KR20060118333A - Treating facility for small river water - Google Patents

Abstract

A facility for effectively treating small river water which does not disturb habitation conditions of living things, does not require a large plot of ground with few operating portions and simple structure, and which is durable against severe natural environment and is installed and maintained at low costs without much spoiling of an appearance of a natural river is provided. A facility for treating water of a small river comprises a pit type vessel(10) installed on a flow path of the river, and an aeration means(20) mounted on the vessel to swirl the river water while aerating river water that flows into the vessel. The pit type vessel has a width wider than half of an effective flow width of the river water, a depth of more than 2 meters from a river bed(1), and a length corresponding to not less than 10 minutes of retention time. The pit type vessel has a length corresponding to not less than 30 minutes of retention time. The aeration means comprises aerators(22) disposed near the bottom of the pit type vessel, pipes connected to the aerators, and a pressurized air supply source(21) for supplying pressurized air to the aerators by the pipes.

Description

Treating facility for small river water

1 is a side cross-sectional view schematically illustrating one embodiment of the present invention;

2 is a side cross-sectional view schematically illustrating another embodiment of the present invention.

3 is a side cross-sectional view schematically illustrating yet another embodiment of the present invention.

4 is a side cross-sectional view schematically illustrating yet another embodiment of the present invention.

Fig. 5 is a side sectional view schematically illustrating yet another embodiment of the present invention.

* Explanation of Main Drawing Codes

One; Inclined plane 2 of the lower bed; Sleep

10; Feet type jaw 20; Aeration means 21; Blower 22; Aerator

The present invention relates to a river, in particular an urban river purification device.

At the stage of population concentration and urbanization, urban streams can be reduced to urban pollutant outlets by their increased pollution, making them unable to serve as drinking water sources or for other purposes. By the maintenance of sewage pipes, sewage is classified as a collecting pipe, and separated from the river water, it is transferred to a sewage end treatment plant for treatment and discharge. Therefore, the river water does not seem to be exposed to large-scale contaminants, but the inflow of sewage due to contaminants into the sewer pipe, the inflow of domestic sewage, the inflow of contaminated surface water, the dumping of contaminants and the concrete of the surface, Due to dry weathering, urban streams are degraded to such an extent that they lose their self-cleaning function. The deterioration of urban rivers is due to the limitations of the self-cleaning action due to the decrease of the flow rate, the reduction of waterside area by the maintenance of the river, the reduction of the flow path and the increase of pollution. Since urban rivers are in contact with tens of thousands or hundreds of thousands of people, efforts are being made to significantly improve the quality of water in order to satisfy citizens' needs for a pleasant environment and to utilize water resources effectively.

Stream water quality can be determined based on biochemical methods such as DO, BOD, COD, etc., or water quality can be determined through the living organisms (surface organisms). As BOD and COD increase in river water, oxygen consumption increases rapidly and therefore dissolved oxygen (DO) decreases rapidly, thus losing the river's self-cleaning capacity. Rivers that have lost their self-cleaning ability not only smell, they also limit their habitat. Urban rivers lose their self-cleaning capacity and can reach tens of ppm of BOD and COD above grades 4 and 5 and even grades. These streams do not recover their quality unless they are treated specially along with the prevention of contamination.

There are several points to consider in improving the water quality of rivers, especially urban rivers.

First, it should be compatible with the biological ecological environment for the purpose of water quality improvement. Inhabitants of rivers are not to be the result of the evangelism of purposes and means of great disturbance to the conditions of habitat, such as the habitat of fish, flocks and descents.

Second, urban rivers have extremely limited idle spaces for water purification facilities due to river maintenance, such as river banking, for the purpose of utilizing space by dense facilities.

Third, there should be a structure with durability that can be conserved and easily restored even under flood conditions such as a sudden increase in yield due to rainfall.

Fourth, it is difficult to have high installation and maintenance costs because there is little economic effect that the water quality improvement of the river can be directly calculated.

Fifth, the flow path of rivers should be minimized and the facilities should be effective without significantly harming the appearance of natural rivers.

The conventional stream water quality improvement method is a mainstream method of applying a conventional sewage treatment method. Japanese Patent Laid-Open No. 7000983A2 discloses a method of treating contaminated river water in a manner similar to a general sewage treatment process by arranging various tanks by a water treatment method of rivers. This treatment method requires the construction of a separate large-scale water treatment plant, which is expensive in facility costs and operation costs, and has problems in large-scale treatment plants. Japanese Patent Application Laid-Open No. 61230787A2 discloses a method for treating river water by forming ceramic structures for converting the water flow of the river and trapping the ceramic particles trapped in the structure. In addition, Japanese Patent Laid-Open No. 7016586A2 discloses a method for purifying river water and the like by porous particulate matter. These technologies are very likely to lose equipment or equipment when the quantity suddenly increases, and there is no fundamental countermeasure. The most commonly used methods are techniques such as gravel contact oxidation, which use aeration or non-aeration fixed-phase contact media. However, this method has a large flow resistance and requires a large baffle or a long installation tank for sufficient contact. During heavy rains, air gaps between the gravel may be blocked by soil and the aeration may not be smooth due to the resistance of the medium. Sewage treatment methods, including methods using other contact media, have virtually no applicable means beyond the application of sample stream water in a laboratory. In addition, fish cannot pass through treatment facilities containing such stationary contact media. This is because the contact oxidation method requires a seamless contact between the treated water and the contact medium.

Another method of improving the water quality of the conventional stream is to improve the water quality by using the self-cleaning function by keeping the stream as close to the natural state as possible. For example, by adjusting the height of the river bed to form a stream or a small waterfall to increase the amount of dissolved oxygen to increase the self-cleaning action of the river. The increase of dissolved oxygen in river water can be promoted by the formation of vortices such as waterfalls. However, since the river bed gradient is already defined, if a stream or waterfall is formed in one section, the area around which the flow rate decreases and the yield increases. It is not so effective because it occurs in a stream or waterfall section that is long enough to increase contact with air by vortex formation for a few minutes. In addition, although it is close to the natural state, it is likely to be easily swept and damaged by sedimentation or loss by heavy rain. Alternatively, the composition of aquatic plants or waterside plants can increase the dissolved oxygen in rivers and increase the self-cleaning effect by using the respiration of plants. However, this method also does not have a large site for sufficient effect that can be applied to river maintenance, and there is a high risk of loss due to heavy rain.

Another technique is the water collecting method. A screen pipe is placed in the basement of the bottom of the river to collect the groundwater in the sump and discharge into the stream with a pump. In addition to using river groundwater, the soil layer is used as a filter bed. It is obvious that the ground layer, which is cut off from the air supply and light, cannot continuously act as a filter bed.

The object of the present invention is not to interfere with the habitat conditions of living organisms such as fish, small wounds and descents, and does not require a lot of separate sites. This is to provide an effective river water purification device without significantly harming the appearance of natural rivers.

Another object of the present invention is to provide a stream water purification apparatus that can improve the river water quality of the low water supply to the water quality of higher tertiary water or more.

The present invention provides a stream water purification apparatus comprising a pit-type tank installed on a flow path of a river and aeration means mounted in the tank for swirling and swirling the stream water introduced into the tank.

The present invention preferably aeration of the pit-shaped tank and the stream water introduced into the tank having a width of 1/2 or more of the effective flow width of the river, a depth of 2 m or more at the bottom, and a length of 10 minutes or more in average residence time. Provided is a stream water purification device comprising aeration means mounted to the tank while swirling.

The aeration means preferably consists of an aerator arranged near the bottom of the pit type tub, a pipe connected to the aerator and a pressurized air supply source for supplying pressurized air to the aerator by the pipe.

The stream water purification apparatus of the present invention is preferably applied to urban rivers, but can also be applied to general rivers that have lost their self-cleaning ability. Most preferably, the pit-shaped bath of the present invention has a width of 2/3 or more of the effective flow of the river flow, a depth of 3 to 5 m on the riverbed, and a length of 30 minutes or more. Typical urban rivers are, for example, about 10 cm deep, several meters per minute flow rate, and about 10 meters wide. Assuming that the average depth of the river is 20 cm, the flow rate is 5 m per minute, and the river width is 30 m, the size of the pit-shaped tank is 30 m * 15 m * 4 m when the average residence time is 1 hour and the depth of the tank is 4 m.

The pit-shaped jaw generally consists of a front wall, a rear wall, sides and a bottom. The inflow and outflow of the river water of the pit-type furnace is made by the flow of the river without using a pumping means. When the pit-shaped jaw is fitted with heights of the front wall and the rear wall similarly to the slope of the lower bed, the inlet and the outlet part may form a small waterfall by the slope of the lower bed or may be similar to the height of the lower bed. The pit-type tank is preferably installed in a gentle slope of the lower bed so that the step between the existing lower bed, the front wall and the rear wall is small, and the flow of the inlet and the outlet is smoothed so that small and small drops of aquatic organisms are allowed.

The aeration in the pit-like tank arranges the aeration so that the inflow water forms a vortex in the vertical direction so that the inflow does not flow out immediately. Preferably, a plurality of vortices in the vertical direction are formed at the bottom of the pit-like tub in a plurality of rows in the flow direction of the stream. The aeration means is made by supplying an air source such as a blower or a compressor directly or in a tank and supplying it to an aerator installed near the bottom of the pit tank through a pipe. The aerator may be in the form of an air jet or diffuser, such as a porous plate or disc type. It is not specifically limited in form. It may be simply a hole formed in the pipe installed in the pit-like tub or in the case of a screen pipe formed by rolling the wire.

Adjacent or rear wall slopes of the rear wall of the pit bath may be intermittently operated with an ejector, air jet or water jet to disperse the deposited particles into the vortex area. The pump is not basically used for the inflow or outflow of the stream water of the pit-type tank, but pipes connected to the pump may be installed to drain water during maintenance.

In the present invention, the pit-shaped jaw is not particularly limited, but in particular, the wall including the front wall and the sub-wall is preferably made of a concrete jaw in terms of construction or durability. The floor is also generally made of impermeable concrete, but may have a permeable bottom structure to allow inflow of river groundwater. In order to prevent the inflow of a large weight material such as rocks or stones, the screen may be installed on the upper part of the front wall of the pit-shaped tub, but the screen is not particularly recommended. The pit-shaped jaw may cause the rear wall to be inclined at 60 ° or less, preferably 15 ° to 45 ° from the vertical. Since the aeration tank is not placed near the rear wall of the pit-type tank, the aeration intensity is dropped or the vortex is relaxed on the rear wall slope by tilting the rear wall so that the particles suspended by the vortex settle and enter the vortex section along the wall. Thus, suspended particles (mainly sand) in the pit tank can be maintained at a certain level. The bottom near the rear wall of the pit-like jaw may have a sump that can collect particles. The sump may be provided with a pump pipe to intermittently infiltrate sediment particles by a pump or an ejector and send them to the vortex area, or may be separated by a pump. Alternatively, a separate hopper-type pit for sedimentation of particles may be installed downstream of the pit-type bath and the sedimented particles may be returned to the pit-type bath or periodically dredged through a connecting pipe using a pump. The pump is preferably moved along the guide of the leg built on top of the rear wall of the pit bath and inhaled to separate particles deposited on the sump. The recovered particles may be temporarily deposited at the edge of the stream to be treated separately or returned to the first half of the pit bath for use as a fluid medium.

The pit bath of the present invention can also be charged with a fluidized contact medium. The fluidized contact medium is preferably a particulate contact medium which can float in the vortex region and settles in the vortex relaxation region. Porous natural or artificial ceramic particles or mineral particles, for example, roasted ceramic balls or zeolite particles can be used. The fluidized bed contact medium used in the present invention preferably has a high specific gravity that is not lost. In the present invention, heavier particles such as sand can also be used. These heavier particles can be recovered by sedimentation in the vortex mitigation zone, so they only need to be supplied with losses.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a side cross-sectional view schematically illustrating an embodiment of the present invention, wherein the pit-like jaw 10 is introduced by the slope of the lower bed when the height of the front wall and the rear wall is adjusted similarly to the gradient of the lower bed 1. The bulge forms a small waterfall and the outflow can be similar to the height of the bed. The aeration in the pit-like tank arranges the aerator 22 so that the inflow river water forms a vortex in the vertical direction so that the inflow water does not flow out immediately. Preferably, a plurality of vortices in the vertical direction are formed at the bottom of the pit-like tub in a plurality of rows in the width direction of the stream. The aeration means 20 is made by supplying an air source 21, such as a blower or a compressor, directly or in a tank and supplying it to the aerator 22 installed near the bottom of the pit tank through a pipe. The aerator may be in the form of an air jet or diffuser, such as a porous plate or disc type.

Fig. 2 is a side sectional view schematically illustrating another embodiment of the present invention, in which the pit jaw 10 is inclined from the vertical to the flow path in the wall of the rear wall. Since the aeration tank is not placed near the rear wall of the pit-type tank, the aeration intensity falls and the vortices are alleviated to cause particles suspended by the vortex to settle and enter the vortices along the wall to form suspended particles (mainly sand) in the pit-type tank. Can be maintained at a certain level. 3 shows a pit bath 10 with means for dispersing the deposited particles. The latter part of the pit bath may be intermittently operated by mounting an ejector, an air jet 25 or a water jet downward or forward to disperse the deposited particles into the vortex area.

4 and 5 show the structure in which the pit jaw 10 is provided with a sump 15 on the floor near the rear wall. In Fig. 4, the ejector 27 is provided on the sump 15, and the collected particles are sent out to the first half of the pit-type bath. In FIG. 5, the particles collected in the sump 15 are sucked through the suction pipe 31 by the pump 30 moving along the guide rail 42 of the leg 40 formed on the rear wall of the pit-shaped tub, and the filtered water is It flows out through the discharge pipe 32. The recovered particles may be temporarily deposited at the edge of the stream or returned to the first half of the pit bath 10.

The stream water purification device of the present invention has almost no operation mechanism except for the aerator mounted on the pit tank and the piping for supplying the pressurized air, and has little utility or chemical cost except the blower that generates pressurized air. Vortex formation results in no soil deposits at the bottom of the pit and low maintenance costs by only removing rock deposits after regular flooding. In addition, the present invention provides a stream water purification apparatus capable of increasing the efficiency of activated sludge treatment by using particulate medium naturally introduced with the increase of dissolved oxygen.

Claims (17)

A stream water purification device comprising a pit-type tank installed on a flow path of a river and an aeration means mounted on the tank to swirl and swirl the stream water flowing into the tank. The river water purification device according to claim 1, wherein the river water purification device has a width of 1/2 or more of the effective flow width of the river, a depth of 2 m or more in the riverbed, and a length of 10 minutes or more in average residence time. 3. The stream water purification apparatus according to claim 2, wherein the pit-shaped bath has a length of 30 minutes or more on average residence time. 4. The stream water purification according to claim 3, wherein the aeration means comprises an aerator disposed near the bottom of the pit tank, a pipe connected to the aerator and a pressurized air supply source for supplying pressurized air to the aerator by the pipe. Device 5. The stream water purification apparatus according to claim 4, wherein the inflow and outflow of the river water of the pit-type furnace is made by the stream water without using a pumping means. The river water purification system according to claim 5, wherein small streams and descents of aquatic organisms are allowed through the pit-shaped tank. The river water purification apparatus according to claim 6, wherein the front wall and the rear wall of the pit-type tank have a small step between the existing lower bed, and the inlet and the outlet of the pit-type tank have a smooth flow of water or a small waterfall. The river water purification device according to claim 7, wherein the pit-like tank is installed in an area having a gentle slope of the river bed. The river water purification device according to claim 8, wherein the aerators are arranged in a plurality of rows in a flow direction of the stream to form a plurality of vortices. The river water purification device according to claim 9, wherein all or part of the rear wall is inclined from the vertical to the flow path direction. The stream water purification device according to claim 10, wherein the rear wall of the pit-like tank is inclined in a direction of 15 ° to 45 ° from the vertical. 12. The river water purification system according to claim 11, wherein the aeration is not disposed at the bottom of the tank near the rear wall of the pit-type tank so that the aeration intensity is reduced and the vortex is alleviated. The stream water purification apparatus according to claim 12, wherein a sump for collecting sedimented particles is formed at a bottom near the rear wall of the pit-like tank. The apparatus of claim 13, wherein the particles collected in the sump are sucked by a pump, an air jet, or an ejector. 15. The stream water purification system according to claim 14, wherein the pit-like bath is suspended in a vortex region and a particulate contact medium is settled in the vortex relaxation region. The river water purification apparatus according to claim 15, wherein the particles collected in the sump as the introduced particulate contact medium are sucked and supplied by a pump, an air jet, or an ejector. 17. The river water purification apparatus according to any one of claims 4 to 16, wherein the aerator is a disk type, a porous type or simply a hole or a screen formed in an air supply pipe.

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