JP2884492B2 - River water neutralization structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a river water treatment facility, and more particularly to a treatment structure for neutralizing acidified river water.

[0002]

2. Description of the Related Art Acidified river water destroys ecosystems such as river creatures and agricultural crops, cannot be used for drinking water, and causes early deterioration of concrete structures such as dams constructed in rivers. It is a factor in environmental destruction. Causes of river water acidification include the case where rainwater infiltrated into a sulfur mine flows into a river as groundwater and the case where hot spring gushing water or its use water flows in.
It is extremely difficult to directly prevent inflow of acidified water from such sources into rivers. Therefore, at present, a neutralization plant is constructed near a river to neutralize acidified river water.
In the plant, for example, a neutralization material such as lime powder and water and a milk-like liquid substance are generated and neutralized by discharging this into a river, or acidified river water is directly transferred to the plant. After neutralization such as drawing water into the inside and filtering with a neutralizing substance, neutralization such as reflux to the river is performed to improve the acidification of the river water.

[0003] Since sulfur mine and the like, which are the source of acidification of river water, are present in the upstream part of the river, in order to efficiently neutralize all the rivers branching from the upstream part,
It is extremely effective to install a neutralization facility as far upstream as possible. However, according to the above-described neutralization treatment plant, since large-scale construction work is required to build the plant, even if the acidification of river water can be improved, there are many public parks and the like, Environmental destruction around the upstream, a treasure trove of nature, is inevitable. In addition, it is necessary to secure a new distribution route such as a modern road leading to the plant for the management of the plant and the loading and unloading of processing materials, etc. There was an adverse effect of proceeding.

In order to solve this problem, recently, a treatment structure in which a limestone bed composed of a large number of limestones is laid directly on the riverbed has been proposed. According to this treatment structure, the acidified river water permeates the limestone to cause a neutralization reaction, so that the river water can be neutralized, and a plant is not required. It is very effective for environmental protection because only limestone is laid.

[0005]

However, in the conventional treatment structure using a limestone bed, if the particle size of the limestone is small, the contact area with the river water is large and the neutralization reaction is promoted, but the limestone is easily washed away by the river flow. Has the property of
If the particle size is large, it is difficult to flow into the river flow, but the contact area with the river water is small and the efficiency of the neutralization reaction is low. However, the flow velocity, flow rate and even acidity of rivers vary significantly from river to river.
There were problems that the neutralization could not be efficiently performed and that the limestone floor could not be installed properly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a neutralizing structure for river water which uniformly and effectively neutralizes all acidified rivers, does not destroy the surrounding environment of the river, and is extremely effective for environmental conservation. It is in.

[0007]

According to the present invention, there is provided a river water neutralization structure for neutralizing acidified river water by a limestone bed formed of a large number of limestones formed on a river bottom.
The limestone bed, Ri Na by sequentially stacking two or more Limestone particle size of the limestone is different for each layer, and the upper side
The size of the limestone is larger than that of the lower limestone
Neutralization structure of river water, wherein is provided. Departure
In the present description, the two or more limestone layers having different limestone grain sizes for each layer include, for example, a small-grain limestone layer made of small-grain limestone and a large-grain limestone layer made of large-grain limestone. Are laminated to form a limestone floor. Soshi
Te, neutralization processing structure of the present invention, der from the feature by the particle size of the limestone mentioned above, that the larger diameter of the particle size of the early layer of limestone flow velocity was set to smaller diameter particle size of the underlying limestone
You. As a result, the lower layer of small-grain limestone is pressed against the upper layer of large-grained limestone, so that the entire limestone bed is difficult to flow into the river flow, and the lower layer of small-grained limestone has a large contact area with river water. Neutralization is also promoted. Therefore, it is possible to cope with rivers having various properties. In addition, the large-grained limestone disposed above the limestone floor increases the roughness of the riverbed and can reduce the flow velocity of the river, thereby contributing to the reduction of erosion of the revetment and river structures .

Further, according to the present invention, in a neutralization treatment structure for neutralizing acidified river water, a limestone bed composed of a large number of limestones formed on a riverbed is characterized in that through holes are perforated in the limestone. River water neutralization treatment structure is provided. By drilling through holes in the limestone that forms the limestone bed, the contact area between the limestone and the river water is increased, and the neutralization reaction is promoted. Accordingly, even when limestone having a particularly large particle size is used, the neutralization reaction can be efficiently performed. That is, even if limestone having a large particle size is used when the river flow is fast, the reaction efficiency is not impaired, and it is possible to cope with a river having various properties. If a plurality of through-holes are provided in multiple directions, at least one of the through-holes coincides with the flow direction of the river, so that there is also an effect that river water can easily flow through the through-holes.

Here, the acidified river water refers to its pH.
Means approximately 1 to 6 water. According to the present invention, this can be neutralized to approximately 6 to 8. In forming the limestone bed on the riverbed, the riverbed may be excavated as necessary according to the water depth and the nature and shape of the riverbed, and the limestone bed may be buried therein, or the riverbed may have any shape. A limestone bed may be provided directly on the riverbed without any treatment. Also,
Regarding the total length of the limestone bed,
Although it is appropriately determined according to the flow rate and the acidity, it generally ranges from several hundred meters to several kilometers, and does not necessarily need to be formed continuously, and may be formed intermittently.

In the river water neutralization structure according to the present invention, the acidified river water comes into contact with and penetrates the limestone bed thus laid, thereby causing a neutralization reaction between the river water and the limestone. Acidified river water is neutralized. The limestone bed gradually begins to melt due to the neutralization reaction, and if left untreated, the neutralization capacity will decrease, but the melting will cause the limestone bed to shrink and deform, so it is easy to see, and the limestone is appropriately supplemented. By doing so, it is possible to keep the processing capacity constant at all times. In addition, the flow of river water generally has a tendency to increase in velocity from the shore to the center, and the reduced deformation occurs earlier in the center and ages like a mortar. Therefore, the recognition is very easy. The replenishment cycle is generally 5 to 10 years. In addition, the neutralization treatment structure according to the present invention does not require a plant, so that it is not necessary to construct the vicinity of a river, and it is possible to minimize environmental destruction. Therefore, it is extremely effective to install it in the upper river section. In addition, it is economical because it is only necessary to refill limestone once every five to ten years without requiring special facility management.

[0011]

[Examples]
Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a river provided with a river water neutralization structure according to the present invention. The limestone bed 1 is composed of a large-grained limestone layer 4a, a medium-grained limestone layer 4b, and a small-grained limestone layer 4c which are sequentially stacked from the water surface 2 in the direction of the riverbed 2 '. The size of the large-grained limestone 5a is generally a size of a human head, the medium-grained limestone 5b is smaller than a fist size, and the small-grained limestone 5c is smaller than a fist size. Such a limestone floor 1 can be formed extremely easily by excavating the riverbed 2 'to a predetermined depth in advance by an excavator or the like and burying it there.

The oxidized river water is supplied to each of the limestones 5a to 5a.
By contact with 5c, a neutralization reaction occurs to be neutralized. Particularly, even when the flow velocity of the river is high, the limestone is extremely rarely washed away because the large-grained limestone layer 4a is formed above the limestone bed 1. The medium-grain limestone layer 4b and the small-grain limestone layer 4c can also be prevented from being pressed downward by the large-grain limestone layer 4a and flowing out.

Further, the large-grained limestone 5a is provided with a through-hole 6 as shown in FIG. 3, and the river water passes through the through-hole 6 and the contact area is improved. Despite this, the neutralization reaction can be promoted. As shown in FIG. 3A, the perforation of the plurality of through holes 6 in multiple directions has an advantage that the direction of the flowing water can be easily matched. Further, if the through hole 6 is provided, a hook or the like can be hooked on the limestone during transportation, which is convenient for transportation.

On the other hand, due to aging, each limestone begins to melt, and the limestone bed 1 is reduced and deformed as a whole, and becomes a limestone bed 1 'in FIG. That is, large-grain limestone 5
a is medium limestone 5a ', medium limestone 5b is small limestone 5b', and small limestone 5c is fine limestone powder 5.
c 'or disappears. Aging, large-grained limestone 5a
The through-hole 6 gradually increases, and the contact area with the river water can be further increased. Thereafter, the large-grain limestone 6a splits from the through-hole 6 to have a medium-grain size. Such a reduced deformation of the limestone bed 1 ′ is likely to occur early in the central part of the river where the flow velocity is high, and thus the limestone bed 1 ′ is deformed into a mortar shape with a concave central part. . If the limestone bed is found to have deteriorated, the limestone bed 1 of FIG. 1 can be regenerated very easily simply by supplementing it with new large-grain limestone.

Next, another embodiment of the present invention will be described. FIG. 4 is a vertical cross-sectional view of a river water neutralization structure according to the present invention. This embodiment has a structure in which a limestone floor 11 is partitioned by a plurality of weirs 12 extending in a transverse direction of a river. The weir 12 is disposed slightly above the water surface from the bottom of the limestone floor 11. It is not always necessary to provide the weir 12 so as to cross the entire width of the river. If the weir 12 is provided, the flow velocity can be reduced.

By providing the weir 12 in this manner, the river water flows down the limestone floor 11, then joins and overflows at the top of the weir 12, and again flows down to the limestone floor 11 on the downstream side. Accordingly, since the river water uniformly penetrates the entire limestone bed 11, the neutralization reaction can be further promoted. FIG.
As in the example, when the limestone bed is formed from a plurality of limestone layers, the river water penetrates into the lower limestone, and the river water becomes homogeneous, so that the secular change of the limestone bed becomes uniform,
The limestone replenishment cycle can be constant. FIG.
Uses a weir 12 ′ having an opening 14 penetrating in the water flow direction as the weir 12 in FIG. 4. Since the river water can pass through the opening 14, the river water permeates the lower limestone more efficiently, and the neutralization reaction can be promoted and the river water can be homogenized. Although only one opening 14 is provided in FIG. 5, a plurality of openings 14 may be provided or an arbitrary hole may be formed.

[0018]

As described above, according to the river water neutralization treatment structure of the present invention, it is possible to effectively neutralize the acidification of a river having various properties uniformly. it can. Furthermore, since the construction does not require large-scale creation of the surrounding environment of the river, it can contribute to environmental conservation and can be installed in the upstream part of the river, which is a source of river water acidification. Neutralization treatment can be effectively performed over the entire downstream river that branches.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a river provided with a river water neutralization structure according to the present invention.

FIG. 2 is a cross-sectional view of a river showing an aspect of the neutralization structure of FIG. 1 after aging.

FIG. 3 (a) Large-grained limestone 5a with perforations 6 drilled
FIG. (B) It is a figure which shows the mode that FIG. 3 (a) was split.

FIG. 4 is a longitudinal sectional view showing another embodiment of the neutralization treatment structure according to the present invention.

FIG. 5 is a view showing a weir 12 ′ having an opening 14;

[Explanation of symbols]

 1. Limestone floor 2. Water surface 2 '. Riverbed 3. Land 4a. Large grain limestone layer 4b. Medium grain limestone layer 4c. Small grain limestone layer 13. River water

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-237997 (JP, A) JP-A-53-18239 (JP, A) JP-A-1-10784 (JP, A) JP-A-4- 200696 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C02F 1/66 C02F 1/28 C02F 3/06

Claims (3)

(57) [Claims] 1. A river water neutralization structure for neutralizing acidified river water by means of a limestone bed formed of a large number of limestones formed on a riverbed, wherein the limestone bed has a particle size of the limestone for each layer. Is composed of two or more layers of different limestone layers one after another, and the particle size of the upper limestone is lower than that of the lower limestone.
River water neutralization structure characterized by being larger than the particle size . By wherein limestone bed comprising a number of limestone formed in riverbed, in the neutralization process structure to neutralize the acidified river water, river water, characterized in that drilled holes in the limestone Neutralization treatment structure. 3. The system according to claim 1, wherein at least one weir that partitions the limestone bed is arranged in a direction transverse to the river.
Or the river water neutralization structure according to 2.