JP4370699B2 - Wastewater treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a household wastewater treatment device, and more specifically, wastewater from kitchens, washrooms, baths, laundry, etc. and human wastewater from flush toilets are combined in the septic tank, and discharged water treated underground. The present invention relates to a processing method and apparatus for further processing in a septic tank and allowing the treated water to permeate the soil in its own site.
[0002]
[Prior art]
Instead of a single septic tank for human wastewater, merger septic tanks that simultaneously treat household wastewater such as kitchens, toilets, baths, and laundry and human wastewater are becoming widespread, and the treated water is generally discharged into rivers. However, in order to avoid the impact on the river when the discharge destination is inconvenient, it is possible to dispose of it in the soil on your own site instead of releasing it into the river without causing any other trouble. For example, Japanese Patent No. 2960324 and Utility Model Registration No. 3025819 are convenient because of their possible relationship.
[0003]
In Japanese Patent No. 2960324, inflow sludge is separated by a cyclone-type separation tank in the previous stage, and the supernatant water is treated by a biological treatment method in a treatment apparatus having a double structure of a porous ceramic filter medium packed bed and a crushed stone filter medium packed bed. After purification, it is allowed to penetrate into the ground.
[0004]
Utility model registration No. 3025819 provides a treatment medium layer filled with wood chips such as sawdust in the treatment tank, and a perforated sprinkler pipe is embedded in the treatment medium layer to treat the wastewater to be treated. The wastewater is infiltrated into the medium layer and purified by a biological treatment method in the treatment medium layer, and then infiltrated into the ground.
[0005]
[Problems to be solved by the invention]
Combined septic tanks are generally larger in size than single septic tanks, but when treated water penetrates into the soil, it is necessary to carry out sufficient purification treatment to prevent soil contamination. In general, there are drawbacks in that the size and complexity of the treatment tank is increased, and maintenance management becomes complicated.
[0006]
In Japanese Patent No. 2960324, the inflow sludge is separated by a cyclone type separation slag in the front stage to prevent clogging of the filter medium in the processing apparatus in the rear stage, but the sludge precipitated in the separation slag is taken out and discarded. Therefore, disposal of the untreated sludge becomes a problem. In addition, Utility Model Registration No. 3025819 is complicated to maintain because the wood strip itself filled in the treatment tank itself is an organic matter, so that it has poor durability and needs to be frequently replaced.
[0007]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wastewater treatment apparatus capable of performing a sufficient purification process under the use of an underground penetration type septic tank with a small and relatively simple configuration. .
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a type in which treated water flowing out from a combined septic tank is further purified in a ground penetration type septic tank and permeated into the ground. Adopting a cylindrical treatment tank structure, a sprinkler pipe is provided at the center, and a first treatment layer, a second treatment layer, and a third treatment layer are sequentially provided on the outer periphery thereof. Is a treatment layer having a solid-liquid separation function filled with highly porous inorganic particulate filter media. The second treatment layer is formed by a water-permeable block with forced air supply, promoting aerobic digestion by aeration and food chain. The third treatment layer is a treatment layer having an anaerobic digestion function filled with a porous inorganic particulate filter medium having water absorption and water permeability.
[0009]
By adopting the vertical multi-tubular structure, the treatment tank can be made small, and the wastewater introduced into the water spray pipe in the center is first subjected to solid-liquid separation treatment in the first treatment layer, and then aerobic by aeration in the second treatment layer. Purified by digestion promotion and food chain, and further anaerobic digestion treatment in the third treatment layer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
[0011]
As shown in FIGS. 1 and 2, the wastewater treatment apparatus as an application target of the present invention further purifies treated water having a BOD of about 20 ppm or more flowing out from the combined septic tank 1 in the underground infiltration septic tank 2. Adopt a model that can penetrate into
[0012]
As a special configuration of the present invention for the above-mentioned type, as the underground infiltration type septic tank 2, a sprinkler pipe 4 having a large number of small-diameter holes around the center of the borehole 3 excavated in the ground as shown in FIG. A first treatment layer 5 is formed in a cylindrical shape around the water spray pipe 4 and filled with a porous inorganic particulate filter material, and a cylindrical second made of permeable concrete is formed around the first treatment layer 5. The 3rd processing layer 7 which arrange | positioned the processing layer 6 and filled the porous inorganic granular filter material around the 2nd processing layer 6 is formed, and the circumference | surroundings of the 3rd processing layer 7 are the soil which forms the pit 3 is there. Furthermore, the pipe end of the introduction pipe 8 is opened near the upper end of the sprinkling pipe 4 to introduce the discharged water from the combined septic tank 1 into the upper end of the sprinkling pipe 4, and the first treatment layer 5, the second treatment layer 6, and the third. The treatment layer 7 is sequentially purified so as to infiltrate the soil in the self-site as treated water of BOD 10 ppm or less.
[0013]
The second treatment layer 6 is provided with a large number of ventilation holes 9 penetrating in the heel direction, and at least the bottom of the water treatment tube 4, the first treatment layer 5, the second treatment layer 6, and the third treatment layer 7. 4, on the bottom of the first treatment layer 5 and the second treatment layer 6, a water stop plate 10 for preventing gravity permeation is laid, and the water stop plate 10 is provided with an air supply hole 11 communicating with the vent hole 9. A plurality of air supply holes 12 that open to the bottom of one treatment layer 5 are provided, and a pressurized air supply source is provided to the air supply holes 11 and 12 via an air supply pipe 13 and an air supply line 14 provided in the water stop panel 10. 15 is connected so that air can be forcibly supplied to the air holes 9 in the first treatment layer 5 and the second treatment layer 6 as necessary. Note that the air supply holes 12 may be omitted and air may be supplied only to the second treatment layer 6.
[0014]
On the upper end of the boundary between the second treatment layer 6 and the third treatment layer 7, a manhole side block 16 is placed in a state in which a vent hole 9 is opened therein, and a lid plate is placed in the inspection hole at the upper end. 17, and the first treatment layer 5 is provided with a test pipe 18 penetrating below the water stop 10 in a substantially vertical manner with its upper end opened near the middle part of the manhole side block 16. In addition, a small-diameter water passage hole is formed near the lower end of the water test tube 18 so that treated water can be collected. Prior to the installation of the water stop plate 10, a granular filter medium equivalent to the third treatment layer 7 is laid at the bottom of the well 3 before the water stop plate 10 is installed.
[0015]
As the particulate filter medium forming the first treatment layer 5, for example, a porous inorganic moisture adjusting filter medium mainly composed of calcium silicate crystals and having a porosity of about 80% is suitable, and has excellent water absorption and adsorptivity. 0.9-1.0, which is about the same as water, and therefore has a high degree of bacterial habitat, has characteristics as a fermentation aid, solid-liquid separation necessary for water treatment, temperature adjustment, oxygen A function such as supply is exhibited, and the particle size is preferably in the range of 5 to 25 mm. Otani stone or barley stone is good as the filter medium, and both may be mixed in an appropriate ratio. Other suitable filter media are Kanuma earth, zeolite, pumice, volcanic stone, coke and clay, and shale. There are artificial filter media baked, and some of them can be mixed for convenience.
[0016]
As the second treatment layer 6, it is preferable to adopt a cylindrical configuration in which several stages of water-permeable short cylindrical concrete blocks are stacked, thereby excellent water absorption and water permeability, and forced air supply to the air holes 9. Based on the activated sludge treatment function by aerobic bacteria.
[0017]
As the particulate filter medium forming the third treatment layer 7, for example, it may be composed of a porous granule mainly composed of zeolite, or may be a foamed concrete granule such as lightweight aerated concrete. , Excellent in water retention and water permeability, as long as it is an inorganic filter medium having a specific gravity of 0.9 to 1.0 and about the same as that of water, a plurality of types of filter medium may be mixed, and the particle size is 5 to 25 mm. However, it is preferable that the filter medium has a moderately larger diameter than the filter medium used for the first treatment layer 5. In addition, the filter medium of the third treatment layer 7 is coated with a fine powder of shell fossil and mixed in the state to gradually exude the mineral contained in the shell fossil to improve the growth of anaerobic bacteria. It can be expected to have a positive effect on nearby plants.
[0018]
In the above embodiment, only one unit is illustrated, but several units may be arranged in parallel as the amount of treated wastewater increases, and in that case, a sufficient interval between adjacent underground penetration septic tanks 2 may be provided. It is important to keep.
[0019]
Under the above-described configuration, the treated wastewater pretreated and discharged from the combined septic tank 1 is introduced into the sprinkling pipe 4 in the underground seepage septic tank 2 through the introduction pipe 8, and a large number of small-diameter holes in the sprinkling pipe 4. To the first treatment layer 5. The BOD source is adsorbed and adhered to the filter medium forming the first treatment layer 5 and is filtered, and the water held in the gap between the filter medium is discharged and solid-liquid separation (SS removal) is performed. When the water content in the filter medium reaches about 65%, the fermentation conditions are adjusted and aerobic fermentation is started, and the aerobic digestion of the organic sludge source grows to richer cells than the initial cells under the fermentation conditions. Therefore, it is used for energy necessary as nutrients such as nitrogen and used for the formation of new cellular constituents of bacteria (synthesis of microbial cells). The organic matter is decomposed into carbon dioxide gas and water by oxidation. In addition, abundant dissolved oxygen is maintained by the air supplied from the air supply hole 12 in the water stop board 10, and aerobic digestion is accelerated | stimulated.
[0020]
The sewage discharged from the filter medium in the first treatment layer 5 is absorbed by the second treatment layer 6 having good water absorption and water permeability. In the second treatment layer 6, oxidation is promoted by promoting the generation of aerobic bacteria because the dissolved oxygen is abundantly maintained by the air forcedly supplied from the air supply holes 11 to the air holes 9 in the waterstop 10. Decomposition accelerates and organic matter is decomposed into carbon dioxide and water. When organic substances are consumed by such a reaction, the cell constituents themselves are then oxidized, and this oxidation action is called endogenous respiration and is a pillar of aerobic digestion. Due to the deficiency, the bacteria die sequentially, and the constituents of the dead cells become nutrients for the living bacteria. Endogenous respiration continues until the nutrients of bacteria are consumed in the organic sludge, and the food chain is performed.
[0021]
The sewage filtered by the second treatment layer 6 is immersed in the third treatment layer 7 and finally filtered, but anaerobic digestion is performed at this stage. Organic substances such as carbohydrates, proteins, fats and oils, amino acids, urea, etc. contained in organic sludge sources are first produced by a group of bacteria called facilitating anaerobes (facultative anaerobic bacteria, substrate-degrading bacteria) under anaerobic conditions. High molecular organic substances are decomposed relatively quickly into low molecular intermediate products. The filter medium in the third treatment layer 7 is prevented from being clogged due to gravity permeation because the specific gravity is approximately the same as that of water.
[0022]
As described above, in the first treatment layer 5, the second treatment layer 6, and the third treatment layer 7, the solid-liquid separation treatment and the biological treatment of both aerobic and anaerobic are used, and there is no generation of excess sludge and secondary pollution. The treated water, which has been treated without consideration, is absorbed into the soil by soil capillary infiltration.
[0023]
【The invention's effect】
As described above, according to the present invention, the following various effects can be obtained.
[0024]
Solid-liquid separation treatment by the first treatment layer 5 filled with the inorganic particulate filter medium, aerobic biological treatment by the second treatment layer 6 made of the water-permeable block with forced air supply, and the third treatment layer 7 filled with the inorganic particulate filter material Since anaerobic biological treatment by sewage is used to purify sewage, there is almost no generation of excess sludge even though a facility for removing sludge from the wastewater from the combined septic tank 1 is not installed. In addition, the waste water can be effectively purified and permeated into the soil, so that not only the device can be downsized and the maintenance of the device is remarkably simple, but also the maintenance cost is low. Does not contaminate the soil.
[0025]
Since the intermediate second treatment layer 6 in the three layers of the first treatment layer 5, the second treatment layer 6, and the third treatment layer 7 is made of a water permeable block, this makes it possible to provide 3 Not only can the processing layer of the layer be formed clearly, but the construction work is remarkably simple, and the manhole side block 16 is also conveniently installed.
[0026]
As a result of the implementation, in a processing apparatus (for 10 persons) whose outer dimensions of the third processing layer 7 are 1.2 m in length, 1.2 m in width, and 1.4 m in height, BOD and SS are 2000 ppm and 2500 liters / day. The amount of treated water collected from the test pipe 18 was as shown in FIG.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view illustrating a wastewater treatment apparatus of the present invention.
FIG. 2 is a cross-sectional plan view of the apparatus of FIG.
FIG. 3 is a measurement result table of treated water according to an example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Merger septic tank 2 Underground penetration type | mold septic tank 4 Sprinkling pipe 5 1st process layer 6 2nd process layer 7 3rd process layer 8 Introducing pipe 9 Vent hole 10 Water stop board 11 Air supply hole 12 Air supply hole 13 Air supply pipe 14 Air supply line 15 Pressurized air supply source 16 Manhole side lump 18 Sample pipe

Claims (10)

The discharge water flowing out from the merged septic tank (1) is introduced into the underground penetrating septic tank (2) through the introduction pipe (8) and further purified in the underground penetrating septic tank (2) to penetrate into the ground. In the model, as an underground penetrating septic tank (2), a sprinkling pipe (4) is erected at the center and an introduction pipe (8) is opened near the upper end thereof, and the outer periphery of the sprinkling pipe (4) A first treatment layer (5) having a solid-liquid separation function filled with a porous inorganic particulate filter medium, a second treatment layer (6) having an aerobic digestion function formed by a water-permeable block, and porous inorganic particles The third treatment layer (7) having an anaerobic digestion function filled with the filter medium has a vertical multi-tubular treatment tank structure, and the second treatment layer (6) has a large number of ventilation holes in the vertical direction. In addition to drilling (9) in the penetrating state, the water pipe (4), the first treatment layer (5) and the second treatment The water stop panel (10) is laid on the bottom of (6), and the water stop panel (10) is provided with an air supply hole (11) communicating with the vent hole (9), and the air supply hole (11) is supplied with air. A wastewater treatment apparatus comprising a pressurized air supply source (15) connected via a trachea (13) and an air supply line (14). The manhole side block (16) is placed on the upper end of the boundary between the second treatment layer (6) and the third treatment layer (7) in a state where a vent hole (9) is opened therein. The waste water treatment apparatus as described in. The wastewater treatment apparatus according to claim 1 or 2, wherein an inorganic granular filter medium is laid at the bottom of the waterstop (10). The waterstop (10) is provided with a number of air supply holes (12) that open to the bottom of the first treatment layer (5), and the air supply holes (12) are provided with an air supply pipe (13) and an air supply pipe (14). The waste water treatment apparatus of any one of Claim 1 thru | or 3 which connected the pressurized air supply source (15) through the. Under the condition of penetrating the first treatment layer (5), the upper end of the water test tube (18) is located near the middle part of the manhole side lump (16) with its lower end opened below the waterstop (10). The wastewater treatment apparatus according to any one of claims 1 to 4, wherein the wastewater treatment apparatus is disposed so as to open. The wastewater treatment apparatus according to any one of claims 1 to 5, wherein the first treatment layer (5) is formed of a porous inorganic particulate filter material mainly composed of calcium silicate. The wastewater treatment apparatus according to any one of claims 1 to 5, wherein Otani stone and / or barley stone is adopted as the porous inorganic particulate filter material forming the first treatment layer (5). The waste water treatment apparatus of any one of Claim 1 thru | or 7 which comprised the 2nd process layer (6) with the water-permeable concrete block. The wastewater treatment apparatus according to any one of claims 1 to 8, wherein the particulate filter medium forming the third treatment layer (7) is composed of a porous granule mainly composed of zeolite. The wastewater treatment apparatus according to any one of claims 1 to 8, wherein a foamed concrete granule is adopted as the particulate filter medium forming the third treatment layer (7).

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