JPH0613118B2 - Fluidized bed biological treatment equipment for wastewater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention supplies waste water from below to a fluidized bed provided in a treatment tank to form an upward flow in the tank, and the upward flow constitutes a fluidized bed. The present invention relates to a fluidized bed type biological treatment device which fluidizes carrier particles to be treated, and anaerobically or aerobically treats wastewater with microorganisms carried by the carrier particles.

(Prior art) In the conventional device, in order to satisfactorily flow the carrier particles by supplying the liquid to the lower part of the fluidized bed as much as possible, the gravel particles with different particle sizes under the fluidized bed, such as the support bed in the sand filter, are used. A support bed was used, and the particle size distribution of gravel in the support bed was larger at the bottom and gradually decreased toward the top.

(Problems to be Solved by the Invention) Although the liquid can be uniformly supplied to the lower part of the fluidized bed by the above, when the operation is continued for a certain period of time, the same kind of microorganisms as the microorganisms on the carrier particles are used to support the bed. The gap between the gravel forming the structure is closed and the support bed is closed, and as a result, the flow of carrier particles is impaired and the operation cannot be continued due to the pressure increase.

For this reason, there is also an attempt to provide a support plate in the shape of an insole on the bottom of the processing tank, form a fluidized bed on the support plate, disperse the nozzles to the support plate, and supply the liquid to the lower portion of the fluidized bed through the nozzles. However, in this case, the adjacent space between the nozzles on the support plate becomes a dead space, and the carrier particles are deposited here, and the deposited carrier particles are fixed to each other by the microorganisms they carry and the dead space is gradually expanded. There is a problem to say.

(Means for Solving Problems) Therefore, according to the present invention, a plurality of nozzles for ejecting a liquid are dispersedly arranged at the bottom of a processing tank, the plurality of nozzles are knitted into a plurality of groups, and each group is sequentially provided with a liquid. Is provided.

(Operation) Assuming that the plurality of groups are, for example, the first and second groups, the liquid is supplied to the nozzles of the first group by the switching means to be ejected at a certain time during operation, whereby the fluidized bed is formed. Fluidize. Then, at a next certain time, the liquid is supplied to the nozzles of the second group by the switching means and jetted, thereby fluidizing the fluidized bed, and when this is finished, the liquid is again supplied and jetted to the nozzles of the first group.

(Example) In each illustrated example, 1 is a treatment tank, 2 is a fluidized bed, and 3a
... is a nozzle of the first group, 3b is a nozzle of the second group, 4 is a switching means exemplified as a switching valve for switching and supplying the liquid to the nozzles of both groups, and the switching means is provided to the nozzles of each group. The liquid to be supplied may be an undiluted liquid of waste water or a part of the circulating liquid in the treatment tank.

In the first embodiment shown in FIGS. 1 and 2, an insole-shaped support plate 5 is provided at the bottom of the processing tank 1, and the first and second groups of nozzles 3a ... and 3b ... are arranged in a dispersed manner as a whole. , That is, the first group of nozzles 3a
Are uniformly dispersed and arranged, and the nozzles 3b of the second group are uniformly dispersed and arranged at intervals adjacent to the nozzles of the first nozzle group.

And a header in which piping is connected to the nozzles 3a of the first group.
6a and a header 6b in which piping is connected to the second group nozzle 3b.
Is connected to the switching valve 4, and during operation, the switching valve is operated to supply the stock solution of the waste water or a part of the circulating liquid in the tank to the nozzles 3a of the first group to jet it out, and when the fluidized bed is flowed, The liquid is supplied to the second group of nozzles 3b ... And jetted out to flow in the fluidized bed.

As a result, when the fluidized bed is fluidized by the nozzles of one group, the carrier particles tend to be deposited on the support plate in the interval adjacent to the one nozzle, but next, the carrier particles are switched to the other group. The carrier particles deposited during fluidization of the fluidized bed with the nozzles are easily fluidized, thus supplying wastewater to the group of nozzles alternately or in sequence, and the mutual accumulation of the carrier particles resulting from the growth of microorganisms The sticking phenomenon can be reliably prevented.

The time for supplying the wastewater to the nozzle groups alternately or sequentially is preferably about 1 minute or more and 60 minutes or less.

In the above-mentioned first embodiment, the nozzles of the first group and the second group are individually mounted on the support plate, but the support plate 5 is not provided as in the embodiments of FIGS. 3, 4 and 5. You can also

In the embodiment shown in FIG. 3, two cross-shaped hollow tubes 7a and 7b are arranged at the bottom 1'of the processing tank so as to intersect each other at about 45 ° at the center of the processing tank.
One hollow tube 7a is provided with a first group of nozzles 3a, and the other hollow tube 7b is provided with a second group of nozzles 3b ... so that waste water is switched from the switching valve 4 to each of the tubes 7a and 7b. It is the one.

Further, in the embodiment shown in FIGS. 4 and 5, the bottom portion 1'of the processing tank is formed into parallel valleys having a triangular cross section, and a large number of hollow tubes 8 are laid in parallel in the valleys, and one of them is placed. Nozzles 3a of the first group are provided on the pipes 8a of the above, and nozzles 3b of the second group are provided on the remaining every other pipes 8b, the pipes 8a are the headers 6a, and the pipes 8a are the headers 6b. It is connected to the switching valve 4. in this case,
Each of the nozzles 3a ..., 3b may be mounted so as to eject the liquid toward the bottom of the groove. This is because it is possible to expand the area where the waste water ejected from the nozzle of each pipe fluidizes the fluidized bed.

The operation of the embodiment shown in FIGS. 3 and 4 and 5 is the same as that of the first embodiment.

(Effect) As described above, according to the present invention, the nozzles that are dispersedly arranged at the bottom of the treatment tank and that eject the wastewater to fluidize the fluidized bed are knitted into a plurality of groups, and the nozzles of each group are alternately arranged. Alternatively, since the wastewater is spouted in order, the fluidized bed can be almost uniformly fluidized, and it is possible to prevent the deposited carrier particles from being fixed by the microorganisms to form a dead space.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a first embodiment of the present invention, FIG. 2 is a plan view of the same as above, FIG. 3 is a plan view of a second embodiment, and FIG. 4 is a plan view of another embodiment. FIG. 5 is an enlarged vertical side view of the main part of the above, wherein 1 is a processing tank, 2 is a fluidized bed, 3a is a first group nozzle, 3b is a second group nozzle, and 4 is a switching means. .

Claims (2)

[Claims] 1. A waste fluid is supplied from below to a fluidized bed provided in a treatment tank to form an upward flow in the vessel, and the upward flow fluidizes carrier particles constituting the fluidized bed, whereby carrier particles In a fluidized-bed biological treatment device for treating wastewater with microorganisms carried, a plurality of nozzles for ejecting a liquid are dispersedly arranged at the bottom of a treatment tank, and the plurality of nozzles are knitted into a plurality of groups, A fluidized-bed biological treatment apparatus for wastewater, characterized in that switching means for sequentially supplying liquid to each group is provided. 2. The apparatus according to claim 1, wherein the waste water is a stock solution or a circulating fluid in the tank, and is a fluidized bed biological treatment apparatus.