Water purification agent and water purification method

Abstract

To provide a water quality purification agent for river water, lake water, etc., capable of easily and inexpensively purifying river water, lake water, pond water, or groove water used as they are, and a water quality purification method.SOLUTION: There are provided: a water quality purification agent containing organic matter-removed shells or crushed pieces thereof; and a water quality purification method including a step of bringing processing object water into contact with the water quality purification agent.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a water purification agent suitable for purifying the water quality of river water, lake water, pond water, or pool water with a large water volume, etc., and a water purification method using the same.

Background Art

[0002] Generally, for water purification when the water volume of sewage, wastewater, etc. is small, a sewage and wastewater treatment device is constructed, and for the activated sludge method and its modified methods, and in the case of advanced treatment, subsequently, devices such as a filtration device, coagulation sedimentation method, activated carbon adsorption method, ozone oxidation method, and contact aeration method are connected and installed in the treatment process.

[0003] Currently, for the purification of river water, lake water, pond water, or pool water with a large water volume, etc., since the equipment cost for purification is extremely high, there are few cases where it is implemented, and it is mostly left to the natural self-purification ability or diluted with other water. However, in the case of a large water volume, river water and lake water suitable for water supply are ensuring the target water quality through combinations of respective devices and supplying it to citizens. Also, for sewage, it is collected through sewer pipes, purified to a water quality that satisfies the discharge regulation values by combining treatment devices, and discharged into public waters.

[0004] The methods in that case are, in the case of sewage and wastewater with advanced pollution, the activated sludge method of purifying using microorganisms, and in the case of less dirty water, the sedimentation method, filtration method, coagulation sedimentation method, ozone oxidation method, activated carbon adsorption method, reverse osmosis method, etc. are used to install treatment facilities in a single or continuous process so as to achieve the required water quality.

[0005] Regarding the method of purifying river water, lake water, pond water, or pool water, etc. for use in agricultural water, aquaculture water, and landscape use, an inexpensive and easily maintainable method has not yet been found.

[0006] By the way, as a water purification method using oyster shells, a method has been reported in which fired oyster shells are crushed and submerged in the aeration tank of the activated sludge method to suppress the generation of activated sludge (Patent Document 1). However, the target of such a method is a case where the amount of water is small compared to river water, lake water, pond water, or moat water, etc., and it is necessary to install a predetermined treatment facility such as an aeration tank.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Providing a predetermined treatment facility for water purification targeting river water, lake water, pond water, or moat water, etc. with a large amount of water is not realistic from the perspective of equipment costs. Also, it is not easy to purify lake water, etc. to a water quality that can intentionally satisfy its uses as agricultural water or fishery water. There are already reported cases where it is left to the natural self-purification ability, or cleaner river water is used and flowed into ponds, moats, and marshes for purification by dilution, and these are already known. For this, it is a condition that cleaner river water flows nearby and that a large amount of money is required to ensure the amount of water that can be diluted.

[0009] Therefore, an object of the present invention is to provide a water purification agent and a water purification method for river water, lake water, etc. that can easily and inexpensively purify river water, lake water, etc. using the water as it is.

Means for Solving the Problems

[0010] That is, the present invention relates to the following [1] to [2]. [1] A water purification agent containing shellfish from which organic substances have been removed or a crushed product thereof. 〔2〕A water purification method comprising a step of bringing the water purifying agent according to 〔1〕 into contact with water to be treated.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a water purifying agent and a water purification method for lake water and the like that can be easily and inexpensively purified using river water, lake water, pond water, or moat water as it is.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0013] For the purification of water quality such as river water, lake water, pond water, or moat water, a method that does not require a large installation cost, is easy to maintain and manage, and does not generate a large amount of sludge as a result of purification and does not incur a large cost for its disposal is required.

[0014] The present invention has been made in view of such circumstances, and activates the activities of microorganisms living in water, and by the action of the microorganisms, purifies water such as river water, lake water, pond water, or moat water to a water quality suitable for the intended use. Therefore, it is different from a method using activated sludge containing a large amount of microorganisms such as the activated sludge method. In addition, in the water purification by the method of the present invention, it can be expected that water such as river water, lake water, pond water, or moat water can be purified to a satisfactory level as agricultural water or fishery water.

[0015] Therefore, this invention discloses a method of purifying water quality by submerging a purification device in the river or lake to be purified, rather than installing a purification facility on land. The advantages of this method are that the device is small, the maintenance cost is low, maintenance is easy, and the generation of sludge due to purification is not an issue. In addition, it does not affect the scenery of the natural environment.

[0016] The mechanism by which water purification is achieved by the present invention is presumed to be as follows. Shells, particularly oyster shells which are inexpensive and readily available, are incinerated to remove organic matter, and then crushed into a crushed material (e.g., powder). In one preferred embodiment, the crushed material is mixed with cement or the like to form a compact into a lump. Such shells from which the organic matter has been removed, their crushed material, and / or the compact of the crushed material are placed in a container, for example, in a target river or lake, as a water purification agent. It is hypothesized that one to two weeks after installation, the eluted components will become a source of nutrition for the microorganisms and bacteria in the water, increasing bacterial activity, and at the same time, the types of bacteria that are useful for purifying the water (aerobic bacteria) will become dominant, promoting purification, and as a result, purified water that meets the desired water quality will be obtained.

[0017] A first aspect of the present invention is a water purifying agent comprising shells or crushed shells from which organic matter has been removed. In the first aspect of the present invention, one of the major features is that the components of oyster shells, etc., from which organic matter has been removed (e.g., calcium, magnesium, potassium, iron, boron, etc.) are slowly and continuously distributed in the water to be purified. Another major feature of the present invention is that water purification can be achieved in water under natural environments.

[0018] Due to the above-mentioned features, the present invention is effective for treating large volumes of water such as river water, lake water, pond water, moat water, etc. Another feature of the present invention is that the purification process does not result in the problem of generation of sludge, which is a mass of microorganisms.

[0019] In one embodiment of the present invention, when the aggregated oyster shell components are used as a water purification agent, the amount of water to be purified is determined by the weight of the water purification agent, so that the weight of the water purification agent can be set according to the amount of water to be purified, and the water purification agent can be effectively used. For example, the amount of water to be treated and the water purification agent can be set in the amount to be used as described in the second aspect below.

[0020] The shells used in the present invention may be any shells that live in seawater, freshwater or brackish water, such as clams, short-necked clams, surf clams, oysters, mussels, abalone, turban shells, scallops, cockles, and ark shells. These may be used alone or in combination of two or more types. Among them, oyster shells are preferable from the viewpoint of being easily available in large quantities.

[0021] The crushed shells used in the present invention are not particularly limited, but are prepared by crushing the shells using a crushing roller, a roll press, or the like.

[0022] The obtained crushed shells may be in a state in which the shells do not substantially retain their original shape, and is preferably in a powder form to improve the elution of the shell components, and specifically, the maximum diameter is preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 125 μm or less. The lower limit is not particularly limited, but from the viewpoint of workability, 100 μm or more is preferable.

[0023] In this specification, organic matter refers to organic matter that is normally contained in the shell, such as collagen, elastin, keratin, and fibroin.

[0024] As used herein, "removing organic substances" means substantially removing organic substances from the shells, and "substantially removing" means removing the organic substance concentration contained in the shells to preferably 2% by weight or less, more preferably 1% by weight or less, still more preferably 0.1% by weight or less, and particularly preferably completely removing. The organic substance concentration can be measured using the loss on ignition as an index. By removing organic substances, the elution property of the inorganic components contained in the shells or their crushed materials is improved.

[0025] Examples of the method for removing organic substances from the shells include, for example, a method of firing using a rotary kiln, a method of incinerating using a fixed-bed incinerator, a fluidized-bed incinerator, etc. From the viewpoint of easily recovering the shells from which organic substances have been removed, a method of firing using a rotary kiln is desirable. By firing using a rotary kiln, it is possible to easily achieve substantially removing organic substances from the shells. The conditions for firing the shells or their crushed materials are desirably such that the organic substance concentration in the fired shells or their crushed materials becomes the aforementioned organic substance concentration, and particularly preferably, the conditions are such that the organic substances contained in the shells or their crushed materials are completely removed. By using the fired shells or their crushed materials, the organic substances contained in the shells or their crushed materials are removed, the deposition of excess organic substances in the target lakes, ponds, ditches, etc. is prevented, and furthermore, the elution property of the inorganic components contained in the shells or their crushed materials is improved.

[0026] The shells or their crushed materials used in the present invention may be prepared as described above, but commercially available products such as Celka (manufactured by Kato Industry Co., Ltd.) may also be used. Celka is a powder mainly composed of calcium carbonate obtained by firing oyster shells, and the organic substances have been substantially removed.

[0027] The content of the shells or their crushed materials in the water purifying agent of the present invention is not particularly limited as long as the desired effect can be obtained, but is preferably 80 to 100% by weight, more preferably 90 to 100% by weight, still more preferably 95 to 100% by weight.

[0028] The water purifying agent of the present invention is preferably a shaped body formed into a lump from the viewpoint of easy handling and further sustained effect. The lump refers to the state in which the water purifying agent is in a lump, and the shape thereof includes, but is not limited to, for example, a sphere, a triangular pyramid, a square pyramid, a triangular prism, a square prism, etc. Among them, from the viewpoint of improving the dissolution rate of inorganic components contained in shells or their crushed products, a sphere having a large surface area is preferable.

[0029] When the water purifying agent of the present invention is in a spherical form, the size is preferably 5 to 50 mmφ, more preferably 25 to 50 mmφ, from the viewpoint of improving the dissolution rate. When the water purifying agent of the present invention is in a spherical form, the weight is preferably 5 to 100 g, more preferably 20 to 60 g, from the viewpoints of the dissolution rate and handleability.

[0030] The method for forming the water purifying agent of the present invention into agglomerates includes, for example, adding inorganic binders such as water glass and cement, or organic binders such as vinyl acetate resin adhesives and epoxy resin adhesives, and water to the shells or their crushed material, kneading the mixture with a kneader or the like, shaping the mixture into a desired shape, and drying the mixture. The amount of inorganic binder or organic binder and water to be added is not particularly limited as long as the mixture can be formed into agglomerates. For example, the inorganic binder is preferably 2 to 10% by weight, more preferably 4 to 6% by weight, in the water purifying agent of the present invention, and the water is preferably as little as possible, preferably 1.0% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.1% by weight or less, in the water purifying agent of the present invention.

[0031] The water purifying agent of the present invention may further contain additives according to various purposes as appropriate, so long as the effects of the present invention are not impaired.

[0032] The second aspect of the present invention is a water purification method including a step of bringing the water purifying agent of the present invention obtained as described above into contact with the water to be treated. In the invention of the second aspect, the water to be treated is not particularly limited, and examples thereof include river water, lake water, pond water, or moat water.

[0033] In a method for purifying the water quality of river water, lake water, pond water, moat water, etc., the amount of the water purifying agent used is appropriately set according to the amount of river water, lake water, pond water, moat water, etc. to be purified, the concentration of contaminants contained therein, or the target water quality items, etc. However, in the case of river water, lake water, pond water, moat water, etc. with a water quality that is not suitable for agricultural water, fishery water, or landscape water, from the viewpoints of exhibiting a purification effect and cost-effectiveness, for 1,000 L of such water to be treated, it is preferably 5 g to 500 g, more preferably 10 g to 200 g, and still more preferably 20 g to 100 g. The water purifying agent of the present invention is excellent in that a purification effect can be exhibited even with a small amount of 5 g for 1,000 L of the water to be treated.

[0034] The period for bringing the water purifying agent into contact with the water to be treated is preferably 3 days or more, more preferably 1 week or more, and still more preferably 2 weeks or more in consideration of the rising time when the effect starts to be exerted. The upper limit of the contact period is not particularly limited.

[0035] In order to bring the water purifying agent into contact with the water to be treated, for example, the water purifying agent of the present invention may be introduced into a river, lake, pond, or moat. In order to improve the solubility of the installed water purifying agent and enhance the effect of purifying the water quality of river water, lake water, pond water, moat water, etc., it is preferable to create a flowing water pressure by a pump or the like, or an upward flowing water flow by air. Such a water flow improves the contact property and solubility, and enables the eluted components to be evenly distributed in the water to be purified. Thereby, oxygen is supplied into the water, and the activities of anaerobic bacteria (putrefactive bacteria) that deteriorate the water quality can be suppressed. As a result, the types of microorganisms and bacteria in the water change, and the bacteria that promote purification become the dominant species, thus promoting the purification of the water quality.

[0036] In the above case, by continuously bringing new water into contact with the water purifying agent without interruption, an effect of preventing the clogging of impurities and suppressing the elution of the water purifying agent can also be exerted.

Example

[0037] The present invention will be described in more detail with reference to examples, but the present invention is not limited to such examples only.

[0038] Example 1 Preparation of water purifying agent 100 kg of Cellca (manufactured by Kato Industries Co., Ltd.), 4.8 kg of water glass, and 2 kg of water were mixed and kneaded. The obtained kneaded product was put into a spherical mold with a diameter of about 45 mm and dried to prepare a water purifying agent in the form of a spherical molded body with a diameter of 45 mm and a weight of about 55 g / piece. Cellca is a calcined powder of oyster shells containing about 86% by weight of calcium carbonate. Cellca also contains nitrogen (about 0.3% by weight), phosphoric acid (about 0.3% by weight), potassium (about 0.2% by weight), and magnesia (about 0.7% by weight). Further, as trace components, it contains manganese (about 300 ppm), boron (about 224 ppm), zinc (about 90 ppm), iron (about 343 ppm), copper (about 16 ppm), and molybdenum (about 2 ppm).

[0039] Experimental Example 1 Elution of inorganic components from water purifying agent 18.2 g of the water purifying agent obtained in Example 1 was immersed in 400 mL of ion-exchanged water and allowed to stand at 20°C for 14 days. On the other hand, 72.8 g of oyster shells themselves were immersed in 400 mL of ion-exchanged water and allowed to stand at 20°C for 14 days. Calcium, boron, and copper in the ion-exchanged water after immersion were quantified. The results are shown in Table 1.

[0040] The elution amounts of calcium, boron, and copper were measured using a high-frequency plasma spectroscopic analyzer (manufactured by Seiko Denshi Kogyo Co., Ltd.: SPS1200VR).

[0041]

Table 1

[0042] ※1: The values in Table 1 are the elution amounts of each inorganic component per 1 g of the water purifying agent or the oyster shell itself. ※2: The detection limit in the above quantitative method is 10 μg / L or less.

[0043] From the results in Table 1, it can be seen that for calcium, it is about 165 times, for boron, it is about 3 times, and for copper, even more. The water purifying agent elutes faster. From this, it is found that when using the water purifying agent of the present invention, compared with the case of using the oyster shell itself, it is possible to elute a smaller amount of the inorganic components contained in the oyster shell into the water. As a result, it can be expected to efficiently activate the activities of microorganisms living in the water with a small amount. Moreover, by forming the water purifying agent into a molded body, the water purifying agent can be retained in the target water area for a certain period. Therefore, the water purifying agent as a molded body is also preferable from the viewpoint of maintenance.

[0044] Example 2 Water purification method Two apparatuses (500 L tanks (1, 2)) shown in Fig. 1 were prepared for water purification. 500 L of lake water (3, 4) (Kojima Lake water, Okayama Prefecture), which is the water to be treated, was put into each tank, and 100 g and 50 g of the water purifying agents (5, 6) obtained in Example 1 were respectively put into them. Then, air was sent from the bottom of the tank at a rate of 0.8 L / min through diffusers (7, 8) that turn the air into fine bubbles by blowers (9, 10), and the inside of the tank was continuously stirred by the bubbles. Then, the water quality after 2 weeks and 4 weeks was measured. The water quality items are COD, BOD, suspended matter, and transparency. The results are shown in Table 2.

[0045] ·COD Measured by the method described in JIS K 0102 17. ·BOD Measured by the method described in JIS K 0102 21. ·Suspended matter Measured by the method described in JIS K 0102 14. ·Transparency It was measured by the method described in "Sewage Test Methods" written by the Japan Sewage Works Association.

[0046]

Table 2

[0047] From the results in Table 2, it can be seen that for BOD and suspended solids, purification has advanced highly. As a result, the transparency has also reached 1 m or more, indicating that the purification has been greatly improved. The COD value has also decreased, showing that the purification is progressing. Regarding the COD value, it is considered that it depends largely on the properties of the selected lake water. However, at least from the values related to BOD and suspended solids, the lake water is considered to have been greatly purified.

[0048] Regarding the stirring and mixing of the water to be treated, strong stirring and mixing are not necessary, and gentle stirring to the extent that water moves naturally in the natural environment is sufficient. However, from the perspective of promoting the dissolution of the components of the water purification agent, it is preferable to supply pressurized water by a pump or the like to the water purification agent, for example.

[0049] Example 3 An example of the device when used in practical use (natural environment) The water purification agent of the present invention can be used for purifying the water quality of actual river water, lake water, pond water or moat water, etc. In that case, it is preferable that the water purification agent elutes steadily and easily, and the eluted components are evenly distributed in the target water. Therefore, as an example of the device when used in practical use (natural environment), a device as shown in Figure 2 can be considered.

[0050] Fill the vinyl pipe 12 with the water purifying agent 13 of the present invention, send pressurized water from below the pump (submersible pump 11) submerged in the water to be treated to promote the elution of the water purifying agent, and at the same time, make the eluted components spread over lakes, rivers, ponds, pools, etc. targeted. Also, by exposing the uppermost part of the pipe 12 filled with the water purifying agent 13 above the water surface, oxygen can be dissolved in the water to be treated, and the water to be treated can be kept under aerobic conditions, suppressing the growth of anaerobic bacteria (putrefactive bacteria) and enabling the conditions for activating the activities of aerobic bacteria to be adjusted. With such a water purification method, without providing a dedicated facility that utilizes the activated sludge method or the like for purifying water using a large amount of microorganisms, water purification can be achieved even in water systems with a large amount of water such as river water, lake water, pond water, or pond water.

[0051] Overall, by packing the water purifying agent of the present invention in a container as in Example 2, promoting dissolution with pressurized water or the like, and allowing the dissolved components to spread into the water for the purpose of purification, the purification effect is promoted.

Industrial Applicability

[0052] The water purifying agent of the present invention can be used for purifying the water quality of river water, lake water, pond water, or pond water.

Explanation of Symbols

[0053] 1 Tank (500L) 2 Tank (500L) 3 Lake water 4 Lake water 5 Water purifying agent 6 Water purifying agent 7 Diffuser 8 Diffuser 9 Blower 10 Blower 11 Submersible pump 12 Pipe 13 Water purifying agent

Claims

1. The water purifying agent comprises a molded product obtained by drying a kneaded product containing shells or crushed shells from which organic matter has been removed, water glass and water.

2. 2. The water purifying agent according to claim 1, wherein the shells from which organic matter has been removed are obtained by calcining the shells.

3. 3. The water purification agent according to claim 1 or 2, wherein the shells are oyster shells.

4. The water purification agent according to any one of claims 1 to 3, wherein the crushed material is in powder form.

5. A water purification agent described in any one of claims 1 to 3, which is a molded body formed into a lump shape.

6. A water purification method comprising a step of contacting the water purification agent according to any one of claims 1 to 5 with water to be treated.

7. 7. The method for water purification according to claim 6, wherein the water to be treated is river water, lake water, pond water, or moat water.

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