JP2000061483A - Intense sewage treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an intense treatment of a large amount of treated sewage subjected to treatment in a sewage treatment facility or the like, at a low cost. SOLUTION: The treatment using this equipment comprises: burying a water conduit 20 having a central conduit channel 21a and inclined conduit channels 21b, in treatment soil; covering the upper face of conduit 20 with a water- permeable sheet 24; placing a diffuser pipe(s) 23 on the underside of the water- permeable sheet 24; and supplying treated sewage subjected to treatment in a sewage treatment facility or the like, to the central conduit channel 21a, to allow the sewage to overflow the water conduit 20, to fill the treatment soil 11 with the sewage up to a water level L and to perform the advanced sewage treatment.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an advanced treatment device for wastewater,
In particular, it relates to an advanced processing device that uses soil.

[0002]

2. Description of the Related Art Conventionally, wastewater treated in a sewage treatment plant is usually discharged into a river. However,
The water quality of this wastewater is about 10 to 15 ppm in terms of BOD value, and it is said that pollution of river water cannot be prevented at this level. Therefore, it is popular to further treat the wastewater by sand filtration process as a finish before discharging the wastewater from the sewage treatment plant. Has to replace the sand, which puts a heavy burden on maintenance.

Membrane filtration has been attracting attention as an alternative high-performance treatment method, but the life of the filtration membrane is relatively short.
In order to extend the life, various pretreatment devices and control devices are required, and the treatment cost has not been reduced.

[0004]

Although an advanced treatment method using soil has been proposed in place of such a mechanical method, the conventional soil treatment method is suitable for treating a small amount of high-concentration wastewater, but it has a low concentration and a large amount. It is said to be unsuitable for processing.

The soil-type sewage treatment method is a biofilm method having a maximum specific surface area because it uses microorganisms between soils to perform sewage treatment. This means that although it has a high organic matter resolving power, it is easily clogged. Therefore, as long as the conventional soil purification method is used as it is, no matter how good the water quality after treatment is, there is a limit to the treatment capacity, and it is difficult to adopt it in terms of cost efficiency.

[0006] Therefore, an object of the present invention is how to carry out advanced treatment of a large amount of dirt having a relatively low concentration after being treated at a sewage treatment plant or the like using a river site or the like.

[0007]

In order to solve the above problems, in the present invention, a water conduit having a water guiding groove is buried in a treated soil layer, and the upper surface of the water guiding groove is covered with a water permeable sheet. The air diffuser is arranged on the lower surface or the upper surface, and a structure is provided in which means for supplying dirty water to the water guiding groove is provided so as to flood the treated soil layer to a predetermined water level.

It is preferable that the water guiding groove is formed by a central water guiding groove and an inclined water guiding groove having an inclination that rises outward from both sides of the central water guiding groove.

The water level of the submerged water can be detected by the water level of the distribution basin which supplies the wastewater to the water guiding groove.

A coated soil layer may be provided on the upper layer of the treated soil layer, and a filtration layer may be provided on the lower layer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example in which the advanced processing apparatus of the present invention is installed on a riverbed. As shown in the drawing, there is a sewage treatment plant outside the bank 1, and the treated wastewater is introduced into the branch tank 3 from the drain pipe 2 penetrating the bank 1, and the flow control tanks are branched from the branch tank 3 to the branch pipe 4. The water is supplied to the river 5, but if for some reason, for example, the advanced processing device is overloaded or malfunctions, the water is discharged from the branch tank 3 directly to the river by the discharge pipe 6.

The sewage (treatment wastewater) stored in the flow rate adjusting tank 5 is sent to a plurality of distribution vessels 7 in a controlled amount,
Water is supplied from the distribution basin 7 to the advanced processing device 10. Each of the flow rate adjusting tanks 5 is provided with a plurality of distribution vessels 7 and an advanced processing device 10. As shown in FIG. 2, from the flow rate adjusting tank 5 to the distribution container 7, the sewage having a constant water level L described later is supplied by the pump P. That is, a constant water level sensor 8a and a stop water level sensor 8b are arranged in the distribution basin 7. When the constant water level sensor 8a becomes inoperative, the control unit 9 operates the pump P, and when the sensor 8a operates, the pump P is activated. Stop. Therefore, the sewage is always at the water level L from the headrace 20 (described later).
Sewage is supplied so that it overflows.

The level of the sensor 8b is the level of sewage when the operation of the advanced processing device is stopped. Then, the clogging state of the soil layer or the like can be detected by detecting the time when the level of the sensor 8a decreases to the level of the sensor 8b. In FIG. 1, reference numeral 30 is a drainage basin, and reference numeral 31 is a water level sensor arranged in the middle of the water conduit 20.

As shown in FIGS. 3 and 4, the water conduit 2 is
Reference numeral 0 designates a water conduit main body 21 made of concrete or the like, a grating 22 fixed to the upper surface of the water conduit main body 21, an air diffuser 23 arranged in the grating 22 over the entire length in the longitudinal direction thereof, and an upper surface of the grating 22. A water-permeable sheet 24 covering the The main water guiding channel 21 includes a central semi-circular water guiding groove 21a and inclined water guiding grooves 21b, 21b extending upward from both upper ends of the central water guiding groove 21a.
a communicates with the distribution container 7 (see FIG. 2). The air diffuser 23 has a large number of pores 23 on the surface facing the water permeable sheet 24.
a is provided. Two air diffusers 23 are arranged in the figure, but more air diffusers 23 may be arranged. Each air diffuser 23 is connected to a blower B (see FIG. 2).
The water permeable sheet 24 is made of a mesh or net-like flexible sheet so as not to allow a suspended substance (SS) having a particle diameter of a certain size or more to communicate therewith. The water permeable sheet 24 is preferably fixed to the grating 22 only on both sides thereof or fixed at several places at appropriate intervals so that the water permeable sheet 24 is easily vibrated by air blow from the air diffuser 23.
The air diffuser 23 may be arranged on the upper surface of the seat 24.

FIG. 5 shows a cross section of the advanced treatment equipment 10 using the water conduit 20. As shown, the water conduit 20 is embedded in the treated soil layer 11. A coated soil layer 12 is provided on the soil layer 11. This soil layer 12
It shall be suitable for the growth of plants formed from improved soil obtained by mixing humus and pumice in a proper proportion with the local soil. Also,
The treated soil layer 11 is a pumice stone with a volume of about 40 to 60%,
The rest is formed of relatively well-permeable soil such as sand sand, bark compost, and mulch soil. This treated soil layer 1
It is preferable to provide a filter layer 13 composed of river sand and activated carbon powder in the lower layer of No. 1. Then, as shown in the figure, the layer structure is such that the cross section becomes a substantially inverted trapezoid, and the upper side is 180c.
m, the lower side is about 80 cm, and the thicknesses of the layers 11, 12, and 13 are about 80 cm, 25 cm, and 5 cm, respectively.

Now, from the distributor 7 shown in FIG. 2 to the distribution pipe 7a.
The sewage supplied to the central water guiding groove 21a of the water guiding path 20 is guided upward from below along the inclined water guiding groove 21b, passes through the water permeable sheet 24, and infiltrates into the soil layer 11. At this time, the suspended solids (SS) in the dirty water are captured by the water permeable sheet 24 and the clogging of the soil layer 11 is prevented. Floating substances attached to the water permeable sheet 24 are diffused by the blower B into the air diffuser 2
Vibration due to the discharge pressure of the air blown out from the
It is shaken off into a and 21b. The sewage that has penetrated into the soil layer 11 has the same water level L as the water level of the sensor 8a of the distribution basin 7.
Reach This submerged depth is almost equal to the upper surface of the treated soil layer 11. Then, the air supply by the air diffuser 23 enhances the activity of aerobic bacteria and effectively removes BOD. The treated water permeates into the basement of the riverbed from the side surface and the lower surface of the treatment device 10.

When the inflow of dirty water is stopped, the water-permeable sheet 24
The residue (SS) removed by the process is accumulated in the central water guiding groove 21a as the water level decreases. Further, air is blown directly from the air diffusing pipe 23 to blow off the residue remaining on the water permeable sheet 24. The accumulated floating material is treated by the processing device 10
During the rest period, the water is pressure-fed from the distribution pipe 7a to the central water guiding groove 21a, poured into the drainage basin 30, and collectively discarded.

FIG. 6 shows another example of the advanced processing device 10.
As shown in the figure, the water conduit 20 is arranged in the upper treated soil layer 11a, the lower layer thereof is provided with the ventilation layer 14, and the lower layer thereof is provided with the lower treated soil layer 11b. I understand. The coated soil layer 12 and the filtration layer 13 are the same as the layers 12 and 13 in FIG. 5, and the upper treated soil layer 11a may be the same as the layer 11, but it is preferable to mix iron particles. The aeration layer 14 is a layer having a thickness of 10 to 15 cm, which is filled with a porous material such as pumice, and performs natural supply of oxygen, and at the same time, passes the nitrogen gas generated in the lower treated soil layer 11b through the cylinder 15. And release it. The lower treated soil layer 11b needs a soil component in which denitrifying bacteria are likely to work, and it is particularly preferable to mix a carbon component such as sawdust (ogalite). In addition, it is preferable to partition each soil layer (same in the case of FIG. 5) with, for example, a reinforcing net.

[0019]

As described above, according to the present invention, by covering the water conduit for supplying the sewage to the treated soil layer with the water permeable sheet to capture the floating substances, the clogging of the soil can be prevented and at the same time, Air is blown to the permeable sheet by an air diffuser to prevent suspended solids from adhering to the permeable sheet, and to supply air into the soil to promote the growth of aerobic bacteria.
D can be effectively reduced.

Further, since the sewage treatment is performed in a flooded state,
Massive processing is possible at low cost.

[Brief description of drawings]

FIG. 1 is a plan view showing an outline of an advanced processing device according to the present invention.

FIG. 2 is a side view showing the relationship between the flow rate adjusting tank, the distribution basin and the water conduit.

[Fig. 3] Cross-section of the headrace

FIG. 4 is a perspective view of a water conduit.

FIG. 5 is a sectional view showing an example of an advanced processing device.

FIG. 6 is a cross-sectional view showing another example of the advanced processing device.

[Explanation of symbols]

1 bank body 2 drainage pipe 3 branch tanks 4 branch pipes 5 Flow rate adjustment tank 6 Discharge pipe 7 distribution boxes 8a Constant water level sensor 8b sensor 9 control unit 10 Advanced processing equipment 11 Treated soil layer 11a Upper treated soil layer 11b Lower treated soil layer 12 Covered soil layer 13 Filter layer 14 Ventilation layer 15 cylinders 20 Headrace 21 main body 21a Central water conduit 21b inclined water conduit 22 Grating 23 Air diffuser 23a pore 24 Water-permeable sheet 30 drainage basin 31 Water level sensor B blower L water level P pump

Claims (4)

[Claims] 1. In the treated soil layer, a conduit having a conduit is buried in the treated soil layer, the upper surface of the conduit is covered with a water-permeable sheet, and an air diffuser is arranged on the lower surface or the upper surface of the water-permeable sheet. Advanced treatment equipment for sewage provided with means for supplying sewage to the water guiding groove so as to flood the water to a predetermined water level. 2. The advanced sewage treatment apparatus according to claim 1, wherein the water guiding groove comprises a central water guiding groove and an inclined water guiding groove having an inclination that rises outward from both sides of the central water guiding groove. 3. The advanced sewage treatment apparatus according to claim 1, wherein the flooded water level is detected by the water level of a distribution basin that supplies sewage to the water guiding groove. 4. The advanced sewage treatment apparatus according to claim 1, wherein a coated soil layer is provided above the treated soil layer and a filtration layer is provided below the treated soil layer.