JPH02126999A - Filamentous bacteria bulking treating apparatus - Google Patents

Abstract

PURPOSE:To easily and efficiently treat filamentous bacteria by providing a bacteria picking part formed by extending a small-diameter wire into a liq. contg. filamentous bacteria and a driving part for relatively moving the bacteria picking part with respect to the liq. CONSTITUTION:The bacteria picking part 120 is formed by extending a small- diameter wire into a liq. contg. filamentous bacteria. The bacteria picking part 120 is relatively moved by the moving part 124 with respect to the liq. Namely, the filamentous bacteria in the liq. are collected by the wire, and the bacteria mass is formed, released, and dropped. Accordingly, the structure is simplified, and bulking is efficiently treated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a filamentous bulking treatment device, and particularly to an improvement in the mechanism for physically flocculating filamentous bacteria.

[Prior Art] Abnormal growth of filamentous bacteria can cause extremely serious problems in various water treatment processes. For example, in filamentous bulking in sewage treatment, activated sludge swells and settles due to abnormal growth of filamentous bacteria. Sometimes it disappears.

In other words, activated sludge with filamentous bulking is not separated by natural sedimentation in the settling tank, and flows out together with the treated water, contaminating public water areas, and furthermore, is returned from the settling tank to the aeration tank. The amount of sludge returned is reduced.
Treatment efficiency decreases, making it difficult or impossible to continue water treatment.

FIG. 14 shows a conventional general sewage treatment process, which is comprised of an aeration tank 10 and a settling tank 12.

Then, the inflowing wastewater is introduced into the aeration tank 10, where it is oxidized by aerobic bacteria, and then the mixed liquid is sent to the settling tank 12.

Sludge settles in the settling tank 12, and its supernatant liquid is discharged to the outside as treated water, and the settled sludge is returned to the aeration tank 10.

However, due to changes in various conditions, filamentous bacteria
When abnormally proliferating in 0 etc., filamentous bacteria that spread like algae have a significantly smaller surface area/volume ratio than flocculated bacteria, which is particulate, and therefore have poor sedimentation properties, resulting in so-called filamentous bulking. I end up doing it.

Conventionally, the prevention of the occurrence of filamentous bulking or the treatment after its occurrence has been carried out to reduce filamentous bacteria, such as frequently pulling out bulking sludge, adding chemicals, replacing activated sludge, and adjusting the amount of air. Various measures were taken to eliminate it.

[Problem to be solved by the invention] However, the conventional measures against filamentous bulking as mentioned above have problems such as being extremely large-scale, requiring difficult maintenance and management, increasing costs, and being inefficient. .

In addition, the abnormal growth of filamentous bacteria itself occurs due to various causes, and it also occurs as a matter of wisdom, and the appropriate selection and application of conventional countermeasures requires a high degree of skill.
Delays in taking countermeasures could lead to fatal consequences.

The present invention has been made in view of the problems of the prior art, and its purpose is to provide a filamentous bulking treatment device that can easily and efficiently treat filamentous bacteria.

[Means for Solving the Problems] In order to achieve the above object, the filamentous bulking treatment device according to the present invention includes a fishing part and a driving part.

The fishing bacteria section is formed by extending a thin wire into a liquid containing filamentous bacteria.

Further, the drive section moves the fishing bacteria section relative to the liquid.

Note that it is preferable that the diameter of the thin wire is 1/10 to 1 times the length of the filamentous bacteria to be caught.

[Operation] Since the filamentous bulking treatment device according to the present invention has the above-described means, the small diameter wire of the fishing bacteria section is moved relative to the liquid containing filamentous bacteria by the drive section.

As a result, filamentous bacteria are gradually captured on the wire,
A filamentous bacterial mass is forcibly formed.

When the bacterial mass grows to a certain extent, it falls down due to its own weight, and the wire begins to form a new bacterial mass.

In addition, because the fallen bacterial masses are forcibly entangled,
Since it does not disintegrate easily and forms large flocs, the sedimentation properties in the sedimentation tank are improved and return to the aeration tank is facilitated.

As described above, according to the present invention, rather than preventing the generation of filamentous bacteria itself, the generated filamentous bacteria are forcibly turned into bacterial clumps.
Regardless of the degree, it is extremely effective in preventing or counteracting filamentous bulking.

By making the diameter of the wire of the fishing part 1/10 to 1 times the length of the filamentous bacteria to be caught, the efficiency of catching filamentous bacteria is greatly improved.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a longitudinal cross-sectional view of the filiform bulking treatment device according to this embodiment, and FIG. 2 shows a cross-sectional view.

Note that the treatment device 100 according to this embodiment is installed between an aeration tank 110 and a settling tank 112, as shown in FIG.

A characteristic feature of the present invention is that it is provided with a fishing rod for entangling filamentous bacteria, and for this reason, in this embodiment, a large number of small diameter wires 12 extended radially in multiple stages are provided.
It is equipped with 0.

Each of the small diameter wires 120 is supported by a rotating shaft 122 extending perpendicularly to the axis thereof.

The rotating shaft 122 is connected to the motor 12 constituting the drive section.
As a result, the rotary shaft 122 and the wire 120 can be rotated in the direction of the arrow (■).

Note that a stirring blade 126 is provided at the lower end of the rotating shaft 122.

The rotating shaft 122 and the wire 120 are disposed in a cylindrical housing 128 whose lower surface has a forest-like shape, and an inflow pipe 130 connected to the upper part of the housing 128 is connected to the aeration tank 110. An outflow pipe 132 connected to the lower part is connected to the sedimentation tank 122.

Therefore, the aeration mixture is introduced from the aeration tank 110, and the housing 128 is filled with the aeration mixture up to the liquid level 134.

Then, in balance with the inflow amount, the settling property improving liquid is sequentially sent out from the outflow vibrator 132 to the settling tank 112, and
Drain is discharged from a drain pipe 133 provided at the bottom of the cylindrical housing 128 as necessary.

Furthermore, an air diffuser hole 136 is provided at the bottom of the housing 128 to prevent the inside of the housing 128 from becoming anaerobic.

The filamentous bulking treatment device according to this embodiment is roughly constructed as described above, and its operation will be explained next.

First, when filamentous bacteria grow abnormally in the aeration tank 110 due to some environmental change, an aeration mixture containing a large amount of filamentous bacteria flows into the filamentous bulking treatment apparatus 100 from the inflow pipe 130.

Here, the wire 120 is rotated in the direction of arrow 1 by the motor 124, and the mixed liquid itself is also stirred by the stirring blade 126 provided at the bottom of the rotating shaft 122, so that the filamentous bacteria are It is effectively captured by wire 120 as shown in FIG.

That is, in the initial state shown in FIG.
20 protrudes almost horizontally, and filamentous bacteria 13
8 is entangled with the wire 120 as shown by the arrow ■.

As the filamentous bacteria 138 are continuously entangled with the wire 120, a bacterial mass 140 is formed as shown in FIG. As bacterial mass 140 gradually grows, its weight increases.

As a result, the bacterial mass 1 entangled with the wire 120
40 separates from the wire 120 as shown by the arrow (■), falls down, and settles inside the housing 128, but a portion is transferred to the settling tank 112 by the outflow vibrator 130.

In the sedimentation tank 112, the bacterial mass 140 settles, and the formation of expanded sludge (bulking phenomenon) does not occur despite the abnormal proliferation of filamentous bacteria.

Note that the bacterial mass 140 settled in the sedimentation tank 112 is transferred to the aeration tank 1.
The bacteria mass 140 is returned to the aeration tank 110.
The system does not collapse, and stable wastewater treatment is carried out continuously.

However, the appropriate selection of the wire 120 has a significant influence on the operation and effect of the filamentous bulking treatment device 100.

Therefore, in order to investigate the relationship between the wire and filamentous bacteria, the present inventors investigated the optimal relationship between the type, thickness, and length of the filamentous bacteria and the thickness and length of the wire through actual tests.

The results are shown in Table I below.

As is clear from Table I, in order to efficiently catch filamentous bacteria with a wire, the diameter of the wire must be 1/10 to 1 times the length of the filamentous bacteria, and the circumference of the wire 120. It is desirable that the length is about half the length of the filamentous bacteria.

That is, for filamentous bacteria having thick and long hyphae, such as fungi and filamentous algae, it is preferable to use a thick and strong material such as wire for the wire.

This is because when a wire made of thin material is applied to a thick and long hyphae, filamentous bacteria can easily get caught on the wire.
This is based on the fact that the bacterial mass falls off the wire before it is sufficiently formed, and is not a sufficient countermeasure against bulking.

On the other hand, for example, M, parvicella, H, hyd
For filamentous bacteria having thin and short hyphae such as S. rossis, it is suitable to use a wire made of a thin and flexible material.

This is because when a wire made of thick material is applied to filamentous bacteria with thin and short hyphae, it is difficult for the filamentous bacteria to get caught on the wire, and if it gets caught, it tends to fall off. This is because a stable situation is created and no peeling occurs.

Therefore, among the filamentous bacteria appearing in the aeration tank 110, the type of bacteria that is the main cause of bulking is present in the wire 120.
By selecting , it is possible to carry out efficient fishing of filamentous bacteria.

In addition, 021N, 5phaerotilus, Beg
The hyphal length of filamentous bacteria such as giatoa is indicated as 11,000 Atm or more in the above article (2), but if these filamentous bacteria are predominant, it may reach 200 OAtm or more, so in that case, the wire should be adjusted as appropriate. This creates a need to choose.

However, if the selection is difficult, various wires may be attached together.

As described above, according to the filamentous bulking treatment device according to the present embodiment, the filamentous bacteria are entangled with the wire and separated as a bacterial mass, so that the bulking phenomenon can be effectively prevented with a simple configuration. It is possible to prevent or eliminate it.

Note that in this embodiment, the wire 120 is connected to the rotating shaft 122.
Although an example has been described in which the main wire 120a extends horizontally in multiple stages and radially, a plurality of auxiliary wires 120a may be provided further downward on the main wire 120a extending horizontally, as shown in FIG. suitable.

Providing the auxiliary wire in this manner further improves the removal efficiency of filamentous bacteria, and is particularly effective in forming bacterial clusters of filamentous bacteria having thin and short hyphae.

Furthermore, as shown in FIG. 8, it is also preferable that the wire 120 is not directed horizontally but extends slightly upward.

As a result, the bacterial mass formed by the wire 120 becomes somewhat difficult to fall off, making it possible to increase the size of the bacterial mass.

On the other hand, by slightly protruding the wire 120 downward as shown in FIG. 9, the bacterial mass captured and formed on the wire 120 will fall more easily, and if a small bacterial mass is formed or a large It is effective when removing filamentous bacteria with long hyphae.

Furthermore, as shown in FIG. 10, the main wire 120a extending diagonally downward is connected to the auxiliary wire 1 further downward.
It is also suitable to provide a plurality of 20b.

As a result, there is an advantage that the removal efficiency of filamentous bacteria is further improved compared to the embodiment shown in FIG.

Further, in the first embodiment, the wire 120 is connected to the rotating shaft 122.
We have explained the example of radially extending
1 (A), a device in which the wire 120 is extended in a cross shape, a device in which the wire 120 is extended in the diametrical direction from the rotating shaft 122 as shown in FIG. ), a device in which the wire 120 is extended only to one side by the rotating shaft 122 is also possible.

In particular, when the viscosity of the treated water is high and an excessive load is applied to the motor 124, it is preferable to reduce the number of wires 120 installed.

In addition, if there are a wide variety of types of filamentous bacteria that have appeared, it is necessary to construct a fishing rod with a variety of wire directions and diameters.

Further, in the first embodiment, the aeration tank 110 and the settling tank 112
Although an example has been described in which the treatment device 100 is installed between the steps, it is preferable to install the filamentous bulking treatment device 100 in a route where sludge is returned to the aeration tank 110 by the settling tank 112, as shown in FIG. 12, for example.

By removing the filamentous bacteria in the returned sludge in this manner, it is possible to prevent abnormal proliferation of filamentous bacteria in the aeration tank 110 and suppress the occurrence of bulking.

Furthermore, as shown in FIG. 13, a plurality of fishing parts and drive parts of the filamentous bulking treatment apparatus 100 are installed in the aeration tanks 1 and 10, for example.
It is also suitable to install it inside the building.

In this case, the installation position of the filamentous bulking treatment device 100 is preferably near the aeration mixed liquid transfer port to the settling tank, and if there is no space to separately install the filamentous bulking treatment device 100, or if there is no space to install the filamentous bulking treatment device 100 separately, It is particularly effective when installed in sewage treatment equipment.

In each of the above embodiments, an example was explained in which the wire 120, which is a fishing part, is driven to rotate with respect to a liquid containing filamentous bacteria. It is possible to obtain exactly the same filamentous bulking effect by swirling and stirring.

[Effects of the Invention] As explained above, according to the filamentous bulking treatment device according to the present invention, filamentous bacteria in the liquid can be captured by the thin wire, form a bacterial mass, and be peeled off and dropped. Therefore, it is possible to take effective measures against bulking with a simple configuration.

[Brief explanation of drawings]

1 is a longitudinal cross-sectional view of a filamentous bulking treatment device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the device shown in FIG. 1, and FIG. 3 is a cross-sectional view of the device shown in FIG.
Figures 4 to 6 are explanatory diagrams of the process of forming filamentous bacterial masses in the filamentous bulking treatment device, and Figures 7 to 10 are filamentous bacterial masses according to the present invention. FIG. 11 is an explanatory diagram of the number of wires protruded in the filamentous bulking treatment device according to the present invention, and FIGS. 12 and 13 are explanatory diagrams of an example of wire protrusion in the filamentous bulking treatment device according to the present invention. FIG. 14 is an explanatory diagram of another installation position of the conventional sewage treatment process. 10.110 12.112 Aeration tank Sedimentation basin Filamentous bulking treatment device wire (fishing bacteria section) Rotating shaft motor (drive section) Filamentous bacteria

Claims (2)

[Claims] (1) A filamentous bacteria characterized by comprising: a fishing bacteria part formed by extending a small diameter wire into a liquid containing filamentous bacteria; and a driving part that moves the fishing bacteria part relative to the liquid. Bulking treatment device. (2) The filamentous bulking treatment device according to claim 1, wherein the small diameter wire of the fishing part has a diameter that is 1/10 to 1 times the length of the filamentous bacteria to be caught. Filiform bulking treatment device.