JP2003094056A - Method and apparatus for treating purified water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for reducing an installation area, facilitating operation management, reducing a facility installation cost and an operation cost, and obtaining a high quality clean water. SOLUTION: Raw water is supplied into a treatment tank 1 built in a granulated activated carbon 2 adhering aerobic microbes to the surface thereof, an organic matter in a liquid inside the tank 1 of the raw water supplied into the treatment tank 1 is adsorbed on the surface of the activated carbon 2, and the organic matter is decomposed by the aerobic microbes. A decomposed organic matter and other suspended matter are filtered and separated by a filtration membrane unit 3 dipped into the liquid inside the tank. When the concentration of the suspended matter in the liquid inside the treatment tank 1 increases, the liquid inside the tank is withdrawn from the treatment tank 1. The withdrawing of the liquid inside the tank from the treatment tank 1 is carried out by lifting the liquid surface by increasing a supplied amount of the raw water into the treatment tank 1, and overflowing those from a water withdrawing port 25 formed at a position located higher than the liquid surface inside the tank at a peripheral wall of the treatment tank 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification method and apparatus for obtaining clean water from raw water such as river water, lake water, pond water and groundwater.

[0002]

2. Description of the Related Art The conventional general purification method for water purification is mainly for removing suspended matter and sterilization. As shown in FIG. In this method, a suitable flocculant is added in the settling tank to form a flocculate, which is allowed to settle, then introduced into a sand filter tank filled with sand for filtration, and chlorine is injected again.

However, in such a method, the site area of equipment required per amount of treated water is vast, and in addition, maintenance of delicate operating conditions based on abundant experience is indispensable. That is, in order to maintain a good state of coagulation and sedimentation and filtration in response to fluctuations in the state of raw water, it is necessary to make delicate adjustments to many operating parameters such as chemical injection conditions.

Furthermore, in recent years, the water quality of tap water such as lake water and groundwater has remarkably deteriorated, and problems such as off-flavor and trihalomethane production have occurred. However, conventional general water purification treatment methods deal with these problems. Therefore, more advanced processing technology is required, and various developments have been made in response to this requirement. FIG. 7 shows an example of the currently known advanced water purification treatment method. In FIG. 7, the advanced water purification method is a sand filter tank in which a coagulant is generated by adding an appropriate coagulant to raw water in a coagulating sedimentation tank to precipitate the coagulant, and then ozone is blown into the coagulated sedimentation tank. After filtering and then blowing ozone again, it is allowed to flow into the tank filled with granular activated carbon from above to form a downward flow in the tank to adsorb organic matter etc. to the granular activated carbon and Is to be injected.

However, such a method is very complicated as compared with the conventional general water purification treatment method, and the problems of the above-mentioned general water purification treatment (equipment site area And the need for delicate operation management technology), equipment construction costs and operating costs will rise significantly, and the cost of the resulting water supply will rise significantly. .

An object of the present invention is to solve the above problems, to reduce the site area of the facility, to easily manage the operation, to reduce the facility construction cost and the operating cost, and to obtain a high quality of clean water. And to provide a device.

[0007]

[Means for Solving the Problems and Effects of the Invention] The water purification method according to the present invention is a water purification method for obtaining clean water from raw water such as river water, lake water, pond water, groundwater, etc. Raw water is placed in a treatment tank containing granular activated carbon to which aerobic microorganisms are attached, and the organic matter in the tank liquid, which is the raw water placed in the treatment tank, is adsorbed on the surface of the activated carbon. When the organic matter is decomposed and the decomposed matter of organic matter and other suspensions are filtered by the filtration membrane unit immersed in the tank liquid, and the concentration of the suspension in the tank liquid in the treatment tank becomes high. In addition, the solution in the tank is to be extracted from the processing tank, and the solution in the tank is extracted from the processing tank.
A water outlet is formed at a height above the level of the liquid in the tank on the peripheral wall of the processing tank, and the liquid level is raised by increasing the amount of raw water supplied to the processing tank. Then, it is performed by overflowing from the water outlet.

[0008] The above-mentioned suspension includes, in addition to the hardly decomposable insoluble organic matter, decomposition products of the organic matter separated by filtration by the filtration membrane unit and peeled off from the membrane surface, and other suspensions.

According to the water purification method of the present invention, in one treatment tank, the organic matter in the in-tank liquid, which is the raw water put in the tank, is adsorbed on the surface of the activated carbon, and the organic matter adhering to the surface of the activated carbon is preferably adsorbed. This organic matter is decomposed by aerobic microorganisms, and the decomposed matter of organic matter and other suspensions are simply filtered by a filtration membrane unit immersed in the liquid in the tank. The number will decrease. Therefore, the operation management becomes easy and the operation cost becomes low. In addition, trihalomethane precursors and organic substances that are substances causing off-flavors are decomposed by aerobic microorganisms, and the decomposed products of these organic substances are filtered by a filtration membrane unit immersed in the liquid in the tank. Occurrence can be prevented. Moreover, since other suspended matters are also filtered out by the filtration membrane unit, suspended solids and bacteria are also removed. Therefore, a high degree of clean water is obtained. Further, since the organic matter is decomposed by aerobic microorganisms, a relatively inexpensive microfiltration membrane or ultrafiltration membrane can be used as the membrane used in the filtration membrane unit, and the equipment cost is reduced. Furthermore, when the raw water is river water, the organic matter in the raw water is dilute, which may reduce the decomposition efficiency by the microorganisms or make it impossible for the microorganisms to survive.However, the organic matter is granular with aerobic microorganisms attached to the surface. Since it is adsorbed by activated carbon, organic matter in raw water will be concentrated,
The degradation of the microbial decomposition efficiency is prevented, and the survival of the microorganism is guaranteed.

Further, when the concentration of suspended solids in the tank liquid in the processing tank becomes high, the tank liquid can be withdrawn from the processing tank to prevent an increase in transmembrane pressure during filtration. And the clogging of the membrane due to the suspension is prevented. Further, when the concentration of suspended solids in the bath liquid in the treatment bath becomes high, the withdrawal of the bath liquid from the treatment bath should be performed at a height above the liquid level of the bath liquid on the peripheral wall of the treatment bath. If a water outlet is formed at the position and the liquid level is raised by increasing the amount of raw water supplied to the treatment tank and overflowed from the water outlet, It is possible to prevent activated carbon from being included in the. That is, since the activated carbon has a large specific gravity, the activated carbon does not float to the vicinity of the liquid surface, and as a result, the activated carbon can be prevented from flowing out from the water outlet. Further, since the activated carbon can be prevented from flowing out, it is economical because it is not necessary to newly replenish the activated carbon in order to maintain the treatment ability of the organic matter by the microorganism and the adsorption ability of the activated carbon. If the liquid inside the tank is aerated from below the filtration membrane unit, activated carbon may rise to near the liquid surface.In this case, reduce the amount of aeration when extracting the liquid inside the tank from the treatment tank. Adjust so that activated carbon does not rise near the liquid surface.

Another water purification method according to the present invention is a water purification method for obtaining clean water from raw water such as river water, lake water, pond water, and ground water, in which granular activated carbon having aerobic microorganisms adhered to its surface is used. Raw water is put into the built-in treatment tank, and the organic matter in the tank water, which is the raw water put into the treatment tank, is adsorbed on the activated carbon surface, and this organic matter is decomposed by aerobic microorganisms to decompose the organic matter. Substances and other suspensions are filtered by a filtration membrane unit immersed in the liquid in the tank,
When the concentration of suspended solids in the tank liquid in the processing tank becomes high, the tank liquid is to be withdrawn from the processing tank, and the tank liquid is extracted from the processing tank at the lower end of the peripheral wall of the processing tank. And a water withdrawing pipe connected to the water withdrawing port and extending obliquely outward and having an activated carbon filtering filter.

[0012] The above-mentioned suspension includes, in addition to the hardly decomposable insoluble organic matter, decomposition products of the organic matter separated by filtration by the filtration membrane unit and peeled off from the membrane surface, and other suspensions.

According to another method for purifying water of the present invention, 1
In one treatment tank, the organic matter in the tank liquid, which is the raw water put into the tank, is adsorbed on the activated carbon surface, and the organic matter is decomposed by the aerobic microorganisms adhering to the activated carbon surface. Since the other suspensions are only filtered by the filtration membrane unit immersed in the liquid in the tank, the number of processes is smaller than that of the two conventional water purification treatment methods. Therefore, the operation management becomes easy and the operation cost becomes low. In addition, trihalomethane precursors and organic substances that are substances causing off-flavors are decomposed by aerobic microorganisms, and the decomposed products of these organic substances are filtered by a filtration membrane unit immersed in the liquid in the tank. Occurrence can be prevented. Moreover, since other suspended matters are also filtered out by the filtration membrane unit, suspended solids and bacteria are also removed. Therefore, a high degree of clean water is obtained. Further, since the organic matter is decomposed by aerobic microorganisms, a relatively inexpensive microfiltration membrane or ultrafiltration membrane can be used as the membrane used in the filtration membrane unit, and the equipment cost is reduced. Furthermore, when the raw water is river water, the organic matter in the raw water is dilute, which may reduce the decomposition efficiency by the microorganisms or make it impossible for the microorganisms to survive.However, the organic matter is granular with aerobic microorganisms attached to the surface. Since it is adsorbed by activated carbon, organic matter in raw water will be concentrated,
The degradation of the microbial decomposition efficiency is prevented, and the survival of the microorganism is guaranteed.

Further, when the concentration of the suspended matter in the tank liquid in the processing tank becomes high, the tank liquid can be withdrawn from the processing tank to prevent an increase in transmembrane pressure during filtration. And the clogging of the membrane due to the suspension is prevented. Further, when the concentration of suspended matter in the in-tank liquid in the processing tank becomes high, the in-tank liquid is extracted from the processing tank by a water extraction port formed at the lower end of the peripheral wall of the processing tank,
Also, when the water is extracted through a water withdrawing pipe connected to the water withdrawing port and extending obliquely upward to the outside and having an activated carbon filtering filter, it is possible to prevent activated carbon from being contained in the liquid in the tank to be withdrawn. That is, since the activated carbon is filtered by the filter, it is possible to prevent the activated carbon from flowing out of the water outlet. Further, since the activated carbon can be prevented from flowing out, it is economical because it is not necessary to newly replenish the activated carbon in order to maintain the treatment ability of the organic matter by the microorganism and the adsorption ability of the activated carbon.

In the above two water purification methods, crushed coal raw material coal or crushed coconut shell raw material having a particle size of 0.2 to 2 mm may be used as the granular activated carbon. in this case,
The clogging of the membrane due to activated carbon is prevented.

In the above two water purification treatment methods, a powdery activated carbon having aerobic microorganisms attached to its surface may be incorporated in the treatment tank. The particle size of powdered activated carbon is 20
It is about 200 μm. In this case, since the specific surface area of the powdered activated carbon is larger than that of the granular activated carbon, the adsorption rate of organic matter is improved, and as a result, the decomposition efficiency of organic matter by aerobic microorganisms is also improved. Therefore, it is effective when the quality of raw water is particularly poor or when it is desired to further improve the quality of the obtained clean water. Since the pore size of the membrane is about 0.4 μm, the membrane is prevented from being clogged with the activated carbon powder and the activated carbon powder passing through the membrane.

In the above two water purification methods, it is preferable to aerate the liquid in the tank from below the filtration membrane unit. In this case, a circulating flow of the liquid in the tank is formed in the processing tank,
Since the activated carbon also circulates along this circulation flow, the contact efficiency with the organic matter is improved and the adsorption rate of the organic matter on the activated carbon is also improved. In addition, oxygen is efficiently supplied to the aerobic microorganisms to decompose the organic matter. Further, the activated carbon and air bubbles in the circulating flow separate the deposits on the surface of the film, so that the film is prevented from being clogged and continuous treatment can be performed for a long period of time.

In the above two water purification methods, it is preferable that the coarse material and the easily sedimented material in the raw water are separated by sedimentation in the sedimentation tank before the raw water is put into the treatment tank. In this case, it is possible to prevent the membrane of the filtration membrane unit from being damaged by a coarse material or the like. Further, as described above, when the liquid in the tank is drained from the water drain port, it is possible to prevent the water drain port from being clogged with a coarse material or the like.

The water purification apparatus according to the present invention is a river water,
A water purification device for obtaining clean water from raw water such as lake water, pond water, groundwater, etc., comprising a treatment tank containing granular activated carbon to which aerobic microorganisms adhere, and a filtration membrane unit arranged in the treatment tank. It is provided with a water outlet port at a height position above the liquid level of the liquid in the tank on the peripheral wall of the processing tank,
Further, a liquid level raising means for raising the liquid level of the in-tank liquid by increasing the amount of raw water supplied to the processing tank is provided.

Since the water purification apparatus of the present invention is provided only with a treatment tank containing granular activated carbon to which aerobic microorganisms adhere, and a filtration membrane unit arranged in the treatment tank, the site area of the facility However, it is smaller than an apparatus for performing the above-described two conventional methods. In addition, the facility construction cost and the operating cost are lower than those of the apparatus for performing the two conventional methods described above.

Further, a water outlet is formed at a height position above the liquid surface of the liquid inside the tank on the peripheral wall of the processing tank, and by further increasing the amount of raw water supplied into the processing tank, Since the liquid level raising means for raising the liquid level is provided, the amount of raw water supplied to the processing tank by the liquid level raising means when the concentration of suspended solids in the tank liquid in the processing tank becomes high. Is increased to raise the liquid level of the liquid in the tank, whereby the liquid in the tank can be overflowed and withdrawn from the water outlet. In addition, it is possible to prevent activated carbon from being contained in the liquid in the tank to be extracted, and the same operational effects as described in the water purification method can be obtained.

In the above-mentioned water purification apparatus, a mountain-shaped activated carbon outflow preventing baffle projecting inward of the tank may be provided at a height position below the water outlet on the peripheral wall of the processing tank. In this case, even if the activated carbon rises to the vicinity of the liquid surface due to the function of the baffle, the activated carbon does not hit the baffle and further rise, so that the outflow from the water outlet can be reliably prevented. Moreover, even if the activated carbon moves above the baffle plate, the rising flow due to the aeration device is stopped by the baffle plate, so the activated carbon falls on the baffle plate in combination with the large specific gravity of the activated carbon. , Rolling down along its top surface.

Another water purification apparatus according to the present invention is a water purification apparatus for obtaining clean water from raw water such as river water, lake water, pond water, and ground water, and contains granular activated carbon to which aerobic microorganisms are attached. It is equipped with a treatment tank and a filtration membrane unit arranged in the treatment tank, and a water outlet is formed at the lower end of the peripheral wall of the treatment tank, and a water outlet pipe extending obliquely upward to the outside is connected to the water outlet. The water extraction pipe is provided with an opening / closing valve, and the water extraction pipe is equipped with a removable activated carbon filter.

Since the other water purification apparatus of the present invention is provided only with the treatment tank containing the granular activated carbon to which aerobic microorganisms adhere, and the filtration membrane unit arranged in the treatment tank, The site area is smaller than that of the apparatus for performing the above-described two conventional methods. Also,
Facility construction costs and operating costs are low compared to the devices for carrying out the two conventional methods described above.

Further, a water draining port is formed at the lower end of the peripheral wall of the treatment tank, a water draining pipe extending obliquely upward to the outside is connected to the water draining port, and an opening / closing valve is provided in the water draining pipe to remove the water draining pipe. Since it has a removable activated carbon filter, the on-off valve should be closed at all times and opened when the concentration of suspended solids in the liquid inside the processing tank increases. The in-tank liquid with a high concentration can be withdrawn from the water withdrawal port through the water withdrawal pipe. Moreover, since the activated carbon is filtered out by the filter,
It is possible to prevent activated carbon from being contained in the raw water to be extracted, and the same action and effect as described in the water purification method can be obtained.

In the above two water purification treatment devices, the granular activated carbon may be coal raw material crushed coal or coconut shell raw material crushed coal having a particle size of 0.2 to 2 mm. In this case, the action and effect as described in the water purification method can be obtained.

[0027] In the above two water purification treatment apparatuses, powdery activated carbon having aerobic microorganisms attached to the surface may be further incorporated in the treatment tank. In this case, the action and effect as described in the water purification method can be obtained.

In the above two water purification treatment devices, an aeration device may be arranged in a portion below the filtration membrane unit in the treatment tank. In this case, when the raw water is aerated from the lower side of the filtration membrane unit by the aeration device, the action and effect described in the water purification method can be obtained.

In the above two water purification treatment devices, the filtration membrane unit may include a plurality of flat membrane modules each including two flat membranes and a frame-shaped spacer arranged between the peripheral portions of both flat membranes. In this case, if the flat membrane is a microfiltration membrane, the cost will be low.

In each of the above two water purification treatment devices, it is preferable to arrange a separation tank on the upstream side of the treatment tank to settle and separate the coarse material and the easily sedimented material in the raw water. In this case, before putting the raw water into the treatment tank, it is possible to settle and separate the coarse material and easy sediment in the raw water in the settling separation tank,
The action and effect described in the water purification method can be obtained.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
A description will be given with reference to the drawings. In the following description, substantially the same parts and the same parts will be denoted by the same reference symbols throughout the drawings, without redundant description.

1 to 4 show a first embodiment of the water purification apparatus according to the present invention.

In FIG. 1, the water purification apparatus comprises a treatment tank (1) containing granular activated carbon (2) to which aerobic microorganisms adhere,
The filtration membrane unit (3) arranged in the treatment tank (1) and the treatment tank
The aeration device (4) located below the filtration membrane unit (3) in (1), the blower (5) that sends air to the aeration device (4), and the aeration device (1). Level sensor (19) that detects the level of the liquid in the tank that is the raw water that has been collected, and the processing tank (1)
Settling separation tank (20) that is placed on the upstream side of the tank and that separates coarse and easily settled sediments in raw water, and the tip of the settling separation tank (20) that extends from the settling separation tank (20) near the bottom of the processing tank (1) A raw water supply pipe (6) that extends to the end, and a pump (7) that sends raw water from the sedimentation separation tank (20) into the treatment tank (1) through the raw water supply pipe (6),
A water storage tank (8) for storing the obtained clean water is provided. The level sensor (19) and the pump (7) are connected to a controller (not shown), and the level sensor (19), the pump (7) and the controller cause the water level in the treatment tank (1) to change to the filtration membrane unit (3). )
The raw water supply is controlled so that it is always above the upper end of the.

A water drain port (25) is formed at a height position above the liquid level of the liquid in the bath on the peripheral wall of the treatment bath (1), and a water drain pipe (26) is connected to the water drain port (25). Has been done.
A mountain-shaped activated carbon outflow preventing baffle (24) protruding inward of the tank (1) is provided at a height position below the water outlet (21) on the peripheral wall of the processing tank (1). The upper end of the baffle plate (24) for preventing activated carbon outflow is at the liquid level in the tank and the water outlet (25).
It is at a height position between and (see FIG. 2). Further, the level sensor (19), the pump (7), and the controller increase the supply amount of raw water into the treatment tank (1) to raise the liquid level of the liquid in the tank (1). Liquid level raising means is formed.

The activated carbon (2) is most preferably crushed coal of coal raw material or crushed coal of coconut shell raw material, but granulated activated carbon is also possible. The particle size of activated carbon (2) is 0.1-5
Those in the range of mm are preferable, and those in the range of 0.2 to 2 mm are optimal. Further, it is preferable that the activated carbon (2) has a larger average pore diameter.

The filtration membrane unit (3) comprises a plurality of hollow flat membrane modules (13) as shown in FIG. As shown in FIG. 4, each flat membrane module (13) includes two flat membranes (14) arranged to face each other, and a frame-shaped spacer () disposed between the peripheral portions of both flat membranes (14). 15) and. A suction tube (16) is attached to each flat membrane module (13) so as to communicate with the inside of the hollow part.
Are connected. The suction pipes (16) are collectively connected to one filtered water pipe (17) extending from the water storage tank (8). A suction pump (18) is provided in the middle of the filtered water pipe (17),
By this suction pump (18), the liquid in the tank passes through the flat membrane (14) and is sucked into the flat membrane module (13).
As the flat membrane (14) of the flat membrane module (13), an ultrafiltration membrane or a microfiltration membrane is used, and among them, it is preferable to use a microfiltration membrane having a relatively small suction resistance and a low cost. A capillary module using a hollow fiber membrane can be applied to the filtration membrane unit (3) instead of the flat membrane module (13) using the flat membrane (14).

Next, a water purification method using the above apparatus will be described.

[0038] In advance, coarse or easily sedimented raw water such as river water, lake water, pond water, groundwater, etc. containing a trihalomethane precursor or a substance causing off-flavor is settled and separated in a settling separation tank (20). Raw water is supplied into the treatment tank (1) by the pump (7). At this time, the water level in the treatment tank (1) is the filtration membrane unit (3).
The supply of raw water is controlled so that it is always above the upper end of the water and below the water outlet (25).

Then, air is sent to the aeration device (4) by the blower (5) to aerate the in-tank liquid from below the filtration membrane unit (3) and suck it by the suction pump (18). Then, the organic matter in the liquid in the tank is adsorbed on the surface of the activated carbon (2) and decomposed by aerobic microorganisms, and the decomposed matter of the organic matter and suspended solids, suspensions such as bacteria are filtered membrane unit (3). The filtered water filtered by the flat membrane (14) of the flat membrane module (13) and passed through the flat membrane (14) is sent to the water tank (8) through the suction pipe (16) and the filtered water pipe (17). To be The raw water may contain viruses, so the flat membrane (14) does not have a virus removal function, and in order to avoid microbial contamination during the water distribution process, before sending it to the water tank (8). , Filtered water pipe (1
7) Inject an appropriate amount of chlorine into the filtered water flowing inside, and store it in the water tank (8) as clean water.

When the liquid inside the tank is aerated from below the filtration membrane unit (3), a circulating flow of the liquid inside the tank is formed in the treatment tank (1) due to the air lift effect. That is, the adjacent flat membrane module of the filtration membrane unit (3)
The liquid in the tank, granular activated carbon (2) and bubbles rise between (13),
When the bubbles reach the water surface, they are released into the atmosphere, and the liquid in the tank and the granular activated carbon (2) flow downward between the filtration membrane unit (3) and the peripheral wall of the treatment tank (1) to pass through the filtration membrane unit ( It reaches the lower side of 3) and again rises along with air bubbles between the adjacent flat membrane modules (13) of the filtration membrane unit (3). At this time, turbulence is given to the ascending flow between the flat membrane modules (13) adjacent to each other by the aeration of the inside of the tank liquid from below the filtration membrane unit (3).

The undesirable organic substances present in the raw water are
It is adsorbed by the circulating activated carbon (2) and concentrated on the surface of the activated carbon (2). Since activated carbon (2) also circulates along this circulation flow,
The contact efficiency with the organic matter is improved, and the organic matter adsorption rate on the activated carbon (2) is also improved. In addition, organic matter that is difficult to be biologically treated efficiently in the concentration of raw water can be easily and efficiently decomposed by microorganisms adhering to the surface of activated carbon (2) when it is concentrated on the surface of activated carbon (2). It The organic matter adsorbed on the activated carbon (2) is sequentially decomposed by the adhering microorganisms, so that the performance deterioration of the activated carbon (2) due to saturated adsorption is prevented. In addition, oxygen is efficiently supplied to the aerobic microorganisms to decompose the organic matter.

Further, bubbles rising between the adjacent flat sheet membrane modules (13) of the filtration membrane unit (3) and the activated carbon (2) rub the flat sheet membrane (14), so that the surface of the flat sheet membrane (14) is covered. Since the kimono is peeled off, clogging of the flat film (14) is prevented, and continuous treatment for a long period of time becomes possible.

Then, when the concentration of the suspended solids in the liquid in the treatment tank (1) becomes high, the amount of raw water supplied to the treatment tank (1) is increased by the liquid level raising means. By raising the liquid level of the in-tank liquid in the tank (1) by
The water can be extracted by overflowing from the water outlet (25) through the water outlet pipe (26). Also in this case, it is possible to prevent the activated carbon (2) from being contained in the liquid in the tank to be extracted. That is, since the activated carbon (2) has a large specific gravity,
The activated carbon (2) does not float to the vicinity of the liquid surface, and as a result, the activated carbon (2) can be prevented from flowing out of the water outlet (25). Further, since the activated carbon (2) can be prevented from flowing out, it is economical because it is not necessary to newly replenish the activated carbon in order to maintain the treatment ability of the organic matter by the microorganism and the adsorption ability of the activated carbon. If the liquid inside the tank is aerated from below the filtration membrane unit (3), the activated carbon (2) may rise to near the liquid surface.In this case, the tank for treating the liquid inside the tank (1) The amount of aeration by the aeration device (4) is reduced at the time of extraction from the tank so that the activated carbon (2) does not rise to near the liquid surface.

Even if the activated carbon (2) rises to near the liquid surface due to the function of the activated carbon outflow prevention baffle (24),
Since the activated carbon (2) hits the baffle plate (24) and does not rise further, it is possible to reliably prevent the activated carbon (2) from flowing out from the water outlet (25). Moreover, even if the activated carbon (2) moves above the baffle plate (24), the rising flow in the vicinity of the water extraction port (25) by the aeration device (4) is stopped by the baffle plate (24). Coupled with the large specific gravity of activated carbon (2),
The activated carbon (2) falls on the baffle plate (24) and rolls downward along the upper surface thereof.

FIG. 5 shows a second embodiment of the water purification apparatus according to the present invention. In FIG. 5, the water outlet (30) is formed at the lower end of the peripheral wall of the treatment tank (1),
A water extraction pipe (31) extending obliquely upward to the outside is connected to (30). The drain pipe (31) is bent downwards on the way,
An on-off valve (32) is provided here. Further, the water extraction pipe (31) is provided with a detachable mesh-like activated carbon filter (33). Here, the particle size of the activated carbon (2) in the treatment tank (1) is A, the mesh size of the filter (33) is B, the size of the suspension in the treatment tank (1) is C, and the filtration membrane. When the pore diameter of the flat membrane (14) of the unit (3) is D, the relationship is A>B>C> D. Other configurations are the same as those of the device shown in FIGS.

Next, a water purification method using the above apparatus will be described.

The procedure for treating raw water to obtain clean water is as follows:
This is similar to the case of the device shown in FIGS. The on-off valve (32) should be closed at all times. Then, when the concentration of the suspended matter in the tank liquid in the processing tank (1) becomes high, the open / close valve (32)
When opened, the in-tank solution having a high concentration of the suspension can be extracted from the water extraction port (30) through the water extraction pipe (31). Moreover, since the activated carbon (2) is filtered by the filter (33), it is possible to prevent the activated carbon (2) from being contained in the liquid in the tank to be extracted. Further, since the activated carbon (2) can be prevented from flowing out, it is economical because it is not necessary to newly replenish the activated carbon in order to maintain the treatment ability of the organic matter by the microorganism and the adsorption ability of the activated carbon. Filter (33)
The activated carbon (2) filtered off by means of the gravity returns from the water extraction pipe (31) into the treatment tank (1).

In all the above embodiments, the treatment tank
(1) contains granular activated carbon (2) with aerobic microorganisms attached, but the treatment tank (1) is in addition to the granular activated carbon (2), a powdered activated carbon having a particle size of about 20 to 200 μm. May be built in. In this case, since the specific surface area of the powdered activated carbon is larger than that of the granular activated carbon (2), the adsorption rate of organic matter is improved, and as a result, the decomposition efficiency of organic matter by aerobic microorganisms is also improved. Therefore, it is effective when the quality of raw water is particularly poor or when it is desired to further improve the quality of the obtained clean water. As the powdered activated carbon, similarly to the granular activated carbon (2), crushed coal of coal raw material or crushed coal of coconut shell raw material is most suitable, but granulated activated carbon is also possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a water purification device of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a perspective view showing a filtration membrane unit of the apparatus of FIG. 1. FIG.

FIG. 4 is an exploded perspective view showing a flat sheet membrane module incorporated in the filtration membrane unit of the apparatus of FIG.

FIG. 5 is a configuration diagram showing a second embodiment of the water purification device of the present invention.

FIG. 6 is a flow sheet showing a conventional general water purification treatment method.

FIG. 7 is a flow sheet showing a conventional advanced water purification treatment method.

[Explanation of symbols]

(1) Treatment tank (2) Granular activated carbon (3) Filtration membrane unit (7) Pump (19) Level sensor (25) Drainage port (30) Drainage port (31) Drainage pipe (32) Open / close valve (33) Activated carbon filter

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01D 35/02 B01D 61/14 61/14 63/08 63/08 C02F 1/52 Z C02F 1/52 3 / 10 Z 3/10 3/12 S 3/12 B01D 35/02 A (72) Inventor Tomoki Matsumoto 5-3-3 Nishikujo 5-chome, Konohana-ku, Osaka City Hitachi Shipbuilding Co., Ltd. F-term (reference) 4D003 AA14 AB02 BA02 CA02 CA03 DA07 DA13 DA16 DA19 DA21 EA14 EA25 FA01 4D006 GA07 HA44 JA02A JA04A JA08A KA01 KA31 KA64 KB13 KB14 KB22 KC02 KC14 KC20 KE02Q MA03 MB02 PA01 PB02 PB22 PC51 4D015 BA19 BB01 CA14 FA15 FA17 FA26 4D028 BB02 BC17 CB01 4D064 AA01 BA02

Claims (15)

[Claims] 1. A water purification method for obtaining clean water from raw water such as river water, lake water, pond water, groundwater, etc., in a treatment tank containing granular activated carbon having aerobic microorganisms attached to its surface. Raw water is added, and the organic matter in the tank liquid that is the raw water put in the treatment tank is adsorbed on the surface of activated carbon, and this organic matter is decomposed by aerobic microorganisms to decompose organic matter and other suspended matter. When the concentration of suspended solids in the in-tank liquid in the treatment tank becomes high, the in-tank liquid is extracted from the treatment tank by filtration using a filtration membrane unit immersed in the in-tank liquid. The water withdrawal port is formed in the peripheral wall of the treatment tank at a height position above the liquid level of the liquid inside the treatment tank, and the amount of raw water supplied to the treatment tank is increased. By raising the liquid level, The method for purifying water is characterized in that it is carried out by overflowing the water. 2. A water purification method for obtaining clean water from raw water such as river water, lake water, pond water, groundwater, etc., in a treatment tank containing granular activated carbon having aerobic microorganisms attached to its surface. Raw water is added, and the organic matter in the tank liquid that is the raw water put in the treatment tank is adsorbed on the surface of activated carbon, and this organic matter is decomposed by aerobic microorganisms to decompose organic matter and other suspended matter. When the concentration of suspended solids in the in-tank liquid in the treatment tank becomes high, the in-tank liquid is extracted from the treatment tank by filtration using a filtration membrane unit immersed in the in-tank liquid. The removal from the treatment tank is performed through a water withdrawal port formed at the lower end of the peripheral wall of the treatment tank, and a water withdrawal pipe connected to the water withdrawal port and extending obliquely outward and having an activated carbon filter. Characteristic water purification method Law. 3. The granular activated carbon has a particle size of 0.2 to 2 mm.
3. The purified water treatment method according to claim 1, wherein the crushed coal raw material coal or the coconut shell raw material crushed coal is used. 4. The purified water treatment method according to claim 1, further comprising a powdery activated carbon having aerobic microorganisms attached to its surface in the treatment tank. 5. The purified water treatment method according to claim 1, wherein the inside of the tank is aerated from below the filtration membrane unit. 6. The method according to any one of claims 1 to 5, wherein before the raw water is put into the treatment tank, the coarse material and the easily sedimented material in the raw water are settled and separated in the settling separation tank. Water purification method. 7. A water purification device for obtaining clean water from raw water such as river water, lake water, pond water, groundwater, etc., which comprises a treatment tank containing granular activated carbon to which aerobic microorganisms adhere, and a treatment tank in the treatment tank. Equipped with a filtration membrane unit arranged, a water outlet is formed at a height above the liquid level of the in-tank liquid on the peripheral wall of the processing tank, further increasing the amount of raw water supplied into the processing tank. A water purification apparatus equipped with a liquid level raising means for raising the liquid level of the liquid in the tank by making it. 8. The water purifying apparatus according to claim 7, wherein a mountain-shaped activated carbon outflow preventing baffle projecting inward of the tank is provided at a height position below the water outlet on the peripheral wall of the processing tank. 9. A water treatment apparatus for obtaining clean water from raw water such as river water, lake water, pond water, groundwater, etc., which comprises a treatment tank containing granular activated carbon to which aerobic microorganisms adhere, and a treatment tank in the treatment tank. It is equipped with a filtration membrane unit, and a water outlet is formed at the lower end of the peripheral wall of the treatment tank.The water outlet is connected to a water outlet pipe extending obliquely upward to the outside, and an opening / closing valve is attached to the water outlet pipe. A water purification device that is equipped with an activated carbon filter that has a water extraction tube that is removable. 10. The granular activated carbon is crushed coal raw material coal or coconut shell raw material crushed coal having a particle size of 0.2 to 2 mm.
The water purification apparatus according to any one of 1 to 9. 11. The treatment tank is further provided with powdered activated carbon having aerobic microorganisms attached to the surface thereof.
The water purification device according to any one of 0. 12. The water purification apparatus according to any one of claims 7 to 11, wherein an aeration device is arranged in a portion below the filtration membrane unit in the treatment tank. 13. The filtration membrane unit includes a plurality of flat membrane modules each including two flat membranes and a frame-shaped spacer arranged between peripheral portions of both flat membranes. The water purification device described in. 14. The flat membrane is a microfiltration membrane.
The described water purification device. 15. The separation tank for settling and separating a coarse material and a readily sedimentable material in raw water is disposed on the upstream side of the treatment tank, according to any one of claims 7 to 14. Water purification equipment.