Slow-release solid flocculant and water treatment device

Abstract

To provide a sustained release solid flocculant having sustained releaseability of a polymer flocculant and a water treatment device using the sustained release solid flocculant.SOLUTION: A sustained release solid flocculant 1 comprises: a solid flocculant part 10 that includes a polymer flocculant; and a protection part 50 that protects the solid flocculant part 10 from contact with water. A part of the surface 12 of the solid flocculant part 10 is covered with the protection part 50. The weight average molecular weight of the polymer flocculant is preferably 1000 or larger. A flocculant surface coverage which is a ratio of a surface of the surface 12 of the solid flocculant part 10 covered with the protection part 50 is preferably 20%-99%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sustained-release solid flocculant and a water treatment device. [Background technology]

[0002] Domestic water such as well water and tap water often contains impurities such as sand, iron rust, inorganic substances such as iron ions, inorganic ions, bacteria, etc., and is therefore often treated before use. For example, tap water may become contaminated with the above impurities due to factors such as deterioration of the quality of the raw water or deterioration of the water supply pipes, resulting in a deterioration in the quality of domestic water. Furthermore, well water may become contaminated with the above impurities due to deterioration of the water quality or insolubilization of dissolved ions due to oxidation, resulting in a deterioration in the quality of domestic water.

[0003] Conventional water quality treatment methods for removing the above-mentioned impurities include water treatment methods that use membrane or sand filter media for filtration and methods that use disinfectants such as chlorine agents. Furthermore, water treatment methods that use inorganic or polymeric flocculants to coarsen impurities are known as methods for removing finer particles. Specifically, a method is known in which a flocculant or disinfectant is added to the water to be treated W0, such as well water, to inactivate bacteria and other contaminants through the disinfecting action, and the flocculation action of the flocculant is used to form flocs containing suspended solids, which are then removed by filtration or other means to obtain clean treated water TW. It is preferable that the treatment conditions of the water treatment method change little in order to obtain treated water TW of stable quality. For this reason, it is preferable that the flocculant concentration in the water to be treated W0 change little.

[0004] Generally, when a flocculant is used for flocculation treatment, the flocculant is dissolved in water and then the flocculant solution is injected into the water to be treated using a pump. However, this method has the problem that the pump used is expensive, which increases the cost of purifying the water to be treated. In addition, since the flocculant is assumed to be completely dissolved in water and then injected using a pump, the flocculant is designed to dissolve quickly. Therefore, there is a problem that the flocculant cannot be continuously dissolved little by little into the water to be treated without using a pump.

[0005] To address this problem, a method of providing sustained release at low cost may be considered, in which the polymer flocculant is solidified and the surface of the polymer flocculant is coated with a substance that inhibits dissolution of the polymer flocculant to form a tablet.

[0006] Patent Document 1 discloses a treatment agent for sludge-adhered wood washing wastewater, which is made by granulating a mixture of a polymer flocculant, a pH adjuster, and an adsorbent, and then coating the outer surface of the granules with an inorganic flocculant. This treatment agent for washing wastewater is said to be able to prevent deliquescence and oxidative decomposition and maintain flocculation ability for a long period of time because the outer surface is coated with an inorganic flocculant. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-78717 Summary of the Invention [Problem to be solved by the invention]

[0008] However, inorganic flocculants generally dissolve easily when they come into contact with water, making it difficult to produce a solid flocculant with sustained release of the polymer flocculant based on Patent Document 1.

[0009] The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide a sustained-release solid flocculant in which a polymer flocculant has sustained-release properties, and a water treatment device using the sustained-release solid flocculant. [Means for solving the problem]

[0010] In order to solve the above problems, a sustained-release solid flocculant according to an embodiment of the present invention comprises a solid flocculant portion containing a polymer flocculant and a protective portion that protects the solid flocculant portion from contact with water, and a portion of the surface of the solid flocculant portion is covered by the protective portion.

[0011] A water treatment device according to an aspect of the present invention uses the sustained-release solid flocculant. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide a sustained-release solid flocculant having sustained release properties of a polymer flocculant, and a water treatment device using the sustained-release solid flocculant. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing an example of a sustained-release solid flocculant according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing a solid flocculant portion constituting the sustained-release solid flocculant shown in FIG. [Figure 3] FIG. 10 is a diagram showing an example of a sustained-release solid flocculant according to a second embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a sustained-release solid flocculant according to a third embodiment. [Figure 5] FIG. 1 is a diagram showing an example of a solid flocculant according to a reference embodiment. [Figure 6] 1 is a conceptual diagram illustrating an example of a water treatment device according to an embodiment. [Figure 7] FIG. 7 is a cross-sectional view of an example of a chemical dissolving device that constitutes the water treatment device shown in FIG. [Figure 8] FIG. 8 is a perspective view showing an example of a drug tank constituting the drug dissolving device shown in FIG. [Figure 9] 1 is a graph showing the relationship between water flow time and eluted chlorine concentration. [Figure 10] 10 is a graph showing the relationship between water flow time and turbidity. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a sustained-release solid flocculant and a water treatment device according to an embodiment will be described with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0015] <Slow-release solid flocculant> [First embodiment] A sustained-release solid flocculant according to the first embodiment will be described. FIG. 1 is a diagram showing an example of a sustained-release solid flocculant according to the first embodiment. As shown in FIG. 1, the sustained-release solid flocculant 1A(1) includes a solid flocculant portion 10A(10) containing a polymer flocculant, and a protective portion 50A(50) that protects the solid flocculant portion 10A from contact with water. In the sustained-release solid flocculant 1A, a portion of the surface 12 of the solid flocculant portion 10A is covered with the protective portion 50A.

[0016] (Solid flocculant part) The solid flocculant portion 10A constituting the sustained-release solid flocculant 1A will be described with reference to Fig. 2. Fig. 2 is a diagram showing the solid flocculant portion 10A constituting the sustained-release solid flocculant 1A shown in Fig. 1.

[0017] The solid flocculant section 10A is made of a solid material containing a polymer flocculant. The polymer flocculant may be, for example, one or more selected from the group consisting of nonionic polymer flocculants, anionic polymer flocculants, cationic polymer flocculants, and amphoteric polymer flocculants. A cationic polymer flocculant is preferred because it is more likely to flocculate negatively charged impurities in water, such as sand and bacteria, which may be mixed into domestic water.

[0018] The polymer flocculant typically has a weight-average molecular weight of 1,000 or more, preferably 10,000 to 50,000,000, and more preferably 100,000 to 5,000,000. When the weight-average molecular weight of the polymer flocculant is within the above range, it is preferred because it has high flocculating properties and solubility suitable for sustained release.

[0019] Examples of polymer flocculants include starch, guar gum, tamarind gum, polyethylene glycol (PEG), xanthan gum, polyamine, polydiallyldimethylammonium chloride (PDADMAC), melamine colloid, polydicyandiamide, polyacrylic acid, polymethacrylic acid esters, polyacrylic acid esters, sodium polyalginate, cellulose, moringa, polyalginic acid, polysilica iron (PSI), chitosan, cationic starch, cationic guar gum, polylysine, and polyglutamic acid. Among these, polydicyandiamide, polyacrylic acid, polymethacrylic acid esters, polyacrylic acid esters, and chitosan are preferred because of their high purification performance and proven use as food additives or in water purification and wastewater treatment plants, ensuring safety to the human body.

[0020] The content of the polymer flocculant in the solid flocculant portion 10A is usually 1 to 100% by mass, preferably 10 to 100% by mass. If the content of the polymer flocculant in the solid flocculant portion 10A is within the above range, it is preferable because a part of the flocculant can come into contact with water from the initial stage of use, and the flocculant component can be eluted.

[0021] The solid flocculant portion 10A is a solid material containing a polymer flocculant.

[0022] Examples of the molded body include a powder molded body obtained by molding a powder of the polymer flocculant, a molded body obtained by melting and solidifying the powder, etc. As the powder molded body, pellets, tablets, etc. are usually used.

[0023] Average particle size D of the polymer flocculant powder used as the raw material for powder compacts such as pellets 50 The average particle size D of the powder of the polymer flocculant is, for example, 0.001 to 1000 μm, preferably 0.01 to 10 μm. 50 When the particle size is within the above range, the voids between particles in the tablet can be reduced when the tablet is formed, and the penetration of water into the tablet can be suppressed, thereby improving the dissolution life, which is preferable.

[0024] The polymer flocculant constituting the solid flocculant portion 10A typically absorbs and expands upon contact with water. Therefore, the solid flocculant portion 10A, which is a solid substance containing a polymer flocculant, typically absorbs and expands upon contact with water, such as the water to be treated W0, and dissolves or disintegrates in the water. However, dissolving or disintegrating the solid flocculant portion 10A in water, such as the water to be treated W0, is undesirable because it typically results in a rapid increase in the concentration of the polymer flocculant in the water, impairing the sustained-release properties of the solid flocculant portion 10A. Therefore, in the sustained-release solid flocculant 1A, a portion of the surface 12 of the solid flocculant portion 10A is covered with a protective portion 50 that protects the solid flocculant portion 10A from contact with water. The protective portion 50 will be described later.

[0025] The solid flocculant portion 10A shown in Fig. 2 is an example of a cylindrical pellet formed from a polymer flocculant powder. As shown in Fig. 2, the surface 12 of the solid flocculant portion 10A consists of flat portions 14a (14), 14b (14), which are circular surfaces that form the bottom and top surfaces of the cylinder, and curved portions 15, which are cylindrical surfaces that form the side surfaces of the cylinder.

[0026] Here, S14a and 14b, which are the surface areas of the flat portions 14a and 14b, respectively, and S15, which is the surface area of ​​the curved portion 15, can be calculated by a known method. The total surface area S12 of the surfaces 12 constituting the solid flocculant portion 10A is the sum of S14a, 14b, and S15 (S14a + S14b + S15).

[0027] S14a and 14b can be easily calculated using the diameter D14 of the flat surface of the solid flocculant portion 10A, etc. S15 can be easily calculated using the diameter D14 of the flat surface of the solid flocculant portion 10A and the length L15 of the curved surface of the solid flocculant portion 10A, etc.

[0028] As shown in Figure 1, in the sustained-release solid flocculant 1A, a portion of the surface 12 of the solid flocculant portion 10A shown in Figure 2 is covered with a protective portion 50A. Specifically, in the sustained-release solid flocculant 1A, the cylindrical curved portion 15 of the surface 12 of the solid flocculant portion 10A is the protective agent coated portion 32, which is the surface covered with the protective portion 50A. On the other hand, in the sustained-release solid flocculant 1A, the circular flat portions 14a and 14b of the surface 12 of the solid flocculant portion 10A are the flocculant exposed portion 22, which is the exposed surface without being covered with the protective portion 50A. The protective agent coated portion 32 and the flocculant exposed portion 22 will be described below.

[0029] [Protective coating] In the sustained-release solid flocculant 1A shown in FIG. 1, the cylindrical curved surface portion 15 of the solid flocculant portion 10A shown in FIG.

[0030] Here, the planar portion of the protective agent-coated portion 32 is referred to as a planar portion 34 of the protective agent-coated portion, and the curved portion of the protective agent-coated portion 32 is referred to as a curved portion 35 of the protective agent-coated portion.

[0031] The protective agent coated portion 32 of the sustained-release solid flocculant 1A shown in Fig. 1 is specifically the curved surface portion 35A (35) of the protective agent coated portion. The curved surface portion 35A of the protective agent coated portion corresponds to the cylindrical curved surface portion 15 of the solid flocculant portion 10A shown in Fig. 2.

[0032] The surface area S35A of the curved surface portion 35A can be calculated by a known method. The total surface area S32 of the protective agent coated portion 32 constituting the solid flocculant portion 10A is S35A.

[0033] 1, the length L35 of the curved portion 35A of the protective agent coating portion 32 of the solid flocculant portion 10A is the same as the length L15 of the curved portion of the solid flocculant portion 10A. Also, the diameter D34 of the curved portion 35A of the protective agent coating portion 32 is the same as the diameter D14 of the flat portion of the solid flocculant portion 10A.

[0034] [Exposed flocculant area] In the sustained-release solid flocculant 1A shown in FIG. 1, flat portions 14a and 14b, which are the circular surfaces of the solid flocculant portion 10A shown in FIG.

[0035] Here, the flat portion of the flocculant exposed portion 22 is referred to as a flat portion 24 of the flocculant exposed portion, and the curved portion of the flocculant exposed portion 22 is referred to as a curved portion 25 of the flocculant exposed portion.

[0036] The flocculant exposed portion 22 of the sustained-release solid flocculant 1A shown in Fig. 1 is specifically the flat portions 24Aa(24) and 24Ab(24) of the flocculant exposed portion. The flat portions 24Aa and 24Ab of the flocculant exposed portion correspond to the circular flat portions 14a and 14b of the solid flocculant portion 10A shown in Fig. 2, respectively.

[0037] The surface areas S24Aa and S24Ab of the planar portions 24Aa and 24Ab of the aggregant exposed portion 22 can be calculated by a known method. The total surface area S22 of the aggregant exposed portion 22 constituting the solid aggregant portion 10A is the sum of S24Aa and S24Ab (S24Aa + S24Ab).

[0038] 1, the diameter D24 of the flat surface portions 24Aa and 24Ab of the flocculant exposed portion 22 of the solid flocculant portion 10A is the same as the diameter D14 of the flat surface portion of the solid flocculant portion 10A. The surface area S24 of the flat surface portion 24Aa of the flocculant exposed portion 22 is the same as the surface area S14a of the flat surface portion 14a. The surface area S24 of the flat surface portion 24Ab of the flocculant exposed portion 22 is the same as the surface area S14b of the flat surface portion 14b.

[0039] (Protection Department) The protective part 50A constituting the sustained-release solid flocculant 1A will be described with reference to FIG.

[0040] The protective portion 50A is a portion that protects the solid flocculant portion 10A from contact with water. Specifically, the protective portion 50A covers a portion of the surface 12 of the solid flocculant portion 10A, thereby preventing the solid flocculant portion 10A from absorbing water, expanding, dissolving, or disintegrating upon contact with water, such as the water to be treated WO. Here, the protective portion 50A's ability to protect the solid flocculant portion 10A from contact with water refers to its ability to prevent water from reaching the surface 12 of the solid flocculant portion 10A through the protective portion 50A. Note that the protective portion 50A may absorb water, expand, dissolve, or disintegrate upon contact with water, such as the water to be treated WO, as long as it has the ability to protect the solid flocculant portion 10A from contact with water. Furthermore, it is more preferable for the protective portion 50A to dissolve or disintegrate in approximately the same time as the solid flocculant portion, since this makes it easier to visually confirm the remaining flocculant.

[0041] The protective part 50A contains a protective agent. The protective agent is not particularly limited, and is used as long as it has the effect of protecting the solid flocculant part 10A from contact with water when the protective part 50A is formed.

[0042] Examples of protective agents that can be used include chlorine-containing compounds such as trichloroisocyanuric acid and dichloroisocyanuric acid, and polysaccharides such as starch, guar gum, and tamarind gum. Among these, chlorine-containing compounds are preferred because they increase the chlorine concentration in the treated water TW obtained after water treatment of the water to be treated W0, thereby sterilizing bacteria and the like contained in the water to be treated W0 and oxidizing and flocculating Fe ions and the like to easily obtain treated water TW with a low Fe concentration. Furthermore, it is preferred that the protective agent be primarily composed of dichloroisocyanuric acid or trichloroisocyanuric acid.

[0043] Polysaccharides are also preferred because they have a relatively low water absorption rate, are effective in enhancing the coagulation of the polymer flocculant, and are less reactive with the polymer flocculant, making them safe for humans.

[0044] The protective agent contained in protective part 50A is preferably a chlorine compound or a polysaccharide as its main component, because it can protect the protective agent from contact with water while simultaneously dissolving in the same amount of time as the coagulant and gradually releasing components useful for water treatment. Here, "main component" means the protective agent that is contained in protective part 50A in the largest amount by mass.

[0045] The form of the protective part 50A is not particularly limited as long as the protective part 50A has the effect of protecting the solid flocculant part 10A from contact with water. Examples of the form of the protective part 50A that can be used include a bulk body made of a protective agent and a powder compact obtained by compacting a powder of the protective agent.

[0046] The protective portion 50A shown in FIG. 1 has a cylindrical outer shape and includes an exposed surface 52 exposed to the outside and a portion that is not exposed to the outside and comes into contact with the protective agent coated portion 32 of the solid flocculant portion 10A.

[0047] The exposed surface 52 of the protective portion 50A shown in FIG. 1 consists of exposed flat portions 54Aa (54) and 54Ab (54), which are annular exposed surfaces 52 that form the top and bottom surfaces of the cylinder, and exposed curved surface portions 55A (55), which are cylindrical exposed surfaces 52 that form the side surfaces of the cylinder.

[0048] Here, the surface areas S54Aa and S54Ab of the exposed flat portions 54Aa and 54Ab, respectively, and the surface area S55A of the exposed curved portion 55A can be calculated by a known method. The total surface area S52 of the exposed surfaces 52 constituting the protective portion 50A is the sum of S54Aa, S54Ab, and S55A (S54Aa + S54Ab + S55A).

[0049] The surface area S54Aa of exposed flat portion 54Aa and the surface area S54Ab of exposed flat portion 54Ab can be easily calculated using the diameter D54 of the exposed flat portion of protective portion 50A and the diameter D14 of the flat portion of the solid flocculant portion, etc. The surface area S55A of cylindrical exposed curved portion 55A can be easily calculated using the diameter D54 of the exposed flat portion of protective portion 50A and the length L55 of the exposed curved portion of protective portion 50A, etc.

[0050] (flocculant surface coverage) In the sustained-release solid flocculant 1A, a part of the surface 12 of the solid flocculant portion 10A is covered with a protective portion 50A.

[0051] In the sustained-release solid flocculant 1A, the ratio of the surface 12 of the solid flocculant portion 10A that is covered with the protective portion 50A is called the flocculant surface coverage rate. The flocculant surface coverage rate of the sustained-release solid flocculant 1A is usually 20% or more and 99% or less.

[0052] 1, specifically, the surface area S32 of the protective agent coating portion 32 is the surface area S35A of the curved portion 35A. Also, the surface area S12 of the surface 12 of the solid flocculant portion 10A is the sum (S14a + S14b + S15) of the surface area S14a of the flat portion 14a, the surface area S14b of the flat portion 14b, and the surface area S15 of the curved portion 15. Therefore, in the sustained-release solid flocculant 1A, the flocculant surface coverage is (S35A) / (S14a + S14b + S15).

[0053] In addition, the surface coverage of the sustained-release solid flocculant 1A is preferably 30% or more and 90% or less, more preferably 30% or more and 80% or less. When the surface coverage of the flocculant is within the above range, it is preferable because it can prevent contact with water, improve the dissolution life, and elute the flocculant components necessary for water treatment.

[0054] (water contact ratio surface area ratio) In the sustained-release solid flocculant 1A, the water contact specific surface area ratio, which is the ratio of the surface area S52 of the exposed face 52 of the protective part 50A to the surface area S22 of the flocculant exposed part 22 of the solid flocculant part 10A, is usually 0.1 or more and 100 or less.

[0055] Furthermore, the sustained-release solid flocculant 1A has a water contact specific surface area ratio of preferably 1 or more and 40 or less, more preferably 10 or more and 30 or less. When the water contact specific surface area ratio is within the above range, it is preferable because it can prevent water contact and improve the dissolution life while allowing the flocculant components necessary for water treatment to elute.

[0056] (action) The sustained-release solid flocculant 1A comprises a solid flocculant portion 10A that absorbs water, expands, and dissolves or disintegrates in water such as the water to be treated W0 upon contact with the water, and a protective portion 50A that covers a portion of the surface 12 of the solid flocculant portion 10A. The protective portion 50A has the effect of preventing water from reaching the surface 12 of the solid flocculant portion 10A through the protective portion 50A, and protects the solid flocculant portion 10A from contact with water.

[0057] Therefore, when the sustained-release solid flocculant 1A comes into contact with water such as the water to be treated W0, the exposed portion of the surface 12 of the solid flocculant portion 10A absorbs water, expands, and dissolves or disintegrates in the water, releasing the polymer flocculant. On the other hand, even when the portion of the surface 12 of the solid flocculant portion 10A that is covered with the protective portion 50A comes into contact with water, the water is prevented from reaching the surface 12 of the solid flocculant portion 10A through the protective portion 50A. Therefore, when the sustained-release solid flocculant 1A comes into contact with water such as the water to be treated W0, the sustained release of the polymer flocculant into the water is exhibited compared to when a flocculant made of the solid flocculant portion 10A without the protective portion 50A is used.

[0058] In addition, when the protective part 50A is configured to release a protective agent into water upon contact with water such as the water to be treated W0, contacting the sustained-release solid flocculant 1A with water such as the water to be treated W0 can release the protective agent in the protective part 50A into the water. For example, when the protective agent contained in the protective part 50A is a chlorine-containing compound, the chlorine-containing compound can be released into the water. When the chlorine-containing compound is a water-soluble substance that releases chloride ions, contacting the sustained-release solid flocculant 1A with water such as the water to be treated W0 can increase the chloride ion concentration in the water.

[0059] In this way, by releasing the protective agent in the protective section 50A into the water and increasing the chloride ion concentration in the water, it becomes possible to oxidize and coagulate iron, for example, when the water to be treated W0 contains Fe.

[0060] [Second embodiment] A sustained-release solid flocculant according to the second embodiment will be described. FIG. 3 is a diagram showing an example of a sustained-release solid flocculant according to the second embodiment. As shown in FIG. 3, the sustained-release solid flocculant 1B(1) includes a solid flocculant portion 10B(10) containing a polymer flocculant, and protective portions 50Ba(50) and 50Bb(50) that protect the solid flocculant portion 10B from contact with water. In the sustained-release solid flocculant 1B, a portion of the surface 12 of the solid flocculant portion 10B is covered with the protective portions 50Ba and 50Bb.

[0061] The sustained-release solid flocculant 1B according to the second embodiment uses protective parts 50Ba (50) and 50Bb (50) instead of the protective part 50A of the sustained-release solid flocculant 1A according to the first embodiment, and the other components are the same as those of the sustained-release solid flocculant 1A. For this reason, the same reference symbols are used for the same components in the sustained-release solid flocculant 1B according to the second embodiment and the sustained-release solid flocculant 1A according to the first embodiment, and the description of the components and their functions is omitted or simplified.

[0062] (Solid flocculant part) As shown in FIG. 3, in the sustained-release solid flocculant 1B, a part of the surface 12 of the solid flocculant portion 10B shown in FIG. 2 is covered with a protective portion 50B.

[0063] The solid flocculant portion 10B is the same as the solid flocculant portion 10A, including its shape. Therefore, a description of the solid flocculant portion 10B will be omitted. However, the protective portions 50Ba and 50Bb that cover a portion of the surface 12 of the solid flocculant portion 10B are different in shape from the protective portion 50A that covers a portion of the surface 12 of the solid flocculant portion 10A.

[0064] Specifically, in the sustained-release solid flocculant 1B, the circular flat portions 14a and 14b of the surface 12 of the solid flocculant portion 10B are surfaces coated with the protective portions 50Ba and 50Bb, respectively, and constitute the protective agent coated portion 32. On the other hand, in the sustained-release solid flocculant 1B, the cylindrical curved portion 15 of the surface 12 of the solid flocculant portion 10B is the flocculant exposed portion 22, which is an exposed surface that is not coated with the protective portion 50B. The protective agent coated portion 32 and the flocculant exposed portion 22 will be described below.

[0065] [Protective coating] In the sustained-release solid flocculant 1B shown in FIG. 3, the flat portions 14a and 14b, which are the circular surfaces of the solid flocculant portion 10B shown in FIG.

[0066] Here, the planar portion of the protective agent-coated portion 32 is referred to as a planar portion 34 of the protective agent-coated portion, and the curved portion of the protective agent-coated portion 32 is referred to as a curved portion 35 of the protective agent-coated portion.

[0067] The protective agent coating portion 32 of the sustained-release solid flocculant 1B shown in Figure 3 is specifically the planar portions 34Ba(34) and 34Bb(34) of the protective agent coating portion. The planar portions 34Ba and 34Bb of the protective agent coating portion correspond to the circular planar portions 14a and 14b of the solid flocculant portion 10B shown in Figure 2, respectively.

[0068] The surface areas S34Ba and S34Bb of the planar portions 34Ba and 34Bb of the protective agent-coated portion 32 constituting the solid flocculant portion 10B can be calculated by a known method. The total surface area S32 of the protective agent-coated portion 32 constituting the solid flocculant portion 10B is the sum of S34Ba and S34Bb (S34Ba + S34Bb).

[0069] 3, the diameter D34 of the planar portions 34Ba and 34Bb of the protective agent-coated portion 32 of the solid flocculant portion 10B is the same as the diameter D14 of the planar portion of the solid flocculant portion 10B. The surface area S34 of the planar portion 34Ba of the protective agent-coated portion 32 is the same as the surface area S14a of the planar portion 14a. The surface area S34 of the planar portion 34Bb of the protective agent-coated portion 32 is the same as the surface area S14b of the planar portion 14b.

[0070] [Exposed flocculant area] In the sustained-release solid flocculant 1B shown in FIG. 3, the cylindrical curved surface portion 15 of the solid flocculant portion 10B shown in FIG.

[0071] Here, the flat portion of the flocculant exposed portion 22 is referred to as a flat portion 24 of the flocculant exposed portion, and the curved portion of the flocculant exposed portion 22 is referred to as a curved portion 25 of the flocculant exposed portion.

[0072] The flocculant exposed portion 22 of the sustained-release solid flocculant 1B shown in Fig. 3 is specifically the curved surface portion 25B (25) of the flocculant exposed portion. The curved surface portion 25B of the flocculant exposed portion corresponds to the cylindrical curved surface portion 15 of the solid flocculant portion 10B shown in Fig. 2.

[0073] The surface area S25B of the curved surface portion 25B can be calculated by a known method. The total surface area S22 of the flocculant exposed portion 22 constituting the solid flocculant portion 10B is S25B.

[0074] 3, the length L25 of the curved portion 35B of the flocculant exposed portion 22 of the solid flocculant portion 10B is the same as the length L15 of the curved portion of the solid flocculant portion 10B. Also, the diameter D24 of the curved portion 25B of the flocculant exposed portion 22 is the same as the diameter D34 and the diameter D14 of the flat portion of the solid flocculant portion 10B.

[0075] (Protection Department) The protective parts 50Ba and 50Bb constituting the sustained-release solid flocculant 1B will be described with reference to FIG.

[0076] Other than their shapes, the protective parts 50Ba and 50Bb are the same as the protective part 50A of the sustained-release solid flocculant 1A according to embodiment 1. Therefore, the shapes of the protective parts 50Ba and 50Bb will be explained below.

[0077] The protective portions 50Ba and 50Bb shown in Figure 3 each have a cylindrical outer shape and have an exposed surface 52 exposed to the outside and a portion that is not exposed to the outside and comes into contact with the protective agent coating portion 32 of the solid flocculant portion 10B.

[0078] The exposed surface 52 of the protective portion 50Ba shown in Figure 3 consists of an exposed flat portion 54Ba (54), which is a circular exposed surface 52 that forms the top surface of the cylinder, and an exposed curved portion 55Ba (55), which is a cylindrical exposed surface 52 that forms the side surface of the cylinder.

[0079] Here, the surface area S54Ba of the exposed flat portion 54Ba and the surface area S55Ba of the exposed curved portion 55Ba can be calculated by a known method. The total surface area S52 of the exposed surface 52 constituting the protective portion 50Ba is the sum of S54Ba and S55Ba (S54Ba + S55Ba).

[0080] In addition, the exposed surface 52 of the protective portion 50Bb shown in Figure 3 consists of an exposed flat portion 54Bb (54), which is a circular exposed surface 52 that forms the bottom surface of the cylinder, and an exposed curved portion 55Bb, which is a cylindrical exposed surface 52 that forms the side surface of the cylinder.

[0081] Here, the surface area S54Bb of the exposed flat portion 54Bb and the surface area S55Bb of the exposed curved portion 55Bb can be calculated by a known method. The total surface area S52 of the exposed surfaces 52 constituting the protective portion 50Bb is the sum of S54Bb and S55Bb (S54Bb + S55Bb).

[0082] The total surface area S52 of exposed surfaces 52 constituting protective portions 50Ba and 50Bb of sustained-release solid flocculant 1B is the sum of S54Ba, S55Ba, S54Bb, and S55Bb (S54Ba+S55Ba+S54Bb+S55Bb).

[0083] Note that the surface area S54a of exposed flat portion 54Ba and the surface area S54b of exposed flat portion 54Bb can be easily calculated using the diameter D54 of exposed flat portions 54Ba and 54Bb, etc. Furthermore, the surface area S55Ba of exposed curved surface portion 55Ba and the surface area S55Bb of exposed curved surface portion 55Bb can be easily calculated using the diameter D54 of exposed flat portions 54Ba and 54Bb and the lengths L55Ba and L55Bb of exposed curved surface portions 55Ba and 55Bb, etc.

[0084] (flocculant surface coverage) In the sustained-release solid flocculant 1B, a part of the surface 12 of the solid flocculant portion 10B is covered with protective portions 50Ba and 50Bb.

[0085] In the sustained-release solid flocculant 1B, the flocculant surface coverage is the proportion of the surface 12 of the solid flocculant portion 10B that is covered with the protective portions 50Ba and 50Bb. The flocculant surface coverage of the sustained-release solid flocculant 1B is within the same numerical range as the flocculant surface coverage of the sustained-release solid flocculant 1A. The reason for this is the same as that for the flocculant surface coverage of the sustained-release solid flocculant 1A, so an explanation will be omitted.

[0086] 3, the surface area S32 of the protective agent coating portion 32 is the sum (S34Ba + S34Bb) of the surface areas S34Ba and S34Bb of the flat portions 34Ba and 34Bb. The surface area S12 of the surface 12 of the solid flocculant portion 10B is the sum (S14a + S14b + S15) of the surface area S14a of the flat portion 14a, the surface area S14b of the flat portion 14b, and the surface area S15 of the curved portion 15. Therefore, in the sustained-release solid flocculant 1B, the flocculant surface coverage is (S34Ba + S34Bb) / (S14a + S14b + S15).

[0087] (water contact ratio surface area ratio) In the sustained-release solid flocculant 1B, the water contact specific surface area ratio, which is the ratio of the surface area S52 of the exposed surface 52 of the protective parts 50Ba and 50Bb to the surface area S22 of the flocculant exposed part 22 of the solid flocculant part 10B, is within the same numerical range as the water contact specific surface area ratio of the sustained-release solid flocculant 1A. The reason for this is the same as the reason for the water contact specific surface area ratio of the sustained-release solid flocculant 1A, so an explanation will be omitted.

[0088] (action) The action of the sustained-release solid flocculant 1B is similar to that of the sustained-release solid flocculant 1A, and therefore a description thereof will be omitted.

[0089] [Third embodiment] A sustained-release solid flocculant according to the third embodiment will be described. FIG. 4 is a diagram showing an example of a sustained-release solid flocculant according to the third embodiment. As shown in FIG. 4, the sustained-release solid flocculant 1C(1) includes a solid flocculant portion 10C(10) containing a polymer flocculant, and protective portions 50Ca(50) and 50Cb(50) that protect the solid flocculant portion 10C from contact with water. In the sustained-release solid flocculant 1C, a portion of the surface 12 of the solid flocculant portion 10C is covered with the protective portions 50Ca and 50Cb.

[0090] As shown in FIG. 4, a sustained-release solid flocculant 1C according to the third embodiment is formed into a cylindrical shape as a whole by combining a solid flocculant portion 10C, a protective portion 50Ca, and a protective portion 50Cb.

[0091] The solid flocculant portion 10C of the sustained-release solid flocculant 1C according to the third embodiment is the same as the solid flocculant portion 10A of the sustained-release solid flocculant 1A according to the first embodiment, except for its shape. In addition, the protective portion 50Ca and the protective portion 50Cb of the sustained-release solid flocculant 1C according to the third embodiment are the same as the protective portion 50A of the sustained-release solid flocculant 1A according to the first embodiment, except for their shape.

[0092] For this reason, the same reference symbols are used for the same components in the sustained-release solid flocculant 1C of the third embodiment and the sustained-release solid flocculant 1A of the first embodiment, and descriptions of the components and their functions are omitted or simplified.

[0093] (Solid flocculant part) As shown in FIG. 4, in the sustained-release solid flocculant 1C, a part of the surface 12 of the solid flocculant portion 10C shown in FIG. 2 is covered with a protective portion 50C.

[0094] The solid flocculant portion 10C is the same as the solid flocculant portion 10A except for its shape. Therefore, the shape of the solid flocculant portion 10C will be described below, and other aspects of the solid flocculant portion 10C will not be described.

[0095] The solid flocculant portion 10C is a rounded rectangular columnar member formed when the cylindrical sustained-release solid flocculant 1C is cut along its height using two parallel planes to separate it into two arched columns and one rounded rectangular columnar member.

[0096] Specifically, the rounded rectangular pillar that is the solid flocculant portion 10C is a pillar whose cross section obtained by cutting the solid flocculant portion 10C perpendicularly to the height direction is a rounded rectangle consisting of two parallel straight lines and two arc-shaped curves connecting the ends of these two straight lines. The two arched pillars are the protective portions 50Ca and 50Cb.

[0097] The solid flocculant portion 10C has six surfaces: flat surfaces 24Ca(24), 24Cb(24), 34Ca(34), and 34Cb(34), and curved surfaces 25Ca(25) and 25Cb(25).

[0098] [Protective coating] In the sustained-release solid flocculant 1C shown in Figure 4, of the six surfaces, the flat surfaces 34Ca and 34Cb are surfaces covered with the protective portions 50Ca and 50Cb, which are protective agent-coated portions 32. The flat surfaces 34Ca and 34Cb are the flat surfaces 34Ca and 34Cb of the protective agent-coated portion.

[0099] The surface areas S34Ca and S34Cb of the planar portions 34Ca and 34Cb of the protective agent-coated portion 32 constituting the solid flocculant portion 10C can be calculated by a known method. The total surface area S32 of the protective agent-coated portion 32 constituting the solid flocculant portion 10C is the sum of S34Ca and S34Cb (S34Ca + S34Cb).

[0100] [Exposed flocculant area] In the sustained-release solid flocculant 1C shown in Figure 4, of the six surfaces, flat surfaces 24Ca and 24Cb and curved surfaces 25Ca and 25Cb are exposed surfaces that are not covered by protective portion 50C and form flocculant exposed portion 22. Flat surfaces 24Ca and 24Cb are flat surfaces 24Aa and 24Ab of the flocculant exposed portion, and curved surfaces 25Ca and 25Cb are curved surfaces 25Ca and 25Cb of the flocculant exposed portion.

[0101] The surface areas S24Ca and S24Cb, and S25Ca and S25Cb, respectively, of the flat portions 24Ca and 24Cb and the curved portions 25Ca and 25Cb of the flocculant exposed portion 22 that constitutes the solid flocculant portion 10C can be calculated using a known method. The total surface area S22 of the flocculant exposed portion 22 constituting the solid flocculant portion 10C is the sum of S24Ca and S24Cb and S25Ca and S25Cb (S24Ca+S24Cb+S25Ca+S25Cb).

[0102] (Protection Department) The protective parts 50Ca and 50Cb constituting the sustained-release solid flocculant 1C will be described with reference to FIG.

[0103] The protective portions 50Ca and 50Cb shown in Figure 4 are each an arched columnar body, and have an exposed surface 52 exposed to the outside and a portion that is not exposed to the outside and comes into contact with the protective agent coating portion 32 of the solid flocculant portion 10C.

[0104] The exposed surface 52 of the protective portion 50Ca shown in Figure 4 consists of an exposed flat portion 54Caa (54) which is an arched exposed surface 52, an exposed flat portion 54Cab (54) which is an arched exposed surface 52, and an exposed curved portion 55Ca (55) which is a curved exposed surface 52.

[0105] Here, the surface areas S54Caa and S54Cab of the exposed flat portions 54Caa and 54Cab, and the surface area S55Ca of the exposed curved portion 55Ca can be calculated by a known method. The total surface area S52 of the exposed surface 52 constituting the protective portion 50Ca is the sum of S54Caa, S54Cab and S55Ca (S54Caa+S54Cab+S55Ca).

[0106] In addition, the exposed surface 52 of the protective portion 50Cb shown in Figure 4 consists of an exposed flat portion 54Cba (54) which is an arched exposed surface 52, an exposed flat portion 54Cbb (54) which is an arched exposed surface 52, and an exposed curved portion 55Cb (55) which is a curved exposed surface 52.

[0107] Here, the surface areas S54Cba and S54Cbb of the exposed flat portions 54Cba and 54Cbb and the surface area S55Cb of the exposed curved portion 55Cb can be calculated using a known method. The total surface area S52 of the exposed surfaces 52 constituting the protective portion 50Cb is the sum of S54Cba, S54Cbb, and S55Cb (S54Cba + S54Cbb + S55Cb).

[0108] The total surface area S52 of the exposed surfaces 52 constituting the protective portions 50Ca and 50Cb of the sustained-release solid flocculant 1C is the sum of S54Caa, S54Cab, S55Ca, S54Cba, S54Cbb, and S55Cb. Specifically, this sum is S54Caa + S54Cab + S55Ca + S54Cba + S54Cbb + S55Cb.

[0109] (flocculant surface coverage) In the sustained-release solid flocculant 1C, a part of the surface 12 of the solid flocculant portion 10C is covered with protective portions 50Ca and 50Cb.

[0110] In the sustained-release solid flocculant 1C, the flocculant surface coverage is the proportion of the surface 12 of the solid flocculant portion 10C that is covered with the protective portions 50Ca and 50Cb. The flocculant surface coverage of the sustained-release solid flocculant 1C is within the same numerical range as the flocculant surface coverage of the sustained-release solid flocculant 1A. The reason for this is the same as that for the flocculant surface coverage of the sustained-release solid flocculant 1A, so an explanation will be omitted.

[0111] In the sustained-release solid flocculant 1C shown in Fig. 4, the surface area S32 of the protective agent coating portion 32 is the sum (S34Ca + S34Cb) of the surface areas S34Ca and S34Cb of the flat portions 34Ca and 34Cb. The surface area S12 of the surface 12 of the solid flocculant portion 10C is the sum of the surface areas S24Ca, S24Cb, S34Ca, and S34Cb of the flat portions 24Ca, 24Cb, 34Ca, and 34Cb and the surface areas S25Ca and S25Cb of the curved portions 25Ca and 25Cb. Specifically, this sum is S24Ca + S24Cb + S34Ca + S34Cb + S25Ca + S25Cb. Therefore, for sustained-release solid flocculant 1C, the flocculant surface coverage is (S34Ca+S34Cb) / (S24Ca+S24Cb+S34Ca+S34Cb+S25Ca+S25Cb).

[0112] (water contact ratio surface area ratio) In the sustained-release solid flocculant 1C, the water contact specific surface area ratio, which is the ratio of the surface area S52 of the exposed surface 52 of the protective parts 50Ca and 50Cb to the surface area S22 of the flocculant exposed part 22 of the solid flocculant part 10C, is within the same range as the water contact specific surface area ratio of the sustained-release solid flocculant 1A. The reason for this is the same as the reason for the water contact specific surface area ratio of the sustained-release solid flocculant 1A, so an explanation will be omitted.

[0113] (action) The action of the sustained-release solid flocculant 1C is similar to that of the sustained-release solid flocculant 1A, and therefore a description thereof will be omitted.

[0114] [Reference form] A solid flocculant according to a reference embodiment will be described. FIG. 5 is a diagram showing an example of a solid flocculant according to a reference embodiment. As shown in FIG. 5, the solid flocculant 5D(5) includes a solid flocculant portion 10D(10) containing a polymer flocculant and a protective portion 50D(50) that protects the solid flocculant portion 10D from contact with water. In the solid flocculant 5D, a portion of the surface 12 of the solid flocculant portion 10D is covered with the protective portion 50D.

[0115] The solid flocculant 5D according to the reference embodiment uses a protective part 50D (50) instead of the protective part 50A of the sustained-release solid flocculant 1A according to the first embodiment, and the other members are the same as those of the sustained-release solid flocculant 1A. Therefore, the same reference symbols are used for the same members in the solid flocculant 5D according to the reference embodiment and the sustained-release solid flocculant 1A according to the first embodiment, and the description of the members and their functions is omitted or simplified.

[0116] (Solid flocculant part) As shown in FIG. 5, in a solid flocculant 5D, a part of the surface 12 of the solid flocculant portion 10D shown in FIG. 2 is covered with a protective portion 50D.

[0117] The solid flocculant portion 10D is the same as the solid flocculant portion 10A, including its shape. Therefore, a description of the solid flocculant portion 10D will be omitted. However, the protective portion 50D that covers a portion of the surface 12 of the solid flocculant portion 10D has a different shape from the protective portion 50A that covers a portion of the surface 12 of the solid flocculant portion 10A.

[0118] Specifically, in solid flocculant 5D, the circular flat surface portion 14a of the surface 12 of solid flocculant portion 10D is a surface covered with protective portion 50D, which is a protective agent coated portion 32. On the other hand, in solid flocculant 5D, the circular flat surface portion 14b and the cylindrical curved surface portion 15 of the surface 12 of solid flocculant portion 10D are a flocculant exposed portion 22, which is an exposed surface that is not covered with protective portion 50D. The protective agent coated portion 32 and the flocculant exposed portion 22 will be described below.

[0119] [Protective coating] In the solid flocculant 5D shown in FIG. 5, the flat portion 14a, which is the circular surface of the solid flocculant portion 10D shown in FIG.

[0120] Here, the planar portion of the protective agent-coated portion 32 is referred to as a planar portion 34 of the protective agent-coated portion, and the curved portion of the protective agent-coated portion 32 is referred to as a curved portion 35 of the protective agent-coated portion.

[0121] The protective agent coating portion 32 of the solid flocculant 5D shown in Fig. 5 is specifically the flat surface portion 34D(34) of the protective agent coating portion. The flat surface portion 34D of the protective agent coating portion corresponds to the circular flat surface portion 14a of the solid flocculant portion 10D shown in Fig. 2.

[0122] The surface area S34D of the planar portion 34D of the protective agent coated portion 32 constituting the solid flocculant portion 10D can be calculated by a known method. The total surface area S32 of the protective agent coated portions 32 constituting the solid flocculant portion 10D is S34D.

[0123] 5, the diameter D34 of the flat surface 34D of the protective agent-coated portion 32 of the solid flocculant portion 10D is the same as the diameter D14 of the flat surface of the solid flocculant portion 10D. The surface area S34 of the flat surface 34D of the protective agent-coated portion 32 is the same as the surface area S14a of the flat surface 14a. The surface area S34 of the flat surface 34D of the protective agent-coated portion 32 is the same as the surface area S14b of the flat surface 14b.

[0124] [Exposed flocculant area] In the solid flocculant 5D shown in FIG. 5, the flat surface portion 14b and the cylindrical curved surface portion 15 of the solid flocculant portion 10D shown in FIG.

[0125] Here, the flat portion of the flocculant exposed portion 22 is referred to as a flat portion 24 of the flocculant exposed portion, and the curved portion of the flocculant exposed portion 22 is referred to as a curved portion 25 of the flocculant exposed portion.

[0126] The flocculant exposed portion 22 of the solid flocculant 5D shown in Figure 5 is specifically a flat portion 24D (24) and a curved portion 25D (25) of the flocculant exposed portion. The flat portion 24D of the flocculant exposed portion corresponds to the flat portion 14b of the solid flocculant portion 10D shown in Figure 2. The curved portion 25D of the flocculant exposed portion corresponds to the cylindrical curved portion 15 of the solid flocculant portion 10D shown in Figure 2.

[0127] The surface area S24D of the flat portion 24D and the surface area S25D of the curved portion 25D can be calculated by a known method. The total surface area S22 of the flocculant exposed portion 22 constituting the solid flocculant portion 10D is the sum of S24D and S25D (S24D + S25D).

[0128] 5, the length L25 of the curved portion 35D of the flocculant exposed portion 22 of the solid flocculant portion 10D is the same as the length L15 of the curved portion of the solid flocculant portion 10D. Also, the diameter D24 of the curved portion 25D of the flocculant exposed portion 22 is the same as the diameter D34 and the diameter D14 of the flat portion of the solid flocculant portion 10D.

[0129] (Protection Department) The protective portion 50D constituting the solid flocculant 5D will be described with reference to FIG.

[0130] Other than its shape, the protective part 50D is the same as the protective part 50A of the sustained-release solid flocculant 1A according to the first embodiment. Therefore, the shape of the protective part 50D will be explained below.

[0131] The protective portion 50D shown in FIG. 5 has a cylindrical outer shape and includes an exposed surface 52 exposed to the outside and a portion that is not exposed to the outside and comes into contact with the protective agent coated portion 32 of the solid flocculant portion 10D.

[0132] The exposed surface 52 of the protective portion 50D shown in Figure 5 consists of an exposed flat portion 54D (54), which is a circular exposed surface 52 that forms the top surface of the cylinder, and an exposed curved portion 55D (55), which is a cylindrical exposed surface 52 that forms the side surface of the cylinder.

[0133] Here, the surface area S54D of exposed flat portion 54D and the surface area S55D of exposed curved portion 55D can be calculated by a known method. The total surface area S52 of exposed surface 52 constituting protective portion 50D is the sum of S54D and S55D (S54D + S55D).

[0134] Note that the surface area S54 of exposed flat surface portion 54D can be easily calculated using the diameter D54 of exposed flat surface portion 54D, etc. The surface area S55D of exposed curved surface portion 55D can be easily calculated using the diameter D54 of exposed flat surface portion 54D and the length L55D of exposed curved surface portion 55D, etc.

[0135] (flocculant surface coverage) In the solid flocculant 5D, a part of the surface 12 of the solid flocculant portion 10D is covered with a protective portion 50D.

[0136] In solid flocculant 5D, the flocculant surface coverage is the proportion of the surface 12 of solid flocculant portion 10D that is covered with protective portion 50D. However, the flocculant surface coverage of solid flocculant 5D is usually lower than that of sustained-release solid flocculant 1A.

[0137] 5, specifically, the surface area S32 of the protective agent coating portion 32 is the surface area S34D of the flat surface portion 34D. The surface area S12 of the surface 12 of the solid flocculant portion 10D is the sum (S14a + S14b + S15) of the surface area S14a of the flat surface portion 14a, the surface area S14b of the flat surface portion 14b, and the surface area S15 of the curved surface portion 15. Therefore, in the solid flocculant 5D, the flocculant surface coverage is (S34D) / (S14a + S14b + S15). However, in the solid flocculant 5D, the flocculant surface coverage tends to be less than 30%.

[0138] (water contact ratio surface area ratio) In the solid flocculant 5D, the water contact specific surface area ratio, which is the ratio of the surface area S52 of the exposed surface 52 of the protective portion 50D to the surface area S22 of the flocculant exposed portion 22 of the solid flocculant portion 10D, is within the same range as the water contact specific surface area ratio of the sustained-release solid flocculant 1A. The reason for this is the same as that for the water contact specific surface area ratio of the sustained-release solid flocculant 1A, so explanation will be omitted.

[0139] (action) The action of solid flocculant 5D is similar to that of sustained-release solid flocculant 1A, and therefore a detailed explanation is omitted. However, in solid flocculant 5D, the degree of coverage of solid flocculant portion 10D by protective portion 50D is usually low, so the polymer flocculant tends to dissolve relatively easily from solid flocculant portion 10D, and sustained release tends to be low.

[0140] <Water treatment equipment> Next, a water treatment device according to an embodiment will be described. The water treatment device according to an embodiment is a device that uses the sustained-release solid flocculant 1 according to the embodiment.

[0141] Fig. 6 is a conceptual diagram showing an example of a water treatment device according to an embodiment. As shown in Fig. 6, a water treatment device 500 according to an embodiment includes a pump 200 that sends water to be treated W0 to a chemical dissolving device 100, the chemical dissolving device 100, and a filter 300 that filters post-treatment water W2 discharged from the chemical dissolving device 100. A sustained-release solid flocculant 1 according to an embodiment is placed in the chemical dissolving device 100.

[0142] In water treatment device 500, water to be treated W0 introduced into inlet line 410 is pumped to main line 420 by pump 200. During water treatment, water to be treated W0 is introduced into main line 420, sustained-release inlet line 430, and chemical dissolving device 100. Within chemical dissolving device 100, post-contact water W1 is produced from water to be treated W0 by water treatment using sustained-release solid flocculant 1, and is discharged outside chemical dissolving device 100 as post-pass water W2. The post-pass water W2 discharged outside chemical dissolving device 100 flows through sustained-release discharge line 440 and main line 460, and is introduced into filter 300, where it is filtered to produce treated water TW. The treated water TW discharged from filter 300 flows through discharge line 470 and is discharged.

[0143] On the other hand, when water treatment is not performed, the untreated water W0 sent to the main line 420 flows, for example, through the untreated line 450 and the main line 460, and is introduced into the filter 300, where it is filtered to produce untreated filtrate W3. The untreated filtrate W3 discharged from the filter 300 is discharged via the discharge line 470. (drug dissolving device)

[0144] Fig. 7 is a cross-sectional view of an example 100A of the chemical dissolving device 100 constituting the water treatment device 500 shown in Fig. 6. As shown in Fig. 7, the chemical dissolving device 100A includes a container section 110, a chemical tank 120A (120) disposed in the container section 110, and an introduction section 130 that introduces the water to be treated W0 into the container section 110.

[0145] The container 110 includes a container body 111 and a lid 112, which together form a space inside the container 110. The container body 111 has a disk-shaped bottom surface 111a and a cylindrical peripheral wall 111b, and is open at the top. The lid 112 is shaped so as to be easily attached to and detached from the top end of the container body 111. Specifically, the lid 112 has a disk-shaped top surface 112a and a peripheral wall 112b that extends downward from the outer periphery of the top surface 112a and is slightly larger than the peripheral wall 111b of the container body 111. Note that the container 110 may have a shape different from that shown in FIG. 7, as long as it is capable of forming a space inside.

[0146] A chemical tank 120A containing sustained-release solid flocculant 1 is disposed within container portion 110. In chemical dissolution device 100A, by removing lid portion 112 from container body portion 111 and disposing chemical tank 120A within container portion 110, it is possible to introduce sustained-release solid flocculant 1 into container portion 110 without touching the sustained-release solid flocculant 1.

[0147] As shown in Figures 7 and 8, chemical tank 120A comprises a disk-shaped bottom surface portion 121 and a cylindrical peripheral wall portion 122 extending upward from the outer peripheral edge of bottom surface portion 121 and surrounding the space above bottom surface portion 121. Bottom surface portion 121 of chemical tank 120A may have a shape different from the shape shown in Figures 7 and 8, such as a substantially square, as long as it is a shape that allows at least one of sustained-release solid flocculant 1 and dispersion portion 145 to be placed thereon. In addition, peripheral wall portion 122 may also have a shape different from the shape shown in Figures 7 and 8, such as a rectangular tube.

[0148] The chemical tank 120A includes an inlet 123 for introducing the water to be treated W0 and the like into the space surrounded by the peripheral wall 122 via the inlet 130, and an outlet 124 for discharging post-contact water W1 obtained by contacting the introduced water to be treated W0 with the sustained-release solid flocculant 1 to the outside. The inlet 123 is provided approximately at the center of the bottom 121 and is a through-hole that penetrates the bottom 121 in a circular shape when viewed in the thickness direction. The outlet 124 is also circular when viewed in the thickness direction of the bottom 121. When the water to be treated W0 is supplied to the sustained-release solid flocculant 1 via the inlet 123, components such as the polymer flocculant contained in the sustained-release solid flocculant 1 dissolve in the water to be treated W0, thereby obtaining post-contact water W1. In addition, in the drug dissolving device 100A, a dispersion section 145 described below is placed on the inlet 123, and the flow of liquid such as the water to be treated W0 introduced through the inlet 123 is dispersed in the dispersion section 145.

[0149] The chemical dissolving apparatus 100A includes an inlet pipe 151 for introducing the water to be treated W0 into the bottom surface 111a of the container body 111, and a discharge pipe 152 for discharging the post-contact water W1 generated in the chemical dissolving apparatus 100A as post-passage water W2 to the outside of the chemical dissolving apparatus 100A. The space inside the inlet pipe 151 and the space inside the inlet section 130 form an inlet flow path 141. The space outside the inlet section 130 and the space inside the discharge pipe 152 form a discharge flow path 142. A partition wall 153 is provided between the inlet pipe 151 and the discharge pipe 152 to separate them. A drain plug 154 is provided at the lower end of the discharge pipe 152 to remove water from inside the chemical dissolving apparatus 100A.

[0150] In the bottom surface portion 121, it is preferable that the multiple outlets 124 each have the same shape. The outlets 124 are not particularly limited in shape, position, number, etc., as long as they are capable of discharging the post-contact water W1. For example, the multiple outlets 124 may be elongated holes extending in the radial direction, or arc-shaped holes extending in the circumferential direction. Furthermore, the position of the outlets 124 in the chemical tank 120A is not limited to the bottom surface portion 121. The outlets 124 may be provided in, for example, the peripheral wall portion 122. Even in a modified example of the chemical tank 120A in which the outlets 124 are provided in the peripheral wall portion 122, the treated water W0 can be brought into substantially uniform contact with the sustained-release solid flocculant 1.

[0151] As shown in Figure 8, peripheral wall 122 of chemical tank 120A is cylindrical. Bottom surface 121 of chemical tank 120A is disk-shaped, and the imaginary central axis of cylindrical peripheral wall 122 passes through the center of bottom surface 121. In chemical tank 120A, eight discharge ports 124 are provided along the circumference of bottom surface 121.

[0152] A dispersion unit 145 is further provided above the inlet 123 and outlet 124 of the chemical tank 120A, positioned between the inlet 123 and the sustained-release solid flocculant 1 to cover the inlet 123 and disperse the flow of the water to be treated W0 from the inlet 123 toward the sustained-release solid flocculant 1. The chemical dissolving apparatus 100 uses the dispersion unit 145 to uniformly contact the dispersed water to be treated W0 with the entire lower part of the sustained-release solid flocculant 1, thereby enabling components such as the polymer flocculant contained in the sustained-release solid flocculant 1 to be substantially uniformly dissolved in the water to be treated W0. Furthermore, the use of the dispersion unit 145 in the chemical dissolving apparatus 100 can prevent, for example, granular sustained-release solid flocculant 1 from suddenly flowing out of the chemical dissolving apparatus 100. As a result, it is easy to maintain a substantially constant dissolved concentration of the sustained-release solid flocculant 1 in the water to be treated W0.

[0153] The dispersion portion 145 is a structure in which a large number of gaps are distributed in the thickness direction and the radial direction. Specifically, the dispersion portion 145 is a multi-particle deposit formed by stacking a large number of granular materials. Because the dispersion portion 145 is a multi-particle deposit, it is easy to obtain.

[0154] The dispersion section 145 has the function of dispersing the flow of the water to be treated W0 introduced into the inlet 123 in a concentrated manner by passing the flow through gaps in the dispersion section 145. The dispersion section 145 also has the function of rectifying the flow of the water to be treated W0 in the chemical tank 120A. The dispersion section 145 is placed inside the peripheral wall section 122 and on the bottom surface section 121 so as to cover the inlet 123.

[0155] The dispersion section 145 may be a structure other than a multi-particle deposit, as long as it can disperse the water to be treated W0 and bring the water to be treated W0 into substantially uniform contact with the lower part of the sustained-release solid flocculant 1. The dispersion section 145 may be, for example, a laminated structure of multiple sheets of nonwoven fabric, a laminated structure of multiple sheets of woven fabric, a three-dimensional fiber structure in which fibers are entangled, or a porous member having a structure similar to that of a sponge.

[0156] As shown in Figure 8, in the chemical dissolving apparatus 100A, a mesh member 125 is placed on the bottom surface 121 where the inlet 123 of the chemical tank 120A is formed and below the dispersion section 145 so as to cover the inlet 123. Therefore, in the chemical dissolving apparatus 100A, the mesh member 125 is interposed between the inlet 123 and the dispersion section 145. The mesh member 125 has many meshes that are smaller than the inlet 123. Furthermore, the meshes of the mesh member 125 are large enough to prevent the passage of particles that make up the dispersion section 145, but are large enough to allow the water to be treated W0 to pass through.

[0157] The introduction part 130 is a substantially cylindrical pipe that is connected from below the bottom surface part 121 to the introduction port 123 of the bottom surface part 121. The inside of the introduction part 130 forms an introduction flow path 141 through which the water to be treated W0 flows.

[0158] A discharge flow path 142 is provided in the space inside the container body 111 and outside the introduction part 130 of the chemical dissolving apparatus 100A. The post-contact water W1 obtained by dissolving components such as the polymer flocculant contained in the sustained-release solid flocculant 1 in the water to be treated W0 is introduced into the discharge flow path 142 via the discharge port 124. The post-contact water W1 flowing through the discharge flow path 142 is discharged to the outside of the chemical dissolving apparatus 100A via the discharge piping 152. When the post-contact water W1 is discharged to the outside of the chemical dissolving apparatus 100A, it becomes the passed water W2, which is the water to be treated W0 discharged from the chemical dissolving apparatus 100A. Note that the post-contact water W1 flowing through the discharge flow path 142 in the chemical dissolving apparatus 100A and the passed water W2 discharged to the outside of the chemical dissolving apparatus 100A usually have the same composition. <effect> The operation of the water treatment device 500 incorporating the chemical dissolving device 100A will be described. First, the water to be treated W0, such as well water, is introduced into the inlet pipe 151. The water to be treated W0 may contain impurities such as inorganic substances such as Fe, Mn, and sand; bacteria; and the like. The water to be treated W0 passes through the inlet flow path 141 in the inlet section 130 and is introduced into the chemical tank 120A via the inlet 123. Within the chemical tank 120A, the water to be treated W0 is introduced into the gaps in the dispersion section 145, thereby dispersing the flow. As a result, the water to be treated W0 introduced from below the sustained-release solid flocculant 1 comes into almost uniform contact with the sustained-release solid flocculant 1.

[0159] When the water to be treated W0 comes into contact with the sustained-release solid flocculant 1, the polymer flocculant in the solid flocculant section 10 dissolves in the water to be treated W0, thereby obtaining post-contact water W1. The post-contact water W1 passes through the discharge port 124 from inside the chemical tank 120A and flows down to the discharge flow path 142 below the discharge port 124. The post-contact water W1 flowing through the discharge flow path 142 reaches the discharge pipe 152 and is discharged from the chemical dissolving device 100 as post-passage water W2.

[0160] In the post-contact water W1 and the post-pass water W2, impurities such as suspended matter contained in the water to be treated W0 are captured by the polymer flocculant, forming flocs. When the post-contact water W1 and the post-pass water W2 containing these flocs pass through the filter material in the filter 300 located downstream of the chemical dissolving device 100, the flocs are removed, and treated water TW with a reduced impurity content is obtained.

[0161] In addition, as long as the protective section 50 has the effect of protecting the solid flocculant section 10 from contact with water, if the protective section 50 absorbs water, expands, dissolves, or disintegrates upon contact with water, such as the water to be treated W0, the post-contact water W1 may contain a protective agent, which is a component of the protective section 50. If the post-contact water W1 contains a protective agent, this protective agent can also remove impurities from the water to be treated W0. For example, if the protective section 50 is made of a water-soluble chlorine-containing compound, when the water to be treated W0 containing Fe ions is introduced, the Fe ions and chloride ions may react in the post-contact water W1, producing insoluble suspended matter. In this case, filtering the insoluble suspended matter makes it possible to obtain post-treatment water TW from which Fe ions have been removed.

[0162] The post-contact water W1 obtained by contacting the water to be treated W0 with the sustained-release solid flocculant 1 preferably has a polymer flocculant concentration of 0.001 mg / L or more and 1000 mg / L or less, more preferably 0.01 mg / L or more and 1 mg / L or less. If the concentration of the polymer flocculant in the post-contact water W1 is within the above range, it is preferable because it exhibits appropriate flocculation properties and improves water purification performance.

[0163] In cases where the water treatment device 500 further includes a chemical dissolving device 100 that holds a sustained-release solid flocculant 1, the concentration of the polymer flocculant in the passed water W2 obtained by discharging the treated water W0 from the chemical dissolving device 100 is preferably within a specific range. That is, the concentration of the polymer flocculant in the passed water W2 is preferably 0.001 mg / L or more and 1000 mg / L or less, more preferably 0.01 mg / L or more and 1 mg / L or less. If the concentration of the polymer flocculant in the passed water W2 is within the above range, it is preferable because it exhibits appropriate flocculation properties and improves water purification performance.

[0164] In addition, when the post-contact water W1 in the drug dissolving device 100 circulates without further treatment within the drug dissolving device 100 and is discharged outside the drug dissolving device 100 as post-passage water W2, the composition of the post-contact water W1 and the post-passage water W2 will be substantially the same. [Example]

[0165] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0166] [Example 1] (slow-release solid flocculant) The sustained-release solid flocculant 1A according to the first embodiment was produced by the following procedure: As shown in Fig. 1, the sustained-release solid flocculant 1A includes a solid flocculant portion 10A and a protective portion 50A.

[0167] <Solid flocculant section> As the raw material for the solid flocculant section 10A shown in Figure 1, a polymethacrylate ester-based cationic polymer flocculant powder (KP201G manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 3,000,000) was crushed in a mill mixer and then classified using a 350 μm sieve to prepare a powder.

[0168] 0.7 g of the above flocculant powder was placed in a cylindrical powder molding die with a diameter of 8.6 mm and pressure-molded at 25°C and 20 MPa to obtain a flocculant tablet with a diameter of 8.6 mm and a thickness of 10 mm. This flocculant tablet was used as solid flocculant part 10A.

[0169] <Protection Department> A hollow cylindrical protective agent tablet (XS-90H manufactured by Shikoku Chemical Industry Co., Ltd.) containing trichloroisocyanuric acid as a main component, having an outer diameter of 30 mm, an inner diameter of 8.6 mm, a thickness of 10 mm, and a mass of 15 g was prepared as the raw material for protective part 50A shown in Fig. 1. This protective agent tablet was used as protective part 50A.

[0170] <Preparation of release solid flocculant> A flocculant tablet having a diameter of 8.6 mm and a thickness of 10 mm as the solid flocculant part 10A was fitted into the hollow part having an inner diameter of 8.6 mm and a thickness of 10 mm of the protective agent tablet as the protective part 50A, and the sustained-release solid flocculant 1A shown in Figure 1 was obtained.

[0171] <Flocculant surface coverage> The surface coverage of the sustained-release solid flocculant 1A was 69.9%.

[0172] <Water contact ratio / surface area ratio> The water contact specific surface area ratio of the sustained release solid flocculant 1A was 19.3 (1930%). (Water treatment equipment) The water treatment device 500 shown in FIGS. 6 to 8 was used.

[0173] (Measurement of chlorine concentration and turbidity) <Device configuration> First, as the water to be treated W0 to be introduced into the water treatment device 500, simulated turbid water with a turbidity of 100 NTU was prepared by adding a commercially available kaolin reagent to tap water. Next, six pieces of the sustained-release solid flocculant 1A were placed in the chemical tank 120 in the chemical dissolving device 100 of the water treatment device 500.

[0174] <Water treatment cycle> The following water treatment cycle was performed using a water treatment device 500 in which a sustained-release solid flocculant 1A was placed in the chemical tank 120. First, the water to be treated W0 was introduced into the water treatment device 500, and the flow rate of the inlet flow path 141 in the chemical dissolving device 100 was set to 15 L / min. In the chemical dissolving device 100, the sustained-release solid flocculant 1A was dissolved in the water to be treated W0 to generate post-contact water W1. The post-contact water W1 was discharged outside the chemical dissolving device 100 as post-passage water W2. The post-passage water W2 discharged outside the chemical dissolving device 100 was introduced into the filter 300 and filtered to obtain post-treatment water TW. The filtration section of the filter 300 had an inner diameter of 250 mm, and was piled with activated carbon to a thickness of 5 L, sand filter material with a particle size of 0.35 mm to a thickness of 6 L, and gravel with a particle size of 10 mm to a thickness of 4 L. The above treatment was considered as one water treatment cycle, and this cycle was carried out over one hour. After one cycle of the water treatment was completed, the filter 300 was backwashed with tap water.

[0175] <Repeated water treatment cycle> The above-mentioned one-hour water treatment cycle and backwashing were alternated, and the water treatment cycle was carried out seven times. The total water flow time, excluding the backwashing time, was seven hours.

[0176] <Measurement of chlorine concentration> The eluted chlorine concentration [ppm] was measured for the post-passage water W2 discharged outside the chemical dissolving device 100 and before being introduced into the filter 300. The results are shown in Figure 9. The horizontal axis of Figure 9 represents the total water flow time, excluding the time for backwashing. From FIG. 9, it was found that the eluted chlorine concentration was 5 to 10 ppm throughout the 7-hour water flow period, with little fluctuation in concentration, and that the protective agent contained in protective part 50A was able to be stably and gradually released.

[0177] <Turbidity measurement> The turbidity [NTU] of the treated water TW discharged outside the filter 300 was measured. The results are shown in Figure 10. The horizontal axis of Figure 10 represents the total water flow time, excluding the time for backwashing. Furthermore, "5 NTU" in Figure 10 represents the WHO tap water quality turbidity standard. Furthermore, "50 NTU" in Figure 10 represents the average turbidity of the untreated filtrate W3 discharged from the filter 300 when no sustained-release solid flocculant was placed in the chemical tank 120 in the chemical dissolving device 100 and no water treatment was performed. From FIG. 10, it was found that the turbidity of the treated water TW was below 5 NTU throughout the seven-hour water flow period, and that the polymer flocculant contained in the solid flocculant portion 10A was able to be stably and gradually released.

[0178] <Remaining state of solid flocculant in sustained-release solid flocculant> In the sustained-release solid flocculant 1A in the chemical tank 120, the solid flocculant portion 10 remained even after 7 hours of water flow.

[0179] <Evaluation> The sustained-release solid flocculant 1A of Example 1 was capable of stable sustained release of two components, the protective agent contained in the protective portion 50A and the polymer flocculant contained in the solid flocculant portion 10A, and remained even after 7 hours of water flow. Therefore, it was found that the sustained-release solid flocculant 1A of Example 1 is useful as a sustained-release solid flocculant.

[0180] [Reference example 1] <Turbidity measurement> Using water treatment device 500, the turbidity [NTU] of the water to be treated W0 in main line 460 before being introduced into filter 300 was measured without passing the water through chemical dissolving device 100. Specifically, the turbidity [NTU] of the water to be treated W0 in main line 460 was measured when the water to be treated W0 was circulated through main line 420, untreated line 450, and main line 460. The results are shown in FIG. From FIG. 10, it was found that the turbidity of the water to be treated W0 was about 50 NTU throughout the seven-hour water flow period.

[0181] [Example 2] (slow-release solid flocculant) A sustained-release solid flocculant 1A according to the first embodiment was produced in the same manner as in Example 1, except that a different flocculant powder was used as the raw material for the solid flocculant portion 10A. Specifically, the raw material for the solid flocculant portion 10A was a powder obtained by crushing a polymethacrylate ester-based cationic polymer flocculant powder (KP201L manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 500,000) in a mill mixer and then classifying it with a 350 μm sieve.

[0182] Other than the composition of the solid flocculant portion 10A of the sustained-release solid flocculant 1A of Example 2, that is, the shape and size of the solid flocculant portion 10A and the protective portion 50A of the sustained-release solid flocculant 1A were the same as those of the sustained-release solid flocculant 1A of Example 1. Therefore, the flocculant surface coverage and water contact specific surface area ratio of the sustained-release solid flocculant 1A of Example 2 were the same as those of the sustained-release solid flocculant 1A of Example 1.

[0183] (Measurement of residual rate of solid flocculant) First, one tablet of sustained-release solid flocculant 1A was immersed in a container containing 100 mL of tap water. Next, the tap water in the container was replaced every hour, and this replacement was repeated five times, for a total of six hours of immersion. After immersion for 6 hours, the protective portion 50A of the sustained-release solid flocculant 1A was separated from the solid flocculant portion 10A. Weight W of solid flocculant part 10A a Measure W a The weight W of the solid flocculant part 10A before the immersion test b Divided by (W a / W b ). This W a / W b was taken as the residual rate of the solid flocculant. W of solid flocculant part 10A after immersion for 6 hours a is 0.527g, W b The residual amount was 0.7 g, so the residual rate was 75.3%.

[0184] [Example 3] (slow-release solid flocculant) A sustained-release solid flocculant 1B according to the second embodiment was produced by the following procedure. As shown in Fig. 3, the sustained-release solid flocculant 1B includes a solid flocculant portion 10B and protective portions 50Ba and 50Bb.

[0185] <Raw materials for solid flocculant> As the raw material for the solid flocculant portion 10B shown in FIG. 3, the same flocculant powder as in Example 2 was prepared.

[0186] <Ingredients for the protective part> A trichloroisocyanuric acid reagent (XS-90H manufactured by Shikoku Chemical Industry Co., Ltd.) was used as the raw material for the protective parts 50Ba and 50Bb shown in FIG. 3, and the reagent was powdered and classified using a 350 μm sieve to produce a protective agent powder.

[0187] <Preparation of release solid flocculant> First, 0.55 g of protective agent powder was placed in a cylindrical powder molding die with a diameter of 8.6 mm. Next, 0.7 g of flocculant powder was placed on top of the protective agent powder in the powder molding die. Furthermore, 0.55 g of protective agent powder was placed on top of the flocculant powder in the powder molding die. These three layers of powder were pressure-molded at 25°C and 20 MPa to obtain sustained-release solid flocculant 1B with a diameter of 8.6 mm, a protective portion 50Bb thickness of 5 mm, a solid flocculant portion 10B thickness of 10 mm, and a protective portion 50Ba thickness of 5 mm.

[0188] <Flocculant surface coverage> The surface coverage of the sustained-release solid flocculant 1B was 30.1%.

[0189] <Water contact ratio / surface area ratio> The water contact specific surface area ratio of the sustained release solid flocculant 1B was 1.4 (140%).

[0190] (Measurement of residual rate of solid flocculant) The residual rate of the solid flocculant portion was measured in the same manner as in Example 2, except that the sustained-release solid flocculant 1B was used instead of the sustained-release solid flocculant 1A of Example 2. W of solid flocculant part 10B after immersion for 6 hours a is 0.221g, W b The residual amount was 0.7 g, so the residual rate was 31.5%.

[0191] [Reference example 2] (Solid flocculant) Solid flocculant 5D was prepared by the following procedure: As shown in Fig. 5, solid flocculant 5D includes a solid flocculant portion 10D and a protective portion 50D.

[0192] <Raw materials for solid flocculant> As the raw material for the solid flocculant portion 10D shown in FIG. 5, the same flocculant powder as in Example 2 was prepared.

[0193] <Ingredients for the protective part> The same protective agent powder as in Example 3 was prepared as the raw material for protective portion 50D shown in FIG.

[0194] <Preparation of sustained-release solid flocculant> First, 0.7 g of flocculant powder was placed in a cylindrical powder molding die with a diameter of 8.6 mm. Next, 1.1 g of protective agent powder was placed on top of the flocculant powder in the powder molding die. These two layers of powder were pressed at 25°C and 20 MPa to obtain solid flocculant 5D with a diameter of 8.6 mm, a solid flocculant portion 10D thickness of 10 mm, and a protective portion 50D thickness of 10 mm.

[0195] <Flocculant surface coverage> The solid flocculant 5D had a surface coverage of 15.0%.

[0196] <Water contact ratio / surface area ratio> The solid flocculant 5D had a water contact specific surface area ratio of 1.0 (100%).

[0197] (Measurement of residual rate of solid flocculant) The residual rate of the solid flocculant portion was measured in the same manner as in Example 2, except that solid flocculant 5D was used instead of sustained-release solid flocculant 1A in Example 2. W of solid flocculant part 10D after immersion for 6 hours a is 0.125g, W b Therefore, the residual rate was 17.9%.

[0198] [Comparative Example 1] (Solid flocculant) The solid flocculant portion 10A of Example 2 was used as solid flocculant 5E as it was. Solid flocculant 5E consists only of the solid flocculant portion 10A shown in Figure 2 and is the same material as solid flocculant portion 10A, but for convenience it is referred to as solid flocculant 5E. For this reason, solid flocculant 5E does not have a protective portion 50.

[0199] <Flocculant surface coverage> The solid flocculant 5E did not have the protective portion 50, and therefore the flocculant surface coverage was 0%.

[0200] <Water contact ratio / surface area ratio> Since the solid flocculant 5E does not have the protective portion 50, the water contact specific surface area ratio was 0 (0%).

[0201] (Measurement of residual rate of solid flocculant portion (solid flocculant)) The residual rate of the solid flocculant portion (solid flocculant) was measured in the same manner as in Example 2, except that solid flocculant 5E consisting only of solid flocculant portion 10A was used instead of sustained-release solid flocculant 1A in Example 2. W of solid flocculant part 10A (solid flocculant 5E) after immersion for 6 hours a is 0g, W b The residual amount was 0.7 g. Therefore, the residual rate was 0%.

[0202] From the results of the above Examples 1 to 3, Reference Examples 1 and 2, and Comparative Example 1, it was found that the residual rate of the solid flocculant portion 10 increases when the protective portion 50 covers the surface of the solid flocculant portion 10 at a specific ratio.

[0203] The sustained-release solid flocculant and water treatment device according to the above-described embodiment can be applied to a water purification device installed at the entrance of a building (POE), a water purification device installed at the point of use (POU), and the like. [Explanation of symbols]

[0204] 1, 1A, 1B, 1C Slow-release solid flocculant 5, 5D, 5E Solid Flocculants 10, 10A, 10B, 10C, 10D Solid flocculant part 12 Surface 50, 50A, 50Ba, 50Bb, 50Ca, 50Cb, 50D Protection section 100 Drug dissolving device 500 Water Treatment Equipment

Claims

1. a solid flocculant portion containing a polymer flocculant; a protective portion that protects the solid flocculant portion from contact with water, A part of the surface of the solid flocculant portion is covered with the protective portion, The protective agent contained in the protective part is water-soluble and contains a chlorine-containing compound as a main component that releases chloride ions into water, The protective part is a powder compact obtained by molding a powder of the protective agent.

2. The sustained-release solid flocculant according to claim 1, wherein the polymer flocculant has a weight-average molecular weight of 1,000 or more.

3. 3. The sustained-release solid flocculant according to claim 1, wherein the flocculant surface coverage, which is the ratio of the surface of the solid flocculant portion that is covered with the protective portion, is 20% or more and 99% or less.

4. The polymer flocculant is one or more selected from the group consisting of nonionic polymer flocculants, anionic polymer flocculants, cationic polymer flocculants, and amphoteric polymer flocculants, the sustained-release solid flocculant according to any one of claims 1 to 3.

5. The sustained-release solid flocculant according to any one of claims 1 to 4, wherein the polymer flocculant is a cationic polymer flocculant.

6. The sustained-release solid flocculant according to any one of claims 1 to 5, wherein the protective agent is mainly composed of dichloroisocyanuric acid or trichloroisocyanuric acid.

7. A water treatment device using the sustained-release solid flocculant according to any one of claims 1 to 6.

8. The water treatment device according to claim 7 , wherein post-contact water obtained by contacting the water to be treated with the sustained-release solid flocculant has a concentration of the polymer flocculant of 0.001 mg / L or more and 1000 mg / L or less.

9. Further provided is a drug dissolving device that holds the sustained-release solid flocculant; The water treatment device according to claim 7 , wherein the concentration of the polymer flocculant in the water after passing through the chemical dissolving device is 0.001 mg / L or more and 1000 mg / L or less.

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