JP3459231B2 - Algae removal equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing algae, and more particularly, to algae contained in raw water by minimizing the amount of chemicals such as chlorine used or without using chemicals. The present invention relates to a device for removing algae that can be used as water (drinking water).

[0002]

2. Description of the Related Art Conventionally, as for clean water, raw water taken from rivers, lakes and marshes is purified by using a plurality of water treatment steps such as filtration at a water purification plant.

By the way, in recent years, when domestic wastewater, agricultural wastewater, factory wastewater, etc., flow into rivers, lakes and marshes, the water in rivers, lakes and marshes becomes eutrophic, and a large amount of algae is generated. There is. When trying to obtain clean water by purifying raw water containing a large amount of algae by eutrophication, substances such as 2-MIB and diosmin derived from algae cause mold odor and high chromaticity problems. Becomes

As a means for solving the problems of musty odor and high chromaticity of clean water, good water quality can be obtained by introducing a so-called advanced water purification process using ozone (O ₃ ) or activated carbon in the water treatment process. Trying to get clean water.

[0005]

By the way, ozone (O
₃ ) or the introduction of a highly purified water treatment process using activated carbon or the like, particularly when performing intermediate ozone treatment, the problem of algae removal in the pretreatment step becomes a problem. This is because a large amount of flocs that should hardly flow into the ozone (O ₃ ) treatment process due to floc formation in the pretreatment process, flocculation and sedimentation, and poor flocculation and sedimentation due to the characteristics of algae in the sand filtration process. This is because there is a risk that flocks will flow in and collect due to the action of ozone (O ₃ ), causing unnecessary trouble such as scumming in the ozone reaction tank.

In order to deal with this, it is unavoidable that a high concentration chlorine agent is injected into the raw water in the chemical precipitation step to maintain the flocculating property of the floc by killing algae, and an excessive amount of the flocculant is added. It is added to manage the flocculating property of the floc, but by injecting this chlorine agent, it is possible to remove residual chlorine, ozone (O ₃ ) and activated carbon in the advanced water treatment process of the subsequent treatment process. An unnecessary reaction occurs between the two, which causes waste of ozone (O ₃ ), a decrease in the adsorption capacity of activated carbon due to chlorine, and the production of trihalomethanes which are cancer-inducing substances. In addition, for algae among algae,
It is known that the action of a chlorine agent causes a troublesome problem that the agar-shaped pods forming colonies are dissolved and a large number of single cells enclosed in the pods are released into water.

In addition, when the advanced water purification process using ozone (O ₃ ) or activated carbon is not carried out, a higher concentration of chlorine agent is injected into the raw water to kill the algae to improve the sedimentation of flocs. While maintaining it, it stops the photosynthetic reaction by the algae, stops the generation of oxygen from the cells of the algae, and prevents the flocs from rising. However, in such a method, the chlorine agent is caused to act at a high concentration on the raw water having a high pH value containing a large amount of the trihalomethane precursor derived from algae, so that the generation of trihalomethanes is extremely advanced. There was a problem that it would create an easy situation.

In view of the problems in purifying raw water containing a large amount of algae to obtain clean water, the present invention minimizes the amount of chemicals such as chlorine used, or does not use chemicals. It is an object of the present invention to provide an algae removing device for removing algae contained in algae and making it usable as tap water.

[0009]

In order to achieve the above object, the apparatus for removing algae of the present invention comprises a downward flow type filter in which fibers settling in water whose apparent density can be adjusted are entangled.
A piece of fiber formed into a non-woven fabric with a certain thickness
It is characterized in that a short piece of fibrous filter material bound by a weight is introduced.

In this algae removing device, a fibrous filter material in the form of a short piece that sinks into water whose apparent density can be adjusted is introduced into a downflow type filter, so that the required filtration is performed. In order to meet the processing conditions such as speed and washing interval, the apparent density, further, by adjusting the porosity of the fiber to be the filter medium, it is possible to perform an optimal filtration process according to the properties of the raw water, which allows Even if a large amount of algae is contained in the raw water, the algae contained in the raw water can be used for the subsequent treatment step with a simple configuration to minimize the amount of chemicals such as chlorine used or without using chemicals. The raw water can be made ready for use as tap water by efficiently and surely removing it to such an extent that it does not hinder and passing through a water treatment process such as normal filtration. Especially, as a fibrous filter material, entangle the fibers
A piece of fiber formed into a non-woven fabric with a certain thickness is
Uses a short piece of fibrous filter material bound by a weight
By doing so, the apparent density can be easily adjusted.
To manufacture a short piece of fibrous filter material that can
You can

Further, the downflow type filter is provided with air and / or
Alternatively, a mechanism for backwashing the fibrous filter material with wash water can be provided.

As a result, it is possible to automatically and easily wash the short-piece fibrous filter material put into the down-flow type filter, and maintain the filtration efficiency well for a long period of time. can do.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the algae removing device of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the algae removing apparatus of the present invention. This algae removal device is a downflow type filter 1
The filter 1 itself has a volume, shape, etc.
It can be appropriately set according to the amount of treated water and the like, and is not particularly limited, but in the present embodiment, a cylindrically formed one is used. Then, in the filter 1, a short amount of a fibrous filter material 10 in the form of a short piece that sinks in water whose apparent density can be adjusted is set in a predetermined amount, in the present embodiment, about 1/2 of the height of the filter 1. I am trying to throw it in. The amount of the fibrous filter material 10 can be appropriately set depending on the amount of treated water and the like.

At the lower and upper positions of this filter 1,
Connect multiple pipes to each. Specifically, at the lower position of the filter 1, an air supply pipe 2 and a cleaning water supply pipe 3 (reverse cleaning mechanism) for cleaning the fibrous filter medium 10 loaded in the filter 1, a filtration process. The treated water outlet pipe 4 for discharging the treated water, the waste water outlet pipe 5 for discharging the water in the filter 1 to lower the water level in the filter 1, and the chlorine water supply pipe 8 are connected. . Further, an exhaust pipe 6 and a raw water supply pipe 7 for supplying raw water to the upper position of the filter 1.
Connect. Further, the washing water after washing the fibrous filter medium 10 introduced into the filter 1 is discharged to a position above the layer of the fibrous filter medium 10 introduced into the filter 1 of the filter 1. For connecting the wash water outlet pipe 9. If necessary, a valve 2 may be attached to each pipe connected to the filter 1.
1, 31, 41, 51, 61, 81, 91 are arranged respectively.

In this case, the lower surface of the layer of the fibrous filter medium 10 charged in the filter 1 is connected to the lower position of the filter 1, the air supply pipe 2, the wash water supply pipe 3, the treated water outlet pipe 4, In order to be retained above the respective connection ports of the waste water outlet pipe 5 and the chlorine water supply pipe 8, a mesh body such as a perforated plate or expanded metal is formed in the vicinity of the lower portion of the filter 1 so as to be retained. A partition plate 1A that allows water and air to pass through and through which the fibrous filter material 10 does not pass is arranged to partition the inside of the filter 1.

As the short piece fibrous filter medium 10, various forms can be adopted. In this embodiment, as shown in FIG. 2 and FIG. 3, fibers such as polyester filaments are entwined with each other and randomly arranged, and if necessary,
Partially fused or adhered to form a non-woven fabric having a certain thickness, and a size suitable for use as a filter medium, for example, a diameter or one side is several mm to several tens mm, preferably A piece cut into a three-dimensional fiber piece 11 such as a cylinder, a cube, or a rectangular parallelepiped having a diameter of about 5 mm to about a dozen mm is used. Then, in order to adjust the apparent density of the fibrous filter medium 10 and prevent the fiber piece 11 itself from separating, the fiber piece 11 is penetrated through the fiber piece 11 as shown in FIG. Weight 12 that formed
Alternatively, as shown in FIG. 3, a staple-shaped dead weight 12
To be bound by In addition, as shown in the reference example of FIG. 4, the short piece fibrous filter medium 10 has both ends (FIG. 4 (A)) or one end (FIG. 4 (A)) of a fiber bundle 13 formed by bundling fibers such as polyester long fibers. It is also possible to use the one shown in FIG. 4 (B) bound by a ring-shaped weight 12. In this case, metal, heavy plastic, or the like can be used for the weight 12, but since the weight 12 is in direct contact with raw water, the fiber piece 11 and the fiber bundle 13 are formed. The material suitable for food hygiene is adopted so that the treated water can be used as drinking water together with the fiber.

As a result, the fibrous filter material 1 in the form of a short piece is formed so as to meet the processing conditions such as the required filtration rate and cleaning interval.
The apparent density of 0 is set to be larger than 1.0 so as to settle in water, and further, the porosity of the fibers to be the filter medium (between the short fibrous filter media 10 and between the fiber pieces 11 and the fiber bundles 13). (The porosity between the fibers constituting the) is maintained at an appropriate value over a long period of time, and the air or the cleaning water supplied from the air supply pipe 2 or the cleaning water supply pipe 3 as the back-cleaning mechanism. Thus, it is possible to easily adjust so that the backwashing is carried out with certainty, and it is possible to perform an optimum filtration treatment according to the property of the raw water. In addition, this makes it possible to inexpensively manufacture the short-piece fibrous filter medium 10 that easily sediments in water and can be easily adjusted.

Next, a method of using the algae removing device will be described. Cyanobacteria mainly of the genus Microcystis, such as water-bloom, have a strong reproductive ability especially in the summer when the water temperature is high. Therefore, the water of the water source such as rivers and lakes for taking the raw water may have a color like dissolved green tea due to the reproduction of cyanobacteria. like this,
When purifying raw water containing a large amount of algae such as cyanobacteria to obtain clean water, the raw water is directly introduced from the raw water supply pipe 7 into the down-flow type filter 1 in which the fibrous filter medium 10 is introduced. To do so. Since the apparent density of the fibrous filter medium 10 is set to be greater than 1.0, the fibrous filter medium 10 is settled in water and can be adapted to any filtration flow rate due to the downward flow. The filter material 10 is retained as a layer having a certain thickness on the partition plate 1A,
The raw water introduced into the filter 1 flows through the layer of the fibrous filter medium 10 from the upper side to the lower side.
Then, at this time, the porosity of the fibers as the material of the fibrous filter material 10 (between the short fibrous filter materials 10 and the fiber pieces 11).
Or the porosity between the fibers constituting the fiber bundle 13) is set according to the required processing conditions such as filtration rate and washing interval, specifically, the type (size) and amount of algae contained in the raw water. By doing so, the algae contained in the raw water are fibrous filter media 10
Only the water that has been captured, removed and filtered by the layer (1) is discharged via the treated water outlet pipe 4 connected to the lower part of the filter 1 and supplied to the treatment equipment in the subsequent stage. In this case, even for cyanobacteria mainly of the genus Microcystis such as blue-green algae that exist in the form of a relatively large colony, the porosity of the fibers of the fibrous filter medium 10 is adjusted, specifically, the porosity is set to be large. By doing so, most of the algae contained in the raw water, for example, 80 to 90%, can be captured and removed without reducing the filtration efficiency.

By the way, if the raw water is continuously filtered in this manner, the fibrous filter medium 10 will eventually come out.
The voids in the fibers become clogged with algae, and the head loss is gradually rising. If this head loss exceeds a predetermined value, the filtration efficiency of the raw water will be significantly reduced. Therefore, in such a case, the supply of the raw water to the filter 1 is stopped. next,
The water in the filter 1 is discharged through the waste water outlet pipe 5, and the water level in the filter 1 is lowered to a water level suitable for air cleaning. After that, when air for cleaning the fibrous filter medium 10 is supplied from the air supply pipe 2 into the filter 1, this air flows through the layer of the fibrous filter medium 10 from the lower side to the upper side, and the reverse cleaning is performed. By being performed, the short-piece fibrous filter media 10 are moved relative to each other so as to float, and algae clogged between the short-flame fibrous filter media 10 and between the fibers constituting the fiber pieces 11 and the fiber bundles 13, Other suspended matter can be removed by blowing it away. The air supplied from the air supply pipe 2 is discharged from the exhaust pipe 6 connected to the upper position of the filter 1. Simultaneously with or separately from this, when wash water for washing the fibrous filter medium 10 is supplied from the wash water supply pipe 3 into the filter 1, this wash water causes a layer of the fibrous filter medium 10 to flow. By flowing from the lower side to the upper side and performing back washing, the short-piece fibrous filter media 10 are moved to each other so as to be floated up, and the short-fiber-like fibrous media 10 and the fiber pieces 11 and the fiber bundles are moved. Thirteen
It is possible to remove algae and other suspended matter clogged between the fibers constituting the water together with the washing water. This wash water supply pipe 3
The wash water supplied from the above is discharged from the wash water outlet pipe 9 connected to a position above the layer of the fibrous filter medium 10 charged in the filter 1 of the filter 1.

In the same manner, filtration of raw water and washing of the fibrous filter medium 10 are repeated in the same manner.

In this case, if necessary, the water in the filter 1 is discharged through the waste water outlet pipe 5 so that the fibrous filter medium 10 is almost exposed and the chlorine water supply pipe 8 is discharged.
Therefore, it is possible to supply about 2.0 to 4.0 mgCl ₂ / L of chlorine water into the filter 1 and immerse the fibrous filter medium 10 in chlorine water. This chlorine water dipping process
For example, after the fibrous filter medium 10 is washed, it may be performed for about 30 minutes, or once a week, or for about 60 minutes at a time when almost no water is used at night. You can also This sterilizes bacteria that produce slime (for example, high molecular weight polysaccharides) that blocks the voids between the fibers that form the fiber pieces 11 and the fiber bundles 13 of the fibrous filter medium 10 and also decomposes the slime itself. Then, the fibrous filter medium 10 can be returned to a clean original state. When the set time of immersion of the chlorine water is completed, the chlorine water is discharged from the waste water outlet pipe 5, and thereafter, the filtration of the raw water and the washing of the fibrous filter medium 10 are similarly repeated.

By using this algae removing device, the inflow of algae to the next step can be remarkably reduced, and an excessive burden on the water treatment step after the next step such as a floc formation pond and a sand filter pond. Can be reduced.

As a result, algae contained in the raw water can be efficiently and surely removed to the extent that they do not interfere with the subsequent treatment steps, without using chemicals such as chlorine to the minimum or without using chemicals. By going through a water treatment process such as ordinary filtration, the raw water can be made ready for use as tap water.

As described above, the algae removing apparatus of the present invention is
Although described based on the embodiment, the present invention is not limited to the structure described in the above embodiment, and the structure can be appropriately changed without departing from the spirit of the invention. Further, the algae removing device of the present invention,
In addition to being used for directly filtering raw water containing algae,
By directly introducing the treated water that has been subjected to the chemical precipitation step into the filter 1, it can be used for removing floc algae floating in the treated water. As a result, it is possible to reduce an excessive burden on the water treatment process after the next process such as a sand filter.

[0026]

According to the apparatus for removing algae of the present invention, a short-piece fibrous filter material that sinks in water whose apparent density can be adjusted is introduced into a downflow type filter. Therefore, it is necessary to adjust the apparent density and further the porosity of the fiber to be used as the filter medium so as to meet the required processing conditions such as the filtration rate and the cleaning interval, and perform the optimum filtration process according to the properties of the raw water. Therefore, even if a large amount of algae is contained in the raw water, the algae contained in the raw water can be used with a simple structure to minimize the amount of chemicals such as chlorine used or without using chemicals. The raw water can be made ready for use as tap water by efficiently and reliably removing soybeans to the extent that it does not interfere with the subsequent treatment steps and undergoing a water treatment step such as ordinary filtration. Especially as a fibrous filter material,
Formed into a non-woven fabric with a certain thickness by entwining fibers
Fibrous filtration in the form of short pieces composed of fiber pieces bound by weights
By using the material, the apparent density can be easily
Producing short length fibrous filter media that can be adjusted at low cost
Can be built. By using this algae removal device, troubles such as aggregation of flocs and scumming in the advanced water purification process using ozone (O ₃ ) or activated carbon, especially ozone (O ₃ ) treatment process can be prevented. Also, it is possible to prevent waste of ozone (O ₃ ) and a decrease in adsorption capacity of activated carbon due to chlorine, and further to prevent generation of trihalomethanes which are cancer-inducing substances.

Further, the downflow type filter is provided with air and / or
Alternatively, by arranging a backwashing mechanism for the fibrous filter material with washing water, it is possible to automatically and easily wash the short piece-like fibrous filter material put into the downflow type filter. Therefore, the filtration efficiency can be favorably maintained over a long period of time.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the algae removing device of the present invention.

FIG. 2 shows an example of a fibrous filter material, (A) is an external view,
(B) is a sectional view.

FIG. 3 shows an example of a fibrous filter material, (A) is an external view (front side), (B) is an external view (back side), and (C) is a sectional view.

FIG. 4 shows a reference example of a fibrous filter material, (A) is an external view of a fiber bundle in which both ends are bound with a weight, and (B) is an external view of a fiber bundle in which one end is bound with a weight.

[Explanation of symbols]

1 filter 1A partition board 2 Air supply pipe (reverse cleaning mechanism) 3 Wash water supply pipe (back washing mechanism) 4 Treated water outlet pipe 5 waste water outlet pipe 6 exhaust pipe 7 Raw water supply pipe 8 Chlorine water supply pipe 9 Wash water outlet pipe 10 Fibrous filter media 11 fiber pieces 12 weights 13 fiber bundle

Claims (2)

(57) [Claims] 1. A downflow type filter is entangled with fibers settling in water whose apparent density can be adjusted to a certain thickness.
Fiber pieces formed into a non-woven fabric are bound by a dead weight.
An apparatus for removing algae, characterized in that a short piece of fibrous filter material formed is introduced. 2. The apparatus for removing algae according to claim 1, wherein a downflow type filter is provided with a backwashing mechanism for the fibrous filter material by air and / or wash water.