JP3806064B2 - Soil purification equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a purification facility such as high-concentration heavy oil-contaminated soil.
[0002]
[Prior art]
Soil contaminated with poorly water-soluble organic substances such as oil due to waste disposal at factories, oil spills from oil tanks, illegal dumping of industrial waste, etc. has a great impact on the ecosystem in the ground. In addition, when oil or the like pollutes groundwater or vaporizes or volatilizes and pollutes the air, there is a risk of harming the human body.
[0003]
There are various conventional purification methods for contaminated soil, and examples include a soil cleaning method and a bioremediation treatment (biological treatment). The soil cleaning method is based on the principle that if soil is cleaned and classified, soluble pollutants can be eluted in water or a solvent such as cleaning agent, and the contaminants can be concentrated in fine soil particles. The contaminated soil is washed with water or a solvent.
[0004]
Bioremediation treatment (biological treatment) activates aerobic microorganisms in contaminated soil and decomposes oil in soil by spraying high-resolution microorganisms to increase the number of bacteria. Is the method.
[0005]
[Problems to be solved by the invention]
The soil cleaning method requires a lot of know-how in plant equipment, and the cost increases. And it is difficult to select a cleaning agent. In addition, when a large amount of water is used, a problem remains in the water treatment method after washing.
[0006]
On the other hand, bioremediation treatment (biological treatment) is low in treatment efficiency when the concentration is high, and purification is performed when the target pollutant has a high molecular weight, such as heavy oil, and a complicated molecular structure. Difficult and requires a long time to repair.
[0007]
Therefore, by combining the features of these purification methods, the contaminants are decomposed from soil contaminated with poorly water-soluble organic substances such as oil, and high-concentration and high-molecular-weight contaminants, which were difficult with the conventional technology, are removed. As a construction method capable of treating the soil, a combination of a soil purification method and a bioremediation treatment (biological treatment) has been proposed as described in JP-A-10-211486.
[0008]
A combination of this soil remediation method and bioremediation treatment (biological treatment) reduces the concentration of contaminated soil by reducing the high concentration of oil and oil that is difficult to break down by microorganisms by the soil washing method as a pretreatment process. The contaminated soil is purified by decomposing the residual oil by subsequent bioremediation (biological treatment). By adopting the two-stage method in this way, it is possible to cope with oil contamination that could not be purified by the conventional method using only microorganisms.
[0009]
And this soil purification method combined with bioremediation treatment (biological treatment) is a soil remediation process, if undegraded oil or persistent oil remains even after microbial decomposition treatment. By repeating the method, it is possible to efficiently separate and remove oil. As a result, the purification work period was shortened compared to the conventional method, and administrative expenses and other expenses could be saved.
[0010]
However, as a pre-treatment process, the soil washing method is followed by the bioremediation treatment (biological treatment), and then the equipment used in the soil washing method and the bioremediation treatment (biological treatment) ) Is used as a completely separate facility, and there is no cooperation between the facilities. The soil after soil washing treatment is transported to a completely different place, where bioremediation treatment (biological treatment) is performed. It was carried out.
[0011]
For this reason, the same equipment used in each treatment process, such as drainage equipment, can be installed separately for the soil cleaning method and the bioremediation treatment (biological treatment), resulting in wasted equipment costs and installation space. It was. Furthermore, since such a drainage facility is provided with a side groove at the site periphery for each site of each processing step and liquid is collected here, it is difficult to manage the effective use of drainage well.
[0012]
In addition, if undegraded oil or persistent oil remains after bioremediation treatment (biological treatment), the soil remediation method and bioremediation treatment (biological treatment) will be repeated. Furthermore, since there is no cooperation between the facilities of both processing steps, the processing steps may not proceed smoothly in terms of, for example, transporting contaminated soil or purified soil.
[0013]
The object of the present invention is to eliminate the inconveniences of the conventional examples described above, as a facility used in a construction method that combines a soil remediation method and a bioremediation treatment (biological treatment), to make the facilities of both treatment steps cooperative, By installing equipment, it is possible to smoothly transition to both treatment processes, further reduce the purification work period and management costs, reduce equipment costs and installation space , and discharge particularly large amounts in the equipment. The object is to provide a soil remediation facility that can efficiently use water efficiently.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is an apparatus used in a soil purification method in which contaminated soil is washed by soil washing treatment as a pretreatment step and then purified by bioremediation treatment, and the soil washing treatment equipment and bioremediation treatment are used. Install the equipment adjacent to each other in the same site so that continuous treatment is possible, and install the water collection equipment used for soil washing treatment and bioremediation treatment in the site as a shared area. In a soil remediation facility equipped with embankment, a yard for soil cleaning is placed in the center of the site, a downward slope is formed toward the center of the site, and a yard for performing this soil cleaning and bioremediation processing are performed The boundary with the yard is the lowest elevation of all sites and the entire An oil-water separator that installs a water collection facility at this boundary portion so that the waste water from the tank is concentrated, and provides a kettle in the water collection facility, and installs the drained water collected in the kettle in the site The gist is to send to .
[0015]
According to the first aspect of the present invention, since the soil washing treatment facility and the bioremediation treatment facility are installed adjacent to each other so as to be capable of continuous treatment in the same site, the efficiency from the soil washing treatment to the bioremediation treatment is improved. It can be transferred well, and also when this process is repeated, it can smoothly return from the bioremediation process to the soil washing process. Thereby, it becomes possible to purify below the purification target value within a predetermined construction period. Further, both facilities can be arranged in a limited installation space, and the facility cost can be reduced.
[0016]
The water collection facility used for soil cleaning treatment and bioremediation treatment is installed in the site as a shared facility, and all large amounts of cleaning water, contaminated water, and rainwater discharged from both treatment processes are discharged from the site. It is easy to make effective use of wastewater.
[0017]
The drainage water is collected according to the gravity according to the dynamic gradient of the site without providing a special water collection facility or flowing out of the site.
[0018]
In addition, oil and other pollutants separated by the oil-water separator installed at the site are disposed of as waste, and the remaining water including wastewater such as rainwater is recycled as cleaning water and is subjected to soil washing treatment as it is. Can be used in etc.
[0019]
By arranging the yard for soil washing treatment at the center of the site and forming a downward slope toward the center of the site, water collection from the entire planar site is promoted. And since the yard which performs the soil washing process which uses a lot of water is arrange | positioned in the center part of a site, water collection efficiency is good.
[0020]
Leakage of discharged water to the outside of the site is prevented by providing embankments on the outer periphery of the entire site.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the soil purification facility of the present invention, and FIG. 2 is a longitudinal front view of the same. The equipment of this embodiment is a purification equipment for soil contaminated with high-concentration and high-molecular-weight pollutants such as heavy oil, and after washing the contaminated soil by soil washing treatment as a pretreatment process, Is a facility used in the soil remediation method to purify the soil, and in a horizontally long rectangular site 1, a yard (hereinafter referred to as a cleaning yard) 2 for performing a soil cleaning process, and a bioremediation process after the soil cleaning process A yard 3 (hereinafter referred to as a bio yard) to be performed is arranged.
[0022]
FIG. 1 shows an example of such an arrangement example. A washing yard 2 that performs soil washing treatment is formed in a square shape on the slightly front side of the center, and a bioyard 3 is arranged in an inverted L shape from the right side to the rear. . A temporary storage place 4 for contaminated soil such as heavy oil-contaminated soil with a high concentration is provided on the left side of the cleaning yard 2.
[0023]
The entire site 1 is provided with asphalt pavement 16 at the bottom, or the asphalt pavement 16 is provided at the bottom of the cleaning yard 2 as shown in FIG. 2, and the bottom of the bioyard 3 and the temporary storage place 4 for contaminated soil is blocked. A water sheet 5 is laid, and a water-permeable crushed stone layer 11 is provided on the water-impervious sheet 5.
[0024]
Then, the cleaning yard 2 is formed horizontally at the lowest position in the site 1, and the bottoms of the bioyard 3 and the temporary storage place 4 for the contaminated soil are inclined downward toward the cleaning yard 2, and the entire site 1 is mortar-shaped. (See FIG. 2).
[0025]
At the boundary between the cleaning yard 2 and the bio yard 3, the lowest elevation of all sites 1 is provided, and a water collecting groove 6 which is a common water collecting facility is provided in a square shape. Is provided. The pot 7 is constructed, for example, by placing bottom plate concrete on the corrugated pipe ridge. Moreover, the position of the pot place 7 in the water collecting groove 6 provided in the square can be not only the four corners but also any side (see FIG. 3).
[0026]
Furthermore, another water collecting groove 8 directed toward the water collecting groove 6 is provided over the entire bottom of the site 1 as shown in FIG. For example, as shown in the figure, the water collecting groove 8 is formed such that a groove 8a directly connected to the water collecting groove 6 is radially formed toward the water collecting groove 6 with a gradient of about 3%, and the groove 8b is formed with respect to the groove 8a. Arranged in the shape of a letter.
[0027]
Each of the water collecting grooves 6 and 8 is made of reinforced concrete, and crushed stones 9 with high water permeability are packed inside as shown in FIG. The water-impervious sheet 5 is continuously laid in the water collecting grooves 6 and 8 and the crushed stone 9 is filled on the water-impervious sheet 5.
[0028]
As a result, in the entire flat site 1, a water collection system directed to the central washing yard 2 is formed, and all the drainage water (water, rainwater, drainage) of all sites 1 is centrally collected by the dynamic gradient. The water is collected intensively at No.6.
[0029]
Further, a bank (bank) 10 is provided at the outer periphery of the site 1 to prevent the discharged water from leaking outside the site 1, and a bank (bank) 10 is also provided at the outer periphery of the bioyard 3.
[0030]
The discharged water from the water collecting groove 6 can be recycled as cleaning water by sending it to the oil / water separator 12. For example, as shown in FIG. 5, an oil / water separator 12 is installed in the cleaning yard 2 in the site 1, and a submersible pump 13 is disposed in the corrugated pipe of the pottery 7 for drainage of the pottery. Connected to the oil / water separator 12.
[0031]
Next, an example of a method for purifying high-concentration heavy oil-contaminated soil using such equipment will be described based on the process diagram of FIG. The contaminated soil is deposited in the temporary storage place 4 of the contaminated soil formed in the site 1, and then the contaminated soil is cleaned by a soil cleaning process as a pretreatment process. This cleaning process is performed in the cleaning yard 2 adjacent to the contaminated soil temporary storage 4 within the same site 1 and is carried into the cleaning yard 2.
[0032]
In the washing yard 2, as a soil washing process, for example, a mixing step in which contaminated soil is introduced and mixed in a separation tank containing water, a step of supplying an alkaline agent to the separation tank, and bubbles are supplied to the separation tank. And a levitating step for levitating a slightly water-soluble organic substance such as oil to the water surface. Then, the cleaning process is performed again until the soil after the soil cleaning process satisfies a predetermined purification target value. When the cleaning target value after the soil cleaning process is reached, the soil is carried into the adjacent bioyard 3.
[0033]
In the bioyard 3, as a bioremediation treatment (biological treatment), for example, a process of further treating residual contaminants in the residual soil with an aerobic microorganism is carried out. As this treatment method, conventionally known bio-pharming method and biopile method are used. The compost method, forced aeration method, bioreactor method and the like are appropriately adopted. Also in this step, as shown in FIG. 5, if industrial water or the like is sprayed on the soil and the predetermined purification target value is not reached, the process returns to the first soil cleaning treatment step, and this is repeated until the predetermined purification target value is reached. If it reaches, it will be recognized as clean soil and the processing will be completed.
[0034]
Thus, until it reaches a predetermined purification target value in the bioremediation process step, it returns to the soil cleaning process step, and this is repeated, but the cleaning yard 2 and the bioyard 3 are adjacent in the same site 1, Contaminated soil can be easily carried in and out, leading to shortening of the purification work period.
[0035]
In addition, all the effluents used in the cleaning yard 2 and the bio yard 3, drainage, rainwater, etc., flow into the water collecting grooves 8 arranged throughout the site 1, and then a mortar-shaped site. According to the hydrodynamic gradient of 1, all the water flows down to the water collecting groove 6 in the center of the site 1 according to the gravity, is concentrated there, and does not flow out of the site 1.
[0036]
In this case, since the water collecting grooves 6 and 8 are filled with crushed stones 9 having high water permeability, water collection from the entire site 1 is promoted in a planar manner as a whole. Moreover, since the water collection groove | channel 6 is arrange | positioned around the washing yard 2 which uses a lot of water, water collection is performed efficiently.
[0037]
The discharged water pumped to the oil / water separator 12 installed in the washing yard 2 by the submersible pump 13 disposed in the pottery 7 is separated by the oil / water separator 12 and the collected contaminants such as oil are collected. After being disposed of, the remaining water is recycled as cleaning water, or used as water spray in the bioyard 3 shown in FIG. The shortage of water is supplied from tap water, locally generated water or industrial water. Even when the remaining water is recycled, the washing yard 2 and the bioyard 3 are close to each other in the same site 1 and the water collection facility is located in the central washing yard 2. Can be done easily.
[0038]
The arrangement of the contaminated soil temporary storage area 4, the cleaning yard 2, and the bioyard 3 is not limited to the above-described embodiment, and is continuously arranged from the left side to the rear side of the cleaning yard 2 as shown in FIG. The contaminated soil temporary storage 4 may be formed in the shape of a letter, and the lead / oil-contaminated soil temporary storage 14 and the natural purification soil temporary storage 15 may be provided on the right and left sides of the cleaning yard 2. 2 is preferably located in the center of the site 1 and collected in a water collecting groove 6 provided around the cleaning yard 2.
[0039]
【The invention's effect】
As described above, the soil purification equipment of the present invention is arranged in the same site adjacent to both treatment processes as equipment used in the construction method combining the soil purification method and bioremediation treatment (biological treatment). In addition, by installing common facilities, it is possible to smoothly move to both treatment processes, further reduce the purification work period and management costs, reduce equipment costs and installation space, By installing a water collecting facility around the washing yard where the entire site is formed in a mortar shape and the soil washing treatment is arranged in the center, not only can all the discharged water in the site be efficiently collected here. The waste water can be used efficiently and effectively.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of a soil purification facility of the present invention.
FIG. 2 is a longitudinal front view showing an embodiment of the soil purification equipment of the present invention.
FIG. 3 is a plan view of a water collection system showing an embodiment of the soil purification facility of the present invention.
FIG. 4 is a longitudinal side view of a water collecting groove showing an embodiment of the soil purification facility of the present invention.
FIG. 5 is a longitudinal sectional front view of an installation example of an oil / water separator and a submersible pump showing an embodiment of a soil purification facility of the present invention, and a watering condition to a yard.
FIG. 6 is a plan view of another arrangement example of the yard showing the embodiment of the soil purification equipment of the present invention.
FIG. 7 is a purification treatment process diagram using the soil purification equipment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Site 2 ... Cleaning yard 3 ... Bioyard 4 ... Temporary storage place of contaminated soil 5 ... Water shielding sheet 6 ... Catchment channel 7 ... Kamaba 8 ... Catchment channel 8a, 8b ... Gutter 9 ... Crushed stone
10 ... Fill 11 ... Permeable crushed stone layer
12… Oil / water separator 13… Submersible pump
14 ... Lead / oil-contaminated soil temporary storage 15 ... Natural purification soil temporary storage
16 ... Asphalt pavement

Claims (1)

After the contaminated soil is washed by soil washing treatment as a pretreatment process, it is a device used in the soil purification method that purifies by bioremediation treatment. Soil washing treatment equipment and bioremediation treatment equipment are continuously treated in the same site. In the soil purification equipment that is installed adjacent to the site so that it can be used, the water collection equipment used for soil washing treatment and bioremediation treatment is shared in the site, and embankment is provided on the outer periphery of the entire site, A yard for soil cleaning is placed in the center of the site, and a downward slope is formed toward the center of the site.The boundary between the yard for soil cleaning and the yard for bioremediation is The lowest elevation and concentrate the drainage of all sites through the catchment channel A soil purification facility characterized in that a water collection facility is installed at the boundary of the water, a pot is provided in the water collection facility, and the discharged water collected in the pot is sent to an oil / water separator installed in the site .

Images