JPH0673676B2 - Method and apparatus for biological treatment of organic wastewater - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for biologically treating various organic wastewater such as sewage, various organic industrial wastewaters, human waste, septic tank sludge and the like. .

[Prior Art] Conventionally, the most typical means for biologically treating organic wastewater is activated sludge treatment.

An apparatus for treating activated sludge mainly consists of an aeration tank and a sedimentation basin, and is widely used at present because of its great advantage that it has a wide range of application.

[Problems to be Solved by the Invention]

However, the activated sludge treatment device, which has the advantage of having a wide application range, has the following disadvantages.

Since it requires an aeration tank and sedimentation tank, the installation area is large and construction costs are high.

SS carryover from the settling basin is inevitable.

The quality of treated water is governed by the settling property of activated sludge.

To obtain treated water from which SS is highly removed, an over-process such as sand filtration must be added. For this reason, the installation area and the construction cost are further increased.

There were problems such as.

The present invention is intended to eliminate these various drawbacks in the conventional activated sludge treatment, and by utilizing the water surface of the tank, the biological treatment and solid-liquid separation due to excess SS removal are also possible. An object of the present invention is to provide a biological treatment method for organic sewage and an apparatus for the same.

[Means for Solving the Problems]

The present invention divides the inside of the tank having the raw water inflow section into a plurality of sections by vertical partition walls, so that each section is immersed and retained by the levitation material, and the treated water outflow section and the cleaning section are respectively provided above the overlayer of each section. A drainage / outflow section is provided, and air for cleaning the air of each overlayer is air-moved from the lower part of the overlayer of each of these sections by moving horizontally to each section at a predetermined time interval and is supplied to each section. The layer is air-washed, the raw water is purified in other overlayers, and the SS that has been air-washed and removed is taken out as wash drainage from the upper part of the overlayer by upward flow of the raw water. By making the lower part of each compartment inside to communicate with each other, biological treatment and solid-liquid separation by filtration can be effectively performed in a single device, eliminating the need for a separate settling tank that was conventionally installed. To obtain clear treated water without being influenced by the sedimentation properties of microorganisms. It is those that can be.

[Action]

Raw water, which is organic waste such as sewage, flows into the tank from the raw water inflow section at the lower part of the tank, and SS with good sedimentation is separated by sedimentation. The raw water from which this good SS has been separated and removed is
It flows through the overlayer of the levitation material that is dipped and held in each of the upper compartments by upward flow, but at the same time, the fine SS that has not been settled and separated is excessively removed and at the same time forms each overlayer. Since an aerobic or anaerobic biofilm is developed on the surface of the material, soluble BOD in the raw water is removed, and by keeping the upper layer aerobic, NH _{4 in} the raw water is
-N is also nitrified.

If the upper part of the tank is kept aerobic by aeration or the like, a part of the soluble BOD is removed due to the presence of the floating activated sludge.

In addition, when the lower part of each section in the tank is set as a communicating settling section, the settling separation of SS in the raw water is promoted.

In this way, the treated water that has been clarified by the removal of SS in the raw water by sedimentation and excess as well as the biological removal of organic matter and NH ₄ -N becomes like a spring from the top of each section. It flows out and flows out of the system through the treated water outlet pipe through each treated water outlet.

Now, as such treatment is continued, the amount of SS trapped in the overlayer increases, the overresistance increases due to the growth of the biofilm, and the predetermined overresistance (usually about 1000 to 1400 mmH ₂ O is selected). Once reached, the overlayer is washed.

That is, while the air cleaning device slowly moves the lower part of the material layer in each section in the horizontal direction, a large amount of air is ejected,
A large amount of air is sent in from the bottom of the overlayer. This operation violently disturbs the inside of the superlayer due to the floating material in that section, and the trapped SS is washed out. like this,
It is not necessary to stop the inflow of raw water into the tank during the air cleaning operation, and the cleaning wastewater containing a large amount of SS that has been washed out in the cleaning section flows out of the system from the cleaning wastewater distribution pipe through the treated water outflow section at the top. To do. At this time, in the sections other than the air cleaning, the treatment is continued and clear treated water is flowing out. Then, when the air cleaning of the overlayer of one section is completed, the air cleaning device horizontally moves to the adjacent section, and air-cleans the overlayer of the section.

If a floating material with a specific gravity of less than 1.0 is used as the material for forming the overlayer, such as styrofoam, polyurethane foam, polypropylene, etc., it is easy to hold the overlayer in the upper part, and there is a disturbing effect due to air bubbles during air cleaning. Good and effective cleaning is performed, and continuous processing is possible in which, while cleaning a part of the overlayer, a purification process of raw water is performed in a part other than air cleaning.

In addition, the wastewater from each section is discharged together with the raw water or separately into the tank, and the SS in the wastewater is separated by sedimentation. At this time, if a polymer flocculant or the like is added to the cleaning wastewater, SS in the cleaning wastewater can be rapidly settled and separated. Therefore, it is not necessary to use clear treated water for cleaning the overlayer by the floating material, and the production efficiency of the treated water is increased.

In addition, it is preferable to fixedly deploy an air diffuser for supplying air to each compartment at the bottom of each compartment, and when performing aerobic biofilm treatment in an overstory, supply air from these air diffusers. However, when the anaerobic biofilm treatment is performed in the upper layer, it can be dealt with only by stopping the supply of air from the air diffuser.

In this way, organic sewage such as sewage, in a single tank, It is highly purified by a series of removal mechanisms called.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. The upper part of the tank 1 is divided into a plurality of vertical partition walls 2.
Within each compartment, there is an overlayer 3 filled with sponge, lightweight aggregate, perlite, plastic particles, wood chips, glass microballoons, etc., which has a specific gravity of less than 1.0 and floats in water. Is suppressed by the water-permeable support member 4 and the overlayer 3 is immersed and held in water,
Each treated water to each compartment top is treated water outlet 5 for overflow provided are continuous to the treated water outlet pipe 6 via a valve _61.

The lower part of each compartment in the tank 1 is a communicating sedimentation part 7, and a raw water inflow pipe 8 for introducing organic wastewater such as sewage is opened in the sedimentation part 7. It does not necessarily have to be provided. Reference numeral 9 denotes a concentrated portion of the settled sludge formed at an appropriate position on the bottom of the tank, and a sludge pipe 10 is connected to the concentrated portion.

Further, a rail 11 is provided on the water surface of the tank 1, and a trolley 14 having an aeration blower 12 and a drive unit 13 is movably mounted on the rail 11, and an air pipe is provided at a discharge portion of the aeration blower 12.
The air pipes 15 are connected to each other, the air pipes 15 extend below the vertical partition wall 2, and an air cleaning device 16 composed of an air diffusing pipe is connected to the tip of the air pipes 15. The air cleaning device 16 moves horizontally as the carriage 14 travels. It is like this.

The cleaning waste water outlet pipe through a valve 17 ₁ in the treated water outflow part 5 provided in each compartment upper partitioned by vertical partition walls 2 1
7 is not continuous, it is to allow the outside of the system is taken out of the treated water and detergent drain with switching operation of the valve 6 ₁ of the treated water outlet pipe 6. That is, since the overlayer 3 of the levitation material is in a state in which the levitation is blocked by the support member 4,
While flowing the raw water during the over-layer washed with upflow, while flowing the raw water during the over-layer washed with upflow, closing valve _61, opening the valve 17 _1, large amounts discharging cleaning air from the air cleaning apparatus 16 Then, a violent gas-liquid mixed phase flow is generated in the tank, and the material is fluidized. As a result, it was trapped in the upper layer 3 until then.
The SS and the SS caused by the proliferating microorganisms are separated, and the wash water containing a large amount of SS flows out of the system through the wash drainage outflow pipe 17.
If such an operation is continued for a required time (usually 1 to 1.5 hours), the SS concentration of the cleaning drainage outflow pipe 17 decreases to a predetermined value, so at this point, the supply of the air for cleaning air is stopped and the valve 17 ₁
The closed and opened valve 6 ₁ of the treated water outlet pipe 6, returns to the normal processing state, clear treated water flows out.

In addition, like the illustrated example, a diffusing plate 19 or a diffusing pipe, which is connected to the blower 18 in the tank and is used to supply air to the overlayer 3 of each compartment, is provided, and the aerobic biofilm is formed in the overlayer 3. When the treatment is performed, air is supplied, and when the anaerobic biofilm treatment is performed in the overlayer 3, the air supply is stopped.

〔The invention's effect〕

According to the present invention, the drawbacks of the prior art are solved and the following remarkable effects are achieved.

Complete purification can be performed only with a tank that corresponds to the anaerobic tank of the conventional activated sludge treatment process, the sedimentation tank that is indispensable in the activated sludge treatment method is not required, and a significant space saving effect can be maintained.

In the conventional activated sludge treatment method, the sand filtration tank after the sedimentation basin, which was indispensable in the case where advanced SS removal is required, is no longer necessary, and the clarified water with SS 10 mg / l or less can always be obtained.

Stable advanced SS without being affected by sedimentation of activated sludge
Removal is achieved. Therefore, maintenance is also very easy.

It is not necessary to stop the inflow of raw water at the time of cleaning the overlayer, and it is not necessary to consume the treated water for the cleaning water, resulting in high production efficiency of the treated water.

Since continuous passing is possible, driving operation is easier than batch operation. In the batch filtration method, a series of sequence operations in which the raw water supply is stopped at the time of overlayer cleaning, the treated water is washed, the cleaning waste water is discharged, and the raw water is supplied again is essential, but in the present invention, such a complicated operation is required. Operation is unnecessary.

No separate settling tank is required to dispose of the wash effluent in the overlayer.

After the SS of the raw water is settled, the treatment is performed in the upper layer, so the clogging of the upper layer is slow.

Soluble BOD can be removed by suspended microorganisms at the bottom of the overlayer, so the BOD to the overlayer by the floating material
The load can be kept small. As a result, a high degree of BOD removal and efficient NH ₄ -N nitrification can be achieved in the overlayer.

[Brief description of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical sectional side view,
FIG. 2 is a plan view and FIG. 3 is a partially enlarged vertical sectional view. 1 ... Tank, 2 ... Vertical partition wall, 3 ... Overlayer, 4 ... Support member, 5 ... Treated water outlet, 6 ... Treated water outlet pipe, 7 ...
… Sedimentation part, 9 …… Raw water inflow pipe, 10 …… Mud pipe, 11 …… Rail, 12 …… Aeration blower, 14 …… Bogie, 15 …… Air piping, 16 …… Air cleaning device, 17 …… Wash drainage pipe, 18…
… Blower, 19… Air diffuser.

Claims (3)

[Claims] 1. Raw water flows in from the lower part of the tank to flow upward,
In the method of biological treatment by allowing the upper part of the tank to be partitioned into a plurality of vertical partition walls, allowing the floating material to pass through each partition to pass through each overlayer, and flowing out from the treated water outflow part of the upper part of the tank, From the lower part of the overlayer of each section, horizontally move the air cleaning device that air-cleans the material of each overlayer, and sequentially supply air to each section at predetermined time intervals to wash each overlayer with air. Organic water is characterized by purifying raw water in the upper layer and removing SS that has been air-cleaned and removed from the upper portion of the upper layer as cleaning drain by upward flow of raw water from the outlet of the cleaning drain in the upper part of the tank. Biological treatment method for sewage. 2. An upper part of a tank having a raw water inflow part at a lower part is divided into a plurality of parts by vertical partition walls, and an upper layer of a levitation material is dipped and held in each part and each upper part of the upper part in each part. A treated water outflow section and a cleaning drainage outflow section are provided,
An air cleaning device that supplies air for cleaning the air of each overlayer to each of the sections is installed horizontally below the overlayer of each of these sections so that the air is removed from the material by air cleaning. The biological treatment device for organic sewage is characterized in that SS is discharged from the upper part of the material layer at the washing drainage outflow part. 3. The biological treatment apparatus for organic sewage according to claim 2, wherein a lower part of each compartment in the tank is a communicating part which is a communicating part.