JPH06142668A - Purifying treatment device for organic sewage - Google Patents

Abstract

PURPOSE:To provide the purifying treatment device consisting of a single treatment tank, by which SS, BOD, COD and chromaticity can be eliminated in a high level without providing an primary sedimentation tank in the pre-stage, and also, a service life of an activated charcoal filled filter medium can be maintained extremely long, more remarkably clarified treated water than by a conventional purifying treatment device is obtained, and also, washing can be executed without wasting the treated water. CONSTITUTION:In a purifying device 1 consisting of a single treatment tank, a sedimenting part, a filling layer B which is provided with a diffuser means in the lower part, and executes filtration by filling a granular filter medium whose void is high, and a filling layer A for treating outflow water of a filling water of the filling layer B by filling activated carbon to which a microorganism adheres are provided in order from the bottom side of the treatment tank through a water feeding member, respectively. Also, this purifying treatment device for organic sewage is provided with a baffle 17 having a foam leading-out part 18 between the filling layer A and the filling layer B, and also, provided with a foam leading-out tube 19 in which one end is opened to the bubbles leading-out part 18, and also, passes through the filling layer A and the other end is opened in a space of the upper part of the treatment tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification device for biologically purifying organic waste water.

[0002]

2. Description of the Related Art The treatment method of organic sewage currently considered to be the most technically superior is "aerobic biological filter" [B
iological Associated Filter
(BAF)]. BAF immerses a packed bed (fixed bed) of granular minerals such as anthracite in water, and while agitating organic sewage (raw water) in a downward flow, performs air aeration from the lower part of the packed bed. It is a device that performs SS filtration and biological treatment at the same time. Therefore, the final settling basin in the activated sludge method is not necessary, and it has a great feature that solid-liquid separation can be performed reliably regardless of the sedimentation property of microorganisms, and it is attracting attention.

However, the conventional BAF has the following drawbacks. Since the amount of SS trapped in the filter bed is as small as about 1 kg / m ³ , direct treatment of sewage or the like causes clogging of the filter bed in a short time and frequent filter bed cleaning is required. Therefore, a first settling basin must be provided in front of the BAF, but there is a problem that the installation area of the first settling basin (called first settling) is large and space saving cannot be achieved. BOD and SS can be highly removed, but chromaticity and COD
The removal cannot be done with one bath of BAF. To clean the filter bed, the treated water produced must be consumed in large quantities as cleaning water. A foul odor may be emitted from the top of the filter bed. And so on.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device capable of solving the above-mentioned drawbacks of the conventional BAF. Specifically, 1. We will develop a new BAF that can treat sewage directly by BAF without providing the first settling in the previous stage, and significantly less clogging of the filter bed. 2. BOD, SS, chromaticity, and COD can be highly removed, and treated water that is significantly clearer than the treated water of conventional BAF can be obtained. 3. Streamline filter bed cleaning so that the filter bed can be cleaned without consuming BAF treated water. 4. Make sure that the device does not emit offensive odors. The purpose is to solve the above problems.

[0005]

The above-mentioned objects can be achieved by the advanced purification apparatus for organic wastewater of the present invention. That is,
1) A packed bed that performs aerobic biological filtration by filling a granular filter medium having a diffusing means in order from the bottom side of the treatment tank through a water-passing member in the purifying device consisting of a single treatment tank. B and the activated carbon to which microorganisms are adhered to fill the packed bed B
A packed bed A for treating the effluent of water is provided, and a baffle having a bubble leading portion is provided between the packed bed A and the filled layer B, and one end is open to the bubble leading portion, and the packed bed is An apparatus for purifying organic sewage, comprising a bubble outlet pipe which penetrates A and has the other end opened in the air above the treatment tank.

2) The apparatus for purifying organic sewage according to 1) above, further comprising means for discharging cleaning wastewater between the packed bed A and the packed bed B. 3) The organic wastewater purification treatment apparatus according to any one of 1) or 2) above, wherein a part of the treated water is returned to the lower part of the packed bed B. In addition, the present apparatus may be provided with a settling section at the lowermost end of the tank so that the precipitate is appropriately drained.

The advanced purification apparatus for organic wastewater of the present invention is provided with a packing layer B filled with a granular filter material inside a purification apparatus consisting of a single treatment tank, and preferably the granular filter material is a three-dimensional network granular material having a high porosity. As a filter medium, microorganisms are immobilized in high concentration inside and on the surface of the voids, water to be treated is passed in an upward flow, and oxygen-containing gas is supplied to the packed bed to enhance biological reaction. allowed the removal of NH ₃ -N not only removal of BOD to establish a condition to be performed on the speed. In addition, the packed bed A filled with the microorganism-adsorbed activated carbon, which is open to the bubble-discharging portion at the upper part of the packed filter bed B and has a bubble-discharging tube penetrating in the center, is provided to obtain the chromaticity of biorefractory treatment. , COD has been removed. Since the apparatus of the present invention realizes the above-mentioned excellent functions by the purification apparatus composed of a single processing tank, the installation area of the apparatus may be about 1/5 as compared with the conventional BAF.

Further, since the advanced purification apparatus for organic wastewater of the present invention performs biological treatment in the packed bed B filled with the three-dimensional mesh-like granular filter material, it is excellent in SS removal performance and can be used in SS such as sewage.
Even if the raw water having a large content is directly passed, the packed bed is not clogged and excellent biological treatment can be performed. further,
The high-level purification apparatus for organic wastewater of the present invention may be provided with a means for discharging cleaning wastewater at an intermediate portion between the packed bed A and the packed bed B, whereby cleaning is performed from an air diffuser provided under the packed bed B. Along with the provision of means for supplying air for use, it was possible to clean the original purification processing equipment.

(Configuration of the Invention) A configuration example of the present invention will be described with reference to FIG. However, the embodiment of the present invention is not limited to this. A purifying device 1 (hereinafter referred to as a purifying device) having a single treatment tank is provided with a packed bed A filled with activated carbon in the form of granules or fibers to which microorganisms are adhered, near the water surface. The packed bed A is supported by a support floor 2 made of a water-permeable member such as a perforated block. A packing layer B filled with a filter medium having a high porosity, for example, a granular filter medium having a three-dimensional network structure, specifically, a rectangular foamed granular filter material of polyurethane foam is provided below the support floor 2. Below the packed bed B, a porous member 5 such as a grating for preventing the falling of the packed filter medium of the packed bed B is provided, and organic wastewater (raw water) 7 such as sewage is purified below the porous member 5. A raw water inflow pipe 8 for supplying the device 1 is provided.

Raw water flows into the purification device 1 through the inflow pipe 8 from the field well 9 in the center of the lower sedimentation portion of the purification device 1. Precipitate C is deposited in the precipitation part. The sediment C is discharged from the sludge discharging section 11 having the valve 10.

The treated water overflow weir 12 is provided at the top of the purification device 1.
Is provided, and the advanced treated water 14 purified by the apparatus of the present invention is discharged from the treated water outflow pipe 13 provided in the overflow weir 12 to the outside of the system. In the configuration of FIG. 1, a cleaning water discharge part is provided near the center of the purification device 1 between the packed bed A and the packed bed B, and a cleaning drain pipe 16 having a valve 15 is connected. However, as a general configuration of the present invention, this flush water discharge section is not essential and is a preferable configuration.

The particle size of the filter medium filled in the packed bed A and the packed bed B of the present invention will be described below. When the activated carbon packed in the packed bed A is granular, the particle size of the activated carbon is 2 to 5
mm is preferred. This is because if it is less than this, the water resistance becomes large, and if it is larger than this, the surface area decreases and the adsorption effect deteriorates. Further, when the activated carbon to be filled is fibrous, it is preferable to fill it in the form of a thread of about 5 to 10 mm. As the filter medium having a high porosity to be filled in the filling layer B, any one may be used, such as a porous multi-blade plastic made from plastic or a rolled plastic, and the like, but a polyurethane having a three-dimensional network structure is particularly preferable. Foam angular granules are preferred, the granules being 10 mm cubes,
Alternatively, a rectangular parallelepiped having a size of 10 × 30 × 30 mm is suitable.

Further, the size of the holes present in the polyurethane foam is preferably such that large holes of about 2 to 3 mm are opened because the microorganisms easily grow inside.
If the size of the holes is too small, the microorganisms grow only on the surface of the polyurethane foam, which is not preferable. If it is too large, the strength becomes too weak, which is not good. The packed bed B may have a height of 1 to 2 m, and the activated carbon packed bed A may have a height of 0.5 to 1.0 m, which is an extremely shallow layer. Further, the porous water-permeable members 5 and 6 such as a lattice have a hole diameter such that a granular filter material such as polyurethane foam does not drop or flow out, and a hole diameter of about 20 mm is preferable. Water-permeable support bed 2 for holding granular activated carbon is 2 to 5 mm
The activated carbon of No. 2 is composed of a water-permeable member such as a perforated block having a diameter of 2 mm or less.

Although not shown in FIG. 1, the purification treatment tank of the present invention enables the treatment of organic wastewater containing ammonia nitrogen, so that a part of the treated water is filled from the upper portion of the treatment tank 1. It is a preferred embodiment to provide a circulation path for returning to the lower part of the layer B.

(Operation of the Invention) The operation of the present invention will be described with reference to FIG. The packed bed B filled with the three-dimensional mesh filter is an area mainly for biological BOD removal and SS filtration. Further, the granular activated carbon packed bed A is a CO of the water to be treated flowing out from the packed bed B due to both functions of the microorganisms propagating on the surface of the activated carbon and the adsorption function of the activated carbon.
This is an area for removing D and chromaticity. When treating the organic wastewater containing ammonia nitrogen, the surface of the activated carbon of the packed bed A is inoculated with nitrifying bacteria, and the denitrifying bacteria are retained inside the three-dimensional mesh-like filter medium of the packed bed B to fill the packed bed B. It is also possible to impart denitrification to and the nitrification function to the packed bed A.

As described above, in the present invention, the purifying device is clearly divided from the bottom to the top by the settling portion, the bed B of the three-dimensional mesh filter and the bed A of the microbial activated carbon, and the functions thereof. Since each layer is partitioned by the porous water-permeable member, each layer does not drop or mix during normal operation and washing.

The point of the present invention is that the inflow water of the microbial activated carbon packed bed A is preliminarily biologically treated so that BOD is hardly contained therein. When contained in a large amount, BOD-assimilating bacteria become dominant species of microorganisms that propagate on the surface of granular activated carbon, and special microorganisms that utilize COD components that are difficult to biodegrade propagate at all on the surface of activated carbon. It's gone.

The apparatus of the present invention is provided with a baffle 17, a bubble outlet 18 and a bubble outlet tube 19 so that the bubbles do not enter the microbial activated carbon packed bed A. This configuration is an important point of the present invention, and if the air bubble outlet 18 is not provided, a large amount of air bubbles discharged from the air diffusing pipe 3 cannot pass through the support bed 2 of the packed bed A during cleaning. . Alternatively, if all of a large amount of air bubbles are allowed to enter the packed bed A of granular activated carbon, there is a problem that the lightweight granular activated carbon rises due to the upward movement of the bubbles. Due to such trouble, the SS filtration effect in the activated carbon layer is deteriorated, and further,
The activated carbon is pulverized and the microorganisms on the surface of the activated carbon are separated or washed away.

The organic wastewater 7 such as sewage flows into the feedwell 9 from the raw water inflow pipe 8 and is easily settled in the raw water.
Is separated by sedimentation in the sedimentation zone, and then flows upward into the packed bed B filled with the polyurethane foam granules having a three-dimensional network structure.

In the packed bed B, microorganisms (mainly BOD-assimilating bacteria) having a high concentration of 15,000 to 20,000 mg / liter are immobilized in the three-dimensional network structure of polyurethane foam. Polyurethane foam filter media with a three-dimensional mesh structure has excellent SS filtration performance, so the packing layer B
By passing through, SS in the raw water is removed by filtration,
The SS of outflow water from the packed bed B is 5 mg / liter or less. Since the specific gravity of polyurethane foam is almost equal to that of water, aeration bubbles are trapped in the network structure of polyurethane foam, resulting in an apparent specific gravity of 1.0 or less and a floating filling layer being formed.

In the packed bed B, however, BOD and SS were highly removed, SS became 5 mg / liter or less, and the SS passed through the support bed 2 made of a water-permeable member such as a perforated block and filled with the microorganism-adsorbed activated carbon. Invades layer A. The water flowing into the packed bed A of the microorganism-attached activated carbon is already SS, BOD,
NH ₃ -N was highly removed, and all decreased to several mg / liter or less, and the COD component which is hardly biodegradable is the main component. The COD component is adsorbed on the activated carbon, and the adsorbed COD component is decomposed by microorganisms adhering to the surface of the activated carbon for a long period of time to undergo so-called biological regeneration.

At this time, most of the air bubbles discharged from the air diffuser 3 do not pass through the support bed 2 after passing through the polyurethane foam granular material packed bed B, and the air bubbles leading to the baffle 17 are discharged. The gas flows out from the bubble outlet pipe 19 into the atmosphere through the portion 18. Therefore, the packed bed A retains the microorganisms on the surface of the activated carbon without being disturbed by bubbles, and enables stable COD and fine SS removal. In addition, a part of the treated water 14 may be recycled under the packed bed B to promote denitrification. As a result, the final treated water 1
In No. 4, SS, BOD, COD, and chromaticity are highly removed, and the water becomes sparkling clear water. Therefore, it can be used for miscellaneous water or for hydrophilic use. Of course, it may be discharged directly to the public water area, and the public water area can be purified by the sewage treatment water. The sediment C is discharged from the mud discharge section 11 by opening the valve 10 from time to time. As described above, the present invention can purify organic sewage such as sewage to a very high degree with a single treatment tank.

Next, a preferred method for cleaning the filter bed of the present invention will be described. That is, while continuing the operation of the purifying device of the present invention, the cleaning drainage outflow valve 15 is opened and the water to be treated in the purifying device 1 is discharged from the cleaning water discharge part to lower the water level of the purifying device 1. At this time, it is preferable to increase the amount of air from the air diffuser 3. Thus, the SS retained in the granular activated carbon packed bed A is discharged from the cleaning drainage outflow passage 16 together with the decrease in the water level. Since most of the SS in the raw water 7 is trapped in the packed bed B, the amount of SS retained in the packed bed A is small, and the packed bed is effectively reduced by diffusing the water level. A can be washed.

Next, when the water level has dropped to the vicinity of the discharge portion of the wash water, the amount of air discharged from the air diffusing pipe 3 is significantly increased (about 5 to 10 times as much as that in the steady process). Then, a violent gas-liquid mixed phase circulating flow is generated in the packed bed B, and the urethane foam granules circulate and flow along with the gas-liquid mixed phase circulating flow. As a result, the SS that has been captured and retained in the packed bed B peels off and flows out of the system from the cleaning drainage outflow passage 16 of the cleaning water discharge section along with the flow of raw water.

If this operation is continued for about 30 to 40 minutes, most of the SS will be expelled, so that the normal air discharge amount is returned from the air diffuser 3 to form the packed bed B again, and the raw water inflow pipe 8 to the raw water 7 If the flow is continued for several tens of minutes, the outflow water from the packed bed B becomes clear, so at this point the valve 15 is closed, the water level is raised, and finally the advanced treatment water flows out from the treatment water outflow pipe 14. To do. In this way, in order to wash the packed bed A and the packed bed B, it is not necessary to consume the treated water to wash the packed bed as in the conventional BAF, and the washing storage tank, the cleaning drainage storage tank, the cleaning water pump All becomes unnecessary.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the process of the present invention will be described below with reference to the apparatus shown in FIG. 1, but this description does not limit the present invention. The sewage having the water quality shown in Table 1 was treated by the purification apparatus of the present invention.

Sewage water quality Table 1 Water temperature: 15 to 17 ° C. pH: 7.2 to 7.3 SS: 80 to 132 mg / liter BOD: 108 to 160 mg / liter COD: 52 to 56 mg / liter

Processing equipment and conditions Table 2 Equipment dimensions: Diameter: 0.4 mφ (round column) Height: 4.5 m Height of packed bed A: 0.8m Height of packed bed B ... 2.5m Bubble outlet pipe diameter ... 0.1mφ

Device operating conditions Table 3 Filtration speed ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 30m / day Air discharge rate from air diffuser ³・ ・ 16Nm ³ / day

Physical Properties of Filler Table 4 Granules of polyurethane foam filled in the filling layer B ...
..... 10x25x25 mm rectangular parallelepiped (1 cell)
3) Granular activated carbon to be packed in the packed bed A ..... Uses spherical coal-based activated carbon with a particle diameter of 2 mm. The raw water of the water quality shown in Table 1 is used for 6 months under the equipment and operating conditions shown in Tables 2 to 4. It was treated continuously for a period of time. Since the microorganisms were sufficiently immobilized in the network structure of the polyurethane foam after 20 days of passing water, a composite sample was collected once every day from the 21st day except Saturdays and Sundays for 24 hours, and water quality analysis was performed. The results are shown in Table 5. The activated carbon packed bed A was filled with activated carbon that had already lost its physical adsorption force.

Water quality of treated water Table 5 pH: 6.8 to 7.0 SS: 1.0 to 2.0 mg / liter BOD: 1.0 to 2.0 mg / liter COD: 4.1 to 5. 2 mg / liter Chromaticity: 10 degrees or less Transparency: 1 m or more As is clear from Table 5, all the items of SS, BOD, COD, chromaticity, and transparency were highly purified water quality.

The cleaning frequency of the filter bed is extremely low, once every 10 days, and the treatment can be continued for a long time. Further, the washing is easy and it is not necessary to use the treated water as the washing water. (Conventional once /
Also, when the activated carbon was taken out and observed under a microscope 2 months after the start of the treatment, microorganisms were satisfactorily propagated on the surface of the activated carbon. As described above, the purification treatment apparatus of the present invention is clearly superior to the conventional BAF in terms of treatment capacity and maintenance.

[0033]

The following effects can be obtained by purifying the organic sewage according to the present invention. 1. SS, BOD, CO of organic wastewater by a single treatment tank
D, chromaticity can be removed at high speed and with high degree. The installation area of the device may be 1/5 of the standard activated sludge method. 2. There is no need to first set up a sedimentation tank, for example sewage can be introduced directly into the apparatus of the invention for treatment. 3. The cleaning of the filter bed is significantly streamlined. The cleaning storage tank, cleaning water supply pump, and cleaning drainage storage tank, which were indispensable for conventional BAF, are no longer required. 4. Since the microorganisms are immobilized at a high concentration on the three-dimensional mesh filter, the biological reaction rate is fast.

5. Since the filter medium itself has voids in the three-dimensional mesh filter medium, the filter bed porosity is extremely large at 95% or more, and therefore the filter bed blockage due to SS is extremely small. It can be doubled. 6. Before the raw water flows into the activated carbon packed bed, B in the raw water
Since the OD is configured to be highly removable, the special microorganisms that assimilate COD, which is difficult to biodegrade, are easily propagated on the surface of the activated carbon, and the COD removal effect and the biological regeneration effect of the activated carbon are improved. 7. From the water surface of the device, activated carbon-treated, clear water literally springs out like a spring, so the driver,
It is very comfortable for the visitor, and has the important effect that pathogenic bacteria and odors do not evaporate from the water surface of the device.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a purification treatment tank of the present invention.

[Explanation of symbols]

 1 Purification device 2 Support bed 3 Diffuser pipe 4 Air supply pipe 5 Porous member 6 Porous member 7 Raw water 8 Raw water inflow pipe 9 Field well 10 Valve 11 Sludge part 12 Overflow weir 13 Treated water outflow pipe 14 Treated water 15 Cleaning Drainage outflow valve 16 Washing drainage outflow pipe 17 Baffle 18 Bubble extraction part 19 Bubble extraction pipe A Packing layer B Packing layer C Precipitate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location B01D 29/62 C02F 1/28 CCQ F ZAB 3/08 ZAB B 3/10 ZAB A 3/34 ZAB 101 D

Claims (3)

[Claims] 1. An aerobic biological filtration device comprising a single treatment tank filled with a granular filter medium having a diffusing means at the bottom thereof in order from the bottom side of the treatment tank through a water passage member. The packed bed B for carrying out the procedure and the packed bed A for treating the outflow water of the packed bed B by filling the activated carbon to which the microorganisms adhere are provided, and a baffle having a bubble leading portion between the packed bed A and the packed bed B is provided. In addition to the above, there is also provided a bubble outlet pipe having one end opened to the bubble outlet portion and penetrating the filling layer A and the other end opened to the air above the processing tank. Sewage purification system. 2. The apparatus for purifying organic wastewater according to claim 1, further comprising means for discharging cleaning wastewater between the packed bed A and the packed bed B. 3. The organic wastewater purification treatment apparatus according to claim 1 or 2, wherein a portion of the treated water is returned to the lower part of the packed bed B.