JPH09206788A - Water quality purification method and water quality purification apparatus used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and continuously execute water quality purification of a water without recovery of floating flocs. SOLUTION: Air bubbles are adsorbed and floated to the flocculated flocs produced by releasing a flocculating agent and air bubbles to polluted raw water W and this water is poured onto a vegetation bed 19 planted with aquatic plants AP and a filter bed 20 formed of pebbles and charcoal to decompose the flocculated flocs with the aquatic plants and the filter bed. For this purpose, an air bubble generating nozzle 10 is disposed below a floating and movable air producing generator 1 successively connected with a pump for sucking the raw water W, flocculating agent tank, ejector and pressurizing tank and the vegetation bed is installed to the circumference of the generator and the filter bed on the vegetation plant. A guiding member 21 which diagonally floats the air bubbles sticking to the flocs toward the air bubble generator and pours the air bubbles onto the filter bed through the air bubble generator and the vegetation bed and the filter bed is disposed. The flocs are decomposed by the filter bed and the aquatic plants and, therefore, the need for the recovery treatment of the flocs is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying water in a water area having a relatively small water flow such as a bay, a pond, a lake, a dam, and an apparatus used therefor, and more specifically, to aeration of the water area and aggregation by aeration. A method for adsorbing and floating air bubbles on flocs and decomposing the flocculated flocs by utilizing an aqueous plant and a filter bed to prevent purification of water quality and its recontamination, and a method for use in this method. Regarding the device.

[0002]

2. Description of the Related Art While environmental problems have been taken up on a global scale in recent years, the problem of water pollution is an important issue that must be solved immediately. In particular, regarding the deterioration of water quality in closed water areas, it is necessary to improve it because it is closely related to our lives.

The most effective method for purifying the water quality in the water area is to improve the sewerage system. However, in areas where the sewerage system is difficult to spread, a direct water purification method is used to directly purify the water area.
Among them, the recently developed pressure floating separation method is used for treating nitrogen and phosphorus organic matter in water bodies.

This pressure floating separation method is mainly used for advanced treatment of sewers, factory wastewater, etc., but when it is used for direct purification of water bodies, a method of collecting and disposing flocs floated by fine bubbles is a problem. Becomes Floating flocs are collected manually or by a collecting device, but in both cases, it is necessary to dispose of the collected filth, which requires maintenance costs, and we are struggling to take measures against it.

When direct purification is carried out by a pressurized flotation separation method using a large system for a short period of time, although it is temporarily purified, recontamination progresses over time, so a compact system should be used as a preventive measure. Even if it is carried out continuously at all times, there are still problems with the method for collecting and disposing of floc flocs.

An aeration method is one of the direct purification methods. This method is to oxidize and decompose organic matter while suspending biological flocs in water by aeration as seen in the activated sludge method. Biological treatment is one of the advanced treatments and is carried out exclusively aerobically, and is a very effective means for purifying polluted raw water by removing nitrogen, ammonia, algae, odor, iron, manganese, and the like. However, bubbles used for aeration generally have a diameter of 1
Since the size is up to several mm, there is a problem that aeration treatment efficiency is poor and purification takes time.

Further, one of the direct purification methods is a vegetation purification method, in which plants such as water hyacinth, rush, reed and the like which are easy to grow and remove are floated on the water surface in order to absorb nitrogen and phosphorus in the water area. To ingest nutrients,
It suppresses the growth of algae (phytoplankton) such as blue-green algae that breed. Vegetation purification relies on the natural circulation of water in the water area to contact plants such as water hyacinth and polluted water, and only the water quality on the surface is improved, resulting in partial treatment and uniform purification of the entire water area. I have a problem.

The present applicant has previously filed a patent application under the name of "water purification method and apparatus used therefor" as a solution to the above drawbacks of the conventional water purification method and water purification apparatus (Japanese Patent Application No. 7-83242). -46185). This method "releases a flocculant and bubbles to polluted raw water, causes the flocs generated by the raw water and the flocculating agent to adsorb the bubbles and float to the water surface, and the flocculated flocs are decomposed by an aqueous plant." It is something.

The apparatus also includes a pump for sucking polluted raw water, a coagulant tank for adding a coagulant to the sucked raw water, an ejector connected to the pump for mixing air into the raw water, and an ejector connected to the ejector. Consisting of a pressurized tank,
A movable fence is installed around the bubble generator that floats on the surface of the water and is movable, and a bubble generating nozzle connected to a pressure tank is provided in the water under the center of the fence so that the bubble generator and fence Between them and an aquatic plant that decomposes flocculated flocs that have surfaced. "

As a result, it is possible to efficiently and continuously purify the water quality without the trouble of collecting the floc, and to prevent recontamination. However, there is a limit to relying only on the aquatic plants for the decomposition of the flocculated flocs, and further efficiency is required.

[0011]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to carry out uniform and quick water purification of the entire water area more efficiently and continuously without the need to collect and dispose of flocs. Especially.

[0012]

The water purification method of the present invention releases a flocculant and bubbles to polluted raw water, and causes the flocs generated by the raw water and the flocculant to adsorb the bubbles and float them. It is characterized in that it is poured into an aqueous plant and a filter bed made of gravel and / or charcoal to decompose agglomerated flocs between the aqueous plant and the filter bed.

That is, it is an effective combination of the aeration method of the direct purification method and the vegetation purification and filter bed method, which does not require the trouble of collecting the floc of flocs and can prevent recontamination.

The features of the apparatus used in this method are as follows. That is, from a pump that sucks polluted raw water, a coagulant tank that adds a coagulant to the sucked raw water, an ejector that is connected to the pump to mix air into the raw water, and a pressure tank that is connected to the ejector. Therefore, a bubble generating nozzle connected to a pressure tank is provided in the water below the bubble generating device that can float and move to the water surface.

Around the air bubble generator, a water-absorbing and air-permeable vegetation bed in which an aqueous plant is planted and floated, and a filter bed made of gravel and / or charcoal are arranged on the vegetation bed. At the same time, the bubbles that adhere to the floc generated by the raw water and the flocculant and float up are inclined toward the bubble generator, and pass through the bubble generator, the vegetation bed and the filter bed to the filter bed. Provide a guiding member for pouring.

In another water quality purifying apparatus of the present invention, a bubble generating nozzle connected to a pressure tank is provided in water below the bubble generating apparatus, and the flow generating apparatus is provided around the bubble generating apparatus.
A drainage mat, a vegetation bed planted with an aqueous plant, a filter bed made of gravel or / and charcoal are sequentially stacked on top of
The float is a bubble generating device, a float, a drainage layer, a vegetation floor, which causes bubbles that adhere to floc generated by the raw water and the flocculant and float up toward the bubble generating device.
It is characterized in that it has a guide surface through which it can be poured into the filter bed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION First, a bubble generator 1 will be described with reference to FIG. The bubble generation device 1 includes a flocculant tank 3, a pump 4, an ejector 5, and a pressure tank 6 provided on the floating table 2. 7 is a suction hose connected to the pump 4.
A strainer 8 is attached to the tip of the strainer. A discharge hose 9 is connected to the pressure tank 6, and a bubble generating nozzle 10 is attached to the tip thereof. Note that 11a, 1
1b is a valve. The bubble generator 1 is movable by a floating table 2. Further, the bubble generating nozzle 10 is installed in the water below the center of the bubble generating device 1 described later.

The polluted raw water W passes through the strainer 8 and the suction hose 7 and is sucked into the pump 4 together with the coagulant, and becomes a gas-liquid mixed liquid by the ejector 5 which sucks air to the pressure tank 6. Sent in. The gas-liquid mixed liquid pressurized in the pressure tank 6 becomes a gas solution, is sent out from the pressure tank 6, and is supplied to the bubble generation nozzle 10 by the discharge hose 9. From the bubble generation nozzle 10, the gas dissolved from the gas solution, that is, air, is continuously discharged as bubbles.

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

This device is outlined by FIG. Reference numeral 12 is a connection tube for attaching and detaching the discharge hose 9, 13 is an outer tube connection tube, 14
Is attached to the connecting cylinder 12 by an inner cylinder. 15 is a lid,
The tip of the inner cylinder 14 is closed.

Reference numeral 16 denotes a group of ejection holes penetrating the inner cylinder 14,
The inner diameter is 2 to 4 mm, and in the embodiment, the diameter is 3 mm.
Reference numeral 17 denotes a screw, which is screwed into an appropriately selected ejection hole 16 so that the number of 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 encloses the inner cylinder 14 so that the front portion (the side opposite to the discharge hose 9) extends beyond the inner cylinder 14. , The tip is open.

Therefore, the gas-dissolved liquid supplied from the discharge hose 9 to the inner cylinder 14 together with the coagulant is a fine ejection hole 16
The jetting from the group and the flow velocity immediately after the jetting from the jetting hole 16 are suppressed by the outer cylinder 18, so that the pressure is released at a stroke. As a result, the gas dissolved in the gas solution, that is, air, becomes a large number of fine bubbles and floats.

The bubble generating nozzle 10 may be installed at a position slightly higher than the bottom of the water. If the amount of air supplied from the ejector 5 is small, a compressor (not shown) is connected to the ejector 5 as needed.

Next, the water purification apparatus will be outlined with reference to FIG. 19 is a vegetation bed, 20 is a filter bed formed on the vegetation bed 19, and is provided around the bubble generating apparatus 1. In the present invention, water-extracted plants such as reeds and cattails are used as the aqueous plants AP in the vegetation purification method. Water absorption as the vegetation floor 19,
A water-based plant AP that employs a sponge block having excellent air permeability and buoyancy, for example, a cellulose sponge block.
Plant seeds and grow. The filter bed 20 has a diameter of 5 to 10c.
Use m gravel or charcoal. Note that gravel and charcoal may be mixed and formed.

Reference numeral 21 denotes an inverted funnel-shaped guide member, which is the mouth 2 of the funnel.
1a and a guide surface 21b that is a conical slope that slopes upward toward the bubble generating device 1. This guide member 21
Is made of reinforced plastics such as glass fiber reinforced plastics. Reference numeral 22 is a well-known ring-shaped fence, which is provided outside the vegetation floor 19 and the filter floor 20 and is movable, and the purifying device blocks movement due to wind or flow.

With the above-mentioned structure, the bubbles discharged from the bubble generating nozzle 10 together with the coagulant adhere to the flocculating flocs and float, but after they obliquely ascend toward the bubble generating device 1 along the guide surface 21b. , Bubble generator 1 and mouth 21a
And the raw water W is poured into the filter bed 20.

The aggregated flocs poured into the filter bed 20 are first decomposed by organisms such as bacteria and protozoa that live in the filter bed 20, and the rest reach the vegetation bed 19. Since the aqueous plants AP are planted in the vegetation bed 19, the remaining flocs are decomposed by the aqueous plants AP.

The aqueous plant AP planted on the vegetation floor 19 is
It absorbs organic substances such as nitrogen and phosphorus in water, propagates, and increases. Further, the purification ability of the gravel and charcoal of the filter bed 20 gradually declines. Therefore, it is convenient to connect the vegetation bed 19 and the filter bed 20 to each other and divide them into a plurality of openable pieces in order to easily remove and replace vegetation groups that have propagated and increased, gravel and charcoal that have deteriorated purification ability, and can be replaced easily. is there. For example, as shown in FIG. 2, it is divided into six pieces. Similarly, the guide member 21 is also divided into six pieces. In the figure, reference numeral 23 is a cylindrical separator, which is a bubble generator 1 and a mouth 21.
Keep the distance from a.

First, the divided guiding member 21 is shown in FIG. Reference numeral 21c is a left and right side plate that connects the mouth 21a and the guide surface 21b, and 21d is an outer plate that connects the upper portions of both side plates 21c. The divided vegetation bed 19 and filter bed 20 are housed in this guide member 21. As shown in FIGS. 6 and 7, it is preferable that the outer edge of the vegetation floor 19 is raised to form the outer wall 19a so that the gravel and charcoal forming the filter bed 20 do not fall outside. The divided guide members 21 are strings,
It is detachably connected by a fastening means such as a chain, a hook and a ring.

Reference numeral 24 is a net for supporting the vegetation floor 19 from below, which is attached to the hook 26 fixed to the upper inner wall of the guide member 21,
Retainably attach the ring 25 attached to the net 24,
The vegetation bed 19 and the filter bed 20 can be taken out together with the net 24. However, if the net 24 is made fine so as to prevent the gravel and charcoal from spilling and the filter bed 20 is wrapped around the net 24, the outer wall 19a is not necessary.

FIG. 8 shows another embodiment. 27 is a float, which is a guide surface 27 that slopes upward toward the bubble generating device 1.
and a buoyancy member 27b such as foam styrol is housed inside. 28 is a weight. This float 27
Are made of reinforced plastics such as glass fiber reinforced plastics.

A drainage mat 29 is detachably mounted on the float 27, the above-mentioned vegetation mat 30 is mounted on the drainage mat 29, and the filter bed 20 is mounted on the vegetation mat 30. The sponge block may be used for the vegetation mat 30.

Reference numeral 31 denotes a drainage outer wall surrounding the outsides of the float 27, the drainage mat 29 and the vegetation mat 30, and a corrugated plate made of plastic is used so that the water oozing out from the drainage mat 29 can be discharged. It can be replaced with a plastic or metal net. 32 is a separator,
The gap between the bubble generator 1 and the float 27 is maintained, and a passage for raising bubbles adsorbing the flocs is formed. A cylindrical body may be used instead of the separator 32 of the corrugated plate. Note that the inner peripheral edge and the outer peripheral edge of the float 27 may be raised to prevent gravel and charcoal of the filter bed 20 from spilling. Further, the float 27, the drainage mat 29 and the vegetation mat 30 can be detachably divided.

[0035]

EFFECTS OF THE INVENTION Since it is not necessary to collect the flocculated flocs that have been floated by the pressure floating separation method, the maintenance is free and the cost can be reduced.

Since a sufficient amount of dissolved oxygen is provided by aeration, the purification efficiency is higher than that in normal plant purification, and the use of air bubbles, especially the fine air bubbles as in the embodiment, increases the air dissolution efficiency and improves the air purification efficiency. improves. Furthermore, since forced circulation of water can be performed during aeration of bubbles, especially fine bubbles, the entire water area can be uniformly and quickly purified.

As a pressure circulation purification facility, water containing microcystis, which is the main causative species of water-bloom, is pressurized in a pressure tank for a certain period of time to destroy the gas vesicles of microcystis, so that the growth of water-bloom is directly Can be suppressed.

The pressure floating separation method, aeration method, vegetation purification method, and filter bed purification method are effective in significantly reducing BOD, COD, SS, etc. in addition to nitrogen and phosphorus-based organic matter treatment, respectively. Therefore, by combining these, more efficient water purification can be achieved.

Since it floats on the surface of the water as a floating island and can be moved to a desired position within the water area, the entire water area can be efficiently purified, and because it uses water-based plants, it is aesthetically pleasing and natural. An environment in harmony with is created.

[Brief description of drawings]

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

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

FIG. 3 is a conceptual diagram of a fine bubble generator.

FIG. 4 is a cross-sectional view of a fine bubble generation nozzle.

FIG. 5 is a perspective view of a divided guide member.

FIG. 6 is a plan view of a divided guide member and the like.

7 is an enlarged end view taken along line AA of FIG.

FIG. 8 is a side sectional view of another embodiment.

[Explanation of symbols]

 1 Bubble Generator 3 Coagulant Tank 4 Pump 5 Ejector 6 Pressurized Tank 10 Bubble Generation Nozzle 19 Vegetation Bed 20 Filter Bed 27 Float 29 Drainage Mat 30 Vegetation Mat AP Water Plant W Raw Water

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication C02F 9/00 502 C02F 9/00 502Z 503 503A 504 504A 504E (72) Inventor Yoshihiro Okabe Okayama Okayama 1 of 463 Shimikami, Ichi (72) Inventor Hideki Tanaka 152 of 512, Sumiwa, Ako City, Hyogo Prefecture

Claims (5)

[Claims] 1. A coagulant and air bubbles are released into polluted raw water, and the air bubbles are adsorbed and floated on the floc generated by the raw water and the coagulant to obtain a filter comprising an aqueous plant and gravel and / or charcoal. A water purification method in which the flocs are poured into a floor and decomposed by flocculation with an aqueous plant and a filter bed. 2. A pump for sucking polluted raw water, a coagulant tank for adding a coagulant to the sucked raw water, an ejector connected to the pump for mixing air into the raw water, and a pressurizer connected to the ejector. A bubble-generating nozzle that is connected to a pressurized tank is provided in the water below the bubble-generating device, which is composed of a tank and floats above the water surface and is movable. A vegetation bed that is air-permeable and breathable, and a filter bed made of gravel and / or charcoal is placed on the vegetation bed, and bubbles that float by adhering to the floc generated by the raw water and the flocculant are formed. A water purification device which is provided with an air bubble generator and a guide member which is slanted upward toward the generator and can be poured into the filter bed between the vegetation bed and the filter bed. 3. The water purification apparatus according to claim 2, wherein a movable floating fence is provided around the vegetation floor and the filter bed. 4. The guide member is divided into a plurality of vegetation beds and filter beds, and each divided vegetation bed and filter bed is attached to and detached from each divided guide member surrounding the vegetation floor and filter beds. The water purification device according to claim 2 or 3, which is supported by a free net. 5. A pump for sucking polluted raw water, a coagulant tank for adding a coagulant to the sucked raw water, an ejector connected to the pump for mixing air into the raw water, and a pressurizer connected to the ejector. A bubble generating nozzle connected to the pressure tank is provided in the water below the bubble generating device which is composed of a tank and floats on the water surface and is movable, and on a float arranged around the bubble generating device, Drainage mats, vegetation beds planted with aqueous plants, filter beds made of gravel and / or charcoal are stacked in sequence, and the floats generate bubbles by adhering to floc flocs generated by raw water and flocculant. A water purification device having a guide surface that is slanted upward toward the device and can be poured into the filter bed through the space between the bubble generator and the float, drainage layer, vegetation bed, and filter bed.