JP3851385B2 - Wastewater treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wastewater treatment apparatus, and more particularly, to a wastewater treatment apparatus suitable for a sewage treatment facility that performs wastewater treatment by an anaerobic / aerobic filter bed in which an aerobic filter bed is combined with an anaerobic filter bed. .
[0002]
[Prior art]
In recent years, even in a relatively small sewage treatment facility, removal of nitrogen and phosphorus is often demanded for preventing eutrophication. Traditionally, small-scale sewage treatment facilities are easy to maintain, and so filter bed type biological treatment equipment has been used in many cases. The air bed method is often used.
[0003]
FIG. 3 shows an example of a conventional wastewater treatment apparatus for carrying out the anaerobic / aerobic filter bed method, in which an aerobic filter bed 2 is arranged at the subsequent stage of the anaerobic filter bed 1. Inflow sewage (raw water) flows into the anaerobic filter bed 1 from the pipe 4 through only the sedimentation basin equipment or the pretreatment equipment combined with the sedimentation basin equipment and the first sedimentation basin. The water that has been anaerobically treated in the anaerobic filter bed 1 is sent to the aerobic filter bed 2 through the pipe 5 and subjected to aerobic treatment, and is sent from the pipe 6 to a treated water tank or the like. It returns to the anaerobic filter bed 1 as circulating water (nitrification liquid) by the piping 7. Reference numeral 8 denotes an air diffuser for introducing air (oxygen) into the aerobic filter bed 2.
[0004]
[Problems to be solved by the invention]
As described above, the conventional anaerobic / aerobic filter bed wastewater treatment apparatus is provided with the anaerobic filter bed 1 and the aerobic filter bed 2 separately. Therefore, it is necessary to install a large number of small treatment tanks, which causes problems such as an increase in installation area, deterioration in workability, and complexity of the system.
[0005]
For this reason, it has also been proposed to stack anaerobic filter beds and aerobic filter beds in one treatment tank, but in this case, consideration for aeration and cleaning of the aerobic filter bed is insufficient, There was a difficulty in practicality.
[0006]
Therefore, the present invention integrates the anaerobic filter bed and the aerobic filter bed into one treatment tank to reduce the installation area and the like, and can also sufficiently diffuse and wash the aerobic filter bed. It aims to provide a wastewater treatment device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the wastewater treatment apparatus of the present invention is a wastewater treatment apparatus in which an anaerobic filter bed and an aerobic filter bed are integrated, and an anaerobic filter bed portion is provided at the lower part of the treatment tank. The aerobic filter bed is disposed at the bottom of the treatment tank, the raw water inflow part and the precipitated sludge extraction part are provided at the bottom of the treatment tank, the treatment water discharge part and the washing drainage discharge part are provided at the top of the treatment tank, and the anaerobic filter bed is provided. between the parts and aerobic basin portion partitioned by Gu drawing board, a water collecting nozzle provided in the compartment drawing board, a diffuser means above the partition plate, the cleaning air introduced washing water introduction portion downwards Each of the water collecting nozzles has a tubular body portion that vertically penetrates the partition plate, and the upper portion of the partition plate is disposed above the partition plate. Provide a strainer with an opening that does not allow the filter medium filled in A vertical slit is provided in the body portion, and a through hole is provided above the slit. When the filter medium of the aerobic filter bed is air-washed by the slit and the through hole, the water is ejected from each water collecting nozzle. It is characterized by uniform air volume . Furthermore, the present invention is characterized in that a pressure levitation separation device is provided in the preceding stage of the raw water inflow portion.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an example of a sewage treatment facility using the effluent treatment device of the present invention, and an example in which a pressurized flotation separation device 12 is installed upstream from a wastewater treatment device 11 by an anaerobic / aerobic filter bed method. Is shown.
[0009]
The waste water treatment apparatus 11 has an anaerobic filter bed 14 disposed at the lower part of the treatment tank 13 and an aerobic filter bed 15 disposed at the upper part, and a sedimentation chamber having an appropriate volume at the bottom of the treatment tank. 13a is formed, and a raw water inflow pipe 16 into which raw water treated by the pressurized flotation separation apparatus 12 flows and a sludge extraction pipe 17 for extracting the precipitated sludge are provided. A treated water discharge pipe 18 for discharging treated water and a cleaning drainage pipe 20 for discharging cleaning wastewater through a trough 19 are provided. Further, the anaerobic filter bed portion 14 and the aerobic filter bed portion 15 are partitioned by a partition plate 22 having a water collecting nozzle 21, and in the support layer 23 provided on the upper portion of the partition plate 22. A diffuser 24 is provided, and a cleaning water introduction pipe 25 and a cleaning air introduction pipe 26 for introducing cleaning water and air when the aerobic filter bed 15 is cleaned are provided below the partition plate 22. ing. Furthermore, a circulation pipe 27 for circulating the nitrification liquid is provided between the top and bottom of the processing tank 13.
[0010]
As shown in FIG. 2, the water collection nozzle 21 provided in the partition plate 22 is provided on a tubular body portion 21 a penetrating the partition plate 22 in the vertical direction and on an upper surface portion of the partition plate of the tubular body portion 21 a. A strainer 21b, a vertical slit 21c provided in the vicinity of the lower end of the tube portion 21a below the partition plate 22, and a through hole 21d provided above the slit 21c. In 21b, an opening is formed so that the filter medium filled above the partition plate 22 does not pass through. The water collection nozzle 21 has a function of making the amount of air ejected from each water collection nozzle 21 uniform when the filter medium is air-washed by the slit 21c and the through hole 21d.
[0011]
That is, in the air cleaning of the aerobic filter bed 15, the air that has flowed from the cleaning air introduction pipe 26 to the lower side of the partition plate 22 is jetted to the upper side of the partition plate 22 through the water collection nozzle 21. At this time, most of the air flows into the tube body portion 21a from the through hole 21d of the water collecting nozzle 21, and the remaining air pushes down the water surface below the partition plate 22 by the pressure, and opens by lowering the water surface. It flows into the tubular body portion 21a from the lower slit 21c. And since it will be in the state where the amount of pushing down of the water surface and the amount of air which flows in into pipe part 21a from slit 21c are in balance, it is from each water collection nozzle 21 by aligning the level of each water collection nozzle 21. The amount of air ejected into the aerobic filter bed 15 can be made constant, and uniform air cleaning can be performed. Moreover, even if there is a slight level difference, a substantially uniform ejection amount can be obtained, and even if a level difference that does not reach the slit 21c occurs in part, most of the air flowing in from the upper through hole 21d is Since the water collection nozzle 21 surely ejects into the aerobic filter bed 15, the entire aerobic filter bed 15 can be sufficiently washed with air.
[0012]
Thus, by providing the anaerobic filter bed part 14 and the aerobic filter bed part 15 in one processing tank 13, the installation area in the waste water treatment device 11 is reduced, the workability is improved, and the system is improved. Simplification and the like can be achieved. In addition, the aerobic filter bed can be washed efficiently, and the generated sludge can be easily treated.
[0013]
Further, as is well known, the pressurized flotation separation device 12 can be treated in a short time, can collect separated sludge at a high concentration, and is not easily affected by the concentration of pollutants in raw water. Therefore, by providing the pressurized flotation separation device 12 in the previous stage of the waste water treatment device 11, the load flowing into the anaerobic filter bed 14 can be reduced, and the capacity of the anaerobic filter bed 14 can be reduced. While being able to make small, obstruction | occlusion of the contact material of the anaerobic filter bed part 14 and generation | occurrence | production of a scum can be decreased. Furthermore, since the anaerobic filter bed part 14 can perform a stable and good treatment, the processability in the aerobic filter bed part 15 can also be improved.
[0014]
The inflowing sewage (raw water) flows into the raw water tank 29 through the screen 28 and is then sent to the pressurized flotation separation device 12 through the pipe 31 by the submersible pump 30. Note that a flow rate adjusting function can be added to the raw water tank 29 as necessary. The raw water sent to the pressurized flotation separator 12 is mixed with the pressurized air dissolved water supplied from the pipe 32 at the inflow portion to the pressurized flotation separator 12, and the suspended components in the raw water are dissolved in the pressurized air. The apparent specific gravity is reduced by adhering to fine bubbles generated from water, and separated as floating sludge (floss) at the upper part of the tank of the pressurized flotation separation device 12. The levitation sludge is scraped off by the scraper 33 and sent from the path 34 to the sludge storage tank 35, and the sludge precipitated at the bottom of the pressurized levitation separator 12 is sent from the path 36 to the sludge storage tank 35. The sludge density | concentration at this time is 3 to 5%, and is high concentration compared with the gravity concentration in the conventional sludge concentration tank.
[0015]
In addition, sludge generated from the anaerobic filter bed 14 and the aerobic filter bed 15 is returned to the raw water tank 29 through the sludge extraction pipe 17 and the washing drainage discharge pipe 20 and processed again by the pressurized flotation separator 12. Thus, it is possible to achieve a unified sludge generation location and a high concentration. Therefore, in a relatively small sewage treatment facility where the amount of sludge generated greatly affects the running cost, the running cost can be significantly reduced.
[0016]
A part of the water treated by the pressurized flotation separation device 12 is withdrawn into the pipe 37 on the outlet side, pressurized by the pump 38, and mixed with the compressed air supplied from the compressor 39 in the mixing tank 40. Then, it is supplied and mixed into the raw water from the pipe 32 as pressurized air dissolved water.
[0017]
Since the water treated with the pressure flotation separation device 12 in this way has a higher removal rate of suspended components compared to the normal precipitation treatment, the inflow load to the anaerobic filter bed portion 14 is reduced, and anaerobic correspondingly. It is possible to reduce the capacity of the filter bed 14. Further, in the floatation process, components that easily float, such as hair, oil, and scum, can be removed almost completely, so that the contact material blockage and the occurrence of scum in the anaerobic filter bed portion 14 are reduced. In addition, since stable and good treatment is possible in the anaerobic filter bed part 14, the processability in the aerobic filter bed part 15 into which water treated in the anaerobic filter bed part 14 flows is also improved.
[0018]
In this way, the raw water that has been treated by the pressurized flotation separation device 12 and flows into the waste water treatment device 11 is mixed with the nitrating solution flowing from the circulation pipe 27 at the bottom of the treatment tank 13 and flows through the anaerobic filter bed portion 14. It rises and a predetermined anaerobic process is performed here. The water subjected to the anaerobic treatment passes through the water collecting nozzle 21 of the partition plate 22 and rises into the aerobic filter bed portion 15, and a predetermined aerobic treatment is performed. At this time, the air supplied from the compressor 41 is introduced from the air diffuser 24 installed below the aerobic filter bed 15. The treated water that has been subjected to anaerobic / aerobic treatment in the waste water treatment device 11 is sent from the treated water discharge pipe 18 to the treated water tank 42, and a part of the treated water is drawn out to the circulation pipe 27 and passed through the pump 43. Circulate to the bottom.
[0019]
Cleaning of the filter medium of the aerobic filter bed 15 is performed by performing air washing by introducing air from the cleaning blower 44 through the cleaning air introduction pipe 26 and the water collection nozzle 21 into the aerobic filter bed 15. This is performed by introducing a part of the treated water in the treated water tank 42 through the pump 45 and the washing water introduction pipe 25 as washing water. The cleaning wastewater generated during the cleaning flows out from the trough 19 to the cleaning drainage discharge pipe 20 and is returned to the raw water tank 29. Also, the sludge extracted from the sludge extraction pipe 17 at the bottom of the tank is returned to the raw water tank 29 and mixed with the raw water in the same manner as the washing waste water, and is sent again to the pressurized flotation separation device 12 for the flotation separation process.
[0020]
Thus, by combining the wastewater treatment device 11 in which the anaerobic filter bed portion 14 and the aerobic filter bed portion 15 are integrated with the pressurized flotation separation device 12, the efficiency and size reduction of the wastewater treatment device 11 are achieved. In addition, sludge can be collected effectively.
[0021]
In addition, since the wastewater treatment apparatus of the present invention can perform solid-liquid separation to some extent by providing the above-described sedimentation chamber at the bottom of the treatment tank, the pressure flotation separation apparatus in front of the wastewater treatment apparatus or a normal It is also possible to omit the gravity sedimentation basin.
[0022]
【The invention's effect】
As described above, according to the wastewater treatment apparatus of the present invention, the anaerobic filter bed and the aerobic filter bed are integrated into one treatment tank, so that the installation area can be reduced and the workability can be improved. Can be simplified. Moreover, the aerobic filter bed can be washed efficiently, and the wastewater treatment efficiency can be greatly improved. Furthermore, by combining the pressure levitation separator in the previous stage, the inflow load of the anaerobic filter bed can be reduced, and the processing efficiency can be further improved.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an example of a wastewater treatment facility using a wastewater treatment apparatus of the present invention.
FIG. 2 is a partial cross-sectional front view showing an example of a water collection nozzle.
FIG. 3 is a system diagram showing an example of a conventional waste water treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Waste water treatment apparatus, 12 ... Pressure floating separator, 13 ... Treatment tank, 14 ... Anaerobic filter bed part, 15 ... Aerobic filter bed part, 16 ... Raw water inflow pipe, 17 ... Sludge extraction pipe, 18 ... Treatment Water discharge pipe, 19 ... Trough, 20 ... Washing drain discharge pipe, 21 ... Water collecting nozzle, 22 ... Partition plate, 23 ... Support layer, 24 ... Air diffuser, 25 ... Washing water introduction pipe, 26 ... Cleaning air introduction Pipe, 27 ... Circulation piping, 29 ... Raw water tank, 35 ... Sludge storage tank, 40 ... Mixing tank, 42 ... Treated water tank

Claims (2)

It is a wastewater treatment device that has an anaerobic filter bed and an aerobic filter bed in an integrated structure, with an anaerobic filter bed at the bottom of the treatment tank and an aerobic filter bed at the top, and at the bottom of the treatment tank and a settled sludge draw-off unit water inlet provided, provided with a treated water discharge portion in the processing tank top and detergent drain discharge portion, between said anaerobic filter bed section and aerobic basin unit at ward faceplate A wastewater treatment apparatus having a partition , a water collection nozzle provided on the partition plate, an air diffuser provided above the partition plate, and a cleaning water introduction unit and a cleaning air introduction unit provided below, respectively , The water nozzle has a tube portion that penetrates the partition plate in the vertical direction, and an opening is formed on the top surface of the partition plate of the tube portion so that the filter medium filled above the partition plate does not pass through. And a slit in the vertical direction in the tubular body part below the partition plate and The through hole provided above the slit by the said slit and the through hole, the filter media of the aerobic filter bed section, characterized in that a uniform amount of air ejected from the water collecting nozzle when air washing wastewater Processing equipment. The wastewater treatment apparatus according to claim 1, wherein a pressure levitation separator is provided upstream of the raw water inflow section.

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