JP2000296395A - Intra-site underground percolation treatment of living waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intra-site underground percolation treatment method for living waste water which is capable of executing a stable treatment in spite of the occurrence of an abrupt load fluctuation in raw waste water, hardly gives rise to clogging and allows the collection of treated water. SOLUTION: The raw waste water added with the biological symbiosis bacteria is evenly sprayed from between the middle stage layers of a reactor vessel 1 which is constituted by alternately laminating porous granular layers 6 and wood grain layers 7 in plural stages, disposing a cover soil layer 3 added with the biological symbiosis bacteria thereon and disposing a compost layer 4 added with the biological symbiosis bacteria on the lowermost layer. While the aerobic state is maintained by the air blasted from air introducing pipes 10 disposed between the middle stage layers in the vessel and between the middle stage layers and the lower stage layers during the percolating and descending in the vessel, mainly the BOD pollution components of the raw waste water are subjected to an activated sludge treatment and the treated water is percolated under the ground. Part thereof is collected by a sampling means and is subjected to a water quality analysis. The amount of the biological symbiosis bacteria to be added and the blasting rate of the air are adjusted according to the water quality data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an underground infiltration treatment method in a premises for collectively collecting domestic wastewater and treating BOD pollutants in the wastewater mainly by activated sludge treatment.

[0002]

2. Description of the Related Art Conventionally, in an area where a sewer is not fully equipped, drainage treatment of domestic wastewater discharged from general households, restaurants, settlements, and the like is performed by an underground infiltration treatment method on site.

This in-site underground infiltration treatment method treats domestic wastewater, that is, kitchen wastewater from a kitchen, washbath drainage from a washroom and a bathroom, laundry wastewater from a laundry, and human waste from a toilet. Collects treated water from a single septic tank at a time, introduces it into a fixed-volume reactor tank formed underground on the site, and treats BOD pollutant components in wastewater mainly with microorganisms to allow BOD to penetrate underground. After treating to below the emission standard value (20 ppm or less), treated water is permeated underground.

[0004] The structure of a conventional general reactor tank is as follows.
The top layer is a covering layer of about 20 cm in thickness, the bottom layer is a mulch layer of about 20 cm in thickness, and the middle layer is an irregular crushed stone of 1 cm in thickness. .5
It is formed by laminating about 2 m. The peripheral side surface of the reactor tank is made of a cylindrical or square tubular non-permeable material.

[0005] In addition, above the crushed stone layer of the reactor tank,
A plurality of watering tubes provided with a plurality of watering nozzles are provided so that the collected domestic wastewater can be watered on average.

Further, activated sludge is attached to the crushed stone as a seed fungus to inhabit microorganisms for purifying domestic wastewater.

Next, the operation method will be described.
The collected domestic wastewater is introduced into a sprinkler pipe, and water is uniformly sprayed from the spray nozzle onto the surface of the crushed stone in the reactor tank. The sprinkled domestic wastewater descends naturally between the stacked crushed stones, and comes into contact with the microorganisms in the activated sludge during this time, so that the BO is discharged.
By the time the D pollutant is mainly treated and passes through the lowermost humus layer, the underground seepage is below the allowable discharge standard value, and the treated water is discharged by underground seepage.

[0008] However, there are some problems in the treatment in such a conventional reactor tank. In other words, in the short term of about six months or one year after starting use,
Crushed stones cause clogging, causing overflow when a large amount of domestic wastewater flows in at one time. Odor is generated due to the accumulation of slime and the generation of slime, etc. In addition, due to the above-mentioned state change, domestic wastewater is not sufficiently treated and permeates underground, causing pollution of groundwater. It is a problem.

[0009] In addition to the above problem, the habitat of the microflora in the reactor tank is poor.
D If the microorganisms living in the reactor tank are abruptly damaged due to a sudden change in the pollution load or the inflow of various chemicals, the removal rate of the BOD pollutant component is greatly reduced. There is a problem such that the purification process cannot be performed due to death, and the condition is further deteriorated.

[0010] In such a case, first,
It is necessary to reduce the inflow of domestic wastewater, to reduce the processing load in the reactor tank and to cure microorganisms, or to clean the clogged reactor tank or replace crushed stones. However, such a task requires considerable effort and cost. Also, it is often the case that the processing is continued as it is without noticing that it is in such a state.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages of the prior art and can maintain a tough microbial flora which can be stably treated even if a sudden change in the pollutant load occurs in the raw wastewater.
It is an object of the present invention to provide a method for infiltration of underground effluent from domestic wastewater, which is less likely to cause clogging, requires less effort, enables sampling of treated water, and is inexpensive and safe.

[0012]

Means for Solving the Problems One aspect of the present invention is to collect a domestic wastewater consisting of a whole or a part of a kitchen drainage, a washing bath drainage, a washing drainage or a toilet septic tank drainage, and to constitute a filter material. In the underground infiltration treatment method in which BOD pollutant components are mainly activated sludge treatment and treated water is penetrated underground while being introduced into the reactor tank and permeating down the reactor tank, the lamination in the reactor tank is performed. As a configuration, a middle layer in which a porous granular material layer and a wood grain layer are alternately stacked in a plurality of stages, a soil covering layer on which a biosymbiotic bacterium is added, and a biosymbiotic bacterium added below the middle layer The compost layers are arranged and configured respectively, and between the middle layer, the domestic wastewater is added to the living wastewater in an amount corresponding to the analysis result of the water quality of the treated water described below. In the sprinkler tube, water is sprinkled on average. While the active wastewater is penetrating and descending in the reactor tank, the aerobic state is introduced by air introduced from the air introduction pipes arranged between the middle tank and the middle tank and the lower compost layer. While maintaining, the activated sludge is treated mainly with the BOD pollutant component, and the treated water discharged in this manner and discharged from the lowermost compost layer of the reactor tank is discharged underground, and a part of the treated water is discharged into the reactor tank. The water quality is analyzed and confirmed by sampling water provided by a sampling means attached to a part of the bottom of the slab, and the amount of the biosymbiotic bacteria added and the amount of air introduced by the air introduction tube are controlled according to the obtained water quality data. This is a method for infiltration treatment of underground effluent from domestic wastewater.

[0013] Therefore, according to the method of infiltrating underground effluent of domestic wastewater according to one aspect of the present invention, biosymbiotic bacteria live in the raw wastewater and in the reactor tank, and air is introduced into the reactor tank. It is aerated by the air introduced through the pipes, providing an environment in which microorganisms can actively live. Therefore, the symbiotic bacterium can suitably and stably treat the BOD pollutant component in the raw wastewater. In addition, as a result, the BOD value of the treated water is reduced, and a stable treated water quality that does not cause groundwater contamination is obtained.

As described above, the raw wastewater is introduced from between the middle layers of the reactor tank, so that even if a large amount of the wastewater is introduced at once, the reactor tank has room at the upper part. The portion of the drainage exceeding the amount of descent per unit time is once transferred to the upper part of the reactor tank and is held. Therefore, even in such a case, there is no possibility that the reactor tank overflows to cause a new trouble. The raw wastewater once retained here is subjected to activated sludge treatment under an aerobic condition as described above while gradually descending thereafter.

In the middle layer of the reactor tank, a porous granular material layer and a wood particle layer are alternately laminated in a plurality of stages, so that the permeability is good and air can be sufficiently taken into the voids. It is possible to improve the heat retention. Therefore, the inhabitation activity of microorganisms becomes more active, and stable treatment can be performed.

Since the inside of the reactor tank is always in an aerobic state due to the provision of a porous granular material layer in the middle layer and the introduction of air through an air introduction pipe, There is no accumulation of sludge or generation of slime, and there is no need for internal cleaning due to clogging or the like, so that labor and cost can be reduced.

In addition, the action of decomposing organic substances by the symbiotic bacterium does not generate odorous gas in the process and is effectively decomposed into carbon dioxide and water, so that the generation of sludge is extremely small. This eliminates the need to clean the reactor tank for a long period of time.

Further, the treated water is pumped up with a submersible pump to collect water, the quality of the water is analyzed and confirmed. According to the obtained water quality data, the amount of biosymbiotic bacteria added to the raw wastewater and the reactor Since the amount of air introduced into the predetermined part in the tank is appropriately controlled, the activated sludge treatment can always be performed under optimum conditions. In general, in the case of microbial treatment, the quality of treated water is difficult to stabilize for several days after the start of operation, so it is appropriate to increase the number of samplings and take an action earlier, which can be performed.

The present invention relates to a method for treating underground effluent of domestic wastewater in a method according to item 1 of the present invention, wherein the biosymbiotic bacteria are 60-85% of aerobic bacteria and 20-5% of facultative anaerobic bacteria. ,
An anaerobic bacterium having a composition ratio of 20 to 5% is employed.

Therefore, according to the method for infiltrating underground effluent of domestic wastewater according to the second aspect of the present invention, when there is no abnormality in the raw wastewater, the inside of the reactor tank is always in an aerobic state. The above symbiotic bacterium can be treated with only an aerobic bacterium. However, in consideration of, for example, abnormalities in the toilet septic tank and its drainage, or in cases where the corner of the reactor tank becomes pseudo-anaerobic, more safety is anticipated. Since aerobic bacteria and mainly anaerobic bacteria coexist as the biosymbiotic bacteria, even if the inside of the tank becomes anaerobic, it is possible to sufficiently treat the anaerobic bacteria.

As described above, three types of bacteria, aerobic bacteria, anaerobic bacteria, and facultative anaerobic bacteria, symbiotically coexist as the organism symbiotic bacteria because of the organic matter in the domestic wastewater, which is the treated water. This is because, even when a situation occurs in which the substance is wrapped by the colloid, the decomposition can be favorably continued.

According to the observations made by the present inventor, if the water to be treated has become anaerobic or pseudo-anaerobic, for example, the organic matter in the introduced raw wastewater is wrapped in a substance such as colloid. When a situation occurs, even if aeration treatment is performed in the presence of only aerobic bacteria, those organic substances are hardly decomposed, and simply move downward in the reactor tank. It only precipitates down in the interior.

On the other hand, in the tank in such a situation,
If it is assumed that the biosymbiotic bacterium in which a facultative anaerobic bacterium and an anaerobic bacterium coexist with an aerobic bacterium is to be present, it becomes possible to decompose the organic matter wrapped in the above-mentioned colloid, and it is possible to perform a good decomposition. The activities will continue and BOD pollution components will be able to be treated to the required level.

[0024] This is because, under the above-described conditions, when aerobic bacteria are allowed to coexist with facultative anaerobic bacteria and the above-mentioned symbiotic organisms in which anaerobic bacteria coexist, first, the anaerobic bacteria and the anaerobic bacteria are used. It is because the anaerobic bacterium works to break the colloidal membrane surrounding the organic matter and to start the decomposition of the organic matter inside, and then the aerobic bacterium acts to further promote the decomposition of the organic matter. Can be estimated.

The ratio of each bacterium is obtained from the results of repeated experiments. When the water to be treated is in the above-described condition, 60 to 85% of aerobic bacteria, The composition ratio of the anaerobic bacterium 20 to 5% and the anaerobic bacterium 20 to 5% is optimal.

[0026] The third aspect of the present invention is the method of the first aspect of the present invention, wherein the living effluent is infiltrated into the ground under the premises, and the biosymbiotic bacterium is a yeast, an ascomycete, or a cellulolytic bacterium mainly composed of aerobic bacteria. , Proteolytic bacteria mainly composed of facultative anaerobic bacteria,
Lactic acid bacteria and Bacillus subtilis, photosynthetic bacteria mainly composed of anaerobic bacteria,
Adopt a complex microbial bacterium, which is a group of bacteria including nitrifying bacteria, nitrogen fixing bacteria, acetic acid bacteria and butyric acid bacteria, adsorbed and fixed to the carrier, symbiotic, and cultured to a bacterial concentration corresponding to the target substrate concentration of domestic wastewater. It was done.

Therefore, according to the method for treating permeation of underground effluent of domestic wastewater according to the third aspect of the present invention, the aerobic bacteria, facultative anaerobic bacteria and anaerobic bacteria belong to the reactor tank. Since the above-mentioned symbiotic bacterium in which bacteria exist is employed, as described above, the organic matter can be more efficiently decomposed even in a pseudo-anaerobic and anaerobic state than in the aerobic state. And stable processing can be surely performed.

The above-mentioned biosymbiotic bacteria are used by being adsorbed and fixed on a carrier. When the concentration of the substrate in the raw wastewater is high, it is necessary to increase the ratio of the biosymbiotic bacteria to be added. However, simply increasing the addition amount causes a problem that the addition amount of the carrier increases at the same time. That is,
The carrier is also an object to be decomposed, and it is not preferable that the number of carriers is increased more than necessary. Therefore, the potency of the symbiotic bacterium, that is, the concentration thereof corresponds to the concentration of the substrate, and is used by adsorbing and immobilizing the carrier, thereby increasing the useless decomposition products. Processing can be performed efficiently without using

The biosymbiotic bacterium constituted by the bacterial group can ensure its safety. When the biosynthetic bacterium starts its activity in the reactor tank, a new biosymbiotic bacterium is biosynthesized in the reactor tank. Therefore, the microflora in the reactor tank is in a favorable state that is resistant to fluctuations in the raw wastewater.

In a fourth aspect of the present invention, in the method for treating underground infiltration of domestic wastewater according to the first aspect of the present invention, the sampling means is erected from a part of the bottom of the reactor tank, and the upper end thereof is displayed on the ground. A guide pipe that has been discharged, a treated water pit configured by closing the lower end of the guide pipe with a lid having a small hole, and a treated water collecting pipe connected to the treated water pit. And a submersible pump inserted into the treated water pit through the guide tube, the submersible pump being used to pump up the treated water collected in the treated water pit and to sample it on the ground. It consists of a pump.

Therefore, according to the method for infiltration of underground effluent of domestic wastewater according to the fourth aspect of the present invention, the structure is simple, easy to manufacture and difficult to break, and the sampling of treated water can be easily performed. .

Further, since the treated water pit is formed by closing the lower end of the guide tube with a lid having a small hole, the treated water accumulated in the treated water pit is always removed.
Since the permeate is discharged into the basement from the bottom in appropriate amounts, new treated water can be sampled accurately in real time.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. The drawings show an example of equipment for implementing the method for infiltrating underground effluent of domestic wastewater according to the present invention, and FIG. 1 is a longitudinal side view of the reactor tank,
FIG. 2 is a partially cutaway perspective view showing a piping configuration in the reactor tank.

First, the equipment used in the present invention will be described. As shown in FIG. 1, the reactor tank 1 is configured to be embedded in the underground 2, and a top soil layer 3 containing a biosymbiotic bacterium is added to the top layer, and a compost containing a biosymbiotic bacterium added to the bottom layer. A layer 4 is disposed, a middle layer is disposed therebetween, and the side surface is surrounded by a rectangular tubular non-permeable material 5. Here, as the water-impermeable material 5, a plastic material such as vinyl chloride, polyester or ABS, a concrete material, or the like is preferably used.

The size of the reactor tank 1 should be determined according to the amount of domestic wastewater to be treated, that is, the amount of raw wastewater to be introduced. When the BOD contamination concentration is about 5 to 0.6 m ³ / day and the BOD contamination concentration is about 250 to 500 ppm,
A volume of about mx 2 m x 2 m depth, that is, a size of about 8 m ³ is appropriate.

The middle layer of the reactor tank 1 has a particle size of 4 to 4.
A porous granular layer 6 in which porous granules of about 7 mm are spread to a thickness of about 25 cm, and a wooden grain of about 3 to 10 mm in thickness of 2 mm
The wooden grain layer 7 laid down to about 5 cm is alternately arranged in a plurality of stages (6-7
).

Here, as the material of the porous granular material, polystyrene, polyester, polyethylene, polypropylene, or the like which is expanded to increase the surface area, zeolite, ceramic, or the like is preferably used.

As the wood grain, a grain sawdust or a small chip-shaped wood piece is preferably used.

The covering soil layer 3 has a thickness of about 25 cm.
Each of the compost layers 4 has a thickness of about 25 cm, and each layer contains a biosynthetic bacterium in each of the carriers 1 to 1.5.
Lay about Kg.

As shown in FIGS. 1 and 2, a water-impermeable porosity of 30 to 30 is provided between the porous granular layer 6 and the wood particle layer 7 constituting the middle layer in the reactor vessel 1. Using a pipe of about 50 mm, a plurality of watering pipes 8 branched between the middle layers are provided, and raw water can be evenly watered from a plurality of watering nozzles 9 arranged in the watering pipes 8. I do. Each sprinkling nozzle 9 has an opening 2 to prevent clogging.
It is preferable to cover a net of about 3 mm.

A non-permeable material is provided between the wood particle layer 7 and the porous granular layer 6 constituting the middle layer of the reactor tank 1 and between the porous granular layer 6 and the compost layer 4 therebelow. A plurality of air introduction pipes 10 branched from between the layers are provided by using a pipe having a diameter of about 30 to 40 mm. A plurality of ejection holes 11 are arranged in these air introduction pipes 10 so that air can be introduced on average. Further, the other end of the air introduction pipe 10 is connected to a blower (not shown).

The sampling means is formed in one section of the bottom of the reactor tank 1. The sampling means comprises a treated water collecting pipe 12, a treated water pit 15, a submersible pump 13, and a guide pipe 14 for setting the submersible pump 13.

The guide tube 14 has a water-impermeable diameter of 200
Using a straight pipe of about 300 mm in length and about 2600 to 2800 mm in length, this is erected on a part of the bottom of the reactor tank 1, the upper end is exposed on the ground, and the lower end is a bottom lid with a small hole. close.

In order to accurately sample the treated water at the present time in real time, the above-mentioned pores are collected first, and the treated water remaining below is gradually penetrated into the underground little by little. It is for renewing the treated water.

A part of the bottom of the guide tube 14 is dug in a pit shape to about 550 mm, and crushed stone is laid on it to a thickness of about 50 mm, and the guide tube 14 is set up thereon. The lower end of the guide tube 14 closed by the lid serves as a treated water pit 15 for storing treated water. In addition, the lid is the bottom of the treated water pit 15, and as described above, a small hole is formed therein. Can be infiltrated.

The treated water collecting pipe 12 is configured to have a plurality of branches by using a water-impermeable pipe having a diameter of about 100 mm. A part of the base is installed so as to be able to collect water on average, and the ends of the bases, each of which is concentrated and connected, are connected to the upper part of the treated water pit 15.

In the treated water collecting pipe 12, a plurality of holes having a diameter of about 50 mm for receiving the treated water are formed at regular intervals, and these holes are covered with a net to prevent foreign matter such as compost from entering. So that Thereby, a part of the treated water is always introduced into the treated water pit 15.

Further, in the treated water pit 15,
A submersible pump 13 is inserted from the ground through the guide pipe 14 so that the treated water introduced into the treated water pit 15 can be collected on the ground. Thereby, at any time, the treated water is analyzed and the water quality is confirmed, and according to the obtained water quality data, the amount of the biosymbiotic bacteria added to the domestic wastewater to be introduced and the amount of air introduced into the middle layer and the like are controlled. With this, the state of treatment of wastewater is appropriately managed, and contamination of groundwater is prevented before it occurs.

The treated water thus collected is returned to the raw wastewater, if necessary, so that the microorganisms in the raw wastewater are more active and more stable treatment is possible.

Here, the symbiotic bacterium will be described.
The biological symbiotic bacterium is an aerobic bacterium effective for purification, a facultative anaerobic bacterium and a anaerobic bacterium group selected carefully from an innumerable group of microorganisms existing in the natural world. Depending on the temperature of the waste water, for example, the temperature of the raw waste water is 25 to 35 ° C.
If the temperature is below 25 ° C, the psychrophilic bacterium that prefers a lower temperature among the psychrophilic bacteria if the temperature is lower than 10 ° C. Select and use.

[0051] These bacterial groups include mainly yeasts, ascomycetes and cellulose-degrading bacteria including aerobic bacteria, protein-degrading bacteria including mainly facultative anaerobic bacteria, lactic acid bacteria and Bacillus subtilis. Complex microbial groups in which photosynthetic bacteria including anaerobic bacteria, nitrifying bacteria, nitrogen-fixing bacteria, acetic acid bacteria, butyric acid bacteria and the like coexist can be employed.

These bacterial groups are aerobic bacterial groups of 60-85.
%, The facultative anaerobic group is about 20 to 5%, and the anaerobic group is about 20 to 5%.

These complex microorganisms are co-cultivated,
As a carrier at that time, one or more kinds of brown rice flour, rice bran, bran and fibrous materials are combined with one or more kinds of proteins, corn powder, nitrogen minerals, vitamins and minerals. It is possible to employ a mixture of the above-mentioned components.

The concentration (titer) of the bacterial group in the carrier is as follows:
The concentration is adjusted according to the substrate concentration of the raw wastewater to be applied, and this is mainly performed by adjusting the concentration of the bacterial stock solution at the time of inoculating the bacteria on the carrier. If the concentration of bacteria at the time of inoculation is increased, the concentration of bacteria at the time of completion of cultivation is not necessarily proportionally increased, but increases accordingly. The appropriate concentration of the bacterium according to the substrate concentration of the raw wastewater can be determined experimentally.

The complex microorganism group is a microorganism which exists in nature and works effectively for purification, and in any case, selects a safe group of microorganisms.

The mechanism of purification by the symbiotic microorganisms described above finds an effective purification effect by the action of microorganisms carried out in nature, and makes this effect artificially and effectively. According to the findings of the present inventors, various organic substances undergo oxidative degradation by aerobic bacteria under aerobic conditions, and under anaerobic and pseudo-anaerobic conditions, anaerobic bacteria and facultative anaerobic bacteria , Each of which is assigned to a different role and subjected to decomposition processing. Therefore, in the present invention, three types of bacterial groups coexist in case that all or a part of the reactor tank becomes anaerobic or pseudo-anaerobic. In addition, the biosymbiotic bacterium newly undergoes biosynthesis in association with such a decomposing activity, is repeatedly proliferated, and a stable purification action is continued.

In addition, in order for the above-mentioned symbiotic fungi to perform an effective activity, temperature, p
It is necessary that H, dissolved oxygen content, nutrient balance, trace elements, enzymes and the like are suitable.

In the present invention, as described above, the bacterium to be used is selected depending on the temperature of the target raw wastewater. When the raw wastewater is domestic wastewater, it is preferable to use it by selecting from mesophiles in summer and from psychrophilic or psychrophilic bacteria in winter.

The pH is preferably about 5.5 to 8.5, but the pH of domestic wastewater is generally preferable because it is substantially in this range. Further, the dissolved oxygen content is preferably about 1 to 1.5 ppm, which can be ensured because the air is introduced through the air introduction pipe 10 disposed in the reactor tank.

On the other hand, as a nutrient balance, an appropriate amount of salts of nitrogen and phosphorus is necessary for oxidative decomposition under aerobic conditions. In addition, trace elements such as potassium, sodium, calcium, and magnesium act as osmotic pressure regulators that maintain a constant osmotic pressure in the body against external environmental changes in the growth and metabolism of microorganisms, and catalytic activities that activate enzymes. Is necessary for Further, bicarbonate, phosphate and the like are also required because they provide a buffering action for keeping the pH in the living body constant. Enzymes also play an important role in the oxidative degradation of various bacteria under aerobic conditions.

Fortunately, when the raw wastewater is domestic wastewater, each of these components is contained in an appropriate amount, so that various organic substances can be effectively oxidized and decomposed. It is.

In addition, the action of decomposing organic substances by the above-mentioned symbiotic microorganisms is characterized in that the generation of odorous gas is not generated in the process and the decomposition is effectively performed into carbon dioxide and water, so that the generation of sludge is extremely small. Has become.

The amount of the biosymbiotic bacteria added to the raw wastewater is B
Carriers which are about 3 to 4% of the OD pollution load (g / day) are preferably around 10 g / day for each carrier.

Next, the method of permeating the wastewater underground into the premises according to the present invention will be described. First, the reactor tank 1
The air from the air blower is introduced into the air introduction pipe 10 disposed between the middle layer and the middle tank and the lower layer in the inside, and the air is discharged from the ejection holes 11 so that the inside of the reactor tank 1 is cooled. Make it aerobic.

On the other hand, domestic wastewater including kitchen wastewater, washbasin wastewater, laundry wastewater and toilet wastewater from a septic tank is removed through a filter to remove coarse foreign substances. The water is introduced from the middle layer of the tank 1, and water is evenly sprayed into the tank from the water spray nozzle 9 provided in the water spray pipe 8.

Here, the raw wastewater is introduced from the middle layer between the reactor tanks 1 when the raw wastewater is discharged in large quantities at a time and exceeds the lower precipitation per unit time. However, the excess amount is temporarily transferred to the upper part of the reactor tank 1 and held there, so that an overflow from the reactor tank 1 does not cause a new trouble.

In addition, the raw effluent is, in principle, contained in the kitchen at a rate of 10% with the carrier per day.
Add about g daily. At the start of the operation, the amount of the symbiotic bacterium to be added is preferably about 2 to 3 times the usual amount.

The sprinkled raw wastewater gradually descends through the wood grain layer 7 and the porous particulate layer 6 in the reactor tank. During this time, the raw wastewater contacts the symbiotic bacterium under an aerobic condition, and is mainly treated with BOD pollutant components. The BOD concentration is such that the permeation treatment is acceptable.
The treated water is discharged into the basement immediately below the reactor tank 1 by permeation treatment.

A part of the treated water is collected in the treated water pit 15 by the treated water collecting pipe 12 and checked by the submersible pump 13 to check the quality of the treated water. . Then, according to the water quality data obtained by analyzing this, the processing conditions are fed back to optimally control the amount of the biosymbiotic bacteria added and the amount of air for aeration.

[0070]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but these are for explaining the effects of the present invention, and the present invention is not limited thereto.

<Embodiment> Domestic wastewater according to the present invention is treated as domestic wastewater having a BOD pollutant concentration of 480 ppm on average and a wastewater volume of 0.6 m ³ / day on average, discharged from various places in a general household composed of four family members. We decided to treat by the underground infiltration treatment method in the premises.

First, the reactor vessel 1 was prepared for construction, and the outer frame of the reactor vessel 1 was formed with a thickness of 7 mm.
Using a vinyl chloride resin plate of mm, create a frame with an open top and bottom of 1.8 m long × 2 m wide × 2.2 m deep, and place it in the ground 2 under the same size as the above outer frame. A hole was dug and embedded so that the upper part of the outer frame was at the same level as the ground surface.

Next, in one of the bottom corners of the outer frame,
The sampling means is constituted. First, a vinyl chloride resin pipe having an outer diameter of 264 mm, an inner diameter of 250 mm, and a length of 2700 mm was used as the guide pipe 14, and was made to stand upright on a part of the bottom corner of the reactor tank 1, and the upper end was exposed on the ground. At the lower end, a bottom lid having two small holes having a diameter of 3 mm was attached to a vinyl chloride resin plate having a diameter of 264 mm and a thickness of 7 mm.

Next, a pit-shaped hole having a diameter of about 270 mm and a depth of about 550 mm was dug in a part of the bottom corner of the reactor tank 1, and crushed stone was laid on the bottom at a thickness of about 50 mm. Then, the lower end of the guide tube 14 with the bottom lid was placed in the hole, and buried with soil excavated to a pit-shaped level, and the buried portion of the guide tube 14 was used as the treated water pit 15.

Next, the treated water collection using a vinyl chloride resin pipe having an inner diameter of 80 mm is provided below the compost tank 5 at the bottom of the reactor tank 1 so that a part of the treated water can be collected on average. Three water pipes 12 were branched in parallel, and the end of the base where the three pipes were gathered was connected to the upper part of the treated water pit 15. A plurality of holes having a diameter of 50 mm were formed in the treated water collecting pipe 12 at equal intervals, and a wire mesh having a diameter of 3 mm was hung in the holes to prevent foreign matter from entering.

A small submersible pump 13 was inserted into the treated water pit 15 from the ground through the guide tube 14 so that the treated water introduced therein could be sampled on the ground.

In the outer frame, compost is spread as a lowermost layer of the reactor tank 1 to a thickness of about 20 cm, and 1 kg of a carrier of a biosymbiotic bacterium having the following composition is evenly distributed throughout the inside. To form a compost layer 4.

<Composition of Symbiotic Organisms> Among aerobic bacteria, yeasts, ascomycetes and cellulose-degrading bacteria, as facultative anaerobic bacteria, from protein-degrading bacteria, lactic acid bacteria and Bacillus subtilis, and photosynthesis as anaerobic bacteria From among bacteria, nitrifying bacteria, nitrogen-fixing bacteria, acetic acid bacteria and butyric acid bacteria, those belonging to mesophilic bacteria and those belonging to psychrotrophic bacteria are selected in half respectively, and aerobic bacteria group 70%, facultative Anaerobic group 20% and Anaerobic group 10%
At the ratio of And these bacteria group symbiosis,
The amount of stock solution added when inoculating the bacteria is cultured as a normal amount,
The carrier was adsorbed and fixed on a mixture of brown rice flour, bran, protein, corn powder, vitamins and minerals. Prior to the treatment in the examples, it was confirmed that the above biosymbiotic bacteria were safe by an acute toxicity test with fish killifish and an oral acute toxicity test with mice.

Also, the upper surface of the lowermost compost layer 4 and the porous granular layer 6 constituting the middle layer in the reactor tank
On the upper surface of each, four air introduction pipes 10 each using a vinyl chloride resin pipe having an inner diameter of 30 mm were arranged in parallel and branched. Further, a plurality of ejection holes 11 are formed in the air introduction pipe 10 in a lateral direction so that air can be sent into the tank evenly.

On the air introduction pipe 10, an average particle diameter of 6 mm
The expanded polystyrene is spread to a thickness of about 25 cm to form the porous granular layer 6, and the wood grain layer 7 is formed by spreading sawdust having an average particle size of 4 mm to a thickness of about 25 cm thereon. And
This is repeated three times to form a six-layer structure.
The layer, the porous granular layer 6, was constituted.

Next, on the upper surface of the porous granular material layer 6,
Four sprinkler pipes 8 each using a vinyl chloride resin pipe having an inner diameter of 35 mm were arranged in parallel and branched. Further, the water spray pipe 8 is provided with a plurality of water spray nozzles 9 so that the raw wastewater can be evenly sprayed into the tank. The sprinkling nozzle 9 was covered with a metal mesh having a mesh size of 3 mm to prevent clogging, so that foreign matter did not enter.

Finally, a cover soil having a thickness of 2
The covering soil layer 3 was formed so as to cover about 0 cm so as to be at the same level as the ground surface. In addition, 1 kg of the carrier was added to the inside of the covering soil layer 3 so that the symbiotic bacteria having the above-described composition were distributed evenly on the whole, and the preparation of the reactor tank 1 was completed.

The domestic wastewater discharged from each place is
After passing through a 50-mesh wire net to remove coarse foreign substances, they were once received by a commercially available square measure and then introduced into the reactor tank 1 as raw wastewater. In the kitchen wastewater of the above-mentioned domestic wastewater, for 5 days from the start of operation, the biosymbiotic bacterium of the above-described composition was added together with the carrier at a rate of 20 g / day (BOD per day)
Then, 10 g / day (equivalent to 3.5% of the daily BOD pollution load) was added daily for both carriers.

When the above preparations were completed, the treatment of domestic wastewater was started by the method for infiltrating underground ground of domestic wastewater according to the present invention. Then, after 3 days, 10 days, 1 month, and once a month thereafter, the treated water is sampled for 13 months.
Data on the processing status was collected by the following measurement items and measurement methods, and the results are summarized in Table 1.

<Measurement Items and Methods> 1. Measurement of pH Measurement is carried out in accordance with JIS K0102 12.1. 2. Measurement of BOD It is measured based on JIS K01021. 3. Judgment of the odor of the treated water The odor of the treated water is smelled and expressed by smell.

[0086]

[Table 1]

As can be seen from the results of the water quality tests shown in Table 1, three days after the start of operation, a sewage odor was felt that was weak to the odor of the treated water, but the pH value was 6.8 and the BOD value was 2
It was 0 ppm, which was an acceptable value for underground seepage treatment. Further, after 10 days, the treatment became more stable and the odor of the treated water was not felt, and the BOD value was about one digit.

During this time, the condition of the reactor tank was quite stable, and the reactor tank was not clogged and hindered the introduction of raw wastewater. No treatment was possible in a stable state throughout the year.

[0089]

As described above, according to the method for infiltrating underground effluent of domestic wastewater according to the first aspect of the present invention, symbiotic organisms inhabit the raw wastewater and the reactor tank, and The inside is aerated by the air sent from the air introduction pipe, so that the microorganisms can actively inhabit the environment. Therefore, the above-mentioned biosymbiotic bacteria suitably and stably treats the BOD pollutant component in the raw wastewater. be able to. As a result,
The value of the BOD of the treated water is reduced, and a stable treated water quality without causing contamination of groundwater is obtained.

Since the raw wastewater is introduced from the middle layer of the reactor tank, even if a large amount of the raw wastewater is drained at one time, the raw wastewater is once transferred to the upper part of the reactor tank and held there. As a result, no new trouble occurs due to overflow from the reactor tank. The raw wastewater once reserved here, while gradually descending thereafter,
Activated sludge is treated under aerobic conditions as described above.

In the middle layer of the reactor tank, a porous granular material layer and a wood particle layer are alternately laminated in a plurality of stages, so that the permeability is good and air is sufficiently taken into the voids. As a result, the heat retention is also improved, and the inhabitation activity of the microorganisms is further enhanced, and stable treatment can be performed.

Further, since the inside of the reactor tank is always in an aerobic state, there is no accumulation of sewage sludge or generation of slime, and there is no need to clean the inside due to clogging or the like, thereby reducing labor and cost. .

[0093] In addition, the action of decomposing organic substances by the symbiotic bacterium does not generate odorous gas in the process and is effectively decomposed into carbon dioxide and water, so that the generation of sludge is extremely small. This eliminates the need to clean the reactor tank for a long period of time.

Further, the treated water is pumped up with a submersible pump to collect water, the quality of the water is analyzed, and the amount of the biosymbiotic bacterium added and the amount of air blown are appropriately controlled according to the obtained water quality data. As a result, the vehicle can be operated under optimal conditions. Generally, in the case of microbial treatment, the quality of treated water is difficult to stabilize for several days after the start of operation, so that an action can be taken earlier by increasing the number of samplings.

According to the method of permeating the wastewater underground in the premises according to the second aspect of the present invention, even if the inside of the reactor tank is in an anaerobic state or a pseudo-anaerobic state, the aerobic bacteria remain in the reactor tank. Since there is the biosymbiotic bacterium which symbiotic facultative anaerobic bacteria and anaerobic bacteria, even if organic matter or the like wrapped in the above-mentioned colloid is introduced in the state, it becomes possible to decompose it, Good decomposition activity continues, BOD and C
OD pollution components can be treated to required levels.

[0096] The reason is that, when there is the symbiotic bacterium in which a facultative anaerobic bacterium and an anaerobic bacterium coexist with an aerobic bacterium, first, the anaerobic bacterium and the facultative anaerobic bacterium work to activate the organic matter. It is presumed that the colloidal membrane surrounding the cell is broken and the decomposition of the organic matter inside starts, followed by the action of aerobic bacteria to further promote the decomposition of the organic matter.

[0097] The ratio of each bacterium that effectively acts in the anaerobic or pseudo-anaerobic state as described above is obtained from the results of repeated experiments.
The optimal composition ratio of 5%, facultative anaerobic bacteria 20 to 5%, and anaerobic bacteria 20 to 5% is optimal, and good results cannot be obtained outside the above proportions.

[0098] According to the method for infiltrating underground effluent of domestic wastewater according to the third aspect of the present invention, the aerobic bacteria, facultative anaerobic bacteria and bacteria belonging to each of the anaerobic bacteria groups are contained in the reactor tank. As the above-mentioned existing symbiotic bacterium was employed, as described above,
In the aerobic state, the organic matter can be more efficiently decomposed even in a pseudo-anaerobic state and an anaerobic state, so that a stable treatment can be surely performed.

The above-mentioned biosymbiotic bacterium is used by being adsorbed and fixed on a carrier. When the concentration of the substrate in the raw wastewater is high, it is necessary to increase the proportion of the biosymbiotic bacterium to be added. However, simply increasing the addition amount causes a problem that the addition amount of the carrier increases at the same time. That is,
The carrier is also an object to be decomposed, and it is not preferable that the carrier is unnecessarily increased. Therefore, the potency of the symbiotic bacterium, that is, the concentration thereof corresponds to the concentration of the substrate, and is used by adsorbing and immobilizing the carrier, thereby increasing the useless decomposition products. Processing can be performed efficiently without using

[0100] The biosymbiotic bacterium constituted by the bacterial group can ensure its safety. When the biosynthetic bacterium starts its activity in the reactor tank, a new biosymbiotic bacterium is biosynthesized in the reactor tank. Therefore, the microflora in the reactor tank is in a favorable state that is resistant to fluctuations in the raw wastewater.

According to the method for infiltrating underground effluent of domestic wastewater according to the fourth aspect of the present invention, the structure thereof is simple, easy to manufacture, hard to break, and easy to sample.

Since a small hole is formed at the bottom of the treated water pit, the treated water accumulated in the pit in the treated water pit is constantly permeated and discharged into the underground in an appropriate amount. Treated water can be accurately sampled in real time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of one embodiment of a reactor tank for carrying out the method for infiltrating underground effluent of domestic wastewater according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a piping configuration of a reactor tank for carrying out the method for infiltrating underground effluent of domestic wastewater according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor layer 2 Underground 3 Soil cover layer 4 Compost layer 5 Non-permeable material 6 Porous granular material layer 7 Wood grain layer 8 Water sprinkling pipe 9 Water sprinkling nozzle 10 Air introduction pipe 11 Jet hole 12 Treated water collecting pipe 13 Submersible pump 14 Guide pipe 15 Treated water pit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D003 AA02 AB09 BA02 BA04 CA02 DA04 DA05 DA20 DA29 EA01 EA11 EA19 EA21 EA23 EA24 EA25 EA30 FA05 4D027 AC01 AC04 AC05 CA01 CA05 CA07 4D040 BB01 BB42 BB91 DD03 DD07 DD11 DD31

Claims (4)

[Claims] Claims: 1. Collecting all or a part of domestic wastewater such as kitchen drainage, washbasin drainage, laundry drainage or toilet septic tank drainage, and introducing the collected wastewater into a reactor tank made of a filter material,
In the underground infiltration treatment method in which the activated sludge is mainly treated with the BOD pollutant component and the treated water penetrates underground during the infiltration and descent in the reactor tank, the granular structure in the reactor tank may be porous granular. A middle layer in which a material layer and a grain layer are alternately stacked in a plurality of layers, a covering layer on which a biosymbiotic bacterium is added, and a compost layer with a biosymbiotic bacterium added below the middle layer. In between the middle layer, the domestic wastewater, after adding the biosymbiotic bacteria to this in a corresponding amount according to the analysis result of the quality of the treated water described below, and then averaged by a sprinkler pipe The air introduced from the air introduction pipes disposed between the middle tank and the middle tank and the compost layer between the middle tank and the middle tank while the domestic wastewater penetrates and descends in the reactor tank BO while maintaining the aerobic state Activated sludge treatment is performed mainly on the pollutant components, and the treated water discharged in this manner and discharged from the lowermost compost layer of the reactor tank is discharged into the basement, and a part of the treated water is discharged to the bottom of the reactor tank. Sampling means provided at the site, water quality is analyzed and confirmed, and according to the obtained water quality data, the amount of domestic wastewater which controls the amount of the biosymbiotic bacteria and the amount of air introduced by the air introduction pipe is controlled. Underground infiltration treatment method. 2. An aerobic bacterium 60-
85%, facultative anaerobic bacteria 20-5%, anaerobic bacteria 20-5%
2. The method according to claim 1, wherein the group of bacteria has the following composition ratio. 3. The biosymbiotic bacteria include yeasts, ascomycetes and cellulolytic bacteria mainly composed of aerobic bacteria, protein-degrading bacteria mainly composed of facultative anaerobic bacteria, lactic acid bacteria and Bacillus subtilis, and anaerobic bacteria. Bacterial groups including photosynthetic bacteria, nitrifying bacteria, nitrogen-fixing bacteria, acetic acid bacteria and butyric acid bacteria mainly composed of bacteria are adsorbed and immobilized on a carrier to coexist, and the bacterial concentration corresponding to the substrate concentration of the target domestic wastewater The underground infiltration treatment method for domestic wastewater in a premises according to claim 1 or 2, wherein a composite microorganism cultivated in the soil is used. 4. A structure in which the sampling means is set upright from a part of the bottom of the reactor tank, and the upper end of the guide means is exposed on the ground, and the lower end of the guide pipe is closed by a lid having a small hole. A treated water pit, a treated water collecting pipe connected to the treated water pit, and a treated water collecting pipe arranged evenly at the bottom of the reactor tank; and a guide pipe provided in the treated water pit. A submersible pump
4. The underground permeation treatment method for domestic wastewater in a premises according to claim 1, comprising a submersible pump for pumping up the treated water collected in the treated water pit and sampling the treated water on the ground.