JP2932155B2 - Water purification method and equipment used for it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of purifying water quality of a water area such as a bay, a pond, a lake, a dam, or a dam where water flow is relatively small, and an apparatus used for the method. A method of purifying water quality and preventing its re-contamination by causing air bubbles to adsorb and float on the flocs and decomposing the flocculated flocs that have floated using aqueous plants,
An apparatus for use in the method.

[0002]

2. Description of the Related Art In recent years, as environmental problems have been taken up on a global scale, the problem of water pollution is an important issue that must be resolved promptly. Deterioration of water quality, especially in enclosed waters, is closely related to our lives, and its improvement needs to be given top priority.

[0003] As a method of purifying water quality in a water area, the construction of a sewer is most effective, but in an area where the sewer is difficult to spread, a direct purification method of purifying the water area is performed.
Among them, the recently developed pressure flotation method is used for the treatment of nitrogenous and phosphorus-based organic substances in water bodies.

[0004] The pressurized flotation separation method is mainly used for advanced treatment of sewage and industrial wastewater, but when it is used for direct purification of water areas, there is a problem in the method of collecting and disposing of flock floated by fine bubbles. Becomes Floating flocs are collected manually or with a collecting device, but both require disposal of the collected filth, which increases maintenance costs and makes it difficult to take countermeasures.

[0005] When direct purification by the pressurized flotation method is performed in a short time using a large system, the purification is temporarily performed, but re-contamination proceeds with the passage of time. Even when the method is used continuously and continuously, problems still remain in the method for collecting and disposing of floating flocs.

[0006] One of the direct purification methods is an aeration method. In this method, organic substances are oxidatively decomposed while floating biological flocks in water by aeration in the activated sludge method. Biological treatment is one of the advanced treatments, and is performed aerobically exclusively, and is an extremely effective means for purifying polluted raw water by removing nitrogen, ammonia, algae, odor, iron, manganese, and the like. However, air bubbles generally used for aeration have a diameter of 1
Due to the size of ~ several mm, there is a problem that the efficiency of aeration treatment is low and the purification takes time.

Further, one of the direct purification methods of vegetation is to use plants such as water hyacinth, rush, reed, etc. which are easy to grow and remove because of the absorption of nitrogen and phosphorus in the water area, and float them on the water surface. Ingest nutrients,
It suppresses the growth of algae (phytoplankton) such as blue-green algae. Vegetation purification relies on the natural circulation of water in water bodies for contact between plants such as water hyacinth and polluted water.Since only water quality improvement on the surface is performed, partial treatment is required, and uniform purification of the entire water area There is a problem.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to efficiently and continuously purify the water uniformly and promptly throughout the water area without the need to collect and dispose of flocs. It is in.

[0009]

According to the water purification method of the present invention, a flocculant and bubbles are released into polluted raw water in a water area, and the bubbles are adsorbed on flocculated flocs generated by the polluted water and the flocculant. It is characterized in that it floats to the surface of the water and decomposes the flocculated flocs by the aqueous plant.

That is, the present invention effectively combines the aeration method of the direct purification method and the vegetation purification method, does not require the trouble of collecting flocculated flocs, and can prevent re-contamination.

[0011] The features of the apparatus used in this method include a bubble generating apparatus which can move by floating on the water surface, a movable fence provided around the apparatus, and an aqueous plant provided between the both. There is a feature. The bubble generator is
It consists of a pump for sucking polluted raw water, a flocculant tank for adding a flocculant to the sucked raw water, an ejector connected to the pump to mix air into the polluted water, and a pressurized tank connected to the ejector. .

An air bubble generation nozzle connected to a pressurized tank is provided in the water below the center of the fence to decompose the flocculated floc that has floated up with an aqueous plant, thereby enabling purification of water and prevention of recontamination.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air bubble generating apparatus 1 comprises a flocculant tank 3, a pump 4, an ejector 5, and a pressurized tank 6 provided on a float 2, as shown in FIG. Reference numeral 7 denotes a suction hose connected to the pump 4, and a strainer 8 is attached to a tip of the suction hose. Reference numeral 9 denotes a discharge hose connected to the pressurized tank 6, and a bubble generating nozzle 10 is attached to a tip of the discharge hose.
In addition, 11a and 11b are valves. Bubble generator 1
Is movable by the floating base 2. The bubble generating nozzle 10 is installed in the water below the center of a fence 26 described later.

Then, the contaminated raw water W sucked into the pump 4 together with the coagulant through the strainer 8 and the suction hose 7 is converted into a gas-liquid mixture by the ejector 5 for sucking air, and becomes a pressurized tank. It is sent to 6. The gas-liquid mixture pressurized in the pressurized tank 6 becomes a gas solution and becomes
From the bubble generating nozzle 1 by the discharge hose 9
0. From the bubble generation nozzle 10, the gas dissolved from the gas solution, that is, air, is continuously discharged as bubbles.

Although a known nozzle can be used as the bubble generating nozzle 10, in the present invention, a "fine bubble discharging device" developed by the present applicant and already applied for a patent (Japanese Patent Application No. 6-2).
98923). This device can continuously generate fine bubbles of several tens of microns or less which are extremely effective for aeration.

This device is outlined with reference to FIG. 12 is a connection tube for attaching and detaching the discharge hose 9, 13 is an outer tube connection tube, 14
Is an inner cylinder attached to the connection cylinder 12. 15 is a lid,
The distal end of the inner cylinder 14 is closed.

Reference numeral 16 denotes a group of ejection holes provided through the inner cylinder 14.
It has a small diameter of 2 to 4 mm inside diameter, and 3 mm in the embodiment.
Reference numeral 17 denotes a screw which is screwed into an appropriately selected ejection hole 16 so that the number of the ejection holes 16 can be adjusted according to the situation.

Reference numeral 18 denotes an outer cylinder which is attached to the outer cylinder connecting cylinder 13 and includes an inner cylinder 14 and a front portion (the side opposite to the discharge hose 9) extends forward of the inner cylinder 14. The tip is open.

Then, the gas solution supplied from the discharge hose 9 to the inner cylinder 14 together with the coagulant is supplied to the fine jet holes 16.
The ejection from the group and the flow rate immediately after the ejection from the ejection hole 16 are suppressed by the outer cylinder 18, so that the gas is discharged while releasing the pressure at a stretch. As a result, the gas dissolved in the gas solution, that is, air, floats as many fine bubbles.

Next, the net 19 provided around the bubble generator 1 will be described with reference to FIG. 2 and FIGS. In the present invention, the aqueous plant AP is used for the vegetation purification method, but the organic matter such as nitrogen and phosphorus in water is absorbed and propagated.
In order to remove and replace the increased plant group, the net 19 holding the aqueous plant AP is pierced. In the example,
As shown in FIG. 2, six pieces 20 which can be connected to each other and opened freely.
To form a net 19.

FIG. 5 shows a fan-shaped mounting frame 21. Reference numeral 22 denotes a hook fixed to the mounting frame 21. Figure 6 shows the net piece 2
3 is shown. Reference numeral 24 denotes a ring which is attached to and detached from the hook 22. 1
Pieces 20 are attached to one mounting frame 21 by one net piece.
23 are attached, and the six pieces 20 are connected to form the net 19.

FIG. 7 shows an embodiment in which a drainage plant AP1 such as reeds and cattails is used as the aqueous plant AP. In this embodiment, a rough net 19b is laid on the thin net 19a, and a sponge block 25 having excellent water absorption and air permeability, for example, a cellulosic sponge block is provided between the rough net 19b and the thin net 19a. To support. The sponge 25 is planted with seeds of the draft plant AP1 and grown.

FIG. 8 shows an embodiment in which a floating plant AP2 such as water hyacinth, rush, reed, etc. is used as the aqueous plant AP. In this embodiment, only the thin net 19a is used, and the floating plant AP2 is floated on the water surface on the net 19a. Therefore, in both embodiments, the removal and replacement of the aqueous plant AP can be performed only by replacing the net 19.

The net 19 is surrounded by a well-known fence 26 for preventing diffusion as shown in FIGS. Then, the bubble generating nozzle 10 is installed so that the bubbles are generated from below the center of the fence 26 so that the generated bubbles are not diffused. The diameter of the fence 26 is set according to the size of the water area, and the water depth of the bubble nozzle 10 is set at a position slightly higher than the bottom. If the air supply from the ejector 5 is small, the compressor 27
Is connected to the ejector 5.

[0025]

According to the present invention, it is not necessary to collect the flocculated flocs floated by the pressurized floating separation method, so that maintenance becomes free and cost can be reduced.

Since sufficient dissolved oxygen is given by aeration, the purification efficiency is higher than that of ordinary plant purification, and the use of air bubbles, particularly fine air bubbles as in the embodiment, increases the air dissolution efficiency and improves the purification efficiency. improves. In addition, air bubbles,
Because water can be forcedly circulated when aerated with fine bubbles,
Purification of the entire water area can be performed uniformly and quickly.

As a pressure circulating purification facility, water containing microcystis, the main causative species of blue-green algae, is pressurized in a pressurized tank for a certain period of time, thereby destroying the gas vesicles of the microcystis. Can be suppressed.

The pressure flotation method, the aeration method, and the vegetation purification method are based on BO and BO treatments, respectively.
Since D, COD, SS and the like are significantly reduced, a more efficient water purification can be achieved by combining them.

As a floating island, it floats on the surface of the water and can be moved to a desired position in the water area, so that the entire water area can be efficiently purified. In addition, since an aqueous plant is used, it is excellent in aesthetics and natural. An environment in harmony with the environment is created.

[Brief description of the drawings]

FIG. 1 is a schematic side view of the entire apparatus.

FIG. 2 is a schematic plan view of the entire apparatus.

FIG. 3 is a conceptual diagram of a fine bubble generation device.

FIG. 4 is a side view of a fine bubble generation nozzle.

FIG. 5 is a plan view of a mounting frame.

FIG. 6 is a plan view of a net piece.

FIG. 7 is an explanatory diagram of an embodiment using a water-extraction plant.

FIG. 8 is an explanatory diagram of an example using a planktonic plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bubble generator 3 Coagulant tank 4 Pump 5 Ejector 6 Pressurized tank 10 Bubble generation nozzle 19 Net 26 Fence AP Aqueous plant W Raw water

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C02F 9/00 502 C02F 9/00 502Z 503 503A 504 504A 504E (72) Inventor Hideki Tanaka 512-152, Kiwa, Aka-shi, Hyogo 152 (56) References JP-A-8-132094 (JP, A) JP-A-60-238198 (JP, A) JP-A-3-98692 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name ) C02F 3/32 C02F 1/24 C02F 1/52 C02F 9/00

Claims (5)

(57) [Claims] 1. A flocculant and air bubbles are released into polluted raw water, and air bubbles are adsorbed on flocculated flocs generated by the raw water and the flocculant to float up to the water surface, and the floating flocks are decomposed by aqueous plants. Water purification method. 2. A pump for sucking polluted raw water, a flocculant tank for adding a flocculant to the sucked raw water, an ejector connected to the pump to mix air with the raw water, and a pressurizer connected to the ejector. Around the bubble generator that can move up and down on the water surface, comprising a tank, a movable fence is provided, and a bubble generation nozzle connected to the pressurized tank is provided in the water below the center of the fence. A water purification device comprising an aqueous plant that decomposes the flocculated flocs that have floated between a bubble generator and a fence. 3. The water purification device according to claim 2, wherein a net is provided between the bubble generation device and the fence. 4. The water purification apparatus according to claim 3, wherein the net comprises a plurality of pieces detachably connected to each other. 5. The water purification apparatus according to claim 4, wherein the piece comprises a mounting frame having a hook and a net piece detachable from the hook of the mounting frame.