JPH0455535A - Drainage manhole - Google Patents

Abstract

PURPOSE:To improve drainage efficiency by providing a ventilation space in communication with an air passage under the bottom of the body of a manhole, a catchment section, a permeable cylinder communicating with the ventilation space and air adsorbent layer around the cylinder. CONSTITUTION:At the beginning of rainfall, precipitation of high concentration of agricultural chemicals is absorbed into the soils 20, while the initial surface water having comparatively high concentration of chemicals flows into the body 1 of manhole, in which excessive fertilizer and chemicals are absorbed in an absorbent layer 13 and the purified water is discharged through a permeable cylinder 9 into a drainage system 15. And then the precipitation having lowered concentration of chemicals passes through the layer 13 and flows from the catchment section 10 directly into the cylinder 9 and is discharged into the system 15. Thereafter air is supplied to an active carbon layer 11 through a ventilation space 6 and an air passage 5 to propagate aerobic bacteria. As a result, drainage can be performed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water collection manhole, and more particularly to a water collection manhole suitable for installation in a golf course or the like to collect surface water containing agricultural chemicals and the like.

(Prior art) Conventionally, hollow concrete manholes have been known as this type of water collection manhole, and when installed on a golf course, they are buried, for example, at intervals of about 40 m, and the bottoms are connected to drainage pipes and permeable ground. It was designed to be connected to a drainage system such as other facilities and discharged for wastewater treatment.

(Problem to be solved by the invention) However, with such a water collection manhole, there is a risk that a large amount of pesticides may be contained in the wastewater discharged at the beginning of a rainfall. It was necessary to provide ancillary facilities for this purpose.

(Means for Solving the Problems) It is an object of the present invention to provide a water collection manhole that eliminates the drawbacks of the conventional water collection manholes and is particularly suitable for use in golf courses. A ventilation space communicating with the ventilation path is provided below the bottom of the manhole body, and a water collection part is provided in the center of the manhole body to prevent water collection from the sides at the upper end and allow water to be collected only from the top surface. A water-permeable cylindrical body communicating with the ventilation space is disposed, and an adsorbent layer consisting of a lower activated carbon-based adsorbent layer and an upper clay-based adsorbent layer is disposed around the cylindrical body. do.

Further, a water collection pipe may be communicated above the adsorbent layer.

(Function) At the beginning of rainfall, the precipitation with the highest pesticide concentration is absorbed into the soil and naturally decomposed by soil microorganisms, and the initial surface water that is not absorbed into the soil, that is, the precipitation with a relatively high pesticide concentration, is absorbed into the manhole body. Fertilizers such as ammonia and phosphorus are adsorbed by the upper clay-based adsorbent layer, then pesticides are adsorbed by the lower activated carbon-based adsorbent layer, and excess fertilizer and pesticides are adsorbed and purified by the adsorbent layer. Water is discharged into the drainage system through the permeable cylinder, and subsequent precipitation with a diluted pesticide concentration passes through the surface of the adsorbent layer and flows directly from the water collection section into the permeable cylinder, reducing the pesticide concentration. Discharged into the drainage system in a dilute form.

In addition, some of the pesticides adsorbed by the lower activated carbon adsorbent layer are decomposed by microorganisms in the soil, especially aerobic bacteria.
Furthermore, the activated carbon-based adsorbent layer is sufficiently supplied with air through the ventilation space, and the growth of aerobic bacteria is maintained well.

Further, by connecting a water collection pipe above the adsorbent layer, excess fertilizer and agricultural chemicals contained in groundwater in the soil can be adsorbed by the adsorbent layer, and the soil condition can be maintained in good condition.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

The first diagram shows an example in which the water collection manhole of the present invention is installed at a golf course. In the diagram, 1 is a cylindrical manhole body made of concrete with a bottom, and the manhole body has an opening 3 at the bottom 2a. Concrete outer cylindrical body 2 with
A ring-shaped ventilation path 5 is defined along the outer periphery of the manhole body 1, and a ventilation space 6 is defined below the bottom 1a of the manhole body 1. . Incidentally, a part of the upper end of the ventilation passage 5 is left as a ventilation lower, and the other part is covered with a cover body 8.

In the illustrated embodiment, the ring-shaped ventilation passage 5 is formed along the outer periphery of the manhole body 1. Although the structure of the ventilation passage 5 is not particularly shown, it is formed in the ventilation space 6 formed below the manhole body 1. There is no particular limitation on the structure as long as it communicates, such as a ventilation vibrator.

Further, a through hole 8 provided in the bottom portion 1a of the manhole body 1 communicates with the ventilation space 6 below.
A water-permeable cylindrical body 9 made of water-permeable concrete is erected above and communicated with this, and a water-permeable cylindrical body 9 made of water-permeable concrete is installed at the upper end of the cylindrical body 9 so that water cannot be collected from the sides and can be collected only from the top surface. Water collection part 1
0 was applied. In the illustrated embodiment, the water collection section 10 is made of a cylindrical body 10a made of concrete, and has a grating 10 installed in the upper opening 10b.
c. Inside the manhole body 1, an adsorbent layer 13 is arranged, which consists of a lower activated carbon adsorbent layer 11 made of granular activated carbon, powdered activated carbon, etc., and an upper clay adsorbent layer 12 made of zeolite, etc. It is set up. Further, the upper surface of the adsorbent layer 13 is filled with sand 14 in order to protect the adsorbent layer 13.

In the figure, 20 indicates soil, 21 indicates grass, and 22 indicates surface water.

According to such a water collection manhole, at the beginning of rainfall,
That is, the precipitation with the highest pesticide concentration is absorbed into the soil 20 and naturally decomposed by soil microorganisms, etc., and the initial surface water that is not absorbed into the soil 20, that is, the precipitation with a relatively high pesticide concentration, flows into the manhole body 1 and is dissolved in the upper layer. Clay-based adsorbent layer 12
Fertilizers such as ammonia and phosphorus are adsorbed by the activated carbon adsorbent layer 11, which is the lower layer, and then agricultural chemicals are adsorbed by the activated carbon adsorbent layer 11, and surplus fertilizers and agricultural chemicals are adsorbed by the adsorbent layer 13, and the purified water is transferred to the permeable cylindrical body 9. The subsequent precipitation with a diluted pesticide concentration passes through the surface of the adsorbent layer 13 and flows directly from the water collection section 10 into the water-permeable cylindrical body 9, where it collects pesticides. Drainage system 15 in a low concentration state
is released into the river. Further, the fertilizer adsorbed by the upper clay-based adsorbent layer 12 is consumed by the lawn 21 planted in the soil 20, and some of the pesticides adsorbed by the lower activated carbon-based adsorbent layer 11 are absorbed by microorganisms in the soil 20. It is decomposed by

In addition, the activated carbon adsorbent layer 11 is sufficiently supplied with air through the ventilation space 6 communicating with the air passage 5, so that aerobic bacteria can thrive and the life of the activated carbon adsorbent layer 11 is extended.

The second diagram shows a modification of the above embodiment.
In the figure, reference numeral 16 indicates a concrete water collection pipe provided with a large number of through holes 16a, and the water collection pipe 16 is made to communicate with the upper part of the adsorbent layer 13. Components that are the same as those in the embodiment described above and which are not particularly described are given the same reference numerals as those in the embodiment described above, and the explanation thereof will be omitted.

According to this water collection manhole, surplus fertilizer and pesticides contained in groundwater in the soil 20 are guided into the manhole body 1 through the water collection pipe 16 and adsorbed by the adsorbent layer 13, so that the soil condition is maintained in good condition. .

(Effects) As described above, the water collection manhole of the present invention collects water according to the pesticide concentration, so surface water with a high pesticide concentration remains on the soil surface even during heavy rainfall. In addition, fertilizers adsorbed by the clay-based adsorbent layer are consumed by plants such as grass planted in the soil, and pesticides adsorbed by the activated carbon-based adsorbent layer are absorbed by soil microorganisms. In addition to being decomposed, the activated carbon-based adsorbent layer is sufficiently supplied with air through the ventilation space communicating with the ventilation path, and even in ground-penetrating water collection manholes, aerobic bacterial growth is maintained. The life of the system adsorbent layer is long, and the adsorbent layer does not need to be replaced frequently.

Furthermore, if a water collection pipe is connected above the adsorbent layer, excess fertilizer and agricultural chemicals contained in groundwater in the soil can be adsorbed by the adsorbent layer, and the soil condition can be maintained in good condition. .

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of an installed state of one embodiment of the water collection manhole of the present invention, and FIG. 2 is a vertical cross-sectional view of a modified example thereof. 1... Manhole body 1a... Bottom 5... Ventilation path 6... Ventilation space 9... Water-permeable cylindrical body lO... Water collection part 11... Activated carbon adsorbent layer 12. ...Clay-based adsorbent layer 13...Adsorbent layer
14...Sand 15...Drainage system 16.
... Water collection pipe 20 ... Soil 21 ... Grass 22 ... Surface water

Claims (1)

[Claims] 1. A ventilation space communicating with the ventilation path is provided below the bottom of the manhole body, and water can be collected only from the top surface at the center of the manhole body, making it impossible to collect water from the sides at the upper end. A water-permeable cylindrical body with a water collection part and a lower end communicating with the ventilation space is arranged, and an adsorption system consisting of a lower activated carbon adsorbent layer and an upper clay adsorbent layer is arranged around the cylindrical body. A water collection manhole characterized by a layer of wood. 2. The water collection manhole according to claim 1 or 2, characterized in that a water collection pipe is communicated above the adsorbent layer.