Treatment device for fluorine-containing water

Abstract

To provide a fluorine-containing water treatment device capable of reliably removing fluorine from fluorine-containing water with excellent fluorine removal efficiency, and of decreasing the amount of wastewater.SOLUTION: The fluorine-containing water treatment device comprises an electrolytic tank 12 filled with fluorine-containing water 11, and the electrolytic tank 12 includes a water tank 14 filled with fluorine-containing water 11. The water tank 14 is divided by four diaphragms 20 into five thin chambers disposed parallel to one direction, with one compartment disposed on the center of the water tank 14, constituting an anode chamber 26 provided with a plurality of anodes 16, and two compartments disposed on either side of the exterior of the anode chamber 26, constituting water injection chambers 24 into which the fluorine-containing water 11 is directly fed. Two compartments each disposed on the outer side of the water injection chambers 24 constitute cathode chambers 22 disposed at either side-face of the interior of the water tank 14. The lower end of the diaphragm 20 is separated from the bottom of the water tank 14 with a gap 21 of a specified distance apart. The fluorine-containing water treatment device comprises two cathodic water outflow ports 30, for the cathodic water removed of fluorine by an electrolytic treatment to flow out therefrom, and an anodic water outflow port 32 disposed on a higher position relative to the position whereat the cathodic water outflow port 30 is disposed, for the fluorine-containing anodic water to flow out therefrom.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a treatment device for removing fluorine from fluorine-containing water.

Background Art

[0002] Depending on the region, groundwater used as drinking water may contain high concentrations of fluorine derived from geology, and a treatment for removing fluorine is necessary to prevent health damage caused by fluorosis. Some treatment devices for removing fluorine from such fluorine-containing water are provided with an electrolytic cell that electrolyzes the fluorine-containing water to obtain cathode water.

[0003] The fluorine-containing water treatment device of Patent Document 1 includes an electrolytic cell that introduces and electrolyzes fluorine-containing water, a porous unglazed plate diaphragm that separates the cathode chamber and the anode chamber, a sand filtration device that filters the cathode water produced in the cathode chamber of the electrolytic cell, and a pH adjustment tank that adjusts the pH of the cathode water filtered by the sand filtration device. The electrolytic cell, the sand filtration device, and the pH adjustment tank are each connected by a connecting pipeline. The cathode water removes fluorine and foreign substances, adjusts the pH, and becomes a product that can be used as drinking water.

[0004] The method for producing electrolyzed ionized water of Patent Document 2 is provided with an electrolytic cell that electrolyzes tap water. The electrolytic cell is provided with one anode and a pair of cathodes sandwiching the anode, and diaphragms are provided between the cathode and the anode to separate and form one anode chamber and two cathode chambers. Pipes for flowing tap water are connected to one anode chamber and the two cathode chambers, respectively. After electrolytic treatment in the electrolytic cell, the electrolyzed ionized water is taken out from the cathode chamber and used as a product.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the case of Patent Document 1 of the above background art, an anode chamber and a cathode chamber are provided, and the principle is the coprecipitation removal of polyvalent metal and fluorine in the cathode chamber. Therefore, when the raw water does not contain polyvalent metal, a product as drinking water cannot be obtained. In the case of Patent Document 2 of the above background art, since one anode chamber and two cathode chambers are provided, the efficiency of obtaining a product is high, but three pipes are required for tap water to flow into each chamber, and there is a lot of equipment.

[0007] This invention has been made in view of the problems of the above background art, and an object thereof is to provide a treatment apparatus for fluorine-containing water that can surely remove fluorine from fluorine-containing water, has good efficiency in obtaining a product obtained by removing fluorine from fluorine-containing water, and has little drainage.

Means for Solving the Problems

[0008] The present invention is provided with an electrolytic cell for electrolyzing fluorine-containing water. The electrolytic cell is provided with a water tank into which the fluorine-containing water flows. The water tank is partitioned into five thin chambers parallel to one direction by four diaphragms. One partition located in the center of the water tank is an anode chamber provided with an anode. The two partitions on both outer sides of the anode chamber are water injection chambers for directly containing the fluorine-containing water. The two partitions on both outer sides of the water injection chambers are partitions along the back sides of the side surfaces on both sides of the water tank and are cathode chambers provided with cathodes. The diaphragm is a ceramic plate. The lower end of the diaphragm is spaced apart from the bottom of the water tank with a gap of a predetermined length. The gap is, for example, 0.5 to 1 mm. On one side of the water tank, two fluorine-containing water inlets for injecting the fluorine-containing water are provided in communication with each of the water injection chambers. On the side surface opposite to the side surface where the fluorine-containing water inlet is provided, two cathode water outlets through which the cathode water from which fluorine has been removed by electrolysis flows out are provided in communication with each of the cathode chambers. On the side surface where the cathode water outlet is provided, an anode water outlet through which the anode water containing fluorine flows out is provided in communication with the anode chamber. The height of the cathode water outlet from the bottom of the water tank is slightly lower than that of the anode water outlet. A pump is connected to the cathode water outlet. The flow rate of the pump is less than the amount of the fluorine-containing water flowing in. The cathode water is drawn out from the cathode water outlet by the pump, and the difference between the fluorine-containing water and the amount of the cathode water drawn out by the pump is discharged as drainage from the anode water outlet, which is a treatment device for fluorine-containing water. The anode water outlet is located, for example, at a height of about 25 cm from the bottom of the water tank and is 5 cm higher than the cathode water outlet. Note that the height of the fluorine-containing water inlet is free.

[0009] A pH adjustment tank is provided downstream of the electrolytic cell. In the pH adjustment tank, there is a pH adjustment water tank into which the cathode water and anode water of the electrolytic cell are introduced. The pH adjustment water tank is partitioned into two thin chambers parallel to one direction by a cation exchange membrane. One chamber becomes a pH adjustment anode chamber having a pH adjustment anode, and the other chamber becomes a pH adjustment cathode chamber having a pH adjustment cathode. On one side surface of the pH adjustment water tank, two cathode water inlets into which the cathode water electrolyzed in the electrolytic cell is injected are provided and communicate with the pH adjustment anode chamber respectively. On the side surface where the cathode water inlets are provided, an anode water inlet into which the anode water electrolyzed in the electrolytic cell is injected is provided and communicates with the pH adjustment cathode chamber. On the side surface opposite to the side surface where the cathode water inlets and the anode water inlets are provided, a treated water outlet through which the treated water with a reduced pH by electrolytic treatment flows out is provided and communicates with the pH adjustment anode chamber. On the side surface where the treated water outlet is provided, a drainage outlet through which the drainage containing fluorine flows out is provided and communicates with the pH adjustment cathode chamber.

Advantages of the Invention

[0010] The fluorine-containing water treatment apparatus of the present invention can surely remove fluorine from the fluorine-containing water even if the raw water does not contain polyvalent metal ions, and can efficiently obtain a product from which fluorine has been removed from the fluorine-containing water, and has less drainage. It has a simple structure, and two cathode chambers can be provided in one anode chamber of the electrolytic cell. Since the anode water in the anode chamber that becomes drainage is less, the yield can be increased. A pH adjustment tank for adjusting the pH by electrolytic treatment is provided in series downstream of the electrolytic cell, which is compact, has a high treatment capacity, and is efficient. In addition, since a water injection chamber for introducing the fluorine-containing water is provided between the cathode chamber and the anode chamber of the electrolytic cell, the cathode water and the anode water do not mix.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show an embodiment of the present invention. The fluorine-containing water treatment apparatus 10 of this embodiment is provided with an electrolytic cell 12 for electrolytically treating fluorine-containing water 11. The fluorine-containing water 11 may be, for example, groundwater, river or marsh water, rainwater, or the like.

[0013] Here, the electrolytic cell 12 will be described. As shown in FIG. 2, the electrolytic cell 12 includes a water tank 14 for containing fluorine-containing water 11. The water tank 14 is made of, for example, acrylic, and includes a rectangular bottom 14a that is long in one direction and side surfaces 14b, 14c, 14d, 14e that are continuous with the bottom 14a. The upper part is closed and provided with a vent for releasing gas and is connected to the atmosphere. The side surfaces 14b and 14c are small rectangles continuous with the short sides of the bottom 14a, and the side surfaces 14d and 14e are large rectangles continuous with the long sides of the bottom 14a. The size of the water tank 14 is, for example, the bottom 14a is 300 mm × 150 mm and the depth is 250 mm or more. Note that in the electrolytic cell 12, the fluorine-containing water 11 flows along the longitudinal direction of the water tank 14, that is, parallel to the side surfaces 14d and 14e, and is electrolytically treated.

[0014] The water tank 14 is partitioned into five thin chambers parallel to the longitudinal direction by four diaphragms 20. One partition located in the center of the water tank 14 is an anode chamber 26 provided with an anode 16. The anode 16 is provided at the center of the water tank 14 and is a platinum wire. It is erected substantially perpendicular to the bottom 14a of the water tank 14. For example, five are provided and arranged at substantially equal intervals parallel to the longitudinal direction of the water tank 14, that is, parallel to the side surfaces 14d and 14e.

[0015] The two compartments outside both of the anode chambers 26 are water injection chambers 24 into which the fluorine-containing water 11 is directly introduced. Electrodes are not provided, and they are surrounded by a pair of diaphragms 20. The two compartments on both sides of the water injection chamber 24 are the outermost compartments, that is, the compartments along the back sides of the side surfaces 14d and 14e, and are cathode chambers 22 in which the cathodes 18 are provided. The cathode 18 is a rectangular stainless steel plate, and is attached along the inner wall surfaces of a pair of side surfaces 14d and 14e along the longitudinal direction of the water tank 14, and its size is such that it substantially covers the inner wall surfaces of the side surfaces 14d and 14e. Incidentally, the width intersecting the flow direction of the anode chamber 26 is, for example, 50 mm, the width intersecting the flow direction of each cathode chamber 22 is, for example, about 25 mm each, and the width intersecting the flow direction of each water injection chamber 24 is 25 mm each.

[0016] The diaphragm 20 is, for example, a porous ceramic plate. The ceramic plate used here has the characteristics of surely preventing the mixing of the solutions in the electrolytic cell 12, allowing ions to pass through in the electrolytic cell 12, having a small electrical resistance during use, and consuming little power. Nylon cloth, fiber filters, etc. having the same function may also be used instead of the ceramic plate. The diaphragm 20 is rectangular, one direction is the length reaching the side surfaces 14b and 14c of the water tank 14, and it is fixed to the side surfaces 14b and 14c. The vertical direction intersecting it is the length reaching a position slightly lower than near the bottom 14a. The lower end portion 20a of the diaphragm 20 has a gap 21 of a predetermined length and is separated from the bottom 14a of the water tank 14. The gap 21 between the lower end portion 20a of the diaphragm 20 and the bottom 14a is, for example, 0.5 to 1 mm. Four diaphragms 20 are provided in the water tank 14, and two are provided between the anode 16 and the cathode 18 respectively. The two diaphragms 20 provided between the anode 16 and the cathode 18 are positioned parallel to each other with a predetermined interval therebetween.

[0017] One side surface 14b of the water tank 14 is located on the upstream side of the fluorine-containing water 11, and on the side surface 14b, a fluorine-containing water inlet 28 into which the fluorine-containing water 11 is injected is provided at a position close to the upper opening. Two fluorine-containing water inlets 28 are provided, and they are respectively provided at positions facing the two water injection chambers 24 and communicate with the water injection chambers 24. On the side surface 14c opposite to the side surface 14b, a cathode water outlet 30 through which the cathode water from which fluorine has been removed by electrolysis flows out is provided. Two cathode water outlets 30 are provided, and they are respectively provided at positions facing the two cathode chambers 22 and communicate with the cathode chambers 22. The cathode water outlet 30 is located at a height of about 20 cm from the bottom 14a of the water tank 14 and is close to the upper opening. Further, between the pair of cathode water outlets 30 on the side surface 14c, an anode water outlet 32 through which the anode water containing fluorine flows out is provided and communicates with the anode chamber 26. The anode water outlet 32 is located at a height of, for example, about 25 cm from the bottom 14a of the water tank 14, which is 5 cm higher than the cathode water outlet 30. Note that the height of the fluorine-containing water inlet 28 only needs to be a position close to the upper opening, and the dimensions are not limited.

[0018] A pump (not shown) is connected to the pair of cathode water outlets 30 to draw out the cathode water at a constant flow rate. At this time, the flow rate of the fluorine-containing water 11, which is the water to be treated, is set to be larger than the flow rate of the cathode water drawn out by the pump. Thereby, the amount of the anode water of the water to be treated that flows in in excess of the drawn-out cathode water is discharged as drainage from the anode water outlet 32.

[0019] Downstream of the electrolytic cell 12, a pH adjustment tank 34 for adjusting the pH of the cathode water is provided. In the electrolytic cell 12, since the pH of the cathode water rises above 10 due to the hydroxide ions generated at the cathode, the pH adjustment tank 34 is installed to lower the pH below 10 by electrolysis treatment to obtain products such as drinking water. The electrolytic cell 12 and the pH adjustment tank 34 are connected in series.

[0020] The pH adjustment tank 34 is provided with a pH adjustment water tank 36 that is approximately the same size as the water tank 14 of the electrolysis tank 12. The pH adjustment water tank 36 is also made of, for example, acrylic, and consists of a rectangular bottom 36a that is long in one direction and side surfaces 36b, 36c, 36d, 36e that are continuous with the bottom 36a. The upper part is closed and provided with a vent for releasing gas, and is connected to the atmosphere. The side surfaces 36b, 36c are small rectangles that are continuous with the short sides of the bottom 36a, and the side surfaces 36d, 36e are large rectangles that are continuous with the long sides of the bottom 36a. In the pH adjustment tank 34, the cathode water and anode water electrolyzed in the electrolysis tank 12 flow along the longitudinal direction of the pH adjustment water tank 36, and are further electrolyzed to lower the pH of the cathode water.

[0021] On the inner wall surface of one side surface 36d along the longitudinal direction of the pH adjustment water tank 36, a pH adjustment anode 38 is provided, and on the inner wall surface of the opposite side surface 36e, a pH adjustment cathode 40 is provided. A cation exchange membrane 42 is provided at the center of the pH adjustment water tank 36. The cation exchange membrane 42 divides the water tank 36 into two thin chambers parallel to the longitudinal direction. The side 36d side becomes a pH adjustment anode chamber 44 having a pH adjustment anode 38, and the side 36e side becomes a pH adjustment cathode chamber 46 having a pH adjustment cathode 40. The pH adjustment anode 38 is composed of a platinum wire or a titanium plate plated with platinum, and the pH adjustment cathode 40 is made of a stainless steel plate or the like. The cation exchange membrane 42 surely prevents the mixing of solutions, allows only cations to pass through, has a small electrical resistance and low power consumption, and the fluorine removed in the electrolysis tank 12 does not move from the pH adjustment cathode chamber 46 to the pH adjustment anode chamber 44.

[0022] One side surface 36b of the pH adjustment water tank 36 is located on the upstream side. On the side surface 36b, at a position close to the upper opening, a cathode water injection port 48 is provided into which the cathode water electrolyzed in the electrolysis tank 12 and flowing out from the cathode water outlet 30 is injected. Two cathode water injection ports 48 are provided, arranged side by side at positions facing the pH adjustment anode chamber 44, and each communicates with the pH adjustment anode chamber 44. On the side surface 36b, at a position close to the upper opening that is approximately the same as the cathode water injection port 48, one anode water injection port 50 into which the anode water electrolyzed in the electrolysis tank 12 is injected is provided, and it communicates with the pH adjustment cathode chamber 46.

[0023] On the side surface 36c opposite to the side surface 36b, there is provided one process water outlet 52 through which the treated water from which fluorine has been removed and the pH has been further lowered flows out. The process water outlet 52 is provided at a position facing the anode chamber 44 for pH adjustment and communicates with the anode chamber 44 for pH adjustment. On the side surface 36c, there is provided one drain outlet 54 containing fluorine. The drain outlet 54 is provided at a position facing the cathode chamber 46 for pH adjustment and communicates with the cathode chamber 46 for pH adjustment. The process water outlet 52 and the drain outlet 54 are provided at arbitrary positions close to the upper opening. The total amount of water flowing out from the process water outlet 52 and the drain outlet 54 is substantially equal to the amount of water injected from the pair of cathode water inlets 48 and the anode water inlet 50. Thereby, the water level in the pH adjustment water tank 36 becomes substantially constant. The treated water taken out from the process water outlet 52 has a low fluorine content and a pH of 10 or less, and becomes a product that can be used as drinking water. If necessary, further filtration treatment or the like may be performed.

[0024] Next, an example of the treatment method by the fluorine-containing water treatment apparatus 10 will be described. The flow rate of the fluorine-containing water 11 in the electrolytic cell 12 is, for example, 48 l / h, and when the yield is 85%, 7.2 l / h of drainage is discharged. The voltage of the electrolytic cell 12 is about 110 V, the current is 1 A × 2, and the total current is 2 A. The yield is 80 - 95%. The voltage of the pH adjustment tank 34 is about 130 V, and the current is 0.75 A. By the fluorine-containing water treatment apparatus 10 of this embodiment including the electrolytic cell 12 and the pH adjustment tank 34, the fluorine concentration decreases from 2.5 mg / l (fluorine-containing water 11) to 0.8 mg / l or less. The fluorine concentration standard value in the Food Sanitation Law is 2.0 mg / l, and when it is 0.8 mg / l or more, a display of "Avoid drinking for those under 7 years old" is required.

[0025] As shown in FIG. 1, the fluorine-containing water 11 is poured into the water injection chamber 24 from the pair of fluorine-containing water inlets 28 of the electrolytic cell 12. The injected fluorine-containing water 11 also flows from the gap 21 between the lower end portion 20a of the diaphragm 20 and the bottom portion 14a of the water tank 14 into the cathode chamber 22 and the water injection chamber 24, and is filled up to the height of the anode water outlet 32, and electrolysis treatment is performed. In the cathode chamber 22, cathode water from which fluorine has been removed from the fluorine-containing water 11 is generated.

[0026] The cathode water from which fluorine has been removed in the cathode chamber 22 is pumped out from each cathode water outlet 30 and injected into the pH adjustment anode chamber 44 from each cathode water injection port 48 in a pH adjustment tank 34 connected in series downstream of the electrolytic cell 12. The cathode water has a pH exceeding 10 due to the hydroxide ions OH - generated at the cathode 18, but the pH is lowered to 10 or less by the hydrogen ions H + generated in the pH adjustment anode chamber 44 of the pH adjustment tank 34. The treated water in the pH adjustment anode chamber 44 with the lowered pH is taken out from the treated water outlet 52 and made into a product that can be used as drinking water.

[0027] According to the fluorine-containing water treatment apparatus 10 of this embodiment, fluorine can be surely removed from the fluorine-containing water 11, and drinking water can be made from the fluorine-containing water 11. The efficiency of obtaining a product from which fluorine has been removed from the fluorine-containing water 11 is good, and the drainage is small. With a simple structure, two cathode chambers 22 can be provided in one anode chamber 26 in the electrolytic cell 12, and since the anode water in the anode chamber 26 that becomes drainage is small, the drainage can be reduced and the yield can be increased. Since expensive platinum is used for the anode 16 in the anode chamber 26, reducing the number of anode chambers 26 to half that of the cathode chambers 22 has a great cost merit. When the fluorine-containing water 11 is put into the electrolytic cell 12 from the fluorine-containing water injection port 28 communicating with each water injection chamber 24, the fluorine-containing water 11 can flow into the cathode chamber 22 and the anode chamber 26 from the gap 21 between the lower end portion 20a of the diaphragm 20 and the bottom portion 14a of the water tank 14 to fill the water tank 14. Furthermore, there are few pipes and the structure is simple. A water injection chamber 24 separated by a diaphragm 20 is provided between the cathode chamber 22 and the anode chamber 26, and the fluorine-containing water 11 is injected here for electrolysis treatment, so that the cathode water and the anode water do not mix, and the fluorine concentration of the cathode water can be kept low.

[0028] Furthermore, a pH adjustment tank 34 for adjusting the pH by electrolysis treatment is provided in series downstream of the electrolytic cell 12. It has a simple structure, is compact, has a high processing capacity, and is efficient. The pH adjustment tank 34 can easily adjust the pH and can surely prevent fluorine from moving from the cathode chamber 46 for pH adjustment. The product produced by the fluorine-containing water treatment device 10 has a low fluorine content and can prevent health hazards caused by a high fluorine concentration, and can be safely used for drinking. Also, the pH becomes 10 or less, making it suitable as drinking water. If necessary, further filtration treatment or the like may be performed, and it can also be connected and used with devices that perform various treatments such as filtration treatment and sterilization treatment.

[0029] Note that the fluorine-containing water treatment device of this invention is not limited to the above-described embodiment and can be appropriately changed. The size of the water tank of the electrolytic cell, the gap between the diaphragm and the bottom of the water tank, the heights of the respective inlets and outlets, etc. can be freely changed. The materials of the water tank and the electrodes may be other than the above, and those used in ordinary electrolysis treatment can be used.

Explanation of Reference Numerals

[0030] 10 Fluorine-containing water treatment device 11 Fluorine-containing water 12 Electrolytic cell 14 Water tank 14a Bottom 14b, 14c, 14d, 14e Sides 16 Anode 18 Cathode 20 Diaphragm 21 Gap 22 Cathode chamber 24 Water injection chamber 26 Anode chamber 28 Fluorine-containing water inlet 30 Cathode water outlet 32 Anode water outlet 34 pH adjustment tank 36 Water tank for pH adjustment 38 Anode for pH adjustment 40 Cathode for pH adjustment 42 Cation exchange membrane 44 Anode chamber for pH adjustment 46 Cathode chamber for pH adjustment 48 Cathode water inlet 50 Anode water inlet 52 Treated water outlet 54 Drainage outlet

Claims

1. An electrolytic cell for electrolyzing fluorine-containing water is provided. The electrolytic cell is provided with a water tank into which the fluorine-containing water flows. The water tank is partitioned into five thin chambers in one direction by four diaphragms. One partition located in the center of the water tank is an anode chamber provided with an anode. The two partitions on both outer sides of the anode chamber are water injection chambers for directly introducing the fluorine-containing water. The two partitions on both outer sides of the water injection chambers are partitions along the back sides of the side surfaces on both sides of the water tank and are cathode chambers provided with cathodes. The lower end of the diaphragm is spaced apart from the bottom of the water tank with a gap of a predetermined length. On one side of the water tank, two fluorine-containing water inlets for injecting the fluorine-containing water are provided in communication with each of the water injection chambers. On the side opposite to the side where the fluorine-containing water inlets are provided, two cathode water outlets through which the cathode water from which fluorine has been removed by electrolysis flows out are provided in communication with each of the cathode chambers. On the side where the cathode water outlets are provided, an anode water outlet through which the anode water containing fluorine flows out is provided in communication with the anode chamber. The height of the cathode water outlet from the bottom of the water tank is lower than that of the anode water outlet. A pump is connected to the cathode water outlet, and the flow rate of the pump is less than the amount of the fluorine-containing water flowing in. The cathode water is drawn out from the cathode water outlet by the pump, and the difference between the fluorine-containing water and the amount of the cathode water drawn out by the pump is discharged as drainage from the anode water outlet. A treatment device for fluorine-containing water is characterized in that.

2. A pH adjustment tank is provided downstream of the electrolytic cell. The pH adjustment tank is provided with a pH adjustment water tank into which the cathode water and the anode water of the electrolytic cell are introduced. The pH adjustment water tank is partitioned into two thin chambers parallel to one direction by a cation exchange membrane. One is a pH adjustment anode chamber having a pH adjustment anode, and the other is a pH adjustment cathode chamber having a pH adjustment cathode. On one side of the pH adjustment water tank, two cathode water inlets through which the cathode water electrolyzed in the electrolytic cell is injected are provided in communication with the pH adjustment anodic chamber, and on the side surface where the cathode water inlet is provided, an anode water inlet through which the anode water electrolyzed in the electrolytic cell is injected is provided in communication with the pH adjustment cathodic chamber. On the side surface opposite to the side surface where the cathode water inlet and the anode water inlet are provided, a treated water outlet through which the treated water with a reduced pH by electrolysis flows out is provided in communication with the pH adjustment anodic chamber, and on the side surface where the treated water outlet is provided, a drainage outlet through which the drainage containing fluorine flows out is provided in communication with the pH adjustment cathodic chamber. The fluorine-containing water treatment apparatus according to claim 1.

3. The diaphragm is a ceramic plate, and the gap is 0.5 to 1 mm. The fluorine-containing water treatment apparatus according to claim 1 or 2.

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