JPH0642794Y2 - Organic wastewater biological treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel treatment device for purifying various organic wastewater such as sewage, various industrial wastewaters, human waste, and septic tank sludge.

[Conventional technology]

Conventionally, aerobic immersion floor equipment is known. As shown in FIG. 2, this conventional apparatus has a packed bed of arbitrary particles such as anthracite, granular activated carbon, various granular minerals, and plastic particles below the water surface of the tank 21 (called a dipping bed 22).
And an air diffuser pipe 23 for oxygen-containing gas such as air is provided in the lower part of the immersion floor 22. Further, a settling tank 24, a treated water storage tank 28, and a cleaning drainage storage tank 30 are attached to such an aerobic submerged bed apparatus.

Then, the organic sewage (raw water) flows into the tank 21 from the settling tank 24 through the raw water inflow pipe 25 and flows downward or upward in the immersion bed 22 (in the case of downward flow in FIG. 2). At the time of contact with the microorganisms on the surface of the granular material and the bubbles of the oxygen-containing gas diffused from the blower 26 through the diffuser pipe 23, BOD is removed, and the raw water SS is also excessively removed, becoming treated water. Through the treated outflow pipe 27 to the treated water storage tank 28. As such a treatment is continued, the SS and the amount of microorganisms trapped in the immersion bed 22 increase, which makes it difficult to continue the treatment due to an increase in over-resistance, so that it is stored in the treated water storage tank 28. The clarified treated water present is supplied to the lower part of the immersion bed 22 by the pump 29 to wash the immersion bed 22.

The cleaning drainage of the immersion floor 22 is from the upper part of the tank 21
At 30, the cleaning wastewater is supplied to the sedimentation tank 24 by the pump 31 to separate the SS by sedimentation, and the total amount of the raw water and the cleaning wastewater flow rate is supplied to the immersion bed 22 again.

[Problems to be solved by the device]

However, the conventional apparatus shown in FIG. 2 has the following major drawbacks, and a further excellent apparatus and system configuration is desired.

If there is a large amount of raw water SS, a settling tank 24 must be installed in front of the tank 21 to remove most of the SS, as shown in FIG. Otherwise, the clogging (clogging) in the submerged bed 22 will progress rapidly, the aerobic submerged bed apparatus will not be able to operate, and the frequency of cleaning the submerged bed 22 will increase dramatically. Moreover, since the sedimentation / separation speed of the sedimentation tank 24 can be only about 30 m / day at most, the construction cost and installation space of the sedimentation tank 24 become large.

A large amount of cleaning water of 2.5 times the bed volume is required when cleaning the submerged floor 22, and a large amount of the processing water in the treated water storage tank 28 must be used as the cleaning water as shown in FIG. Therefore, the treated water production efficiency is low.

Since the cleaning drainage of the immersion floor 22 is made to flow into the sedimentation basin 24 at the previous stage for disposal as shown in FIG. 2, the total flow rate of raw water and cleaning drainage will flow into the tank 21. As a result, the tank
The water load on 21 has increased and the volume of tank 21 has to be increased. (The more the cleaning frequency increases, the more the amount of water load of the aerobic immersion bed equipment increases drastically.) The problem of the present invention is to completely solve the above-mentioned disadvantages of (1) to (3) in a single tank to remove SS and BOD of organic wastewater. It is an object of the present invention to provide an epoch-making treatment device which can be achieved very effectively and which can treat the treatment wastewater of the submerged bed and produce the treatment water by using the single treatment tank.

[Means for Solving the Problems]

The present invention holds an immersion bed filled with a granular material in the upper part of the tank, and an oxygen-containing gas diffuser is provided inside or under the immersion bed, and the lower part of the tank is used as a settling separator. An organic sewage characterized in that the settling / separating section is provided with a raw water inflow section and a treated water outflow section above the submerged bed, respectively, and cleaning wastewater of the submerged bed is supplied to the settling / separating section. Biological treatment equipment.

[Action]

The organic sewage (raw water) to be treated is guided from the raw water inflow part to the sedimentation separation part in the lower part of the tank, and after the majority of SS in the water is separated by sedimentation, it flows upward into the immersion bed in the upper part. However, the fine SS that could not be completely settled in the settling separation section is excessively removed, and due to the oxygen-containing gas diffused from the diffuser, the biofilm developed on the surface of the granular material under aerobic conditions. Biological treatment is carried out and it becomes treated water, which flows out from the treated water outflow part at the top of the tank.

In such a process, when the over-resistance increased to a predetermined value due to the capture of SS in the immersion bed and the increase in the amount of biofilm, the aeration amount from the air diffuser was rapidly increased to disturb the immersion bed while Or, wash the immersion floor with an upward flow of treated water,
The washing wastewater is supplied to the sedimentation separation unit, and after sedimentation separation, it is reused as washing water in an upward flow.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. 1. In the upper part of the tank 1, anthracite, granular activated carbon, granular lightweight aggregate, sponge granular material, granular plastic, expanded granular plastic, granular A submerged bed 2 filled with any particulate material such as pumice, granular phosphate rock, or zeolite particles is provided. When using a sedimentable granular material having a specific gravity of 1.0 or more, the lower part of the submerged bed 2 is made porous. When the floating particles are supported by the supporting member 3 and the specific gravity is less than 1.0, a porous water-passing member 3'such as a net for preventing outflow of the floating particles is provided on the upper part of the immersion bed 2. The porous water-permeable member 3 ′ may be provided above and below the immersion floor 2 if necessary. An air diffuser 4 for diffusing oxygen or other oxygen-containing gas is provided inside or under the immersion floor 2.

A lower part of the tank 1 is a sedimentation / separation part 5, and a raw water inflow pipe 6 is opened in the sedimentation / separation part 5. Reference numeral 7 is a coagulant injection pipe connected to the raw water inflow pipe 6 as necessary, and 8 is a sludge discharge pipe for sludge settled and separated by the settling separation unit 5.

An overflow ronder 9 is provided above the tank 1 and a treated water outflow pipe 10 is connected to the treated water outflow pipe 10.
A small pit 11 and a treated water storage tank 12 for flowing the cleaning wastewater of the above into a cleaning wastewater storage tank to be described later are interposed, and the treated water storage tank 12 is settled and separated in the tank 1 via a supply pipe 14 having a pump 13. The treated water in the treated water storage tank 12 is connected to the upper portion in the section 5 and can be appropriately supplied to the upper portion in the sedimentation separation section 5.

Furthermore, the small pit 11 is a cleaning drain pipe having a cleaning drain valve 15.
The washing drainage storage tank 17 is connected to the washing drainage storage tank 17, and the washing drainage storage tank 17 is connected to the inside of the sedimentation separation section 5 through a supply pipe 19 having a pump 18 so that the washing drainage in the cleaning wastewater storage tank 17 can be supplied to the sedimentation separation section 5. ing. Further, it is preferable to connect a coagulant injection pipe 7 ′ to the cleaning drainage supply pipe 19.

Then, the sedimentation / separation part 5 of the tank 1 configured as shown in FIG.
Raw water containing SS and soluble BOD is flown into the raw water through the raw water inflow pipe 6, and most of SS in the raw water is settled and separated. (Note that when removing phosphorus and COD from raw water, AIum, FeCI ₃ , P
It is recommended to add an inorganic coagulant such as AC. ) The raw water from which most of the SS has been removed in the sedimentation separation unit 5 is
As an upward flow, it flows into the immersion bed 2 provided above the sedimentation separation section 5, and the fine SS that did not settle is excessively removed and develops on the surface of the granular material that constitutes the immersion bed 2. Soluble BOD is removed by the biofilms
NH ₄ -N is also nitrified depending on the conditions. Immersion floor 2
It is possible to pass SS simultaneously with biological treatment. Oxygen required for respiratory metabolism of the biofilm is supplied by supplying bubbles of oxygen-containing gas from the air diffuser 4.

With the above actions, the three functions of SS sedimentation, biological treatment, and excessive removal of SS proceed extremely effectively in a single tank, and the clarified treated water flows out from the water surface above the tank like a spring.

However, in the immersion bed 2, the over-resistance (abbreviated as anti) of the immersion bed 2 increases as the amount of biofilm increases due to the excessive removal of SS and the progress of biological treatment. At that time (or at regular time intervals regardless of resistance), cleaning of the immersion bed 2 is performed.

An example of the cleaning method of the immersion floor 2 is performed as follows.

The operating procedure is in the following order. (Called the cleaning method (a)) Although the above is an example of a typical cleaning method, the following cleaning method may be adopted. (Called the cleaning method (b)) In any of the above cleaning methods (a) and (b), the water level in the tank 1 is lowered (the drained water is returned to the raw water tank (not shown)) before the procedure, and then the aeration is performed. It is preferable to perform the procedure after the amount is suddenly increased and the washing is performed in the air, because more sufficient washing is performed.

[Effect of device]

As described above, according to the present invention, the following important effects can be obtained and all the drawbacks of the prior art can be solved.

With only a single tank, advanced treatment functions such as sedimentation separation of raw water SS, aerobic biological bed treatment, and excessive removal of SS can be fully exerted. Moreover, biological bed cleaning wastewater treatment and cleaning from cleaning wastewater are performed. Water can be produced. This effect is an outstanding effect that cannot be imagined with conventional devices.

Floor cleaning drainage itself is regenerated as floor cleaning water,
Since the idea of utilizing it has been introduced, the treated water on the floor is used as cleaning water, and the amount consumed is significantly reduced. As a result, the treated water production efficiency is greatly improved.

For raw water with high SS, the sedimentation basin in the previous stage, which is indispensable for conventional equipment, is no longer required, and the construction cost and space reduction effects are remarkable.

When the treatment is stationary, the washing wastewater does not flow into the submerged bed at all, so that the water load on the submerged bed can be reduced and the treatment effect is stabilized. (On the other hand, in the conventional device, the total amount of the raw water flow rate and the washing drainage flow into the immersion bed even during steady-state processing, so the water load is high.)

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a vertical sectional view showing a conventional example. 1,21 ... Tank, 2,22 ... Immersion bed, 3 ... Support member, 3 '... Porous water-passing member, 4,23 ... Diffuser pipe, 5 ... Sedimentation / separation part, 6,25 ... Raw water inflow pipe, 7,7 ′… Coagulant injection pipe, 9… Overflow launder, 10,
27 ... Treated water outflow pipe, 11 ... Small pit, 12, 28 ... Treated water storage tank, 13, 18, 29, 31 ... Pump, 14, 19 ... Supply pipe, 15 ... Wash drain valve, 16 ... Wash drain pipe, 17 , 30… wash drainage tank, 24…
Settling basin, 26 ... blower.

Claims (1)

[Scope of utility model registration request] 1. A dipping bed filled with a granular material is held in the upper part of the tank, and an oxygen-containing gas diffuser is provided inside or under the dipping bed, and the lower part of the tank is used as a sedimentation separation part. An organic material characterized in that a raw water inflow part is provided in the sedimentation separation part and a treated water outflow part is provided above the immersion bed, and cleaning wastewater of the immersion bed is supplied to the sedimentation separation part. Sewage biological treatment equipment.