the column is less than 1 to 10%.

The apparatus for simultaneous determination of the permeability coefficient, dispersion index and effective porosity of a soil according to the present invention is characterized in that a permeability coefficient, a dispersion index and an effective porosity, which are characteristics of aquifer important for groundwater development, management and conservation, The accuracy of the data can be secured and the cost and time for analyzing the characteristics of the aquifer can be drastically reduced.

Fig. 1 is a structural view schematically showing a simultaneous crystallization apparatus according to the present invention.
2 is a flow chart showing each step of determining the permeability coefficient, dispersion index and effective porosity of the soil according to the present invention
3 is a conceptual diagram schematically showing a method of measuring permeability coefficient in the simultaneous determination method according to the present invention.
4 is an actual image of a simultaneous crystallization apparatus used for a column test according to an embodiment.
5 is an actual image of the column (a) column and (b) sample injecting section of the simultaneous crystallization apparatus used for the column test according to the embodiment.
6 is an actual image of two kinds of membranes provided in the simultaneous crystallization apparatus used for the column test according to the embodiment.
7 is an actual image of the fractional water sampler provided in the simultaneous crystal determination apparatus used for the column test according to the embodiment.
8 is a concentration hysteresis curve calculated by the method according to the embodiment.

Hereinafter, the present invention will be described in detail.

The present invention provides a device capable of simultaneously determining the permeability coefficient, dispersion index and effective porosity of a soil so as to analyze the characteristics of the aquifer in the ground for the development, management and conservation of groundwater.

The permeability coefficient of the soil samples in the aquifer in the aquifer is important for determining the amount and rate of groundwater and the dispersion index is important for determining the degree of diffusion of heavy metals or organic pollutants into the groundwater. The effective porosity is very important for determining the actual velocity of groundwater or the amount of groundwater.

Accordingly, the present invention provides a simultaneous determination apparatus capable of simultaneously determining the above three important data with a simple configuration.

Fig. 1 is a conceptual diagram schematically showing a simultaneous crystal determination apparatus 10 according to the present invention.

As shown in FIG. 1, the simultaneous crystallization apparatus 10 according to the present invention includes a sample supply unit 100 for supplying a tracer sample so as to analyze characteristics of an aquifer in a ground layer; A column part 200 filled with a soil sample; A fractionation unit 300 including a reservoir 310 for separating and storing traceer samples supplied to the column unit 200; A permeability coefficient calculating unit 400 for calculating a permeability coefficient of the soil sample, a dispersion index calculating unit 500 for calculating a dispersion index, and an effective porosity calculating unit 600 for calculating an effective porosity.

The sample supply unit 100 may store the tracer sample formed through the opening 110 with the opening 110 and the accommodation space 120 inside the accommodation space 120 and store the stored tracer sample into a column part And a valve member 130 to adjust the supply rate of the tracer sample so that the tracer sample having a predetermined volume can be supplied to the column 200 at a predetermined speed.

The simultaneous crystallization apparatus 10 according to the present invention is a system in which when a tracer solution is supplied from the sample supply unit 100 using the principle of natural drainage, And discharged through the discharge port 220, so that the characteristics of the soil sample can be grasped.

However, the characteristics of the soil samples such as watertightness are different, and when the tracer sample is supplied to the soil with high watertightness, the permeability time of the tracer sample may increase and the measurement time of the permeability of the soil sample may increase. Accordingly, in the present invention, a pressure supply unit (not shown) is additionally provided on one side of the upper part of the sample supply unit 100 to simultaneously supply pressure during the tracer sample injection, thereby reducing the permeation time of the tracer sample, Can be configured to compensate for the same drawbacks.

In order to analyze the characteristics of the aquifer in the groundwater, the tracer sample can use a compound containing ions which can be easily decomposed when contained in the soil and can be easily leached into groundwater. The ions include bromine ions as a representative example . Accordingly, the tracer sample may include various types of compounds including the above-mentioned bromine ion, low molecular weight, and easily decomposable into ions. As the tracer sample, sodium bromide (NaBr) or potassium bromide bromide, KBr) can be used as a representative example.

The column part 200 is filled with the soil sample by forming the receiving space 210 and is connected to the sample supply part 100 and the pipe 140 so that natural drainage by gravity the tracer sample supplied from the sample supply unit 100 may be configured to pass through the soil sample, and the tracer sample supplied from the sample supply unit 100 may be discharged through the soil sample As shown in FIG.

Membranes 230a and 230b are provided in the column section 200. A lower membrane 230a is installed under the column section 200 before filling the soil sample and the soil sample is charged The upper membrane 230b is installed on the upper surface of the soil sample to prevent foreign matter from entering into the column 200 and to uniformly inject the tracer solution, Can be configured to prevent loss.

The sample supply unit 100 and the column unit 200 are made of a transparent material so that the tracer sample supplied to the sample supply unit 100 and the soil sample supplied to the column unit 200 can be visually checked The length of the tracer sample supplied to the sample feeding part 100 and the length of the soil sample filled in the column part 200 are measured so that the distance between the sample feeding part 100 and the column part 200 It is possible to form the scale on the outer surface and to easily measure the volume of the tracer sample and the soil sample by using the lengths of each of the tracer sample and the soil sample and the cross sectional area of the sample feeding part 100 and the column part 200.

The classifying and collecting unit 300 includes a plurality of storage tanks 310 so that the tracer samples discharged through the discharge port 220 of the column unit 200 can be separately stored at predetermined time intervals. 310 may be configured to separately store the tracer samples continuously in another adjacent storage tank 310 when a predetermined volume of tracer samples are supplied for a preset time.

In addition, the fractionation unit 300 may use an automatic fractionation unit 300 provided with a transfer unit and a control unit so as to automatically transfer the storage unit 310 at preset time intervals.

The permeability coefficient calculating unit 400 calculates the permeability coefficient of the soil sample by using the relationship between the descent of the water level and the passage time caused by the tracer sample supplied from the sample supply unit to the column unit 200 through the soil sample having a constant cross- Can be calculated.

For example, the permeability coefficient calculator 400 may calculate the permeability coefficient using the on-parameter permeability equation. The permeability coefficient calculating unit 400 may calculate the permeability coefficient of the sample 200 in accordance with the cross sectional area of the sample supply unit 100 and the column 200 and the length of the soil sample filled in the column 200, After the initial head of the tracer sample and the supply of the tracer sample to the column section 200 are completed, the final head of the tracer sample remaining in the sample supply section 100 and the tracer sample pass through the column section 200 The permeability coefficient of the soil sample can be calculated using the total time required for the soil sample.

The dispersion index calculating unit 500 may calculate the dispersion index of the soil sample by sensing the concentration change of the tracer sample passing through the soil sample. To this end, the dispersion index calculating unit 500 may be connected to the plurality of storage tanks 310 of the fractionation unit 300 to detect a concentration change of the tracer samples separated and stored at predetermined time intervals, And the generated concentration hysteresis curve is fitted to the normal distribution curve, and the dispersion index of the soil sample can be calculated by using an equation to be described later.

The effective porosity calculating unit 600 calculates the average flow velocity of the tracer sample passing through the soil sample using the concentration hysteresis curve of the tracer sample obtained in the plurality of reservoirs 310 of the fractionation unit 300, The specific discharge of the tracer sample obtained by converting the total volume discharged through the discharge port 220 of the column part 200 of the tracer sample supplied from the controller 100 into the unit time and the sectional area of the column part 200 was calculated The effective porosity of the soil sample can then be calculated using the average flow rate.

The apparatus 10 for determining the permeability coefficient, the dispersion index and the effective porosity of the soil according to the present invention as described above is characterized in that the permeability coefficient, dispersion index and effective porosity, which are characteristics of aquifer important for groundwater development, management and conservation, It is possible to determine easily by one experiment using the sample, and it is possible to secure the accuracy of the data and drastically reduce the cost and time for analyzing the characteristics of the aquifer.

FIG. 2 is a process diagram showing each step of determining the permeability coefficient, the dispersion index and the effective porosity of the soil according to the present invention.

As shown in FIG. 2, the method of determining the permeability coefficient, the dispersion index and the effective porosity of the soil according to the present invention is carried out under natural drainage, comprising the steps of (a) collecting a soil sample from the soil, Charging; (b) injecting a tracer sample stored in a sample supply unit into a column portion filled with the soil sample at a predetermined speed; (c) separating and recovering the tracer samples injected into the column portions at predetermined time intervals; (d) after completing the supply of the tracer sample to the column portion, the cross-sectional area of the sample supply portion and the column portion, the length of the soil sample filled in the column portion, the initial head of the tracer sample supplied to the sample supply portion, Calculating a permeability coefficient of the soil sample using the final head of the tracer sample remaining in the tracer sample and the total time spent by the tracer sample to pass through the column; (e) creating a concentration hysteresis curve using the concentration of the tracer sample collected at step (c) at a time interval and the initial concentration of the tracer sample injected at step (b), and calculating a time corresponding to a predetermined concentration ratio Calculating a dispersion index of the soil sample; And (f) a specific discharge calculated in consideration of a total volume of the sample supplied to the column in the step (c) and a total cross-sectional area of the column, And calculating the effective porosity of the soil sample using the average flow rate of the soil sample obtained by applying the time corresponding to the concentration ratio calculated in the step (1).

The step (a) is a step of collecting a soil sample to analyze characteristics of the aquifer and filling the column part with the soil sample.

In this step, an undisturbed sample in which the soil is kept in a natural state can be used as the soil sample. In order to collect the soil sample of Buddhism mentioned above, in this step, Or a thin wall tube method may be used to collect the soil sample.

In the step (b), the tracer sample stored in the sample supply unit is injected into the column portion filled with the soil sample at a predetermined speed.

In this step, an aqueous solution containing sodium bromide (NaBr) or potassium bromide (KBr) may be used as the tracer sample. At this time, the concentration of the tracer sample can be set in consideration of the groundwater concentration in the soil, and it is preferable that the concentration of the bromine ion included in the tracer sample is about 50 times higher than that of the groundwater in the soil. Accordingly, considering that the concentration of bromine ion in general groundwater is about 10 mg / L, the trace sodium sample can be configured to contain sodium bromide at a concentration of 400 to 600 mg / L, Concentration.

In the step (c), the step of separating and recovering the tracer samples injected into the column part at a predetermined time interval and separating and storing the tracer samples flowing out through the column part at predetermined time intervals as described above The concentration of the tracer sample can be calculated by time interval.

The concentration hysteresis curve can be generated using the concentration of the tracer sample calculated for each time interval as described above, and the concentration hysteresis curve can be fitted to the normal distribution curve, and the dispersion index of the soil sample can be calculated at a later stage.

Also, in this step, the concentration of the recovered tracer sample collected at predetermined time intervals is measured, and the concentration of the recovered tracer sample is compared with the initial concentration of the tracer sample supplied to the column in the step (b) The supply of the tracer sample to the column may be stopped to stop the supply of the tracer sample for analyzing the characteristics of the soil sample, and the reaction may be terminated.

Wherein the cross-sectional area of the sample feeding part and the column part, the length of the soil sample filled in the column part, the cross-sectional area of the sample feeding part and the column part in the step (c), the length of the soil sample filled in the column part, The initial head of the tracer sample supplied to the sample supply unit, the final head of the tracer sample remaining in the sample supply unit after the supply of the tracer sample to the column unit is completed, the total time taken for the tracer sample to pass through the column Is used to calculate the permeability coefficient of the soil sample.

In this step, as described above, the permeability coefficient K can be calculated using the equation (1), which is a formula for measuring the permeability of two variables using the Darcy's law shown below (see FIG. 3) so that the permeability coefficient can be calculated ).

[Equation 1]

Figure pat00001

Where A 1 is the cross-sectional area of the sample feed, A 2 is the cross-sectional area of the column, L is the length of the soil sample, t is the total elapsed time, h 0 is the initial head of the tracer sample, and h t is the head at the end of the test .

In the step (e), a concentration hysteresis curve is created using the concentration of the tracer sample collected at the time interval and the initial concentration of the tracer sample injected at the step (b) in the step (c) The variance index of the soil sample can be calculated by calculating the corresponding time.

For example, a concentration hysteresis curve is constructed using the time-dependent concentration of the recovered tracer sample and the initial concentration of the injected tracer sample, the concentration hysteresis curve is fitted to the normal distribution curve, and the concentration ratio of the tracer sample is 16 %, 50%, and 84%, respectively, and then the dispersion index of the soil sample can be calculated. Therefore, the concentration of the time-of-flight tracer sample in the fitted curve can be calculated by setting t (t 0.16 , t 0.5 , t 0.84 ), respectively, as shown below.

The dispersion index can be calculated using the following Equations (2) to (4) derived from the one-dimensional non-reactive advection-dispersion equation (1-D Non-Reactive Advection-Dispersion Equation). For reference, during the above-described calculation process, the molecular diffusion coefficient is negligible because it is much smaller than the mechanical dispersion.

&Quot; (2) "

Figure pat00002

&Quot; (3) "

Figure pat00003

&Quot; (4) "

Figure pat00004

Here, t 0.5 , t 0.16 , and t 0.84 are the times when the ratio of C (t) / C 0 is 0.16, 0.5, and 0.84, respectively. D l is the longitudinal dispersion coefficient, L is the length of the sample,

Figure pat00005
Is the mean flow velocity of groundwater, and α 1 is the longitudinal dispersion index.

For reference, the dispersion index calculating equation can be described as follows. When the solute in the homogeneous porous medium is non-reactive, the one-dimensional advection-dispersion equation is as shown in Equation 5 below.

&Quot; (5) "

Figure pat00006

Where C is the concentration of the tracer sample, t is the time, and the initial and boundary conditions of the indoor pylometry test performed in this study, the hermetic solution for equation (5) is as follows.

&Quot; (6) "

Figure pat00007

In Equation (6), erfc is a complementary error function. Since the solute transport in a porous medium such as a soil sample is governed by mechanical dispersion and effective molecular diffusion, The longitudinal dispersion coefficient can be expressed by the following Equation (7).

&Quot; (7) "

Figure pat00008

Also, when the flow velocity of pollutants is very small, molecular diffusion dominates and the molecular diffusion coefficient represents the longitudinal dispersion coefficient, that is, D ι = D * . However, when the flow velocity of the contaminant is large, the mechanical diffusion is dominant, and the mechanical diffusion coefficient is represented by the following equation (8).

&Quot; (8) "

Figure pat00009

In Equation (6), the value of the compensation error function is generally converged to 0, and the one-dimensional advection-diffusion equation can be expressed by Equation (9).

&Quot; (9) "

Figure pat00010

In Equation (9), erfc can be expressed as Equation (10) and Equation (11) as a compensation error function.

&Quot; (10) "

Figure pat00011

&Quot; (11) "

Figure pat00012

Further, the concentration distribution in the relative concentration change (C / C 0) the concentration hysteresis loop (BT curve) shown may be represented by Equation 12.

&Quot; (12) "

Figure pat00013

In Equation (12), P (-∞, χ) denotes a probability from the distance -∞ to the distance x in the BT curve. The probability distribution according to the distance in the normal distribution curve can be expressed by Equation (13).

&Quot; (13) "

Figure pat00014

In Equation (13), if μ = 0 and σ = 1 (that is, a standard normal distribution curve), it can be expressed as Equation (12), and the longitudinal dispersion coefficient can be calculated by the following Equation (14).

&Quot; (14) "

Figure pat00015

here

Figure pat00016
Is the variance of the tracker travel distance, t is the time it takes for the tracer to reach the distance x, and D ι is the longitudinal dispersion coefficient. The equation (14) can be expressed by the following equation (15) using the velocity of the fluid.

&Quot; (15) "

Figure pat00017

Substituting Equation (16) into Equation (14) and Equation (15) in the normal distribution curve, Equation (17) and Equation (18) can be obtained.

&Quot; (16) "

Figure pat00018

&Quot; (17) "

Figure pat00019

&Quot; (18) "

Figure pat00020

In the above equations (17) and (18), X 0.84 and X 0.16 mean the distance X where the relative concentration ( C / C 0 ) is 0.84 and 0.16, respectively. If the flow velocity of the fluid is relatively large and the molecular diffusion is neglected, the longitudinal dispersion coefficient can be expressed by the following equation (19).

&Quot; (19) "

Figure pat00021

Thus, the longitudinal dispersivity can be expressed as shown in equation (20).

&Quot; (20) "

Figure pat00022

It is generally known that the BT curve at any point in the center of a two-dimensional continuous contaminating plume by a point source can be expressed as a function of time for relative concentration. At this time, the relative concentration ( C / C 0 ) means a ratio of the maximum concentration to an arbitrary time. The maximum concentration is always smaller than the initial concentration. The BT curve of the relative concentration ( C / C max ) to the maximum concentration also has a normal distribution. Therefore, it can be expressed by the following equation (20).

 &Quot; (20) "

Figure pat00023

In Equation 20, t 0.84 and t 0.16 mean the time when C / C max is 0.84 and 0.16, respectively. Substituting Equation (20) into Equation (14), Equation (21) can be obtained.

 &Quot; (21) "

Figure pat00024

Therefore, the longitudinal dispersion index can be calculated using the following equation (22).

&Quot; (22) "

Figure pat00025

Wherein the step (f) comprises: comparing a total discharge time of the sample supplied to the column section with the total discharge time of the sample taken in the fractionation section and a cross-sectional area of the column section, calculating the effective porosity of the soil sample using the average flow rate of the soil sample obtained by applying the time corresponding to the concentration ratio calculated in (e), and calculating the effective porosity as shown below.

First, the average flow rate of the groundwater is calculated from the concentration hysteresis curve obtained in the above step, and the volume of the tracer solution that is not discharged from the total injected amount of the tracer solution is calculated by the following equation (23).

&Quot; (23) "

Figure pat00026

The effective porosity can be calculated by the effective porosity calculating equation as shown in the following Equation (24) using the non-outflow and the average flow velocity of the tracer solution calculated as above.

&Quot; (24) "

Figure pat00027

Where Q is the total amount of tracer samples, q is the non-effluent of groundwater, A 1 is the cross-sectional area of the soil sample, t is the total drainage time,

Figure pat00028
Is the mean velocity of groundwater, and n e is the effective porosity of the soil sample.

According to the method of determining the permeability coefficient, dispersion index and effective porosity of the soil using the simultaneous crystallization apparatus according to the present invention as described above, the permeability coefficient, the dispersion index and the effective porosity, which are characteristics of the aquifer important for development, Can be easily determined by a single experiment and can save a great deal of cost and time. In particular, since the calculation of the permeability coefficient, the dispersion index and the effective porosity are simultaneously performed on the same soil sample, the precision of the aquifer characteristic data is greatly improved .

Hereinafter, the present invention will be described in more detail with reference to examples.

The embodiments presented are only a concrete example of the present invention and are not intended to limit the scope of the present invention.

<Examples>

An indoor column test was conducted to determine the permeability coefficient, dispersion index and effective porosity simultaneously for the soil samples collected in Busan area. The indoor column test was performed as follows. The indoor column test was performed using a simultaneous crystal apparatus as shown in FIG. 4 for column test.

The simultaneous determination device as shown in Fig. 4 includes a column portion as shown in Fig. 5 (a), a sample injection portion as shown in Fig. 5 (b), two kinds of membranes as shown in Fig. 6, And a water separator as shown in FIG.

The column test was conducted using sodium bromide (NaBr) as a tracer sample, and a tracer test was performed for 1,740 seconds (29 minutes) to prepare a concentration hysteresis curve of FIG. 8, and the calculation of permeability coefficient, dispersion index and effective porosity The data for this study are shown in Table 1 below.

Figure pat00029

The permeability coefficient as shown below was calculated by using the above-mentioned expression (1).

Figure pat00030

The data obtained by the concentration hysteresis curve as shown in Fig. 8 is shown in Table 2 below.

Figure pat00031

The average flow velocity and the diffusion coefficient were calculated as shown in the above-described Equations 2 to 4 and the concentration hysteresis curve as shown below, and the dispersion index was calculated using this.

Figure pat00032

Figure pat00033

Figure pat00034

In addition, the data necessary for calculation of effective porosity as shown in Table 3 below were obtained.

Figure pat00035

Using the data in Table 3 and Equations (21) and (22) above, the effective porosity was calculated as shown below.

Figure pat00036

Figure pat00037

Accordingly, when the apparatus for simultaneous determination of the permeability coefficient, the dispersion index and the effective porosity of the soil according to the present invention is used, the aeration coefficient of the soil, the dispersion index, and the aquifer characteristics of the effective porosity can be determined simultaneously and precisely by a simple test I could confirm.

10: Simultaneous determination apparatus 100: Sample supply unit
110: opening 120: accommodation space
130: valve member 140: piping
200: column portion 210: accommodation space
220: discharge port 300:
310: Storage tank 400: Permeability coefficient calculating section
500: dispersion index calculating unit 600: effective void ratio calculating unit

Claims (13)

A sample supply unit having a receiving space formed therein for receiving a tracer sample supplied through an opening and supplying a tracer sample having a predetermined volume at a predetermined speed with a valve member;
A column including a discharge space through which a tracer sample supplied from the sample supply unit passes through the soil sample and is connected to the sample supply unit and is connected to the sample supply unit;
A plurality of storage tanks for separately storing the tracer samples discharged through the discharge port of the column portion at predetermined time intervals;
A permeability coefficient calculator connected to the plurality of reservoirs to calculate a permeability coefficient of the soil sample;
A dispersion index calculating unit connected to the plurality of storage tanks to calculate a dispersion index of the soil sample using a change in concentration of the tracer sample; And
And an effective porosity calculating unit for calculating an effective porosity of the soil sample using the change in concentration of the tracer sample calculated by the dispersion index calculating unit. The method according to claim 1,
In order to measure the head of the tracer sample supplied to the sample supply unit and the length of the soil sample filled in the column unit, the sample supply unit and the column unit are made of a transparent material, And the concavity is formed. The method according to claim 1,
Wherein the outlet is provided with a membrane therein. The method according to claim 1,
Characterized in that the tracer sample comprises sodium bromide (NaBr) or potassium bromide (KBr). The method according to claim 1,
Wherein the sample supply part further comprises a pressure supply part on one side of the upper part. The method according to claim 1,
The permeability coefficient calculating unit calculates,
Sectional area of the sample supply part and the column part; A length of the soil sample filled in the column portion; An initial head of the tracer sample supplied to the sample supply unit; After completion of the supply of the tracer sample to the column portion, the final head of the tracer sample remaining in the sample supply portion; And a total time taken for the tracer sample to pass through the column section, to calculate the permeability coefficient of the soil sample. The method according to claim 1,
The dispersion index calculator calculates,
And the dispersion index of the soil sample is calculated by sensing a concentration change of the tracer sample separated and stored at a predetermined time interval. The method according to claim 1,
The effective porosity-
Calculating an average flow rate using a change in the concentration of the tracer sample, calculating a specific discharge of the tracer sample from the total amount of the tracer sample discharged through the outlet of the column portion, Wherein the effective porosity of the soil sample is calculated using the volume of the tracer sample and the average flow rate. (a) collecting a soil sample from the soil and filling the column sample with the soil sample;
(b) injecting a tracer sample stored in a sample supply unit into a column portion filled with the soil sample at a predetermined speed;
(c) separating and recovering the tracer samples injected into the column portions at predetermined time intervals;
(d) after completing the supply of the tracer sample to the column portion, the cross-sectional area of the sample supply portion and the column portion, the length of the soil sample filled in the column portion, the initial head of the tracer sample supplied to the sample supply portion, Calculating a permeability coefficient of the soil sample using a final head of the tracer sample remaining in the tracer sample and a total time required for the tracer sample to pass through the column;
(e) generating a concentration hysteresis curve using the concentration of the tracer sample collected at step (c) at a time interval and the initial concentration of the tracer sample injected at step (b), and then calculating a time corresponding to a preset concentration ratio Calculating a dispersion index of the soil sample; And
(f) a specific discharge calculated in consideration of the total time of drainage and the cross-sectional area of the column, the total volume of the sample supplied to the column in the step (c) And calculating an effective porosity of the soil sample using the average flow rate of the soil sample obtained by applying the time corresponding to the concentration ratio calculated in the step of calculating the permeability coefficient, the dispersion index, and the effective porosity of the soil. 10. The method of claim 9,
Wherein the soil sample is a sample of Buddhism. 10. The method of claim 9,
Wherein the soil sample is collected using the drilling method in the step (a). 10. The method of claim 9,
Wherein the tracer sample comprises sodium bromide (NaBr) or potassium bromide (KBr) in a concentration of 400 to 600 mg / L. 10. The method of claim 9,
In the step (c), the concentration of the recovered tracer sample is measured at predetermined time intervals, and the concentration of the recovered tracer sample is compared with the concentration of the tracer sample supplied to the column in the step (b) Wherein the supply of the tracer sample to the column is stopped when the concentration difference of the tracer sample supplied to the column is less than 1 to 10%.

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