JP2022054535A - Soil type waste water treatment system - Google Patents

Abstract

To provide a waste water treatment system that effectively purifies excreta and waste water discharged and is easy in a maintenance management.SOLUTION: A soil type waste water treatment system comprises: an original water tank 10 for purifying sewage supplied from a toilet building; a precipitation and separation tank 20 for purifying treated water passing through the original water tank under anaerobic conditions to suppress occurrence of bad odor, scum and sludge; a contact aeration tank 30 for purifying the treated water through the precipitation and separation tank using a transpiration tube and a microbial carrier under favorable conditions; a filtration settling tank 40 for filtering a floating material from the treated water through the contact aeration tank to return the treated water of high oxygen concentration to the original water tank; a decolorizing sterilization tank 45 for decolorizing and sterilizing the treated water through the filtration settling tank; a flow rate control tank 50 to which the treated water via the decolorization sterilization tank is supplied; a soil treatment tank 60 that decomposes organic materials, chemical substances and floating substances contained in the treated water via the flow rate control tank to absorb a coloring component; an aquarium tank 70 for storing the treated water via the soil treatment layer; and a unit for supplying the treated water in the aquarium tank via a water supply unit to supply to a toilet building.SELECTED DRAWING: Figure 1

Description

The present invention relates to a soil-based sewage treatment system.

In general, public toilets installed in mountain huts and temples, mountain trails, riversides, seasides, walking paths, and other campsites where water and sewage pipelines are not maintained are difficult to supply flush water to toilet bowls and are sewage. There are problems of environmental pollution such as bad odor and water quality due to discharge, and the need for a non-discharge circulating flush toilet with the ability to independently purify is being called for.

However, most of the popular toilets are of the natural fermentation pumping type, and in the summer they suffer from a terrible stink and the breeding of pests (see, for example, Patent Document 1). The reason for this is that many treatment tanks are installed in a limited space, and the treatment efficiency is lowered due to insufficient capacity of the treatment tank with respect to the amount of inflowing sewage. As a result, the quality of the final treated water deteriorates, a bad odor remains, and the hue of the treated water also deteriorates.

The sewage discharged from such toilets not only pollutes the water quality of valleys and rivers, but also makes toilet users uncomfortable, so they avoid using the toilet and finally stop the operation of the toilet. It leads to the situation that the facility is closed.

Therefore, in order to treat manure and sewage discharged from public toilets, research is needed to effectively remove organic matter, nitrogen, phosphorus and foul odors and to secure clean treated water.

Japanese Unexamined Patent Publication No. 2006-57417

A technical problem to be solved by the present invention is to provide a sewage treatment system that effectively purifies discharged manure and sewage and is easy to maintain.

In order to achieve the above object, the soil-type sewage treatment system according to the present invention is used.
A raw water tank that purifies the sewage supplied from the toilet building,
A sedimentation separation tank in which treated water is supplied via the raw water tank, purifies the treated water under anaerobic conditions, and suppresses the generation of stinks, scum, and sludge.
A contact aeration tank in which treated water is supplied via the precipitation separation tank and the treated water is purified using an air diffuser and a microbial carrier under favorable conditions.
A filtration settling tank in which treated water is supplied via the contact aeration tank, filters floating matter, and returns the treated water having a high oxygen concentration to the raw water tank.
A decolorization sterilization tank in which treated water is supplied via the above filtration and settling tank to decolorize and sterilize the treated water.
A flow rate control tank in which treated water is supplied via a decolorization sterilization tank, and
A soil treatment tank in which treated water is supplied via the above flow control tank, decomposes organic substances, chemical substances and suspended solids contained in the treated water, and adsorbs pigment components.
A water collection tank that stores treated water that has passed through the above soil treatment tank,
It is characterized by including a device for supplying the treated water in the water collecting tank to the toilet building through a water supply device.

The following configuration is adopted as a preferred embodiment thereof.
(1) The sedimentation separation tank is installed so as to contact the sewage at the lower part of the glazing and the sewage at the upper part of the glazing, and the covered soil that suppresses the generation of scum and sludge that absorbs the bad odor of the sewage. It is characterized by wrapping the coated soil layer on the layer and the upper part of the glazing, and containing a non-woven fabric through which sewage is permeated.
(2) The covered soil layer is characterized in that it is immersed in the treated water in the sedimentation separation tank by 5 to 8 cm.
(3) The covered soil layer is characterized in that the total volume ratio is a mixture of decomposed granite soil 75 to 80%, humus soil 10 to 15%, charcoal 5 to 10%, and pumice stone 5 to 10%. And.
(4) The effective diameter of the decomposed granite soil constituting the covered soil layer is 0.075 to 0.250 mm, and the water content of the decomposed granite soil is 11 to 14%.
(5) The hardness of the covered soil layer is 11.0 to 15.0 mm based on the Yamanaka soil hardness tester.
(6) The filtration settling tank is characterized in that a shell is used as a filter medium for adjusting the pH of the treated water.
(7) The soil treatment tank is arranged in a sprinkler pipe for evenly sprinkling the treated water supplied from the flow rate adjusting tank and a plurality of water sprinkler pipes arranged below the sprinkler pipe so that the treated water permeates and is arranged side by side in the horizontal direction. At the same time, it is stacked in multiple stages in the height direction, decomposes organic substances, chemical substances and suspended solids contained in the treated water, and is placed between the soil blocks that adsorb pigment components and the above soil blocks. It is characterized by including a water passage layer through which treated water passes.
(8) The soil block is installed in contact with the treated water inside the soil block frame and the soil block frame, decomposes organic substances, chemical substances and suspended matter contained in the treated water, and adsorbs pigment components. It is characterized by containing a mixed soil and a non-woven fabric that wraps the mixed soil and allows treated water to permeate inside the soil block frame.
(9) The mixed soil is characterized in that the total volume is mixed at a ratio of decomposed granite soil of 75 to 80%, humus soil of 10 to 15%, charcoal of 5 to 10%, and pumice of 5 to 10%. do.
(10) The effective diameter of the decomposed granite soil constituting the mixed soil is 0.075 to 0.250 m, and the water content of the decomposed granite soil is 11 to 14%.
(11) The hardness of the mixed soil is 11.0 to 15.0 mm based on the Yamanaka soil hardness formula.
(12) The soil treatment tank is characterized by being arranged between the soil blocks and including an air diffuser for supplying air between the soil blocks.
(13) The soil treatment tanks are characterized in that they are installed in a plurality of series inside the container so that they can be used alternately.
(14) The raw water tank is characterized in that the treated water stored in the water collecting tank is supplied, the dye component remaining in the treated water is adsorbed, and the water collecting tank again includes an activated carbon filter tube that shares the treated water. And.
(15) The sedimentation separation tank is characterized by containing a sludge treatment tank in which the sludge separated by sedimentation is housed and ozone is supplied to decompose the sludge.
(16) The treated water stored in the water collecting tank is supplied, the activated carbon filter cylinder that adsorbs the hue component remaining in the treated water and supplies the treated water to the water collecting tank again, and the surplus water is supplied from the water collecting tank. It is characterized by including an evaporation tank for evaporating excess water.

According to the present invention, fresh water must be supplied at the initial stage of operation, but water supply is not required after the start of operation. It is not necessary to do so, it is possible to remove bad odors generated from manure and sewage, purify the color of sewage to the level of fresh water, and reuse the final treated water as flush water for toilets and do not discharge it into rivers. It is possible to prevent pollution of rivers and the like.

Further, according to the present invention, the generation of scum and sludge is suppressed by the soil contact type sedimentation separation tank, and even a small amount of sludge is decomposed by ozone in the sludge treatment tank, so that it is not necessary to carry out the sludge.

Further, according to the present invention, since the watering method of the soil treatment tank is a gravity infiltration method that does not rely on pressurization, it is excellent in energy saving and easy to maintain.

It is a flow diagram which also serves as the block diagram which shows the schematic structure of the soil type sewage treatment system based on the Example of this invention, and an example of the sewage treatment procedure. It is sectional drawing which shows an example of the raw water tank of the soil type sewage treatment system which concerns on this invention. It is sectional drawing which shows an example of the sedimentation separation tank of the soil type sewage treatment system which concerns on this invention. It is sectional drawing which shows an example of the soil treatment tank of the soil type sewage treatment system which concerns on this invention. It is a graph which shows the passing mass percentage of the decomposed granite soil which constitutes the soil treatment tank based on the Example of this invention. It is a graph which shows the biochemical oxygen demand (BOD) removal ability of the soil treatment tank based on the Example of this invention. It is a graph which shows the chemical oxygen demand (COD) removal ability of the soil treatment tank based on the Example of this invention. It is a graph which shows the suspended solids concentration (SS) removal ability based on the Example of this invention. It is a graph which shows the total phosphorus (TP) removal ability based on the Example of this invention. It is a graph which shows the total nitrogen (TN) and ammonia nitrogen (NH ₄ ) removal ability based on the Example of this invention. It is a graph which shows the Escherichia coli removal ability based on the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same reference numeral presented in each drawing represents the same member.

Referring to FIG. 1, the soil-type sewage treatment system 100 based on the embodiment of the present invention includes a raw water tank 10, a settling separation tank 20, a contact aeration tank 30, a filtration settling tank 40, a decolorization sterilization tank 45, and a flow rate adjusting tank 50. It includes a soil treatment tank 60, a water collection tank 70, an activated carbon filter cylinder 75, an evaporation tank 80, and a sludge treatment tank 85.

The soil-type sewage treatment system 100 based on the embodiment of the present invention must supply fresh water at the initial stage of service, but does not require a separate water supply after the start of service, and organic substances and eutrophication-causing substances contained in the sewage. It can remove nitrogen, phosphorus and bad odors, and purify the color of sewage to the level of fresh water. At the same time, it does not discharge the final treated water to the outside and recycles it to contaminate rivers. It is a pro-environmental system that can be prevented. Further, in the soil-type sewage treatment system 100 based on the embodiment of the present invention, the water quality of the purified final treated water is an environmentally friendly system capable of achieving the landscape water standard.

The raw water tank 10 serves to store sewage containing manure, toilet paper, etc. supplied from a toilet bowl or the like in a toilet, which is a source of sewage, and to easily treat the stored sewage in the next process. With the spread of flush toilets, the spread of toilet paper is increasing, and when a large amount of toilet paper flows into the raw water tank in the form of a lump, the phenomenon that the piping in the system is clogged frequently occurs. On the other hand, the raw water tank 10 according to the present embodiment prevents the phenomenon that the piping in the system is clogged by the lump of toilet paper contained in the sewage flowing from the toilet, and removes and dilutes the malodor emitted from the sewage.

The raw water tank 10 based on this embodiment is divided into three tanks (S1, S2, S3), an air diffuser pipe 13 is arranged at the bottom of the first tank S1 and the second tank S2, and a sprinkler pipe 14 is arranged at the top. Is placed. As shown in FIG. 2, the air diffuser 13 is connected to a blower that supplies compressed air, and the treated water having a high oxygen concentration returned from the filtration settling tank 40 is vigorously sprinkled downward on the upper part.

The lump of toilet paper that flows from the toilet building into the raw water tank 10 together with the sewage is diffused by the fine air bubbles generated in the air diffuser tubes 13 arranged on the bottom surfaces of the first and second tanks S1 and S2. Further, the treated water having a high oxygen concentration returned from the filtration settling tank 40 is sprinkled downward from the sprinkler pipe 14 arranged at the upper part of the first and second tanks S1 and S2, and is ammoniacal contained in the sewage. Converts nitrogen to nitrate nitrogen to remove and dilute malodor. Then, the sewage that has reached the third tank S3 is pumped through the drain port 16 and pumped to the settling separation tank 20.

In the settling separation tank 20 based on this embodiment, under anaerobic conditions, anaerobic microorganisms and the like remove organic substances and suppress the generation of sludge, so that the amount of sludge generated is reduced. A plurality of series of sedimentation separation tanks 20 can be installed according to the treatment amount. Further, the settling separation tank 20 is provided with a heat insulating heater for preventing the treated water from freezing in winter.

As shown in FIG. 3, the lower portion of the settling separation tank 20 is supported by the glazing 21, a non-woven fabric 23 for wrapping the coated soil layer 25 is laid on the upper portion of the glazing 21, and the coated soil layer 25 is the glazing 21. It prevents it from leaking to the outside. The covered soil layer 25 has a height of about 40 cm, and the lower 5 to 8 cm is constantly flooded.

The scum generated at the interface between the upper surface of the treated water and the covered soil layer 25 is supplemented as a nutrient for soil microorganisms living in the covered soil layer 25, and is decomposed to suppress the generation of scum in the sedimentation separation tank 20. Will be done.

The covered soil layer 25 is formed by mixing the total volume of decomposed granite soil with 75 to 80%, humus with 10 to 15%, charcoal with 5 to 10%, and pumice with 5 to 10%. The effective diameter of the decomposed granite soil is 0.075 to 0.25 mm, and the water content of the decomposed granite soil is 11 to 14%. The hardness of the covered soil layer 25 is 11 to 15 mm according to the Yamanaka hardness tester standard.
As will be described later, the sedimentation separation tank 20 shown in this embodiment is provided with a sludge treatment tank 85 that accommodates the sludge separated by sedimentation and supplies ozone to decompose the sludge (details will be described later). ).

The treated water that has passed through the settling separation tank 20 is supplied to the contact aeration tank 30. The contact aeration tank 30 based on this embodiment supplies oxygen in the state of fine bubbles from a diffuser tube installed at the lower part. The nitrifying bacteria living in the contact aeration tank 30 use the supplied oxygen to convert ammonia nitrogen in the inflow water into nitrate nitrogen. Further, the inside of the contact aeration tank 30 is filled with a microbial carrier having a good ability to capture organic substances, which promotes the activation of microorganisms in the tank. Here, as the microbial carrier, a foamed carrier having a specific surface area and abundant fine bubbles is used.

The treated water that has passed through the contact aeration tank 30 is sent to the filtration settling tank 40. The filtration settling tank 40 based on this embodiment filters fine suspended solids contained in the treated water that has passed through the contact aeration tank 30. In addition, the filtration settling tank 40 fulfills a suppressive function of stabilizing the sludge contained in the treated water by settling and removing solid matter. The filtration settling tank 40 returns the treated water having a high oxygen concentration to the sprinkler pipe 14 of the raw water tank 10.

Then, the filtration settling tank 40 adjusts the pH of the treated water that has passed through the contact aeration tank 30. The filtration settling tank 40 uses shells as a filter medium, and adjusts the pH of the treated water with calcium from the shells. This is because when the nitrate reaction proceeds in the contact aeration tank 30 and the filtration settling tank 40, the alkali is consumed and the pH of the treated water becomes low. Prevents the change.

The treated water that has passed through the filtration settling tank 40 is sent to the decolorization sterilization tank 45. The decolorization sterilization tank 45 based on this embodiment blows ozone to sterilize harmful pathogens contained in the treated water while the treated water supplied from the filtration settling tank 40 is stored for a certain period of time. Therefore, in this embodiment, an ozone generator (not shown) and an ozone solubilizer (not shown) are used to supply microbubbles to the treated water to increase the ozone solubility in the treated water, and the decolorization sterilization tank 45 It effectively sterilizes harmful pathogens stored in the water and at the same time decolorizes.

Next, the treated water that has passed through the decolorization sterilization tank 45 is sent to the flow rate adjusting tank 50. The flow rate adjusting tank 50 based on this embodiment intermittently supplies a certain amount corresponding to the unit treatment amount of the soil treatment tank 60, which will be described later, to the soil treatment tank 60 while storing the treated water supplied from the decolorization sterilization tank 45. Send water.

The soil treatment tank 60 based on this embodiment is for highly treating the treated water that has passed through the flow rate adjusting tank 50, and can effectively reduce organic substances, chemical substances and suspended solids contained in the treated water. can. Further, the soil treatment tank 60 adsorbs the pigment component contained in the treated water. Since the soil treatment tank 60 is a gravity permeation type rather than a multi-stage membrane treatment method by pressurization, it is excellent in energy saving and easy to maintain.

As shown in FIG. 4, the soil treatment tank 60 includes a sprinkler pipe 61 to which the treated water is supplied from the flow rate adjusting tank 50 and a soil block 65 arranged below the sprinkler pipe 61 to permeate and purify the treated water. A water passage layer 63 arranged between the soil blocks 65 and through which the treated water passes, and a discharge port 69 through which the treated water purified by the soil block 65 is discharged are included.

The sprinkler pipe 61 is arranged in the upper part of the soil treatment tank 60, and the treated water sent from the flow rate adjusting tank 50 by a pump (not shown) is evenly sprinkled downward. The sprinkler pipe 61 is a hollow pipe, and a plurality of discharge holes are arranged at predetermined intervals in the length direction so that the treated water supplied from the flow rate adjusting tank 50 is dropped downward.

A plurality of sprinkler pipes 61 are arranged in a row in a horizontal row on the upper stage of the soil block 65 located at the uppermost part. Such a sprinkler pipe 61 can also be installed between the water flow layers of each stage. The treated water sprinkled from the sprinkler pipe 61 is purified while permeating through the soil block 65 arranged at the bottom.

As described above, a plurality of soil blocks 65 are arranged horizontally side by side inside the soil treatment tank 60 to form the treated soil layer 62. Subsequently, a water flow layer 63 having a constant height is laid so as to cover the entire treated soil layer 62. Then, the treated soil layer 62 is arranged horizontally again on the water passage layer 63. By repeatedly laying the treated soil layer 62 and the water flow layer 63, a sewage treatment device in which the soil blocks 65 are laminated in multiple stages is completed.

On the other hand, the soil treatment tank 60 supplies oxygen to aerobic microorganisms living in the soil block 65 by supplying air from a blower between the treated soil layers 62 stacked in multiple stages. The soil microorganisms that live in the soil block feed on the organic substances remaining in the treated water, resulting in reduction of biological oxygen demand (BOD), chemical oxygen demand (COD), and suspended solids (SS) concentration. Also, it adsorbs the pigment component of the treated water. That is, the soil block 65 supplements organic matter by a filtering action and provides food to soil microorganisms.

The mixed soil 67 constituting the soil block 65, which will be described later, is in charge of the filtration or adsorption action, and the main purification action of the soil block 65 is the decomposition action of organic matter performed by the microorganisms living in the soil block 65.

The soil block 65 includes a soil block frame 66, a mixed soil 67 filled in the soil block frame 66, and a non-woven fabric 68 that wraps the mixed soil 67 and allows the treated water to permeate. The treated soil layer 62 is a treatment tank in which the mixed soil 67 is blocked (integrated) and a plurality of them are horizontally arranged.

The soil block frame 66 provides a space filled with the mixed soil 67 inside. The soil block frame 66 based on the present embodiment is shown as a straight hexahedron shape with an open upper portion, but the scope of rights of the present invention is not limited to this, and can have various shapes. .. Then, the non-woven fabric 68 is prepared inside the soil block frame 66, and the non-woven fabric 68 wraps the mixed soil 67 to prevent the mixed soil 67 from flowing out of the soil block frame 66.

Further, the treated water that has permeated the nonwoven fabric 68 is transmitted to another soil block 65 arranged under the corresponding soil block 65 or a water passage layer 63. In this way, the non-woven fabric 68 is laid inside the soil block frame 66, and the mixed soil 67 is filled in the non-woven fabric 68 to manufacture the soil block 65.

The soil block 65 in the present embodiment is shown so that nine layers are laminated in the height direction inside the soil treatment tank 60, but the scope of rights of the present invention is not limited thereto.

In order to effectively increase the unit treatment amount and purification capacity of the soil treatment tank 60, the composition of the mixed soil 67, the effective diameter and moisture content of the decomposed granite soil as the base material of the mixed soil 67, and the hardness of the mixed soil 67 are optimal. Must be transformed. The mixed soil 67 in this example is composed of decomposed granite soil, humus soil, charcoal and pumice.

Decomposed granite soil is the base material of the mixed soil 67, has excellent water permeability, and is easy to control the particle size.
Humus provides a habitat for soil microorganisms and at the same time feeds on soil microorganisms. The humus is completely decomposed by soil microorganisms after 2 to 3 months, and the decomposed humus provides voids in the mixed soil 67.

Pumice stones serve to regulate the water content of the mixed soil 67. The pumice stone has abundant voids, and when the water content in the mixed soil is high, a certain amount of water is stored in the pumice stone, and when the mixed soil 67 is dry, the water stored in the pumice stone is released. Keep the moisture in the mixed soil constant. In addition, through the function of such pumice stones, it is possible to avoid the phenomenon that decomposed granite soil becomes muddy.

Charcoal serves to provide water permeability and breathability to the mixed soil 67, and at the same time, has decolorization, deodorization, and dephosphorization functions.

The composition of the mixed soil is a mixture of decomposed granite soil 75 to 80%, humus soil 10 to 15%, charcoal 5 to 10%, and pumice stone 5 to 10% in terms of the total volume.

If the humus soil is less than 10% of the total volume of the mixed soil 67, the purification effect by the soil microorganisms is insufficient, and if it exceeds 15%, many voids are formed by the humus soil, and there is a risk that the treated soil layer 62 will sink.

On the other hand, if the amount of charcoal is less than 5% of the mixed soil 67, the water permeability and air permeability of the soil block 65 are lowered, and the pigment component of the sewage is adsorbed, so that decolorization, deodorization and dephosphorization cannot be effectively achieved. If it exceeds 10%, the economy will drop.

Next, the effective diameter of decomposed granite soil will be described.
When purifying sewage using soil, soil microorganisms are the main constituents of purifying sewage, but the factors that determine the amount of treatment are the particle size and porosity of the soil.

The permeability of the fluid passing through the soil gap is greatly affected by the particle size distribution of the soil. The effective diameter of the soil refers to the particle size corresponding to 10% of the passing mass percentage, and the hydraulic conductivity of the soil is determined by the effective diameter (D ₁₀ ). More precisely, the hydraulic conductivity of soil is proportional to the square of the effective diameter D ₁₀ .

The effective diameter of decomposed granite soil is temporarily determined by considering the quality of raw water, planned treatment amount, unit treatment amount, but at the same time, the mixing conditions, material conditions, soil block stacking number conditions, etc. of the mixed soil 67, etc. , Must be determined in consideration of the design conditions of the soil treatment tank 60 under various conditions.

Therefore, the applicant conducted the experiment under the conditions shown in Table 1 below. In Table 1 below, experiments were conducted by applying various effective diameters of decomposed granite soil under various conditions such as the compounding conditions of the mixed soil 67, the material conditions, and the number of layers of soil blocks.

In addition, Table 2 below shows the passing mass (%) according to the particle size of decomposed granite soil.
With reference to Table 2 and FIG. 5, the effective diameter of decomposed granite soil, which preferably belongs to the range of 10% passing mass and falls within the range of 10% passing mass, is 0.075 to 0.250 mm. Therefore, it is preferable to design the optimum effective diameter of decomposed granite soil to be 0.075 to 0.250 mm.

Next, the moisture content of decomposed granite soil according to this example will be described.
It is desirable that the decomposed granite soil constituting the mixed soil 67 according to this embodiment has a water content of 11 to 14%. When the moisture content of decomposed granite soil is less than 11% or exceeds 14%, the decomposed granite soil, pumice stone, and charcoal are not well integrated, and the decomposed granite soil is integrated with the mixed soil 67 through the moisture content of 11-14%. At the same time, it is possible to secure a gap in the mixed soil 67 that enables the movement of sewage.

Next, the hardness of the mixed soil 67 according to this example will be described.
The mixed soil 67 constituting the soil block 65 according to this embodiment is required to have a certain level of hardness. The hardness of the mixed soil 67 is obtained by compacting the mixed soil 67. That is, the mixed soil 67 can be compacted to a constant strength in a state where the mixed soil 67 is filled in the soil block 65 to give hardness to the mixed soil 67.

When compaction is not performed, that is, when the hardness of the mixed soil 67 is low, subsidence of the treated soil layer 62 occurs due to natural consolidation. Then, the subsidence of the treated soil layer 62 induces the subsidence of the entire soil treatment tank 60 including the water passage layer 63. On the other hand, when the compaction is excessively performed, if the hardness of the mixed soil 67 is larger than the standard, the voids are closed, the water permeability and the air permeability are deteriorated, and the purification is not performed.

In consideration of these points, it is desirable to design the hardness of the mixed soil 67 to be 11 to 15 mm based on the Yamanaka hardness tester according to this embodiment. The hardness of the mixed soil 67 using the Yamanaka hardness tester can be measured by piercing the mixed soil 67 with the Yamanaka hardness tester and then confirming the scale penetrating the hardness tester. As a reference, the hardness measuring method using the Yamanaka hardness tester is a widely known measuring method in the field of measuring the hardness of soil.

Hereinafter, a method for producing the soil block 65 will be described.
First, the mixed soil 67 is prepared to produce the soil block 65.

The mixed soil 67 is prepared by blending the decomposed granite soil 75 to 80%, the humus soil 10 to 15%, the charcoal 5 to 10%, and the pumice stone 5 to 10% as the total volume ratio. The effective diameter of the decomposed granite soil constituting the mixed soil 67 is 0.075 to 0.25 mm, and the water content of the decomposed granite soil must satisfy the condition of 11 to 14%.

Then, the soil block frame 65 is prepared, the nonwoven fabric 68 is laid inside the soil block 65, and then the mixed soil 67 is filled in the nonwoven fabric 68.

The mixed soil 67 filled in the soil block 65 is compacted, and the hardness of the mixed soil 67 is confirmed to be 11.0 to 15.0 mm to complete the soil block 65.

The method for manufacturing the soil treatment tank 60 using the soil block 65 is as follows.
After grating (not shown) is installed as a support plate inside the soil treatment tank 60, a plurality of soil blocks 65 are arranged horizontally on the soil block 65 as shown in FIG. 4 to form a treated soil layer 62. Then, a water flow layer 63 having a constant height is laid so as to cover the entire treated soil layer 62. The treated soil layer 62 is laid horizontally on the water flow layer 63 again. In this way, a plurality of soil blocks 65 are arranged in the horizontal direction, and the work of laying the water passage layer 63 on the soil blocks 65 arranged in the horizontal direction is repeatedly carried out, and the soil blocks 65 are multi-staged in the height direction. The laminated soil treatment tank 60 is completed.

On the other hand, in the middle of stacking the soil blocks 65 in multiple stages in the height direction, an air diffuser pipe 64 for supplying air is arranged between the water passage layers 63. A sprinkler pipe 61 for evenly sprinkling the treated water downward is installed on the upper part of the uppermost soil block 65. The effect of the soil treatment tank 60 formed by using the soil block 65 in this way will be described below through Examples.

<Example 1: Experimental method>
Purification treatment of raw water using the soil block 65 according to this example was carried out, and biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), phosphorus, nitrogen, and Escherichia coli were treated. The removal ability was evaluated.

The soil block 65 of this embodiment uses a stainless steel soil block frame 66 and wraps the mixed soil 67 with a non-woven fabric 68. The soil block 65 was designed to have a size of W200 x L400 x H50 mm, and the overall dimensions of the soil treatment tank 60 were designed to be W1.30 x L0.80 x H2.00 m. Pumice stones were laid in the water flow layer 63 between the soil blocks 65. Here, 9 layers of the whole treated soil layer 62 were laminated. The mixed soil 67 according to this example is composed of decomposed granite soil 75%, humus soil 10%, charcoal 10%, and pumice stone 5% in comparison with the total volume. As the raw water, secondary treated water having the properties of BOD 20.0 mg / l, SS 10.0 mg / l, T-P 3.0 mg / l, and T-N 18.3 mg / l was used. The watering period was from August 20 to December 16, 2017, and 7.0 to 10.0 m ³ / day of raw water was supplied to the soil treatment tank 60. In addition, 7.0 L / m ^2. min of air was continuously supplied to the soil treatment tank 60 for 24 hours.

<Example 2: Unit sewage treatment amount>
As a result of operating the soil treatment tank 60 for 108 days, the daily average treatment amount of the soil treatment tank 60, that is, the unit treatment amount was 8.4 m ³ / m ² .day. The amount of treated water for each period of the soil treatment tank 60 is shown in Table 3 below.

<Example 3: Water quality analysis for general items>
The water temperature, pH, and ORP (Oxidation-Reduction Potential) showed similar values for raw water and treated water. The dissolved oxygen content (DO) was higher in the treated water than in the raw water, which is due to the continuous supply of 7.0 L / m ^2. min of air to the soil treatment tank 60 for 24 hours. ..

<Example 4: Biochemical oxygen demand (BOD) removing ability>
Table 4 below shows the BOD removal ability of the soil treatment tank 60.

Referring to Table 4 and FIG. 6, the soil treatment tank 60 showed a stable BOD removal ability as a result of operating at an initial load of 7.5 m ³ / m ² day. After that, on September 19, the load was increased to 8.5 m ³ / m ² day and the experiment was continued for about 5 weeks. As a result, the BOD removal ability was 2.0 mg / l or less, which was the target value (5.0 mg). / L) was satisfied. Then, on October 16, the load was increased to 10 m ³ / m ² day and the experiment was continued for 4 weeks. As a result, the BOD removing ability was 2 mg / l or less, and the target value (5 mg / l) was satisfied.

On the other hand, looking at the relationship between the temperature of raw water and the ability to remove BOD, the load is 10 m ³ / m ² under the conditions where the temperature and water temperature are relatively high from summer to autumn and the biological activity of soil microorganisms is maintained high. It was day, and even if the BOD of the raw water exceeded 20 mg / l, the BOD of the treated water achieved 5 mg / l or less. In winter, when the water temperature was lower than 15 degrees Celsius, the biological activity of soil microorganisms decreased, and the BOD of the treated water exceeded the target value of 5 mg / l. However, even in winter, it is presumed that the BOD of treated water can be adjusted to the target value if the BOD of raw water is maintained at 20 mg / l. Further, when the soil treatment tank 60 is buried underground and the influence of the external temperature is small, it is expected that the BOD of the treated water can be adjusted to the target value even in winter.

On the other hand, looking at the relationship between the load amount and the BOD removal ability, it was confirmed that the BOD removal ability can be maintained at 90% or more even if the load amount increases to 7.5 to 10 m ³ / m ² day. ..

After setting the load to 10 m ³ / m ² day, stable treated water quality could be maintained until the end of November without any significant effect on the BOD removal ability. However, in December, the BOD removal ability tended to decrease, which is considered to be mainly due to the decrease in biological activity due to low temperature.

<Example 5: Chemical oxygen demand (COD) and suspended matter concentration (SS) removing ability>
FIG. 7 shows the chemical oxygen demand (COD) removing ability, and the chemical oxygen demand (COD) of raw water is 30 to 40 mg / l, and the removing efficiency becomes low in winter like the BOD removing ability. rice field. Referring to FIG. 8, the concentration of suspended matter (SS) in raw water was removed by 90% or more until November 11 after the start of operation, but in winter, the concentration of suspended matter (SS) in raw water decreased to about 70%. ..

Looking at the relationship between the load amount and the COD and SS removal ability, the COD and SS removal ability characteristics are stably maintained even when the load amount increases to 7.5 to 10 m ³ / m ² day, similar to the BOD removal ability. Indicated.

<Example 6: Phosphorus removing ability>
Table 5 below shows the total phosphorus (TP) removal amount and removal rate of the soil treatment tank 60 according to the load amount, and FIG. 9 shows the total phosphorus (TP) removal amount of the soil treatment tank 60 according to the measuring institution. It represents the amount of removal.

Referring to Table 5, when the load was less than 8.5 m ³ / m ² day, the total phosphorus (TP) removal rate was 10 to 20%, but the load was 10 m ³ / m ² day or more. If so, total phosphorus (TP) was scarcely removed.

Also, referring to FIG. 9, from October 16th, the load was increased to 10 m ³ / m ² day and treated for 4 weeks, and then the load was reduced to ^{7 m 3 / m 2 day again} for treatment. However, little phosphorus was removed.

<Example 7: Nitrogen removing ability>
The nitrogen removal ability of the soil treatment tank 60 was analyzed. Table 6 below shows the experimental results showing the nitrogen removing ability of the soil treatment layer 60, and total nitrogen (TN), NH ₄ , and NO ₃ were set as the nitrogen items to be analyzed. FIG. 10 shows the experimental results showing the total nitrogen (TN), NH ₄ , and NO ₃ removal ability of the soil treatment tank 60 according to the measuring institution.

As a result of conducting a nitrogen removal capacity experiment of the soil treatment tank 60, referring to Table 6 and FIG. 10, most of the ammonium nitrogen (NH4-N) and nitrite nitrogen (NO ₂ -N) in the raw water are nitrate. It was confirmed that it was converted to nitrogen (NO ₃ -N).

Ammonia nitrogen (NH ₄ -N) and nitrite nitrogen in raw water (NO ₂ -N) go through the nitrate reaction to nitrate nitrogen (NO ₂ -N), but finally nitrate nitrogen. (NO ₂ -N) is converted to nitrogen gas (N ₂ ). However, although it was confirmed that the nitrate reaction proceeded stably in this experiment, the denitrification reaction to nitrogen gas (N ₂ ) was insignificant, and nitrate nitrogen (NO) was used in the treated water. It was confirmed that ₂ -N) was contained in a large amount.

In this way, the total nitrogen in the raw water and the treated water showed similar values regardless of the load. As shown in Table 6 and FIG. 10, the removal rate of ammonia is 89.4%, which is a very high value. This is due to the fact that the dissolved oxygen content (DO) of the treated water is 7 mg / l or more per minute, and the operating conditions of the soil treatment tank 60 are that external air is supplied by the diffuser pipe and nitrification is performed under high opportunity conditions. This is due to the active progress of the reaction.

On the other hand, in order to convert nitrate nitrogen into nitrogen gas, a denitrification reaction by anaerobic microorganisms is required, but in order to cause a denitrification reaction, the inside of the soil treatment layer 60 becomes anaerobic and denitrification. The necessary carbon source (hydrogen donor) is required.

Until the middle of the experiment, it was formed under aerobic conditions, the organic matter concentration in the raw water was low, the conditions required for the denitrification reaction were not met, the nitrate nitrogen (NO ₂ -N) remained, and the total nitrogen concentration changed so much. I didn't. In the latter half of the experiment, that is, in winter, the total nitrogen removal of 10 to 15% progressed as the air temperature and water temperature decreased, the BOD concentration of raw water increased, and the load increased to 10.0 m ³ / m ² day. The reason why the denitrification reaction progressed by a certain amount in the latter half of the experiment is presumed as follows.

In winter, the BOD value of raw water increases due to the decrease in water temperature, and it is presumed that untreated organic matter was used as a hydrogen supply required for the denitrification reaction. Further, it is determined that the SS of the raw water is accumulated in the soil treatment tank 60, so that the load is increased and the inside of the soil treatment tank 60 is partially changed to the anaerobic condition.

<Example 8: Escherichia coli removing ability>
FIG. 11 shows the experimental results showing the E. coli removing ability of the soil treatment tank by a water quality inspection organization. Referring to FIG. 11, the number of coliform bacteria in the raw water is 300 to 3600 ml, but the number of coliform bacteria in the treated water of the soil treatment tank 60 is 100 to 1000 / ml, which clears the effluent standard. On the other hand, if the soil treatment tank 60 described above is operated for a long time, clogging may occur, so the soil treatment tank 60 must be operated alternately. That is, in this embodiment, a plurality of series of soil treatment tanks 60 were installed and used alternately. As an example, as shown in Table 7 below, when three series of soil treatment tanks 60 were used, each soil treatment tank 60 was operated alternately for two months and then rested for one month. Table 7 shows the operation method of the soil treatment tank 60.

When the unit treatment amount is large or in winter, a circulation pump (not shown) is installed in the water collection tank 70 to circulate the treated water stored in the water collection tank 70 to the soil treatment tank 60 to purify the treated water again. Treat and prevent freezing of treated water. In addition, in order to prevent the treatment capacity of the soil treatment tank 60 from decreasing in winter, a heat insulating material (not shown) may be installed on the outer wall of the soil treatment tank 60 to prevent the activity of soil microorganisms from decreasing. can.

The treated water that has passed through the soil treatment tank 60 is sent to the water collection tank 70 through the discharge port 69 installed at the bottom of the soil treatment tank 60. The treated water stored in the water collecting tank 70 is sent to a water supply unit installed in the toilet building provided with the toilet T through the water supply device P, and is used as flush water for the toilet bowl in the toilet building.

On the other hand, in order to further improve the color of the treated water before being sent to the toilet building, the treated water stored in the water collecting tank 70 is used as the treated water stored in the water collecting tank 70 in the activated carbon filter tube 75 in this embodiment. The activated carbon filter tube 75 adsorbs and filters the pigment components and suspended matter remaining in the treated water.

The activated carbon filter tube 75 according to this embodiment decolorizes the treated water. In the treated water, the pigment component contained in the treated water is adsorbed by the soil block 65 and decolorized while passing through the soil treatment tank 60, but in this embodiment, the pigment component remaining in the treated water and the pigment component are performed. An activated carbon filter tube 75 was installed so as to further remove suspended matter and improve the chromaticity of the treated water. The activated carbon filter tube 75 is filled with activated carbon and other filter media, and the pigment components and suspended matter remaining in the treated water are adsorbed and filtered by the activated carbon and other filter media.

The treated water that has passed through the activated carbon filter tube 75 is sent to the water collecting tank 70 again and then supplied to the toilet building by the water supply device P. The water quality of the treated water that has passed through the activated carbon filter tube 75 has achieved the water quality standard for landscape landscaping.

Then, when the treated water is stored in the water collecting tank 70, when the treated water exceeding the storage capacity of the water collecting tank 70 is supplied, the water level sensor (not shown) installed in the water collecting tank 70 generates excess water. It is detected and excess water is supplied from the water collecting tank 70 to the evaporation tank 80.

Then, in the evaporation tank 80, the surplus water supplied from the water collecting tank 70 is evaporated by using an electric heating type evaporator (not shown).

On the other hand, the sludge separated by sedimentation in the sedimentation separation tank 20 is supplied to the sludge treatment tank 85. In this embodiment, about 40% of the treatment amount of the sedimentation separation tank 20 is periodically supplied to the sludge treatment tank 85. The sludge has a water content of 95% or more, and the solid content is mostly composed of dead microorganisms and has a water content of 5% or less. The sludge in the sludge treatment tank 85 is decomposed by utilizing the strong oxidizing power of ozone. In other words, a micro-sized ozone bubble is supplied to the inside of the sludge treatment tank 85, and the strong oxidizing power of hydroxide ion (OH-) generated when ozone is decomposed destroys microbial cells and changes to an inorganic substance. Let me.

Then, the sludge decomposed in the sludge treatment tank 85 is re-supplied to the settling separation tank 20 by a pump (not shown), and is digested as food for aerobic microorganisms.

As described above, the present invention is not limited to the described examples, and various modifications and modifications can be made to the extent that the idea and the scope of rights of the present invention are not exceeded. Therefore, such amendments or modifications belong to the claims of the present invention.

10 Raw water tank 20 Sedimentation separation tank 30 Contact exposure tank 40 Filtration settling tank 45 Decolorization sterilization tank 50 Flow control tank 60 Soil treatment tank 65 Soil block 70 Water collection tank 75 Activated carbon filter cylinder 80 Evaporation tank 85 Sludge treatment tank

Claims (17)

A raw water tank that purifies the sewage supplied from the toilet building,
A sedimentation separation tank in which treated water is supplied via the raw water tank, purifies the treated water under anaerobic conditions, and suppresses the generation of stinks, scum, and sludge.
A contact aeration tank in which treated water is supplied via the precipitation separation tank and the treated water is purified using an air diffuser and a microbial carrier under favorable conditions.
A filtration settling tank in which treated water is supplied via the contact aeration tank, filters floating matter, and returns the treated water having a high oxygen concentration to the raw water tank.
A decolorization sterilization tank in which treated water is supplied via the filtration settling tank to decolorize and sterilize the treated water, and a flow rate adjusting tank in which the treated water is supplied via the decolorizing sterilization tank.
A soil treatment tank in which treated water is supplied via the above flow control tank, decomposes organic substances, chemical substances and suspended solids contained in the treated water, and adsorbs pigment components.
A water collection tank that stores treated water that has passed through the above soil treatment tank,
A soil-type sewage treatment system characterized by including a device that supplies the treated water in the water collection tank to the toilet building through a water supply device. The above sedimentation separation tank
Graching whose lower part is submerged in sewage,
A covered soil layer that is installed on the upper part of the above grading so as to come into contact with sewage and suppresses the generation of scum and sludge that absorbs the malodor of sewage.
The soil-type sewage treatment system according to claim 1, wherein the coated soil layer is wrapped in the upper part of the glazing and includes a non-woven fabric through which sewage is permeated. The soil-type sewage treatment system according to claim 2, wherein the covered soil layer is immersed in the treated water in the sedimentation separation tank by 5 to 8 cm. The claimed soil layer is characterized in that the total volume is mixed with decomposed granite soil of 75 to 80%, humus soil of 10 to 15%, charcoal of 5 to 10%, and pumice of 5 to 10%. Item 2. The soil-type sewage treatment system according to Item 2. The soil formula according to claim 4, wherein the decomposed granite soil constituting the covered soil layer has an effective diameter of 0.075 to 0.250 mm, and the water content of the decomposed granite soil is 11 to 14%. Sewage treatment system. The soil-type sewage treatment system according to claim 4, wherein the hardness of the covered soil layer is 11.0 to 15.0 mm based on the Yamanaka-type soil hardness tester. The soil-type sewage treatment system according to claim 1, wherein the filtration settling tank uses a shell as a filter medium for adjusting the pH of the treated water. The above soil treatment tank
A sprinkler pipe that evenly sprinkles the treated water supplied from the flow rate adjustment tank,
It is placed at the bottom of the sprinkler pipe, and the treated water permeates and is arranged side by side in the horizontal direction. At the same time, it is stacked in multiple stages in the height direction to decompose organic substances, chemical substances, and suspended solids contained in the treated water. And soil blocks that adsorb pigment components,
The soil-type sewage treatment system according to claim 1, wherein the soil-type sewage treatment system is arranged between the soil blocks and includes a water passage layer through which treated water passes. The above soil block
Soil block frame and
A mixed soil that is installed inside the soil block frame in contact with the treated water, decomposes organic substances, chemical substances and suspended matter contained in the treated water, and adsorbs pigment components.
The soil-type sewage treatment system according to claim 8, wherein the inside of the soil block frame includes a non-woven fabric that wraps the mixed soil and allows the treated water to permeate. The above-mentioned mixed soil is characterized in that it is formed by mixing the total volume ratio of decomposed granite soil 75 to 80%, humus soil 10 to 15%, charcoal 5 to 10% and pumice stone 5 to 10%. The soil type sewage treatment system according to 9. The soil-type sewage according to claim 10, wherein the decomposed granite soil constituting the mixed soil has an effective diameter of 0.075 to 0.250 mm and a water content of the decomposed granite soil is 11 to 14%. Processing system. A soil-type sewage treatment system characterized in that the hardness of the mixed soil is 11.0 to 15.0 mm based on the Yamanaka-type soil hardness-type standard. The soil-type sewage treatment system according to claim 8, wherein the soil treatment tank is arranged between the soil blocks and includes an air diffuser for supplying air between the soil blocks. The soil-type sewage treatment system according to claim 1, wherein the soil treatment tanks are installed in a plurality of series inside the container so that they can be used alternately. The raw water tank is characterized in that the treated water stored in the water collecting tank is supplied, the dye component remaining in the treated water is adsorbed, and the water collecting tank again includes an activated carbon filter tube that shares the treated water. Item 1. The soil-type sewage treatment system according to Item 1. The soil-type sewage treatment system according to claim 1, wherein the settling separation tank includes a sludge treatment tank in which the settled and separated sludge is stored and ozone is supplied to decompose the sludge. An activated carbon filter tube to which the treated water stored in the water collecting tank is supplied, adsorbs the hue component remaining in the treated water, and supplies the treated water to the water collecting tank again.
The soil-type sewage treatment system according to claim 1, further comprising an evaporation tank in which surplus water is supplied from the water collection tank and the surplus water is evaporated.

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