JPH0160317B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a wastewater treatment device that treats wastewater containing pollutants such as organic pollutants, and more specifically, the present invention relates to an improvement in a wastewater treatment device that treats wastewater containing pollutants such as organic pollutants, and more specifically, the present invention relates to an improvement in wastewater treatment equipment that treats wastewater containing pollutants such as organic pollutants. The multi-layered treatment section consisting of layers of ceramic granules fixed with living organisms makes the treated water more effective after primary or secondary treatment with activated sludge, etc.
This invention relates to a wastewater treatment device capable of advanced treatment.

Conventionally, the activated sludge method has been mainly adopted as a method for treating polluted wastewater, for example, organic wastewater such as sewage, and the wastewater is purified by the action of its biofilm.

In other words, the activated sludge method uses introduced wastewater and
This process uses the bioassimilation effect of activated sludge to decompose and remove pollutants such as organic substances in an aeration tank that reacts with activated sludge made up of microorganisms. Most of the pollutants can be removed, but in general, there is a considerable amount of residual organic pollutants and water-insoluble suspended solids (hereinafter referred to as SS) in the effluent after this final treatment. It is something that

Therefore, in systems that aim to reuse or circulate treated water after primary or secondary treatment using activated sludge, etc., it is necessary to further improve the water quality by performing advanced treatment of the treated water. There is.

This advanced processing, that is, tertiary processing, is as follows:
Contact aeration equipment is often used for treatment, and this trend has been increasing recently.

The contact aeration device accommodates materials for fixing activated sludge in the tank, and purifies the wastewater by supplying oxygen to the tank and circulating introduced wastewater through aeration by the aeration device. People are starting to do this.

However, in such conventional devices, since the material is simply made of wood, cork, rock, waste such as slag, etc., the effective surface area for the activated sludge is extremely small. Since the BOD load per capacity is also smaller,
This is a disadvantage because the bioassimilation effect of the activated sludge fixed on the material cannot be carried out properly, which deteriorates the wastewater treatment efficiency and leads to the generation of a large amount of unreacted sludge. Ta.

The present invention has been made in order to eliminate the drawbacks of conventional wastewater treatment equipment, and, for example, it is possible to efficiently perform advanced treatment on treated water that has undergone primary or secondary treatment using an activated sludge method, etc. The purpose is to provide a treatment tank, a water supply pipe to the treatment tank, and a coarse grain layer, gravel layer, sand layer, etc. from the bottom side of the tank inside the treatment tank. In addition to forming an overlayer as appropriate, porous ceramic granules are laminated on the upper surface of the overlayer to fix activated sludge, which is made of clay as a main component and is fired with the addition of a pore-forming material. a treatment layer comprising a treatment layer; an air supply device into the treatment tank having one aeration pipe disposed on the treatment layer and the other aeration pipe provided on the lower surface of the sand layer; and a treated water outlet pipe provided with a strainer and installed horizontally at the bottom of the treatment tank.

Hereinafter, the apparatus according to the present invention will be explained based on the attached drawings. In the drawing, C is a treatment tank that performs advanced treatment of the water to be treated, and is made of metal or synthetic resin, and is treated after at least the primary treatment A. It has a size to receive the water to be treated supplied from a storage tank B for storing water, and a supply pipe 1 for supplying the water to be treated is arranged from the upper side of the tank C to the inside. Become.

In addition, in tank C, as shown in the figure, from the lower layer side,
For example, a coarse-grained layer S3 of gravel or bed silica of about 3 cm square, a gravel layer S2 of fine grains of about 4 mm square, and a sand layer S1 of about 1 mm square are formed to form an overlayer S. , on the upper surface of the superlayer S are ceramic particles 2 with a particle size of about 2 to 3 cm square.
are laminated to form the processing layer T.

The ceramic granules 2 have a porous structure made by mainly containing clay, adding a pore-forming material such as sawdust, rice hulls, urethane powder, etc. and firing it, and which is not in contact with wastewater or the like. It has a hardness that does not easily deform or turn into powder even when the treatment tank C is filled with 1 m ³ of activated sludge, and the surface area required for fixing the activated sludge is as vast as 600,000 m ² when the treatment tank C is filled with 1 m 3 of layers. Moreover, the ceramic granules 2 have a shape suitable for culturing and colonizing a series of bacterial cells constituting activated sludge, that is, aerobic bacteria, intermediate bacteria, and anaerobic bacteria.

Note that the raw material for the ceramic granules 2 is composed of a mixture of clay and silica stone, and a pore-forming material is added thereto and fired to form porous ceramic granules 2. It can also be used by being laminated on layer S.

On the other hand, air is supplied into the tank C using an external blower (not shown), an air blower 3 connected to the blower, and an air diffuser 4 connected to the air pipe 3a.
a, 4b.

That is, the illustrated air supply device 3 has a valve 3c.
Upper air diffuser pipe 4a that enables pressure adjustment by
is arranged on the upper surface of the treatment layer T, and the lower aeration pipe 4b, which can be supplied with air by opening the valve 3b, is positioned on the lower surface of the sand layer S1, specifically, on the lower surface of the fine-grained gravel layer S2. It will be arranged. And tank C
A treated water outlet pipe 5 has a strainer 5a disposed at the inner bottom so that its upper surface is in contact with the gravel layer S2.
is installed horizontally.

The outlet pipe 5 is extended to the outside of the tank C and is connected to a separate treated water storage tank. A water supply circuit is formed to enable reverse water supply, and a timer, etc. is connected to the circuit, and SS attached to the superlayer S etc. can be removed by periodically supplying reverse water. ing.

In other words, the strainer 5
SS, etc. attached to the superlayer S and the treated layer T are made to float by the backwash water sent through the a side,
In addition, the SS is transferred to the trough 7 provided above the water surface of tank C.
The SS is placed so as to flow and concentrate, and the SS is configured so that it can be returned to, for example, the primary treatment layer A or other wastewater storage tank through the backwash water supply pipe 8.

The installation position of the trough 7 is determined in consideration of the water surface level in the upper part of the tank C so that the SS in the tank C can be discharged to the outside of the tank depending on the amount of backwash water.

Further, 6 in the figure is a manhole, which is opened and used when filling or carrying out gravel, sand, ceramic granules 2, etc. in the tank C.

9 indicates the drain of tank C.

According to the apparatus according to the present invention having the above configuration, the treated water stored in the storage tank B through the primary treatment A such as the activated sludge method is received into the treatment tank C through the feed pipe 1, and First, the treated water is placed in the upper part of the treatment tank T in the tank C, and under this condition, the air forcedly blown from the blower is diffused by the aeration pipe 4a in the tank C through the blower pipe 3a,
The activated sludge, that is, the ceramic granules, is fixed on the ceramic granules 2 forming the upper layer of the treatment layer T. By contacting the aerobic bacteria living on the surface of the object 2, the intermediate bacteria in the middle part, and the anaerobic bacteria in the back surface,
In this one step, it is possible to treat pollutants such as organic substances in the water to be treated, and also to digest the sludge and remove BOD.

The treated water that has passed through the two layers of ceramic granules further passes through the sand layer S1 and the gravel layers S2 and S3.
The overlayer S mainly removes SS and cleaning progresses, but in parallel with this action, the overlayer S also removes SS that has turned into sludge and is generated during the treatment process.

The treated water purified in this way flows into the outlet pipe 5 from the strainer 5a surface of the outlet pipe 5,
The water is transferred to a treated water storage tank located outside tank C, or is directly reused as precision treated water.

In addition, depending on the amount of water to be treated and the number of times of treatment, SS
If SS accumulates in tank C and the treatment layer T becomes clogged, the supply of water to be treated is temporarily stopped, and the backwash mechanism is used to collect SS in tank C into trough 7. The liquid is discharged to the outside of tank C while

At this time, the two layers of ceramic particles, the sand layer S1, and the gravel layers S2 and S3, which are temporarily shaken by the backwash water, are
Since their specific gravities are different, once the supply of backwash water is finished, they are immediately stacked as before, and there is no problem in reusing them.

Examples will now be described.

Example 1 At the bottom of a treatment tank with a height of 3500 mm and a diameter of 1000 mm, an outlet pipe equipped with a strainer was installed to protrude outside the tank, and an overlayer consisting of gravel and sand was provided on the upper surface of the strainer. Ceramic granules of about 20 to 30 mm square and irregularly shaped and each weighing about 0.5 g are stacked to a height of about 1000 mm on top to form a treatment layer, and the upper part of this treatment layer and the sand layer located on the upper surface of the outlet pipe. Diffusion pipes for supplying air are installed on the lower surface to form the main structure of the treatment layer, and the stored water (BOD 250ppm) after the primary treatment of sake brewing wastewater is introduced as the water to be treated, and the above-mentioned aeration operation and ceramic granules, etc. After 2.5 hours of biofilm treatment and sedimentation treatment using sand, gravel, etc., the BOD of the treated water collected at the outlet pipe was improved to 5.0 ppm.

As described above, the wastewater treatment device according to the present invention includes:
For example, a treatment tank that receives treated water that has been subjected to primary treatment or secondary treatment, a treatment water supply pipe to the treatment tank, and a coarse particle layer or gravel that is inserted into the treatment tank from the bottom side of the tank. A porous ceramic material for constructing an overlayer by appropriately forming layers, sand layers, etc., and fixing activated sludge made of clay as a main component and sintered with a pore-forming material added to the upper surface of the overlayer. a treatment layer formed by laminating granular materials; an air supply device into the treatment tank having one aeration pipe disposed on the treatment layer and the other aeration tube provided on the lower surface of the sand layer; Since this wastewater treatment equipment consists of a treated water outlet pipe that is horizontally installed at the bottom of the treatment tank with a strainer arranged so as to be in contact with the gravel layer, it can be used for primary treatment using the conventional activated sludge method, etc. For treated water after secondary treatment, ceramic granules in the tank,
That is, a cleaning treatment using a porous ceramic granule layer having a large surface area and a suitable shape for colonization of a carrier that serves as a growth base for microorganisms to remove organic pollutants; The SS removal action of the sand and gravel layers in the layered state is synergized, and the refinement treatment of the water to be treated progresses efficiently.

Therefore, the water to be treated can be effectively and highly treated in a short time, the operation can be simplified, and the treatment cost can be greatly reduced.

[Brief explanation of drawings]

The drawing is an explanatory diagram of an embodiment of the wastewater treatment apparatus according to the present invention. 1: Feed pipe, 2: Ceramic granules, 3: Air supply device, 4a, 4b: Diffusion pipe, 5: Outlet pipe, 5
a: strainer, 6: manhole, 7: trough,
8: Backwash water supply pipe, 9: Drain, A: Temporary treatment tank, B: Storage tank, C: Treatment tank, S: Superlayer, T:
processing layer.

Claims (1)

[Scope of Claims] 1. A treatment tank, a water supply pipe to the treatment tank, and a coarse grain layer, a gravel layer, a sand layer, etc. formed in the treatment tank from the bottom side of the tank as appropriate. A treatment layer consisting of porous ceramic granules for fixing activated sludge, which is made of clay as a main component, added with a pore-forming material, and fired, on the upper surface of the overlayer. and an air supply device into the treatment tank, in which one aeration pipe is arranged on the treatment layer and the other aeration pipe is provided on the lower surface of the sand layer, and a strainer is arranged so that the upper surface is in contact with the gravel layer. and a treated water outlet pipe installed horizontally at the bottom of the treatment tank.