JP2006212505A - Wastewater treatment apparatus and wastewater treatment system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the treatment capacity of wastewater in a wastewater treatment apparatus and a wastewater treatment system using it. <P>SOLUTION: The wastewater treatment apparatus is equipped with a treatment tank 6 having a wastewater inflow port 3 and an outflow port 4, the separation membrane 7 provided in the treatment tank 6, the air diffusion pipe 11 provided under the separation membrane 7, the shaking bed 9 formed by oxygen-containing bubbles discharged to the upper separation membrane 7 from the air diffusion pipe 11 and provided on the downstream side of the separation membrane 7 and a reflux means for refluxing the water after passing through the shaking bed 9 to the upstream region of the separation membrane 7. The shaking bed 9 has hydrophilic branches 13 shaken at least at their leading ends by a water stream. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wastewater treatment apparatus for wastewater containing organic matter and a wastewater treatment system using the same.

  Conventionally, as a means to improve the treatment performance of wastewater treatment equipment that decomposes organic matter in wastewater with microorganisms, organic matter per unit volume of the treatment tank is increased by increasing the concentration of microorganisms inside the treatment tank, that is, activated sludge, with a separation membrane. A membrane separation activated sludge method, which is a method for improving the decomposition performance, is known.

  As this membrane separation activated sludge method, for example, there is an apparatus described in JP-A-2-86893 (Patent Document 1). As shown in FIG. 6, this apparatus is provided with a separation membrane 107 and a diffusion pipe 111 provided below the separation membrane 107 in a treatment tank 106, the separation membrane 107 is connected to a filtration pump 105, and the diffusion pipe 111 is a blower. 110. Here, the wastewater containing the organic matter entering the treatment tank 106 from the inlet 103 is oxidized and decomposed by the activated sludge. The treated wastewater passes through the separation membrane 107, is sucked by the filtration pump 105, and is discharged out of the system from the outlet 104. On the other hand, since the activated sludge in the treatment tank 106 is separated by the separation membrane 107, the activated sludge in the treatment tank 106 is kept at a high concentration while being prevented from flowing out of the system.

  In addition, the aerobic bubbles sent out through the air diffuser 111 by the blower 110 supply oxygen consumed by the activated sludge into the treatment tank 106 and lift the adsorbed sludge adhering to the separation membrane 107 by raising the plane of the separation membrane 107. 107 blockage is prevented.

  In addition, since the separation membrane 107 prevents the nitrifying bacteria from flowing out, the nitrogen component in the organic matter decomposed by the action of the nitrifying bacteria is oxidized into nitric acid, and the pH in the treatment tank is remarkably lowered to below the drainage standard value. Or degradation of organic matter degradation.

  In order to prevent this phenomenon, aeration is generally stopped for a certain period of time in the membrane separation activated sludge method. In other words, an intermittent anaerobic tank or an anaerobic tank that does not perform aeration is installed separately and the activated sludge is put in an anaerobic state, so that anaerobic denitrifying bacteria work to reduce nitric acid to nitrogen to increase the pH. Preventive treatment is applied.

  By using such a membrane separation activated sludge method, the activated sludge concentration of the standard activated sludge method can be increased to about 15,000 mg / L to 20,000 mg / L with respect to about 2,000 mg / L. The wastewater treatment performance is improved.

  Further, as a means for further improving the treatment performance of such a conventional membrane separation activated sludge method, there is, for example, one described in JP-A-7-32329 (Patent Document 2). .

  As shown in FIG. 7, the waste water treatment apparatus described here is an attempt to further increase the activated sludge concentration by combining the separation membrane 112 and the biological carrier 113, and the partition plate 115 is disposed in the treatment tank 114. The separation membrane 112 and the biological carrier 113 are provided on the left and right sides of the partition plate 115, and the diffusion tube 116 is provided below the biological carrier 113 as well as the separation membrane 112, and the aerobic bubbles from the diffusion tube 116 are removed. By supplying to the biological carrier 113, the oxidation / decomposition performance of the organic matter was enhanced by the microorganisms attached to the biological carrier 113 at a high concentration.

  Further, a water flow is generated by the aerobic bubbles in the treatment tank 114 after passing through the biological carrier 113 and then upwards on the separation membrane 112, and this separation causes the separation membrane 112 to filter and discharge only the water treated by the biological carrier 113. It was like that.

Further, in order to prevent the separation membrane 112 from being clogged, an aeration tube 117 is provided below the separation membrane 112, and aerobic bubbles are supplied intermittently from the diffusion tube 117.
JP-A-2-86893 Japanese Patent Laid-Open No. 7-32329

  However, in the conventional wastewater treatment apparatus such as Patent Document 2, the water flow generated by the aerobic bubbles flowing out from the diffuser pipe below the separation membrane is generated by the aerobic bubbles from the diffuser pipe below the biological carrier. The water flow from the biological carrier to the separation membrane is stopped, that is, during this time, the treated water cannot be taken out from the system. As a result, there is a problem that the processing performance is lowered.

  Further, in the conventional wastewater treatment apparatus such as Patent Document 1 using the membrane separation activated sludge method, when the concentration of activated sludge is further increased in order to further improve the treatment performance, the activated sludge adhered to the surface of the separation membrane. However, there is a problem in that it cannot be completely removed by water flow or aerobic bubbles, the separation membrane is blocked, and the processing performance is rapidly reduced.

  Furthermore, when aeration is stopped to create an anaerobic state for denitrification, the surface of the separation membrane cannot be cleaned, and during this time, the treated water cannot be taken out from the separation membrane, resulting in a reduction in processing performance.

  Then, this invention aims at improving the processing performance in such a conventional waste water treatment equipment.

  In order to achieve the above object, the wastewater treatment apparatus of the present invention has a treatment tank having a drainage inlet and an outlet, a separation membrane provided in the treatment tank, and a scattering membrane provided below the separation membrane. A trachea, a biological carrier provided downstream from the separation membrane of the water flow formed by the aerobic bubbles released from the diffuser toward the upper separation membrane, and the water flow after passing through the biological carrier The biological carrier is a rocking bed provided with a reflux means for refluxing to the upstream region of the separation membrane.

  Another means is that a partition plate is provided outside the separation membrane as a reflux means, and a swing bed is arranged on the opposite side of the separation membrane via the partition plate.

  Another means is that the rocking bed has a hydrophilic branch that rocks at least at the tip side by a water flow.

  Another means is that the lower end of the partition plate is disposed below the diffuser pipe, and a denitrification bed is provided in the upstream area of the diffuser pipe downstream from the swing bed in the flow path formed by the diffuser pipe and the partition plate. It is a thing.

  Another means is to provide a denitrification floor below the lower end of the partition plate.

  Another means is that a denitrification bed is provided on the opposite side of the diffuser pipe through the partition plate at the lower part of the partition plate.

  Another means is that the water flow cross-sectional area in the denitrification bed is larger than the water flow cross-sectional area in the rocking bed.

  Another means is that the denitrification bed has a hydrophilic branch that swings at least on the tip side by a water flow.

  Another means is that the density of hydrophilic branches in the denitrification bed is higher than the density of hydrophilic branches in the rocking bed.

  Further, as another means, the swing floor includes a trunk provided from the upper end to the lower end of the partition plate and a plurality of hydrophilic branches provided on the trunk, and a vibrating body that vibrates the stem is provided on the trunk. Is.

  Another means is that the vibrating body vibrates the trunk in response to fluctuations in the water flow in the treatment tank.

  As another means, the vibrating body is such that the lower end of the trunk is fixed and a float is provided at the upper end.

  In addition, the other means is an adjustment unit into which treated water flows, and an inlet of the treatment tank in the waste water treatment apparatus of the present invention is connected to the adjustment unit.

  Still other means include an adjustment unit into which treated water flows, an aeration unit provided downstream of the adjustment unit, a precipitation unit provided downstream of the aeration unit, and a sludge storage unit provided downstream of the precipitation unit. The sedimentation part or the sludge storage part is connected to the inflow port in the treatment tank of the wastewater treatment apparatus of the present invention.

  By setting it as the above structures, the waste-water-treatment apparatus which can raise the activated sludge density | concentration in a processing tank, and can improve the decomposition | disassembly performance of organic substance, without clogging a separation membrane is realizable.

  Further, denitrification can be performed by continuous aeration in one tank without providing intermittent aeration or a dedicated anaerobic tank, and a small and highly efficient wastewater treatment apparatus can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows the configuration of a wastewater treatment system and a wastewater treatment apparatus. The wastewater treatment system of the present embodiment includes an adjustment unit 1 that accumulates wastewater and a wastewater treatment device 2 that oxidizes and decomposes organic matter using activated sludge. The waste water treatment apparatus 2 has an inflow port 3 and an outflow port 4, the inflow port 3 is connected to the adjustment unit 1, and the outflow port 4 is connected to the filtration pump 5.

  Next, the waste water treatment apparatus 2 will be described in detail. The waste water treatment apparatus 2 includes a container-like treatment tank 6, a plurality of separation membranes 7 arranged in the central portion of the treatment tank 6 and arranged in a vertical direction at predetermined intervals, and an outer side of these separation membranes 7 group. And a swing bed 9 provided as a biological carrier on the opposite side of the separation membrane 7 via the partition plate 8. Further, an air diffuser 11 connected to the blower 10 is provided below the separation membrane 7, and the lower end of the partition plate 8 is extended below the air diffuser 11.

  Further, the separation membrane 7 has a structure in which two flat membranes are bonded together via a spacer, and the hollow portion is connected to the filtration pump 5.

  The swing floor 9 has a configuration in which a plurality of hydrophilic branches 13 formed of hydrophilic fibers on the trunk 12 are arranged radially from the trunk 12 in the circumferential direction perpendicular to the water flow. Further, the trunk 12 is supported by a swing floor support portion 14 fixed in the processing tank 6. The hydrophilic branch 13 is hydrophilic so that activated sludge can easily adhere to it. Although it has a certain thickness, it has flexibility, the rear end side is attached to the trunk 12, and the front end side is a free end. Because it is, it swings by the water flow.

  Further, a denitrification floor 15 is disposed at the bottom of the treatment tank 6 and below the diffuser pipe and the partition plate. Similar to the rocking floor 9, the denitrification floor 15 has a horizontally provided trunk 16 and a hydrophilic branch 17 having a rear end side fixed to the trunk 16 and a distal end side being a free end. Further, the denitrification bed 15 can enhance its denitrification effect by making the density of the hydrophilic branches 17 higher than that of the rocking bed 9.

  First, domestic wastewater containing organic substances is supplied to the adjusting unit 1, where it temporarily stays and a certain amount is continuously supplied from the inlet 3 to the treatment tank 6.

  Here, air is supplied from the blower 10 to the air diffuser tube 11 and flows out vigorously from the openings 18 provided in the air diffuser tube 11 to the upper separation membrane 7. As a result, a plurality of aerobic bubbles are provided. As a result, the outer surface of each separation membrane 7 rises so as to stroke, and a water flow rises between the separation membrane 7 groups.

  The upper end of the partition plate 8 is located below the water surface 19 in the treatment tank 6, and the water flow guided to the upper side of the separation membrane 7 by the aerobic bubbles is commutated from the upper end of the partition plate 8 to the side. Goes to the upper part of the swing bed 9 and passes through the swing bed 9 as a downward flow. By recirculating the water flow in the treatment tank 6 in this way, the water flow first passes through the separation membrane 7, then passes through the swing bed 9 and returns to the diffusion tube 11, so that the diffusion tube becomes one place, The waste water treatment can be continuously performed without stopping the water flow from the swing bed 9 to the separation membrane 7.

  On the other hand, oxygen is dissolved in the water while the aerobic bubbles flowing out from the air diffuser 11 rise to the water surface 19, and oxygen is supplied to the microorganisms inside the activated sludge. The organic matter supplied from the inlet 3 is oxidized and decomposed by the activated sludge while circulating in the treatment tank 6 in a water stream. The water in the treatment tank 6 is suction filtered by the filtration pump 5 through the separation membrane 7, and the clean treated water that has permeated the separation membrane 7 is discharged through the outlet 4. At this time, the activated sludge floating together with water is also sucked and adheres to and deposits on the surface of the separation membrane 7, but is peeled off by the shearing force of the aerobic bubbles and the water flow flowing on the surface of the separation membrane 7.

  Further, the activated sludge floating on the circulating flow adheres to the hydrophilic branch 13 of the rocking bed 9 and accumulates and is fixed, and the concentration of the sludge in the treatment tank 6 together with the separation and concentration by the separation membrane 7. Keep it high. The organic matter in the treatment tank 6 contacts not only the activated sludge floating, but also the activated sludge adhering to the hydrophilic branch 13, and the oxidation and decomposition are promoted.

  By the way, in the activated sludge deposited on the hydrophilic branch 13, not only bacteria but also food chains such as protozoa, protozoa, rotifer and earthworm, which are higher predators, are generated due to the stability of the scaffold. The animal has a characteristic of producing a large amount of sticky metabolites, and the activated sludge adhering to the hydrophilic branch 13 is firmly fixed and held by the metabolites.

  Further, when the activated sludge adhering to the hydrophilic branch 13 becomes a certain size, the activated sludge at the tip of the hydrophilic branch is peeled off and released again into the water flow due to the swinging of the water flow. Simultaneous dropout is prevented. Further, the peeled activated sludge becomes harder and larger particles than before adhering due to the sticky metabolite.

  In this way, the activated sludge, which was initially fine in the treatment tank 6, is repeatedly coarsened by repeatedly adhering to and peeling from the hydrophilic branch 13, and the particle size is finally larger than the pore size of the separation membrane 7. Become. Although an ultrafiltration membrane or a microfiltration membrane is generally used as the separation membrane 7 for water treatment, a microfiltration membrane having a pore diameter of 0.1 to 0.4 μm is often used as the separation membrane 7 for wastewater treatment. Particles smaller than the pore size permeate the membrane and large particles are blocked, but the most effective influence on the blockage is the particle size close to the pore size. It fits inside the pores of the separation membrane 7 and stagnates to cause clogging.

  Here, the activated sludge floating in the treatment tank 6 of the present invention is a large-sized particle separated from the hydrophilic branch 13, and is much larger than the pore diameter of the separation membrane 7, so that it is sucked into the pores and does not stagnate. Since it passes through the surface of the separation membrane 7, it is possible to increase the activated sludge concentration in the treatment tank 6 and improve the treatment performance without causing the separation membrane 7 to be blocked.

  By the way, as oxygen that has been dissolved in a large amount in the water due to the aerobic bubbles when passing through the separation membrane 7 passes from the upper side to the lower side of the rocking bed 9, it actively participates in the oxidative decomposition of organic matter by microorganisms in the activated sludge. Therefore, the lower portion of the swing bed 9 is in a low oxygen state, and the dissolved oxygen is no longer present in the lower end portion of the partition plate 8. In the denitrification bed 15 arranged in the low oxygen region, activated sludge is deposited and deposited thicker than the rocking bed 9 on the densely arranged hydrophilic branches 17, and most of the oxygen remaining on the surface of the activated sludge is consumed. For this reason, the inner deep part of the hydrophilic branch 17 is far from the surface and anaerobic denitrifying bacteria are the dominant species.

  Here, in the swing bed above the treatment tank 6, ammonia generated by biodegradation by nitrifying bacteria is oxidized as in the following reaction to produce nitric acid and nitrous acid.

NH ₄ ⁺ + 3 / 2O ₂ → NO ₂ ⁻ + H ₂ O + 2H ^{+
_{NO 2 - + 1 / 2O 2}} → NO 3 -
The generated nitric acid or nitrous acid is transported to the denitrification bed 15 by a water flow, and is reduced by the following reaction by the denitrifying bacteria in the denitrification bed 15 to become nitrogen and discharged from the surface of the hydrophilic branch 13 as nitrogen bubbles to the outside. Is done.

2NO ₂ ⁻ +3 (H ₂ ) → N ₂ ↑ + 2OH ⁻ + 2H ₂ O
2NO ₃ ⁻ +5 (H ₂ ) → N ₂ ↑ + 2OH ⁻ + 4H ₂ O
In this way, denitrification can be performed simultaneously with the decomposition of organic substances while continuous aeration in one tank, eliminating the need for intermittent aeration and anaerobic tanks, which was a problem of the membrane separation activated sludge method, and reducing the size of the apparatus. , Processing performance is greatly improved.

In general, denitrification by anaerobic bacteria requires a hydrogen source (H ₂ ) such as alcohol. However, in this embodiment, the organic substance removal and denitrification are performed simultaneously in one tank, and the organic substance serving as the hydrogen source Since it exists abundantly in the treatment tank 6, it is not necessary to input a hydrogen source separately.

  In the present embodiment, the swing bed 9 has been described with the hydrophilic branch 13 extending radially from the trunk 12, but other swings having a function of attaching activated sludge and peeling it off by swinging so as to hold a certain amount. The same effect can be expected by using a floor, for example, a swing bed in which a sponge-like carrier is placed in a lattice cage.

(Embodiment 2)
FIG. 2 shows another embodiment of the present invention. In addition, about the thing which has the structure similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In FIG. 2, a partition plate 8a is provided in place of the partition plate 8 in FIG. Here, the upper end side of the partition plate 8a is opened outward as shown in FIG. Further, a commutator 18 having a conical or triangular prism shape is provided above the opening of the partition plate 8a with the apex facing downward.

  In addition, the wall surface of the treatment tank 6 is also shaped so as to have a uniform cross-sectional area with respect to the water flow in accordance with the partition plate 8a, and further, on the side opposite to the diffuser tube 11 through the partition plate 8a. A denitrification floor 15 a is arranged at the lower part of the swing bed 9, and the cross-sectional area of the water flow in this portion is larger than the cross-sectional area of the upper swing bed 9.

  By the way, assuming that the vibration of the hydrophilic branch 13 is caused by Karman vortices generated in the wake of a cylinder in a steady flow, the vibration frequency is defined by the following equation.

  The Strouhal number is a dimensionless number and takes a substantially constant value within a wide Reynolds number range.

  According to the equation (1), if the flow rate is low, the vibration of the hydrophilic branch 13, that is, the swing is reduced, and the activated sludge may accumulate excessively and cause clogging or dropping. The water flow needs to flow at a certain speed or higher.

  Here, in the example of the first embodiment, separation of the flow occurs before and after the separation membrane 7 and the pressure loss becomes large, and there is a case where the flow velocity flowing through the rocking bed 9 cannot be sufficiently secured. On the other hand, in the vicinity where the water flow near the water surface 19 turns, the flow is greatly disturbed. On the contrary, the hydrophilic branch 13 in the vicinity of the water surface 19 may be in a state where the activated sludge is not sufficiently adhered due to the excessive oscillation.

  Here, in this embodiment, by opening the partition plate 8a outward, the flow before and after the separation membrane 7 is adjusted, and further, the flow toward the oscillating bed 9 is also adjusted by the commutator 20, so that the treated water is shaken. Flowing smoothly toward the moving bed 9, the activated sludge is reduced in the vicinity of the upper and lower ends of the rocking bed 9, and the flow velocity is increased near the center of the rocking bed 9 due to the pressure loss reduction, thereby increasing the hydrophilic branch 13. The activated sludge is uniformly adhered to the entire rocking bed, and the treatment performance can be further improved.

  Moreover, the denitrification floor 15a of this Embodiment shows the example provided in the other side of the diffuser pipe 11 via the partition plate 8a. If it is this structure, it will become possible to arrange | position the rocking | swiveling floor 9 and the denitrification floor | bed 15a on 1 straight line, a structure will become simple and manufacturing cost can be reduced.

  The reason why the cross-sectional area of the water flow in the portion where the denitrification bed 15a is provided is increased is that the flow velocity in this portion is slowed to suppress the swinging of the hydrophilic branch 17, and the amount of activated sludge is increased and activated. This is to increase the anaerobic region inside the sludge and enhance the denitrification effect.

  Note that the denitrification bed 15 can be expected to have the same effect even in other arrangements as long as the water flow that has passed through the rocking bed 9 has a small amount of dissolved oxygen until the diffuser pipe 11 is reached.

(Embodiment 3)
3 and 4 also show other embodiments of the present invention. In addition, about the thing which has the structure similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In FIG. 3, a vibrating body 21 for accelerating the vibration of the trunk 12 by a water flow is provided on the trunk 12 of the swing floor 9 of the waste water treatment apparatus of the present invention. It is necessary to pass the water at a constant speed through the swinging floor 9 to swing the hydrophilic branch 13. However, when a sufficient flow speed cannot be obtained, a vibrating body 21 is separately installed to promote the swinging of the hydrophilic branch 13. To do. Here, the vibrating body 21 has a plurality of wing-like flat plates fixed to the trunk 12 perpendicular to the water flow. The vibrating body 21 vibrates due to the change of the water flow flowing through the rocking floor 9, and thereby the trunk 12 is vibrated to increase the rocking effect of the hydrophilic branch 13, and promote the peeling of the attached sludge even when the flow velocity is not sufficient. can do.

  FIG. 4 further shows that the lower end of the trunk 12 is fixed and a float 22 is provided at the upper end. The float 22 is formed of a hollow resin or sponge, and floats on the water surface 19 by buoyancy. The float 22 vibrates vertically and horizontally as the water surface swells due to aeration and water flow in the treatment tank 6. Thus, the trunk 12 is vibrated, and thereby the swinging of the hydrophilic branch 13 can be promoted.

(Embodiment 4)
FIG. 5 shows another embodiment of the wastewater treatment system of the present invention. As shown in FIG. 5, the wastewater treatment system of the present embodiment includes an adjustment unit 1 that collects wastewater, an aeration unit 23 that treats organic matter with activated sludge, and activated sludge and treated water that are treated by gravity with wastewater treated with the aeration unit 23. And the wastewater treatment apparatus 2 of the present invention for decomposing the activated sludge in the sludge storage unit 25.

  An aeration blower 27 for supplying aerobic bubbles into the waste water is connected to the aeration unit 23 through an aeration pipe 28. Further, the waste water treatment apparatus 2 has an inflow port 3 connected to a sludge storage unit 25 and a sludge supply pump 26, and a filtration pump 5 is connected to the outflow port 4. The discharge side of the filtration pump 5 is an aeration unit 23. Connected to the upstream side.

  First, domestic wastewater containing organic matter is supplied to the adjustment unit 1, where it temporarily stays and a certain amount flows into the aeration unit 23. The inside of the aeration unit 23 is in a state in which a large amount of activated sludge is present. Here, oxygen is supplied from the aeration blower 27 through the aeration pipe 28 to the water to oxidize and decompose organic matter by microorganisms, and then the activated sludge. The treated water containing is supplied to the sedimentation unit 24. In the sedimentation section 24, by slowing the flow, the activated sludge in the waste water is solid-liquid separated into the upper supernatant and the lower sediment by natural sedimentation, and this supernatant is discharged into the river or sewage as discharge water. Is done.

  On the other hand, a part of the sediment is returned to the upstream side of the aeration unit 23 as return sludge and is used again for biological treatment. The remaining sediment is temporarily stored in the sludge storage unit 25 as excess sludge. Excess sludge stored in the sludge storage unit 25 is supplied to the inlet 3 of the wastewater treatment apparatus 2 by the sludge supply pump 26. In the wastewater treatment device 2, the surplus sludge that has flowed in is further oxidized and decomposed, and the remaining treated water is returned to the aeration unit 23 via the filtration pump 5.

  When surplus sludge is treated by the system as described above, surplus sludge that has flowed into the wastewater treatment device 2 increases the concentration of surplus sludge itself, thereby balancing inflow sludge and digested sludge by self-digestion of sludge. There is also a method of reducing the amount of generated sludge so that no excess sludge is generated. However, a solubilizing means (not shown) may be separately provided to decompose the inflowing excess sludge so that microorganisms can be easily treated as food. desirable.

  As the solubilization means, physical methods, chemical methods, and biological methods are known. As physical methods, there are ultrasonic treatment, high-speed jet treatment, mill crushing treatment, and the like. Biological methods such as oxidation treatment, thermal alkali treatment, electrolytic treatment, hydrothermal treatment (high temperature and high pressure treatment) include thermophilic bacteria treatment, and there is a method combining these, and any method may be used.

  Further, the solubilization treatment is performed by supplying surplus sludge to the treatment tank 6 once, sucking it from the treatment tank 6, performing the solubilization treatment, and returning it to the treatment tank 6. In addition, since the quantity of the sludge to solubilize is a part of the excess sludge in a processing tank, even the activated sludge required for decomposition | disassembly is not solubilized.

  By the way, in general, surplus sludge in a wastewater treatment system using biological treatment such as the standard activated sludge method is discharged out of the system, and after concentration and dehydration, it is incinerated or disposed of in landfill. In recent years, this treatment is very expensive and the shortage of landfill sites has become a serious problem.

  Therefore, in order to fundamentally reduce treatment costs, it is required to reduce the amount of excess sludge generated in the wastewater treatment system.

  However, the sludge reduction system that is currently used generally returns the solubilized surplus sludge to the aeration unit 23 as it is for decomposition, and its reduction capability depends on the processing performance of the aeration unit, and is dependent on the capability of the aeration unit 23. If there is no room, the quality of the treated water deteriorates, so that there is a problem that the applicable treatment plants are limited.

  By treating the excess sludge with the wastewater treatment system of the present embodiment, the sludge reduction can be widely applied while diverting the existing wastewater treatment system regardless of the capability of the aeration unit 23. Processing costs can be greatly reduced.

  As described above, since the wastewater treatment apparatus and the wastewater treatment system using the wastewater treatment apparatus according to the present invention have high treatment performance, they will greatly contribute to future environmental business.

The block diagram which shows the structure and waste water treatment system of the waste water treatment equipment of this invention The block diagram which shows other embodiment of this invention The block diagram which shows other embodiment The block diagram which shows other embodiment The block diagram which shows other embodiment of the waste water treatment system of this invention. The figure which shows an example of the conventional waste water treatment equipment The figure which shows an example of the conventional waste water treatment equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adjustment part 2 Waste water treatment device 3 Inlet 4 Outlet 6 Treatment tank 7 Separation membrane 8 Partition plate 9 Oscillating floor 11 Diffusing pipe 12, 16 Trunk 13, 17 Hydrophilic branch 15 Denitrification bed 21 Vibrator 22 Float 23 Aeration part 24 Sedimentation section 25 Sludge storage section

Claims (14)

A treatment tank having an inlet and an outlet for drainage, a separation membrane provided in the treatment tank, an air diffuser provided below the separation membrane, and a discharge from the air diffuser toward the upper separation membrane A biological carrier provided downstream from the separation membrane of the water flow formed by the aerobic bubbles, and a reflux means for refluxing the water flow after passing through the biological carrier to the upstream region of the separation membrane, A wastewater treatment apparatus, wherein the biological carrier is a rocking floor. The wastewater treatment apparatus according to claim 1, wherein a partition plate is provided outside the separation membrane as a reflux means, and a swing bed is disposed on the opposite side of the separation membrane via the partition plate. The wastewater treatment apparatus according to claim 2, wherein the swing floor has a hydrophilic branch that swings at least at a tip end side thereof by a water flow. The lower end of the partition plate is disposed below the diffuser pipe, and a denitrification bed is provided in the upstream area of the diffuser pipe downstream of the rocking bed in the flow path formed by the diffuser pipe and the partition plate. Wastewater treatment equipment. The waste water treatment apparatus according to claim 4, wherein a denitrification floor is provided below the lower end of the partition plate. The waste water treatment apparatus according to claim 4, wherein a denitrification floor is provided at a lower portion of the partition plate through the partition plate on the side opposite to the diffuser pipe. The waste water treatment apparatus according to claim 6, wherein the water flow cross-sectional area in the denitrification bed is larger than the water flow cross-sectional area in the rocking bed. The waste water treatment apparatus according to claim 4, wherein the denitrification bed has a hydrophilic branch at least at a tip side thereof that is swung by a water flow. The waste water treatment apparatus according to claim 8, wherein the density of the hydrophilic branches in the denitrification bed is higher than the density of the hydrophilic branches in the rocking bed. The swing bed comprises a trunk provided from the upper end to the lower end of the partition plate and a plurality of hydrophilic branches provided on the trunk, and a vibrating body for vibrating the stem is provided on the trunk. The waste water treatment apparatus as described in one. The wastewater treatment apparatus according to claim 10, wherein the vibrating body vibrates the trunk in response to fluctuations in the water flow in the treatment tank. The wastewater treatment apparatus according to claim 10, wherein the vibrator has a lower end of the trunk fixed and a float is provided at the upper end. The waste water treatment system which connected the adjustment part into which a treated water flows in, and the inlet of the processing tank in the waste water treatment apparatus as described in any one of Claim 1 to 12 to this adjustment part. An adjustment unit into which treated water flows, an aeration unit provided downstream of the adjustment unit, a precipitation unit provided downstream of the aeration unit, and a sludge storage unit provided downstream of the precipitation unit, The wastewater treatment system which connected the part or the said sludge storage part, and the inflow port of the processing tank in the wastewater treatment apparatus as described in any one of Claims 1-12.

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