JP2014217806A - Water purification method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water purification method and apparatus which enable improvement of transparency, reduction of SS, and reduction of BOD and COD.SOLUTION: A water purification method includes: a coagulating sedimentation treatment step 2 of adding a coagulant to water to be treated to perform coagulating sedimentation treatment; a filtration treatment step 3 of filtering treated water obtained in the coagulating sedimentation treatment step 2; a porous concrete block treatment step 5 of bringing treated water obtained in the filtration treatment step 3 into contact with porous concrete blocks carrying aerobic microorganisms to subject the treated water to biological treatment; and an air supply treatment step 6 of mixing air into treated water obtained in the porous concrete block treatment step 5.

Description

  The present invention relates to a water purification method and a water purification device for purifying water such as an aquarium, pond, lake, or river.

Examples of methods for purifying water in aquariums, ponds, lakes, rivers, etc. include, for example, a method in which air is blown into the water and aeration, a method in which bacteria that decompose pollutants and pollutants are introduced, and a chemical or water purification material is introduced. And a method for breeding aquatic plants. However, these methods improve water transparency, reduce suspended suspension (hereinafter referred to as SS), biochemical oxygen consumption (hereinafter referred to as BOD) and chemical oxygen consumption (hereinafter referred to as COD). ) Was not sufficient to achieve the goal of reducing.
In particular, rivers and the like are becoming richer in nitrogen and phosphorus in water due to the inflow of industrial wastewater and the use of agricultural chemicals and fertilizers, but the above treatment methods are effective for water containing phosphorus. It wasn't.

Patent Document 1 describes a water purification method that uses a porous concrete block and a phosphorus adsorbent block to remove organic substances, nitrogen compounds, and phosphorus contained in water.
This method decomposes and removes organic matter in polluted water into carbon dioxide and water, and nitrogen compounds into nitrogen gas, and removes volcanic ash and ferrous sulfate. Phosphorus is adsorbed and removed by a phosphorus adsorbent block obtained by mixing and baking.
However, it is generally considered that microorganisms cannot live when microbial bacteria are mixed in strong alkali cement, but Patent Document 1 does not specifically disclose what is used as microorganisms.

  Patent Document 2 discloses a water purification method comprising a step of passing polluted water through a porous mineral filter medium and a step of removing a suspended matter (floc) in water generated by passing water through a settling tank. There is a description. In this method, in view of the necessity of periodically replacing the phosphorus adsorbent in the method of Patent Document 1, a large amount of microorganisms such as plankton and algae are gathered when the polluted water comes into contact with the mineral filter medium, and flocs are collected. Forming, fixing phosphorus in the floc, and removing the floc by precipitation eliminates the need for frequent replacement of the phosphorus adsorbent.

  Patent Document 3 discloses a method for purifying the water quality of a purification target water area by disposing a water purification material formed by solidifying a mixture of granular aggregate, cement-based solidifying agent and aerobic microorganisms in the purification target water area. Is described.

  However, the methods described in Patent Documents 1 to 3 also improve water transparency, reduce suspended suspension (hereinafter referred to as SS), biochemical oxygen consumption (hereinafter referred to as BOD), and chemical oxygen consumption. It was not sufficient to achieve the purpose of reducing the amount (hereinafter referred to as COD).

JP-A-8-229547 Japanese Patent Laid-Open No. 10-216708 JP 2011-189254 A

  The present invention relates to a water purification method and a water purification apparatus capable of improving transparency, reducing SS, reducing biochemical oxygen consumption (hereinafter referred to as BOD) and chemical oxygen consumption (hereinafter referred to as COD). The purpose is to provide.

As a result of intensive studies by the inventor, the present invention has been completed by finding that the above problems can be solved by combining a coagulation sedimentation treatment, a filtration treatment and a porous concrete treatment.
That is, the present invention relates to a water purification device and a water purification method as described below.

(1) A water purification method for purifying treated water,
A coagulation-precipitation treatment step in which a coagulant is added to the water to be treated to perform the coagulation-precipitation treatment;
A filtration treatment step for filtering the treated water obtained in the aggregation and precipitation treatment step;
A porous concrete block treatment step for biologically treating the treated water obtained in the filtration treatment step with a porous concrete block supporting aerobic microorganisms;
An air supply treatment step of mixing air with the treated water obtained in the porous concrete block treatment step;
Including water purification methods.
(2) The method further includes a phosphorus adsorption treatment step of treating the treated water obtained in the filtration treatment step with a phosphorus adsorbent between the filtration treatment step and the porous concrete block treatment step (1). The water purification method as described in 2.
(3) The aerobic microorganism comprises one or more of Bacillus subtilis, Bacillus thuringiensis, Bacillus sphaericus (1) Or the water purification method as described in (2).
(4) A water purification device for purifying treated water,
A coagulation sedimentation apparatus for performing coagulation sedimentation treatment by adding a coagulant to the water to be treated;
A filtration device for filtering the treated water obtained by separating the flocs obtained from the coagulation sedimentation device;
A porous concrete block device filled with a porous concrete block carrying aerobic microorganisms for biologically treating the treated water obtained by the filtration device;
An air supply device for mixing air with the treated water obtained by the porous concrete block device;
Including water purification equipment.
(5) The method further comprises a phosphorus adsorption treatment device for treating the treated water obtained by the filtration treatment device with a phosphorus adsorbent between the filtration treatment device and the porous concrete block treatment device (4). The water purification method as described in 2.
(6) The aerobic microorganism includes one or more of Bacillus subtilis, Bacillus thuringiensis, Bacillus sphaericus (4) Or the water purification apparatus as described in (5).

  According to the present invention, for treated water, transparency is improved, SS is reduced, biochemical oxygen consumption (hereinafter referred to as BOD), chemical oxygen consumption (hereinafter referred to as COD) is reduced, and phosphorus is reduced. It can be performed.

It is a flowchart figure of the water purification method of this invention. It is a figure which shows an example of embodiment of the water quality purification method of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a flowchart of each processing step performed by the water purification method of the present invention.
The water purification method of the present invention is a combination of the coagulation sedimentation treatment 2, the filtration treatment 3, the phosphorus adsorption treatment 4 and the porous concrete treatment 5 in this order. In addition, the said phosphorus adsorption process 4 is a process provided as needed, when processing the water of the river in which many phosphorus is contained.
The water purification method of the present invention can be applied to the purification of water in aquariums, ponds, lakes, rivers, etc. In the following, an example of using the water purification method of the present invention for purification of water in a fish pond is shown. 1 will be described.

[Coagulation sedimentation process]
First, water (treated water) in the pond 1 is sent to the coagulation sedimentation treatment process 2 by the pump 7. In the coagulation sedimentation step 2, a coagulant is added to water and stirred to agglomerate the SS component contained in the water to agglomerate to form a floc, and floc sedimentation separation that separates the floc from the water containing the floc. Processing 22 is performed.
In the agglomeration treatment step 21, the aggregating agent is added while stirring the agglomeration tank, and the particles floating in the water are agglomerated to flock.

As the flocculant, known ones can be used. For example, aluminum flocculants such as aluminum sulfate and polyaluminum chloride, inorganic flocculants such as iron flocculants such as iron sulfate and iron chloride, and polyacrylamide polymer flocculants. An organic flocculant such as an agent can be used.
In the floc sedimentation process 22, if necessary, a plurality of sedimentation tanks are provided to settle the flocs. If necessary, the solids are removed by passing through a sand filter and a mat filter. The separated water discharged out of the system and from which the floc content has been removed is sent to the next filtration step 3 by the pump 8.

[Filtering process]
In the filtration treatment step 3, the SS component that could not be separated in the coagulation sedimentation treatment step 2 is further separated to improve the water quality. In the filtration process 3, a filtration device is used.
A known apparatus can be used as the filtration apparatus, but it is preferable to use a structure capable of backwashing, and appropriately perform backwashing using regenerated water so that the filter medium can be regenerated.

As a filtration apparatus, what is used for normal water filtration apparatuses, such as a sand filtration apparatus and a filtration mat, can be used. As the filter medium of the sand filter, in addition to gravel, gravel, sand, etc., porous minerals such as anthracite, ceramics, etc. can be used, but quartz sand and anthracite are the most common. The filter medium is preferably filled with a large particle size on the upstream side, a small particle size on the downstream side, and a medium particle size in the center. In the filtration process, different filtration means such as a sand filtration device and a filtration mat may be used in combination.
The water treated in the filtration treatment step 3 is sent to a phosphorus adsorption treatment step 4 provided as necessary after removing solids with a mat filter as necessary.

[Phosphorus adsorption process]
In this phosphorus adsorption treatment step 4, phosphorus contained in water is adsorbed and removed by the phosphorus adsorbent. This phosphorus adsorption treatment process is a process provided as needed when treating river water containing a large amount of phosphorus.
A well-known thing can be used as a phosphorus adsorption agent. For example, it becomes insoluble by contact with porous foam glass with numerous voids and large specific surface area, and phosphorus in wastewater such as coal ash, volcanic ash, blast furnace molten slag, waste molten slag containing a large amount of calcium. A particulate material that produces hydroxyapatite can be used.
The water from which phosphorus has been removed is sent to the porous concrete processing step 5.

[Porous concrete processing process]
In the porous concrete treatment process 5, water is biologically treated by contacting with a porous concrete block containing an aerobic microorganism as an admixture.
Porous concrete is porous concrete having communication holes manufactured by blending a larger ratio of coarse aggregate to fine aggregate than ordinary concrete.

  As the porous concrete block used in the present invention, a porous aggregate having a particle size of about 2.5 mm to 10 mm which is a granular aggregate, a cement paste which is a cement solidifying agent, and a Bacillus subtilis which is an aerobic microorganism ( What was formed by solidifying the mixture with the aerobic natto group classified into Bacillus Subtilis) can be used. Specifically, if a cement paste mixed with aerobic natto bacteria is mixed with porous aggregate and water, this mixture is placed in a mold and molded, then cured, solidified, and demolded. A porous concrete block is obtained.

  The aerobic microorganism preferably includes one or more of Bacillus subtilis, Bacillus thuringiensis, and Bacillus sphaericus. These aerobic microorganisms have excellent alkali resistance and can withstand high temperatures, so they do not die in the production process of water purification materials using cement-based solidifying agents and exhibit excellent water purification effects over a long period of time. To do.

  The shape of the porous concrete block can be an appropriate shape according to the shape of the container for storing the concrete block. However, when a cylindrical container is used as the processing apparatus, the block is formed in a disk shape and is cylindrical. A plurality of sheets are stacked and accommodated so that the surface of the block is perpendicular to the axial direction of the container.

  Due to the porous structure of the concrete block, a large number of micropores contained in the porous structure become suitable habitats for aerobic microorganisms, and the propagation and activities of aerobic microorganisms become active. Since there are many opportunities for contact with water, the action of decomposing pollutants increases and the water purification function is improved.

[Air supply processing]
The air supply treatment process is a process of mixing air with water before returning the water sent from the porous concrete treatment process to the pond 1. As a device for this purpose, a Venturi type mixing device that mixes fluid using a Venturi tube can be used. Thus, by mixing air with water, when the water containing air is returned to the pond, the air becomes fine bubbles in the water of the pond, increasing dissolved oxygen in the water and improving the water quality And it is effective in preventing fish from rising.

The aerobic microorganisms flowing out from the concrete block by the treated water in the porous concrete treatment process are released into the pond together with the treated water mixed with air in the air supply treatment process, thereby purifying the pond water. .
In addition, bubbles present in the water erupt into the water of the pond to increase the amount of dissolved oxygen in the water, thereby preventing the growth of various bacteria and preventing the fish from rising.

An embodiment of the present invention will be described with reference to FIG.
The embodiment described below is merely an example and does not limit the present invention.

By driving the water supply pump 37, the water in the pond is pumped up through the suction filter 41 and supplied to the coagulating sedimentation device 32.
The coagulation sedimentation apparatus 32 consists of a first tank to a sixth tank, and water is first stored in the first tank. Water overflowed from the first tank flows into the second tank. The solid content settled in the first tank moves from the bottom of the first tank to the second tank.
The flocculant is charged into the second tank from the flocculant charging device 51 and mixed with the water in the tank by a stirrer. SS contained in water aggregates to form flocs by the action of the flocculant.
The water containing the floc settles in the third tank, and is then transferred to the fourth layer where the floc is discharged from the bottom of the fourth tank. The water overflowing the fourth tank flows into the fifth tank having the collision plate 52, and the solid-liquid separation is further promoted by the action of the collision plate 52, so that the floc settles. The settled flock is discharged from the bottom of the fifth tank, and the water overflowing the fifth tank removes the solid content floating through the filter medium 42 composed of the sand filter and the mat filter and flows into the sixth tank.

The overflow water in the sixth tank is sent to the sand filtering device 33 by the drainage pump 38, and the SS that could not be settled and separated by the coagulating sedimentation device 32 is removed.
The sand filter 33 is filled with 0.3 m ³ of cinnabar sand having an average particle diameter of 1.5 mm as a filter medium.
The sand filtration device 33 is provided with a backflow cleaning device 44, and when the filter medium is clogged, the backflow cleaning is performed to regenerate the filter medium.
The water treated by the sand filtration device 33 is sent to the mat filter 43, and after removing fine flocs that have passed through the voids of the filtration sand, it is sent to the phosphorus adsorption device 34 in the next step.

The phosphorus adsorption device 34 used was a container filled with particulate phosphorus adsorbent. As the phosphorus adsorbent, porous foamed glass (porous α: manufactured by Tottori Recycling Laboratory Co., Ltd.) was used, and the filling amount was 0.2 m ³ .
The treated water adsorbed with phosphorus is sent to the porous concrete block device 35 in the next step.

The porous concrete block used was a mixture of aerobic natto bacteria mixed with porous aggregate and cement. The block is a porous block with outer dimensions of 400 x 400 x 200 mm and an actual volume of 15 liters. Six blocks are accommodated in a container on a prism and water is passed through the outer surface and holes of the block. A porous concrete block device 35 was obtained.
The water treated by the porous concrete block device is then sent to the air supply device 36.

The water treated by the porous concrete block device 35 is mixed with air by the air supply device 36. A venturi type mixing device was used as the air supply device.
The water mixed with air by the air supply device 36 is discharged into the water of the pond 31 as purified water.

(Test results)
When the water of the fish farm (water volume 50 m ³ ) was purified by the water purification apparatus of the present invention, the water quality was initially 10 to 20 ppm for COD, 10 ppm for BOD, 0.5 ppm for total phosphorus, and 0.2 ppm for phosphorous phosphorus. Yes, the transparency was 10-15 cm, but after 30 days, COD was 3 ppm, BOD was 2 ppm, total phosphorus was 0.2 ppm, phosphate phosphorus was 0.08 ppm, and the transparency was 80-100 cm or more Improved.

DESCRIPTION OF SYMBOLS 1 Pond 2 Coagulation sedimentation treatment process 3 Filtration treatment process 4 Phosphorus adsorption treatment process 5 Porous concrete treatment process 6 Air supply treatment process 7 Pump 8 Pump 21 Coagulation treatment 22 Flock sedimentation treatment 31 Pond 32 Coagulation sedimentation device 33 Sand filtration device 34 Phosphorus Adsorption device 35 Porous concrete block device 36 Air supply device 37 Water supply pump 38 Drainage pump 41 Suction filter 42 Filter medium 43 comprising sand filter and mat filter Mat filter 44 Backflow cleaning device 51 Coagulant feeding device 52 Collision plate 52

Claims (6)

A water purification method for purifying treated water,
A coagulation-precipitation treatment step in which a coagulant is added to the water to be treated to perform the coagulation-precipitation treatment;
A filtration treatment step for filtering the treated water obtained in the aggregation and precipitation treatment step;
A porous concrete block treatment step for biologically treating the treated water obtained in the filtration treatment step with a porous concrete block supporting aerobic microorganisms;
An air supply treatment step of mixing air with the treated water obtained in the porous concrete block treatment step;
Including water purification methods.   The phosphorus adsorption treatment step of treating the treated water obtained in the filtration treatment step with a phosphorus adsorbent between the filtration treatment step and the porous concrete block treatment step. Water purification method.   The aerobic microorganism comprises one or more of Bacillus subtilis, Bacillus thuringiensis, and Bacillus sphaericus, according to claim 1 or 2. The water purification method as described. A water purification device for purifying treated water,
A coagulation sedimentation apparatus for performing coagulation sedimentation treatment by adding a coagulant to the water to be treated;
A filtration device for filtering the treated water obtained by separating the flocs obtained from the coagulation sedimentation device;
A porous concrete block device filled with a porous concrete block carrying aerobic microorganisms for biologically treating the treated water obtained by the filtration device;
An air supply device for mixing air with the treated water obtained by the porous concrete block device;
Including water purification equipment.   5. The phosphorus adsorption treatment apparatus according to claim 4, further comprising a phosphorus adsorption treatment apparatus for treating the treated water obtained by the filtration treatment apparatus with a phosphorus adsorbent between the filtration treatment apparatus and the porous concrete block treatment apparatus. Water purification method.   The aerobic microorganism includes one or more of Bacillus subtilis, Bacillus thuringiensis, and Bacillus sphaericus, according to claim 4 or 5. The water purification apparatus as described.

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