JPS6182894A - Apparatus for fluidized bed type biological treatment of waste water - Google Patents

Abstract

PURPOSE:To prevent settled carrier particles to be bonded firmly by microorganisms by arranging plural numbers of nozzle for ejecting liquid to the bottom of a treating tank, composing said plural nozzles into plural groups, and providing a changeover means for feeding the liquid successively to each group. CONSTITUTION:Upward flow is formed in a tank by feeding waste water to a fluidized bed 2 provided in a treating tank 1 from below, and carrier particles constituting the fluidized bed 2 are fluidized by the upward flow and the waste water is treated by microorganisms supported by the carrier particles. In this apparatus, plural numbers of nozzle 3a, 3b for ejecting liquid are arranged to the bottom of the treating tank 1, and the plural nozzles are composed into plural groups, and the liquid is fed successively by a changeover means 4 to each group. By this constitution, the fluidized bed is fluidized almost uniformly, and formation of dead space due to firm fonding of carrier particles by microorganisms is prevented.

Description

Detailed Description of the Invention (Industrial Application Field) This invention supplies wastewater from below to a fluidized bed provided in a treatment tank to form an upward flow in the tank, and this upward flow forms a fluidized bed. The present invention relates to a fluidized bed biological treatment device that fluidizes carrier particles and treats wastewater anaerobically or aerobically with microorganisms supported by the carrier particles.

(Prior art) In conventional equipment, in order to supply liquid as uniformly as possible to the bottom of the fluidized bed to ensure good fluidization of carrier particles, gravel of different particle sizes is placed under the fluidized bed, like a support layer in sand filtration. The particle size distribution of gravel in the support bed was larger at the bottom and gradually smaller towards the top.

(Problems to be solved by the invention) As described above, it is not possible to uniformly supply the liquid to the lower part of the fluidized bed.
However, if the operation continues for a certain period of time, the gaps between the gravels that make up the support bed will be clogged by the same type of microorganisms that have grown on the carrier particles, and the support bed will become clogged.
Not only is the flow of the carrier particles impaired, but the increased pressure also makes it impossible to continue operation.

For this reason, some attempts have been made to provide a mid-bottom support plate at the bottom of the treatment tank, form a fluidized bed on top of it, install nozzles in a distributed manner on the support plate, and supply liquid to the bottom of the fluidized bed through the nozzles. However, in this case, the space between adjacent nozzles on the support plate becomes a dead space, where carrier particles are deposited, and the deposited carrier particles stick to each other due to the microorganisms they carry, gradually filling the dead space. There is a problem with expanding.

(Means for solving the problem) Therefore, the present invention arranges a plurality of nozzles that eject liquid at the bottom of a processing tank, organizes the plurality of nozzles into a plurality of groups,
It is characterized by providing means for sequentially supplying liquid to each group.

(Function) If the plurality of groups are, for example, the 11th, 2nd, and 2nd groups, during operation, liquid is supplied to the nozzles of the 1st group by the switching means and ejected, and this causes the fluidized bed to flow. become Then, at the next time, the switching means supplies the liquid to the nozzles of the second group and makes it eject, thereby fluidizing the fluidized bed, and when this is finished, the liquid is again supplied to the nozzles of the first group and makes it eject.

(Example) In each illustrated example, 1 is a treatment tank, 2 is a fluidized bed,
3α... indicates the nozzles of the first group, 3b... indicates the nozzles of the second group, μ indicates a switching means exemplified as a switching pulp for switching and supplying liquid to the nozzles of both groups, and the switching means is The liquid supplied to each group of nozzles may be an undiluted solution of wastewater, or may be a part of the circulating liquid in the treatment tank.

In the first embodiment shown in Figs. 1 and 2, a mid-bottom support plate j is provided at the bottom of the processing tank l, and the nozzles 3α and 3b of the first and second groups are dispersed as a whole. In other words, the first
The detailed nozzles 3α are uniformly distributed and arranged, and the nozzles 3btl of the second group are uniformly distributed and arranged at adjacent intervals of the nozzles of the first nozzle group.

Then, the header 6α with piping connected to the first group of nozzles 3α... and the header 6b with piping connected to the second group of nozzles 3b... are connected to the switching pulp valve, and the switching pulp is switched off during operation. After operating the first group of nozzles 3α... to supply the undiluted waste water or a part of the circulating liquid in the tank and ejecting it to flow the fluidized bed, the second group of nozzles 3b... The liquid is supplied and ejected to flow the fluidized bed.

This ensures that when one group of nozzles is fluidizing the fluidized bed, the carrier particles tend to deposit on the support plates at adjacent intervals of said one group, but then switch to the other group of nozzles. During fluidization of the fluidized bed in the nozzles, the deposited carrier particles are easily fluidized, thus feeding the groups of nozzles alternately or sequentially with wastewater, and preventing the deposited carrier particles from interacting with each other due to microbial growth. Sticking phenomenon can be reliably prevented.

It is preferable that the time period for supplying wastewater to the groups of nozzles alternately or sequentially is about 1 minute or more and 60 minutes or less.

In the first embodiment described above, the first group and the 2n nozzle were individually mounted on the support plate, but it can be carried out without providing the support plate 5 as in the embodiments shown in Figs. 3 and 4-5. You can also do it.

In the embodiment shown in FIG. 3, two cross-shaped hollow tubes 7α and 7b are arranged at the bottom l' of the treatment tank, crossing each other at an angle of about 45 degrees at the center of the treatment tank, and one hollow tube 7α has a first A group of nozzles 3α... are provided, and a second group of nozzles 3b... are provided in the other hollow pipe 76 to switch and supply wastewater from the switching pulp ψ to the container pipes 7α and 7b-. It is. .

In addition, in the embodiment shown in Figs. 4 and 5, the bottom l' of the processing tank is formed into a parallel valley with a triangular cross section, and a large number of hollow tubes l are laid in parallel within this valley. The first group of nozzles 3α... are installed in the pipes tα..., and every other tube rb...
A second group of nozzles 3b... is provided in..., and a pipe tα...
is a header 6α, and pipes rb... are connected to the switching pulp 44 through a header 6b. In this case, each nozzle 3a, . . . , 3b may be installed so as to eject liquid toward the bottom of the groove. This is because it is possible to expand the area where the wastewater spouted from the nozzle of the container fluidizes the fluidized bed.

The embodiments shown in FIGS. 3, 4 and 5 are operated in the same manner as the first embodiment.

(Effects) As described above, according to the present invention, the nozzles that eject wastewater at the bottom of the treatment tank to fluidize the fluidized bed are organized into vII groups,
The wastewater is jetted out alternately or sequentially from each group of nozzles, creating a fluidized bed! In addition to uniform fluidization, it is possible to prevent the deposited carrier particles from becoming stuck with microorganisms and creating dead spaces.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal 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 longitudinal sectional side view of the main parts of the same as above, in which / indicates a processing tank, 2 indicates a fluidized bed, 3α indicates a first group of nozzles, 3b indicates a second group of nozzles, and Hiroshi indicates a switching means. . Procedural amendment minister Gengen October 26, 1982

Claims (3)

[Claims] (1) Wastewater is supplied from below to the fluidized bed installed in the treatment tank to form an upward flow in the tank, and this upward flow fluidizes the carrier particles that make up the fluidized bed. In a fluidized bed biological treatment device for wastewater that treats wastewater with supported microorganisms, multiple nozzles that eject liquid are placed at the bottom of the treatment tank, the multiple nozzles are organized into multiple groups, and each group is A fluidized bed biological treatment device for wastewater, characterized in that it is provided with switching means for sequentially supplying liquid. (2) A fluidized bed biological treatment device for wastewater in the device according to claim (1), wherein the wastewater is an undiluted solution or a circulating fluid in the tank. (3) In the device according to claim (1) or (2), all of the plurality of groups of nozzles are evenly distributed and arranged at the bottom of the treatment tank, a fluidized bed biological treatment device for wastewater. .