JPH03258396A - Sewage treating device - Google Patents

Abstract

PURPOSE:To produce treated water with high efficiency by forming a bed packed with a granular filter medium having a specified sp.gr. at the upper part in a tank, providing an air diffuser below or in the filter medium bed, using the lower part as a settling part and furnishing a raw water inlet part to the settling part and a treated water outlet part at the upper part of the tank. CONSTITUTION:The raw water contg. SS, soluble BOD, etc., such as sewage is introduced into the settling part 5 in the tank from the raw water inlet part 6 to settle and separate SS in the raw water. The raw water with the SS separated and removed in the settling part 5 is passed as an upward flow through the bed 2 packed with the granular filter medium having >=1.0 sp.gr. at the upper part of the tank, hence the fine SS which has not been settled and separated at the settling part 5 is filtered off, and the soluble SS is removed and the NH4 is converted to N by the action of the biological membrane deposited on the surface of the filter medium constituting the bed 2. The oxygen necessary for the absorbing action of the biological membrane deposited on the filter medium surface is supplied from the diffuser and allowed to ascend in the bed 2.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a novel treatment device for organic wastewater containing SS, BOD, NH, -N, etc. such as sewage, human waste water, and various organic industrial wastewater. It is related to.

[Conventional technology]

To explain conventional technologies using sewage treatment as an example of a typical organic sewage treatment, the most typical method for sewage treatment is the activated sludge method, which has the important advantage of being widely applicable. and is the most widely used.

On the other hand, in recent years, an aerobic biological filter bed method has been developed. In this method, sewage flows downward through a hearth made of granular filter media such as sand, anthracite, and activated carbon, and air bubbles are raised from a diffuser pipe, etc., and the sewage is treated by countercurrent contact. . In this case, aerobic biofilms such as BOD-assimilating bacteria and nitrifying bacteria are attached to the surface of the filter medium in the hearth, and the biggest feature is that biological treatment and SS filtration removal are performed at the same time in this hearth. It becomes.

In addition, biological denitrification treatment of sewage, etc. is carried out as follows.

On the other hand, in recent years, an aerobic biological bed method and an anaerobic biological filter bed method using filter media such as sand and anthracite have been developed, and biological nitrification and denitrification processes using these have been tested. In other words, a method of performing nitrification and denitrification using the following flow is being experimentally studied.

[Problem to be solved by the invention]

However, the conventional activated sludge treatment method has the following major drawbacks.

■ Three separate tanks are required: an initial sedimentation tank, an air precipitation tank, and a final sedimentation tank, resulting in a large installation area and high construction costs.

■ Aeration power efficiency is good (there is no, so aeration costs are high).

■ Carryover of SS in the final sedimentation tank is unavoidable, and the removal rate of SS in the first sedimentation tank is only about 70%.

■ In order to reduce the SS of the treated water to 20 / It or less, a suitable place for sand is required after the final settling tank.

■ Sedimentability of activated sludge often deteriorates.

Furthermore, the aerobic biological filter bed method also has the following drawbacks.

■ If there is a lot of raw water SS, it is necessary to install a settling tank at the front stage, otherwise the hearth will clog quickly and it is not practical.

■ Even when the raw water BOD is high, the amount of biofilm growth increases and the clogging of the hearth progresses rapidly.
Not applicable.

■ As water for cleaning when the hearth is clogged, clarification from the aerobic biological filter bed device must consume water, which results in poor production efficiency of treated water.

■ A separate sedimentation tank is required to treat washing wastewater.

■ Construction costs are high because the hearth support structure at the bottom of the hearth and the air diffusion system are complicated, and it is not always easy to build a scale amplifier.

In addition, in the conventional biological denitrification treatment, the installation area and construction cost of the equipment are large, and the power of the air blower for nitrification of NH4-11 is also large.
Moreover, the sedimentation and separation of SS in the "initial settling tank" and the "final settling tank" was unstable, which often led to deterioration of the quality of the treated water.

An object of the present invention is to solve all of the drawbacks of the prior art described above and to provide a sewage treatment device that can produce extremely high quality treated water with high production efficiency.

[Means to solve the problem]

In claim 1 of the present invention, a filter layer filled with granular material having a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is provided below or inside the filter layer. A sewage treatment device characterized in that a part is a sedimentation part, a raw water inflow part is provided in the sedimentation part, and a treated water outflow part is further provided in the upper part of the tank. A sewage treatment device characterized in that a washing waste water return path is provided for returning washing waste water during washing of the layer to the settling section, and in claim 3 of the present invention, the filter medium layer is immersed in the upper part of the tank. The lower part of the tank is a settling part, and the settling part is provided with a raw water inflow part, and the upper part of the tank is provided with a primary treated water outflow part.
A filter medium layer filled with a granular filter medium having a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is provided below or inside the filter medium layer, and the lower part thereof is used as a settling part, A second tank having a final treated water outflow part at the upper part of the tank is installed in parallel, and the primary treated water outflow part of the first tank is communicated with the sedimentation part in the lower part of the second tank. A sewage treatment device characterized in that, in claim 4 of the present invention, a filter layer filled with granular filter media having a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is installed in the filter layer. The part of the filter layer above the aeration device is used as an aerobic biofilm treatment section, the section below the aeration device is used as an anaerobic biofilm treatment section, and the lower part of the tank is used as a sedimentation section. A sewage treatment device characterized in that a raw water inlet is provided in the sedimentation part and a treated water outflow part is provided in the upper part of the tank, and in claim 5 of the present invention, the treatment water flowing out from the treated water outflow part in claim 4 is provided. A sewage treatment device is characterized in that a circulation path is provided for circulating part of the water to the lower part of the filter layer, and in claim 6 of the present invention, a granular filter medium having a specific gravity of 1.0 or more is provided in the upper part of the tank. The filled filter layer is immersed and held, an aeration device is installed below or inside the filter layer, the lower part of the tank is used as a sedimentation area, and a raw water inlet is provided in the sedimentation area.
A treatment tank equipped with a secondary treated water outlet and an aerobic biological J-bed device equipped with a hearth of granular filter media with a specific gravity of 1.0 or more are installed side by side,
The sewage treatment device is characterized in that a primary treated water outflow portion of the treatment tank and the aerobic organism are connected to a floor device.

[For production]

First, in the present invention as claimed in claim 1, as shown in FIG. SS of
is separated by sedimentation. The raw water from which SS has been removed in the sedimentation section 5 flows upward through the filter layer 2, but at the same time, fine SS that has not been sedimented and separated in the sedimentation section 5 is removed. Due to the action of the biofilm attached to the surface of the filter medium forming the filter layer 2, soluble BOD is removed and NH
4-N nitrification is performed. Further, oxygen necessary for the respiratory activity of the biofilm attached to the surface of the filter medium is supplied from the air diffuser and rises in the filter medium layer 2.

In this way, the treated water, which has become clear through the removal of SS in the raw water by sedimentation and filtration and the biological removal of organic matter and NH, -), flows out from the upper treated water outlet. I'm going to go.

Trace amounts of SS, BOD, NH, and
- To remove N to a higher degree by polishing, aerobic granules such as anthracite and activated carbon are used in a hearth device (a device that performs aeration from the bottom of the hearth and simultaneously performs biological treatment using a biofilm on the surface of the granular filter medium. It is best to supply the treated water to an aerobic biological filter (called an aerobic biological filter). In this case, since most of the SS and BOD in the raw water have already been removed, the progress of clogging of the aerobic biological filter bed is extremely slow, making maintenance extremely easy.

Now, as SS filtration removal and biofilm treatment progress in the filter layer 2, the resistance of the filter layer 2 increases.
When a predetermined furnace resistance is reached, the filter layer 2 is cleaned.

Various methods can be used to clean the filter layer 2. For example, (a) the amount of air diffused from the air diffuser is suddenly increased to disturb the filter layer 2 and the trapped SS flows in; It is preferable that the SS be allowed to flow out to the upper part along with the upward flow of the raw water, and as in the present invention as claimed in claim 2, this washed waste water is returned to the sedimentation section 5 to separate the SS by sedimentation. It is highly preferred to inject a flocculant, such as a cationic polymer, to promote sedimentation and separation of the SS.

(bl) Before performing the above cleaning operation, the water in the tank is drained to lower the water level, and the amount of aeration is rapidly increased to promote the agitation movement of the filter layer 2.

By such washing, the resistance of the filter medium layer 2 returns to its initial value, so that the aeration amount is reduced again to the steady state amount, and the processing is characterized by the following: As shown in FIG.
Raw water containing soluble substances, soluble BOD, etc. is introduced, and sedimentary SS in the raw water is separated by sedimentation. At this time, an appropriate flocculant may be injected into the raw water in order to promote sedimentation and separation of SS.

Further, it is preferable that the sedimentation section 25 in the first tank 2) has a shape that is advantageous for sedimentation and separation of SS.

The raw water in which most of the SS has been sedimented and separated at the bottom of the first tank 2) is turned upward and enters the filter medium layer 22 from below,
The fine SS that could not be completely settled is removed, and
The soluble BOD component is decomposed and removed by the anaerobic biofilm or aerobic biofilm developed on the surface of the filter medium layer 22 .

In addition, in order to develop an aerobic biofilm on the surface of the filter medium in the filter medium layer 22, an aeration device may be provided below or inside the filter medium layer 22 to diffuse oxygen-containing gas.
To develop an anaerobic biofilm on the surface of the wood, leave it as is without aeration.

Thus, the primary treated water flowing out from the upper part of the filter layer 22 flows from the primary treated water outlet to the settling section 45 in the lower part of the second tank 41, and then enters the filter layer 42 from below. Then, the filter medium layer 42 is kept in an aerobic state by being diffused with oxygen-containing gas by an aeration device, and B is kept on the surface of the filter medium.
An aerobic biofilm containing OD-producing bacteria and nitrifying bacteria develops. Therefore, the remaining 80% of the primary treated water flowing out from the first N2)
D. Ammonia is very effectively removed by the aerobic biofilm that develops within the filter medium 1i42, and at the same time, the remaining fine SS is also highly filtered out, and both ss and aon have a clear concentration of several ■/l. The final treated water gushes out like a spring from the upper part of the filter medium layer 42 and flows out from the purest treated water outlet.

Now, as the treatment continues, the t1 material layer 22 of the first tank 2) and the material layer of the second tank 41? Since the amount of SS trapped in the door material layer 42 increases and the furnace resistance increases, the predetermined resistance (500 F
zO), each F material layer is cleaned. Various methods can be considered for cleaning the filter media layer, and any method may be adopted, but for example, the following A method can be recommended.

To clean the filter layer 22 of the first tank 2), an aeration device is provided below or inside the filter layer 22 to rapidly increase the amount of air diffused, thereby creating an intense gas-liquid multiphase flow within the filter layer 22. , filter layer 2
Push out the SS that had been captured and accumulated within 2.

When cleaning the hearth in a conventional aerobic biological filter bed device,
Although it was necessary to stop the inflow of raw water, in the present invention there is no need to stop the inflow of raw water, and on the contrary, the filtering medium layer 22 SS is washed out together with the air by the inflow of raw water. That is, there is an important advantage that the raw water itself can be used as water for washing the wood.

The washing wastewater containing SS washed out from the filter medium layer 22 of the first cypress 2) flows into the settling section 45 located in the lower part of the second tank 41, and the SS in the washing wastewater is sedimented and separated. Second tank 41
Polymer condensation occurs in the cleaning wastewater flowing into the water! ! If it is possible to add psyllium, the sedimentation and separation of SS in the washing waste water can be significantly promoted.

Next, cleaning of the filter medium layer 42 of the second tank 41 will be explained.

The rate of increase in the furnace resistance of the filter medium layer 42 is slow. because,
This is because most of the SS and BOrl in the raw water have been removed by sedimentation and separation and the filter medium layer 22 in the first tank 2) in the previous stage. However, as the furnace continues to operate for a long period of time, the furnace resistance reaches a predetermined value, so it is necessary to perform cleaning. As soon as the cleaning is performed as follows, the amount of diffused air discharged from the diffuser is significantly increased compared to during normal operation, and the S in the filter medium layer 42 is increased.
S is washed out, and this washing wastewater is sent to the first tank 2) along with the raw water.
) It is preferable to let the SS flow into the sedimentation section 25 to separate the SS. Furthermore, the cleaning waste water of the filter medium layer 42 is recycled to the sedimentation section 45 in the lower part of the second tank 41 to sediment and separate the SS, and the clarified cleaning water is recycled. It is also an extremely preferred embodiment to reuse the wastewater as water for washing the filter medium layer 42, and if a polymer flocculant is added during this recycling, the sedimentation and separation of ss in the recycled washing wastewater can be promoted.

By the cleaning operation as described above, the SS in each I material layer is washed out and the furnace head is returned to its initial value, so the amount of air diffused from the air diffuser is returned to the normal process and the process is restarted.

Furthermore, other preferred processing operations of the present invention according to claim 3 are listed below.

■ If the soluble BOD concentration in the raw water is high (for example, BOI1
1000■/! degree), a part of the final treated water flowing out from the aerobic filter layer 42 of the second tank 41 is guided into the lower part of the first tank 2] to dilute the raw water, and the tP in the tank is
Anaerobic formation within the material layer 22 can be prevented. Of course, when performing anaerobic biofilm treatment on the filter medium layer 22, it is not necessary to perform such an operation.

■ When removing non-biodegradable COD at the same time, powdered activated carbon is added to the primary treated water flowing out from the first tank 2), and the powdered activated carbon particles are captured by the filter layer 42 of the second tank 41. COD is reduced by a mechanism similar to that of a granular activated carbon adsorption tower.
By removing this, the COD adsorption ability of the powdered activated carbon can be maximized, and biological regeneration of the activated carbon by aerobic organisms within the filter medium layer 42 can also be expected.

■ The filter medium of the filter layer 42 of the second tank 41 is higher than that of the first tank 2.
) The amount of SS captured in the filter layer 22 of the first tank 2) is improved by increasing the particle size of the filter layer 22 and increasing the porosity.

(2) When the raw water BOD has a high concentration, it is preferable to maintain the filter layer 22 of the first tank 2) in an anaerobic state to develop a methane-fermenting bacteria biofilm and collect the generated methane gas.

■ When removing phosphate ions, inorganic flocculants such as aluminum sulfate 7-polyaluminum chloride, ferric chloride, etc. are injected into the water, and flocs containing insolubilized phosphorus are first
Sedimentation is carried out in tank 2) or second tank 41.

■ When performing nitrification and denitrification treatment, the filter layer 22 of the first tank 2) is kept in an anaerobic state, and a part of the final treated water in the second tank 4 is transferred to the filter layer 22 of the first tank 2). Circulate to the bottom of layer 22.

In the present invention according to claim 4, as shown in FIG. 3, raw water containing SS substances such as sewage and soluble BOII is caused to flow into the sedimentation part 55 in the tank from the raw water inflow part, and the sedimentation in the raw water is reduced. The SS is precipitated and separated. In this case, it is preferable to inject a flocculant into the raw water for the purpose of accelerating the sedimentation of SS and dephosphorizing it.

The raw water from which SS has been separated and removed in the sedimentation section 55 is reversed upward and preferably sent to the anaerobic biofilm treatment section 52-2 maintained in an anaerobic state below the filter layer 520 and the aeration device. On the surface of the filter medium in this anaerobic biofilm treatment section 52-2, flowing at a countercurrent speed of about 20 to 30 m/day,
Organic acid-producing bacteria, methane-producing bacteria, denitrifying surfaces, etc. are attached, and soluble BOD in the raw water is removed anaerobically, and at the same time, fine SS that has not been completely precipitated in the settling section 55 is removed. removed.

In this way, the raw water that has undergone anaerobic biofilm treatment in the anaerobic biofilm treatment section 52-2 is maintained in an aerobic state above the air diffuser of the filter layer 52. 1
It continues to rise. Air is supplied to the aerobic biofilm processing section 52-1 from the air diffuser below.

Oxygen-containing gas such as oxygen-enriched air is diffused, and aerobic biofilm grows and develops and adheres to the wood surface, and residual B that could not be completely removed in the anaerobic biofilm treatment section 52-2
OD, N11d-N is effectively removed by aerobic microorganisms.

However, the precipitation part is 55.11! Temperature biofilm processing section 52-
2. While flowing through the aerobic biofilm treatment section 52-1, SS in the raw water is removed by precipitation and filtration, and soluble BOD, NH, -N in the raw water undergoes anaerobic biological action →
The clarified treated water removed by aerobic biological action gushes out like a spring from the upper part of the filter layer 52 and flows out from the treated water outflow section.In addition, trace amounts of BOD and SS remain in the treated water. , NH, -N is to be removed to a high degree, the treated water is further treated with biological treatment and overtreatment using an aerobic biological bed filled with granular filter media such as sand, anthracite, and activated carbon. It is best to introduce it to an aerobic biological filter bed device that performs this at the same time.

The anaerobic biofilm treatment section 52-2 not only performs SSO operation and anaerobic biofilm treatment, but also has the following important functions. That is, when the anaerobic biofilm treatment section 52-2 is not present at the bottom of the air diffuser, the sedimentation section 55 is caused by the upward movement of the bubbles discharged from the air diffuser.
However, since the anaerobic biofilm treatment section 52-2 exists, the disturbance of the water flow due to air bubbles from the air diffuser is suppressed. As a result, the turbulence of the water flow does not extend to the settling section 55, and the SS of the raw water can be separated by precipitation under ideal conditions.

Now, as the operation continues, SS is accumulated in the filter layer 52 and the furnace resistance increases, so that the predetermined resistance (500 to 10
00100O), the filter medium layer 52 is washed.

Various methods are conceivable for cleaning the filter layer 52, but for example, the amount of air diffused can be rapidly increased to generate intense water and air currents in the filter layer 52 to disturb the filter layer 52 and remove trapped particles. A method to identify existing SSs is recommended. In cleaning the filter layer 52, in addition to the air diffused from the air diffuser embedded in the filter layer 52, a cleaning air diffuser is also provided under the anaerobic biofilm treatment section 52-2 of the filter layer 52. It is also a preferable means to further diffuse air during cleaning.

During the above-mentioned washing, it is not necessary to stop the inflow of the raw water, and it is preferable that the SS separated from the filter medium layer 52 be pushed out by the Kamioka flow of the raw water.

That is, it is not necessary to use clarified water to wash the filter medium layer 52, which is very rational. In addition, the washing wastewater is collected in the sedimentation section 55.
It is recommended to recycle the wastewater and separate the SS in the washing wastewater by precipitation.If a polymer flocculant such as a cationic polymer is added during the recycling of the washing wastewater, the precipitation of SS in the washing wastewater can be significantly promoted.

In this way, there is no need to stop the supply of raw water when cleaning the filter media layer 52, the clarified water is not consumed as cleaning water, and a separate settling tank or other SS is used to remove SS from the cleaning wastewater. It is also possible to omit the removal equipment.

The present invention according to claim 5 has most of the same effects as the present invention according to claim 4, but further aims at a denitrification effect, and this point will be explained below with reference to FIG. 4.

Inside the filter medium tank 52, oxygen-containing gas such as air is diffused from an aeration device, and the upper part of the aeration device is an aerobic biofilm treatment section 52-L, the lower part is an anaerobic biofilm treatment section 52-2. In the anaerobic biofilm treatment section 52-2, the biofilm on the denitrification surface has developed as the dominant species, so the raw water flowing upward could not be completely settled in the settling section 55. While fine SS is filtered out, biological denitrification (reduction reaction of No□-N to Nt) progresses. The water flowing upward from this anaerobic organism #processing section 52-2 is further transferred to the aerobic biofilm processing section 52 in which a biofilm of nitrifying bacteria has developed as a dominant species.
-1, and using oxygen supplied from the air diffuser, N11. -N nitrification reaction progresses.

Note that the N generated in the anaerobic biofilm treatment section 52-2
The two gas bubbles also pass through the aerobic biofilm treatment section 52-1 and dissipate from the water surface into the atmosphere.

In this way, the clear treated water that gushes out like a spring from the upper part of the filter media layer 52 is discharged into public water bodies, but since this treated water contains N0W-N, the treated water that flows out A part of the water is recycled to the lower part of the filter medium layer 52 and enters the anaerobic biofilm treatment section 52-2 in an upward flow, and the NOX-N in the water is reduced to N and gas by the denitrification surface biofilm. Ru.

In addition, when the organic carbon source in the raw water is insufficient, methanol, ethanol, acetic acid, etc. are added together with the treated water to which the organic carbon source is returned to serve as a hydrogen donor for denitrification.

Furthermore, in the present invention of claim 6, as shown in FIG.
Processing W! Raw water containing SS such as sewage, soluble BOD, etc. is caused to flow into the settling part 85 in the raw water inlet 81 from the raw water inflow part, and the sedimentable SS in the raw water is precipitated. The raw water in which most of the SS has been precipitated and removed is reversed upward and enters the filter layer 82 in the upper part of the tank in an upward flow, and the fine SS that has not been completely precipitated is
At the same time, soluble BOD in the raw water is decomposed and removed by an aerobic biofilm developed on the surface of the filter layer 82 due to the diffusion of oxygen-containing gas from the aeration device.

Therefore, the primary treated water flowing out from the upper part of the filter layer 82 flows into the upper or lower part of the aerobic biological filter bed device 101, and flows downward or upward through the hearth 102 under aerobic conditions. 5S and BOD, which remain in small amounts in the primary treated water, are further purified to a higher degree, and nitrification has also progressed sufficiently, and both 55.BOD and NH*-N are purified. number a
Purified water of t/1 or less can be obtained. The primary treated water flowing into the hearth 102 of this aerobic biological filter bed device 101 is S
Since S and BOD are small, the hearth 102 clogs extremely slowly even with the downward flowing water, and there is no need to clean the hearth 102 for a long time, making maintenance easy. Also, when water is passed through the hearth 102 in an upward flow, there is an important feature that the support bed at the bottom of the hearth 102 will not be clogged because the SS is small.

Now, as the above process continues, the filter medium layer 82
Due to the increase in SS accumulation and the growth of biofilm,
Since the excessive resistance reaches a predetermined set value (1 m, about 8.0), the filter medium layer 82 is cleaned at this point.

Various methods can be considered as the cleaning method, and any method may be adopted. For example, the following method is recommended.

That is, if the amount of air diffused from the aeration device is rapidly increased while raw water continues to flow in, and a strong gas-liquid mixing flow is generated within the filter layer 82, the excess SS content within the filter layer 82 will be washed out. is,
It is carried away by washing wastewater and flows out. This cleaning wastewater containing SS is preferably guided again into the sedimentation section 85 in the lower part of the tank, and if necessary, a flocculant or the like may be injected to promote precipitation and separation of SS within the sedimentation section 85. The cleaning wastewater from which @SS has been separated can be reused as water for cleaning the upper filter medium layer 82.

In this way, after cleaning for a predetermined period of time, the amount of diffused air is returned to the normal state.

Next, the overresistance of the hearth 102 of the aerobic biological filter device 101 also increases, albeit slowly. When the filtration resistance reaches the set value, this hearth 102 will also be cleaned. Although various methods can be used as the cleaning method, the following method is extremely preferable.

That is, the storage tank 110 is interposed in the communication path between the primary treated water outflow part of the treatment tank 81 and the aerobic biological filter device 101.
The secondary treated water is temporarily stored in a storage tank 110, and a flow path is provided for pressurizing the stored primary treated water into the lower part of the hearth 102 of the aerobic biological filter device 101. Therefore, when the aerobic biological filter bed device 101 cleans the bed 102,
The primary treated water in the storage tank 110 is forced into the lower part of the hearth 102 to backwash and agitate the hearth 102 for cleaning.
There is no need to stop air diffusion to keep 02 in an aerobic state. Further, the cleaning waste water is guided to the sedimentation part 85 of the treatment tank 8I in the previous stage, and is allowed to flow into the post-treatment storage tank 110, where it can be reused as cleaning water if necessary.

In this way, cleaning the filter layer 82 of the treatment tank 81 and cleaning the hearth 102 of the aerobic biological filter bed device 101 eliminates the need to waste clear treated water, unlike conventional devices, and High production efficiency.

Further, preferred processing operations of the present invention according to claim 6 are shown below.

■ When removing phosphorus from raw water, inorganic flocculants such as aluminum sulfate, polyaluminum chloride, ferric chloride, and polyferric sulfate are added to the raw water, and the generated flocs are transferred to the filter layer 82 of the treatment tank 81. and of the aerobic biological filter bed device 101 are trapped in the bed 102.

■ When high-level removal of COD is required, powdered activated carbon is added to the raw water or primary treated water, and the powdered activated carbon is poured into the sedimentation section 85 of the treatment tank 81, the filter layer 82, or the aerobic biological filter bed device 101. It is captured in the hearth 102.

■ Chromaticity removal, BOD height removal (e.g. BOD 2
q/I! When performing the following), ozone is diffused from the lower part of the hearth 102 of the aerobic biological filter device 101. It has been found that this operation can significantly increase the ozone absorption efficiency.

〔Example〕

An embodiment of the present invention according to claims 1 and 2 will be described based on FIG. A filter medium layer 2 filled with granular filter medium such as activated carbon or sand is immersed and held in water by a porous support member 3.

When using one of these granular filter media with a specific gravity close to 1.0, the upper part of the filter media layer 2 is covered with a porous support member 3' such as a net to prevent outflow from the upper part of the filter media layer 2. Also, those with a specific gravity of 2.0 or less are preferred because they are easily disturbed by air bubbles or water currents, making cleaning more effective.

An aeration pipe 4 is installed at the bottom of the filter medium Fi2, and diffuses air or other oxygen-containing gas during processing to supply oxygen to the filter medium layer 2. When cleaning the filter medium layer 2, the amount of air diffused is increased to layer 2
It is now possible to perform disturbances.

A part below the aeration pipe 4 in the tank is a sedimentation part 5, and a feedwell 7 connected to a raw water inflow pipe 6 is provided in this sedimentation part 5.
A rake 11 and a scraper 12 for promoting concentration of the settled sludge 10, which are connected to the lower part of the rotating shaft 9 rotated by the drive bag N8, are provided at the inner bottom of the settling section 5.

It is also preferable to make the aeration tube 4 rotatable in the horizontal direction to help equalize the amount of aeration to the filter layer 2. It is preferable to use a hollow shaft so that air from an air blower 13 is introduced into the rotary shaft 9, and to provide an air outlet at a position below the filter layer 2 to connect the air diffuser pipe 4.

Furthermore, an overflow launder 14 is provided at the top of the tank 1, and a treated water outflow pipe 15 is connected thereto, while an overflow long-1
4 is preferably connected to a washing wastewater return pipe 16, and the washing wastewater return pipe 16 is connected to the raw water inflow pipe 6 so as to continue to the sedimentation section 5.

In order to promote sedimentation and separation of SS in the washing wastewater, it is preferable to provide an aggregation pipe 17 made of cationic polymer or the like during the return of the washing wastewater. be.

In the figure, reference numeral 18 denotes an intermediate water drain, which is opened at an appropriate position in the tank 1 and is used to lower the water level in the tank when cleaning the filter layer 2 and promote the agitation movement of the filter layer 2 by aeration. ,1
9 shows a thickened sludge drainage pipe connected to the bottom of the tank.

An embodiment of the present invention according to claim 3 will be explained based on FIG. 2. 2) is a first tank, and a sedimentation part 25 having a sedimentation concentration part 22' at the bottom is formed in the lower part of the tank. A filter layer 22 filled with granular filter media is immersed and held in the upper part of the tank.

Any granular filter medium can be selected for forming the filter medium layer 22. For example, anthracite sand,
Since ceramic has a high specific gravity, it needs to be supported by a porous support member 23 that is strong and allows air bubbles and water to pass through smoothly.

Preferred are buoyant granular filter media (sponge, plastic particles, wood chips, pumice, perlite, glass microballoons, etc.) with a specific gravity of less than 1.0, or those that sink in water but have a specific gravity of slightly less than 1.0. Large light granular filter media
(polyurethane sponge, lightweight aggregate, etc.), and can form an immersed filter medium layer extremely easily by simply throwing it into water.

When using a buoyant granular filter medium with a specific gravity of less than 1.0, a supporting member 23' such as a perforated plate or a net is provided on the top to prevent the material from flowing out, and a light filter medium with a specific gravity of slightly more than 1.0 is used. When using a filter, simple nets 23', 23, etc. may be provided at the top and bottom of the filter medium.In any case, the support member may be provided at the top or bottom, or both, depending on the filter medium used. .

An aeration device, for example, an aeration tube 24 is provided below or inside the filter layer 22 to guide air from an air blower 27 to develop an aerobic biofilm on the surface of the filter layer 22. Aeration is not performed when aeration is performed to develop an anaerobic biofilm on the surface of the filter medium.However, when cleaning the filter medium layer 22, aeration is preferably performed in either case.

First tank 2) A raw water inlet pipe 26 is opened in the inner lower sedimentation part 25 through which raw water from the raw water tank 28 is introduced by a pump 29, and it is preferable that a coagulant injection pipe 30 is connected to the middle of the raw water inlet pipe 26. .

At the top of the first tank 2), there is a primary treated water outlet 31 through which the primary treated water that rises from below and flows through the filter layer 22 flows out.
It is also preferable to provide a circulation pipe 33 having an opening and having a pump 32 that connects the liquid phase portion above the filter medium layer 22 and the lower part of the filter medium layer 22. In Figure 2, 39 is the first tank 2
) shows the sludge drainage pipe connected to the bottom of the tank.

Reference numeral 41 denotes a second tank installed in parallel with the first tank 2), in which the lower part of the tank is a sedimentation part 45, the bottom part is formed with a sedimentation concentration part 42', and the upper part of the tank has the same structure as in the first illustrated example described above. A filter medium layer 42 filled with particles having a specific gravity of 1.0 or more is immersed and held in a porous support member 43, and if necessary, the upper part is covered with a porous support member 43' such as a net, and the filter medium is It is also possible to prevent the layer 42 from flowing out.

An aeration pipe 44 for diffusing oxygen-containing gas, such as air from the air blower 27', is provided below or inside the filter layer 42 to keep the portion of the filter layer above the aeration pipe 44 in an aerobic state. .

An overflow long 46 is provided at the upper part of the second tank 41 to which a final treated water outflow pipe 47 is connected.

49 is a mud drainage pipe connected to the bottom.

Furthermore, the primary treated water outlet 31 of the first tank 2) and the second tank 4
The sedimentation section 45 located in the lower part of the container 1 is communicated with a flow path 40, and it is also preferable that the flocculant injection pipe 30' is opened in this flow path 40.

Note that the cleaning drain pipe 34 is branched to the final treated water outflow pipe 47 of the second tank 41, and the cleaning drain pipe 34 is opened to the raw water tank 28 via the on-off valve 35, or the cleaning drainage pipe 36
The cleaning drainage tank 36 is opened to the pump 37.
It is preferable that the cleaning waste water is returned to the settling section 45 in the lower part of the second tank 41 from the cleaning waste water return pipe 38 connected to the flocculant injection pipe 30''.
If the liquid phase part above 2) and the lower part of the filter layer 22 of the first tank 2) are connected by a circulation pipe equipped with a pump 37' in 4 days,
It is suitable for performing nitrification and denitrification treatment.

An embodiment of the present invention according to claim 4 will be explained based on FIG. The filter medium layer 52 is immersed and held in a porous support member 53, and the upper part thereof is covered with a porous support member 53' such as a wire mesh if necessary.1. This prevents the filter medium layer 52 from flowing out.

An aeration pipe 54 for diffusing oxygen-containing gas, such as air, is buried inside the filter layer 52, and a portion of the filter layer 52 above the aeration pipe 54 is an aerobic biofilm treatment section 52-1, and the aeration pipe 54 The lower part is an anaerobic biological treatment section 52-2. It is preferable that a cleaning aeration pipe 54' for use in cleaning the filter layer 52 is disposed below the filter layer 52.

The portion below the filter medium layer 52 in the tank is a sedimentation section 55, and within this sedimentation section 55 is a feedwell 5 connected to a raw water inflow pipe 56.
7 is provided at the inner bottom of the settling section 55, and a settled sludge 60 connected to the lower part of a rotating shaft 59 rotated by a drive device 58.
A rake 61 and a scraper 62 for promoting concentration are provided.

Note that if the air diffuser 54 is made horizontally rotatable together with the rotating shaft 59 such as the rake 61, air bubbles can be removed from the aerobic biofilm processing section 52-
This is a preferred embodiment because it can be distributed evenly. In that case, it is preferable to make the rotating shaft 59 hollow so that it also serves as an air introduction pipe to the air diffuser pipe 54.

Furthermore, an overflow long 64 is provided at the top of the tank body 51 to which a treated water outflow pipe 65 is connected.
The cleaning drain pipe 66 is connected to the cleaning drainage tank 68 via the on-off valve 67, and the cleaning drainage pipe 66 is connected to the cleaning drainage tank 68 through the on-off valve 67.
The cleaning waste water inside is recycled to the feedwell 57 of the sedimentation section 55 by a pump 63.

In the figure, 50 is a polymer flocculant injection pipe that is injected during the recycling of washing wastewater, and 69 is a thickened sludge drainage pipe connected to the inner garden of the tank.

An embodiment of claim 5 will be described based on FIG.
Most of the structure is the same as the third illustrated example described above, and the same parts are indicated by the same reference numerals.

Furthermore, the treated water outflow pipe 65 is led out of the system via a storage tank 70, while the storage tank 70 is connected to a distribution pipe 74 provided at the bottom of the filter layer 52 via a pump 72 and an on-off valve 73 via a circulation pipe 71. They are connected. Further, the discharge side of the pump 72 is connected to the feedwell 57 in the sedimentation section 55 by a cleaning drain pipe 75 via an on-off valve 76, and the cleaning drainage of the filter medium layer 52 is transferred to the overflow wonder 64. Treated water outflow pipe 65. Preferably, the water is guided from the cleaning drain pipe 75 to the feedwell 57 via the storage tank 70 by the pump 72.
A polymer agglomeration injection pipe 77 is connected to the cleaning drain pipe 75 .

78 is a coagulation injection pipe connected to the raw water inflow pipe 56; 79
is an organic carbon source injection pipe connected to the circulation pipe 71.

Further, in order to promote cleaning of the filter medium layer 52, the filter medium layer 52 is
It is also a preferred embodiment to provide an aeration pipe 54' (see Fig. 3) below the anaerobic biological treatment section 52-2, which diffuses air only during cleaning.

Furthermore, if the embodiment of the present invention of claim 6 is explained based on FIG. The filter medium layer 82 is immersed and held in a porous support member 83, and the upper part thereof is covered with a porous support member 83' such as a net if necessary.
to prevent the filter medium layer 82 from flowing out.

In addition, an oxygen-containing gas such as air is diffused into the lower part or inside of the filter layer 82 to supply oxygen to the aerobic biofilm developed on the surface of the filter medium, and the amount of air diffused when the filter layer 82 is cleaned. In order to increase the cleaning effect and promote the cleaning effect, a diffuser pipe 84 is provided to diffuse air from, for example, an air blower 87.

The lower part of the inside of the treatment tank 81 is configured as a sedimentation part 85.
A raw water inflow pipe 86 connected to a raw water tank 88 and equipped with a pump 89 is opened in the settling section 85 . Raw water inflow pipe 8
6, a flocculant injection pipe 90 is connected to the entry side or the discharge side of the pump 89 as necessary.

An overflow launder 94 is provided at the upper part of the treatment tank 81 to which a primary treated water outflow pipe 95 is connected, and a washing drain pipe 96 equipped with an on-off valve 97 is connected to the washing drain pipe 96.
is opened to the raw water tank 88.

Reference numeral 99 indicates a sludge drain pipe connected to the bottom of the treatment tank 1, and reference numeral 100 indicates the settled sludge in the settling section 85.

Reference numeral 101 denotes an aerobic biological filter bed device, in which a hearth 102 filled with granular filter media such as anthracite sand and granular activated carbon having a specific gravity of 1.0 or more is provided, and an aeration chamber connected to an air blower 107 is provided at the bottom of the hearth 102. A diffuser pipe 104 for use is provided.

Furthermore, the primary treated water outflow pipe 95 at the upper part of the treatment tank 81 is opened in communication with the upper part of the aerobic biological filter bed device 101, and the hearth 1
The primary treated water that has passed through the chamber 02 in a downward flow becomes final treated water and flows out from a final treated water outflow pipe 117 connected to the lower part of the hearth 102. Note that the opening positions of the primary treated water outflow pipe 95 and the final treated water outflow pipe 117 in the aerobic biological filter bed device 101 are upside down from the illustrated example 'h', i, primary treated water It is also possible to make it flow through the hearth 102 in an upward flow and then flow out from the upper part.

Further, a storage tank 1 for temporarily storing the primary treated water flowing into the aerobic biological filter bed device 101 is provided in the middle of the primary treated water outflow pipe 95.
10, a storage tank 110 and an aerobic biological filter bed device 1
01 and the lower part of the hearth 102 and the opening/closing valve 111. pump 1
It is preferable to communicate with a washing water pipe 113 equipped with a water pipe 12 for convenient washing of the hearth 102. Also, a washing drain pipe 96' is connected to the upper part of the aerobic biological filter bed bag 2) 01 to It is also preferable to open into the water tank 88 .

Note that the storage tank 110 is installed at a high place, and the primary treated water in the storage tank 110 is transferred to the aerobic biological filter device t10 by the water level difference.
If the pump 112 is press-fitted into the lower part of the hearth 102 in the hearth 102, the pump 112 can be omitted.

〔Effect of the invention〕

As described above, according to the present invention, the following particularly remarkable effects can be obtained, and the various drawbacks of the conventional technology can be completely solved, and in addition, the present invention can exhibit unique effects that could not be obtained with conventional devices. be done.

■ Sedimentation, separation, and biological treatment can be performed effectively in a single tank, saving space and greatly reducing construction costs.

■ It can be directly applied to raw water with a high concentration of soluble BOI, and has a very wide range of applications.

■ The separation efficiency of SS in raw water is extremely excellent, and the number of SS is stable ■/I! of purified water can be obtained.

■ SS separation efficiency hardly deteriorates even when the processing flow rate fluctuates.

(2) There is no need to stop the flow of raw water when cleaning the filter media layer, and the raw water itself and the cleaning waste water itself can be effectively used as water for cleaning the I material, which is extremely rational.

■ There is no need to provide a separate sedimentation tank to treat filter media cleaning wastewater.

■ Washing wastewater can be used to wash the filter media layer, eliminating the need to consume treated water and increasing the production efficiency of treated water.

■ When a floor device is provided for aerobic organisms in the latter stage, coughing clogs the floor very slowly, so there is less need for cleaning. As a result, the biofilm that has developed on the surface of the filter media does not need to be flushed out of the system any more than necessary, resulting in excellent aerobic biofilm treatment effects, resulting in stable high purification even for raw water with a high BOD. be able to.

[Brief explanation of drawings]

1 to 5 are longitudinal sectional views showing embodiments of the present invention. 1.51...tank, 2.22.42.52.82...
Filter media layer, 3, 3', 23.23', 43.43
', 53.53', 83°83'...Supporting member,
4.24.44.54.54', 84°104...
Diffusion pipe, 5.25.45.55.85...Settling part, 6
, 26.56.86...Raw water inflow pipe, 7,57...
Feedwell, 8.58... Drive device, 9.59.
...Rotating shaft, 10, 60.100...Settled sludge, 11
．． 61... Rake, 12, 62... Raking machine, 13.
27.27', 87.107...Air blower
114, 46, 64, 94... Overflow launder 15, 6
5... Treated water outflow pipe, 16.38... Washing wastewater return pipe, 17, 30.30', 30"178.90.
...Flocculant injection pipe, 18...Intermediate water drain, 19.39
．． 49.69.99...Sludge drainage pipe, 2)...First oak,
22", 42'... Precipitation concentration section, 28.88... Raw water tank, 29.32.37.37', 63.72 89
112... Pump, 31... Primary treated water outlet,
33.48.71...Circulation piping, 34.6,6.75
．． 96.96'...Cleaning drain pipe, 35, 67, 73.
76, 97.111... Opening/closing valve, 36.68... Washing drainage tank, 40... Channel, 41... Second tank, 47.
117...Final treated water outflow pipe, 50.77...Polymer flocculant injection pipe, 52-1...Aerobic biofilm treatment section,
52-2...Anaerobic biofilm treatment section, 70.110...
- Storage tank, 74... Distribution pipe, 79... Organic carbon source injection pipe, 81... Treatment tank, 95... Primary treated water outflow pipe, 101... Aerobic biological filter bed device, 102...Heart, 113...Washing water pipe.

Claims (1)

[Scope of Claims] (1) A filter layer filled with granular filter media with a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an air diffuser is provided below or inside the filter layer. A sewage treatment device characterized in that a part is a settling part, a raw water inflow part is provided in the settling part, and a treated water outflow part is further provided in the upper part of the tank. (2) The sewage treatment apparatus according to claim 1, further comprising a washing waste water return path for returning washing waste water during washing of the filter medium layer to the settling section. (3) A first tank in which a filter layer is immersed and held in the upper part of the tank, the lower part of the tank is a sedimentation part, a raw water inlet is provided in the sedimentation part, and a primary treated water outflow part is provided in the upper part of the tank. Then, a filter layer filled with granular filter media with a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is installed below or inside the filter layer, the lower part is the settling part, and the upper part of the tank is and a second tank provided with a final treated water outflow part are installed in parallel, and the primary treated water outflow part of the first tank is communicated with the settling part in the second tank. sewage treatment equipment. (4) A filter layer filled with granular filter media with a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is buried in the filter layer to remove the upper part of the filter layer from the aeration device. The area below the air diffuser is used as an aerobic biofilm treatment section, and the lower part of the tank is used as a settling section, with a raw water inflow section provided in the settling section, and a treated water outflow section at the top of the tank. A sewage treatment device characterized by having a section. (5) The sewage treatment apparatus according to claim 4, further comprising a circulation path for circulating a portion of the treated water flowing out from the treated water outflow portion to the lower part of the filter medium layer. (2) A filter layer filled with granular filter media with a specific gravity of 1.0 or more is immersed and held in the upper part of the tank, and an aeration device is installed below or inside the filter layer, and the lower part of the tank is used as a settling part. A treatment tank with a raw water inlet in the sedimentation part and a primary treated water outlet in the upper part of the tank, and an aerobic biological filter bed device equipped with a hearth of granular filter media with a specific gravity of 1.0 or more are installed side by side. A sewage treatment device characterized in that the primary treated water outflow portion of the treatment tank and the aerobic biological hearth device are communicated with each other.