TWI483904B - Water treatment method and water treatment device - Google Patents

Description

Water treatment method and water treatment device

Embodiments of the present invention relate to a water treatment method and a water treatment device.

Recently, due to the development of industry or the increase in population, it has become an effective use of water resources. In order to effectively utilize water resources, it is important to purify various wastewaters such as industrial wastewater or domestic wastewater for reuse.

In order to purify the wastewater, it is necessary to separate and remove water-insoluble matter or impurities contained in the water. As a method of purifying waste water, for example, a membrane separation method, a centrifugal separation method, an activated carbon absorption method, an ozone treatment method, and a precipitation removal method of a floating substance added via a coagulant are used. By using such a water treatment method, it is possible to remove a chemical substance that is greatly affected by the environment of phosphorus or fluorine contained in the wastewater, and to remove oil or ink or the like dispersed in the water.

Conventionally, in order to remove a harmful fluorine-based substance from a wastewater containing fluorine, it is generally known that a calcium or aluminum agent is used. However, in wastewater such as the glass industry, in addition to fluoride ions, there is a combination with boron. There are many cases of fluoroboric acid ions (BF ₄ ^- ). As a method of removing this fluoroboric acid ion, a method of decomposing using an aluminum compound or a method of absorbing by a chelating resin or the like is known.

For example, as a method of decomposing using an aluminum compound, Patent Document 1 proposes to carry out precipitation separation by converting aluminum fluoride into tetrafluoroborate ions and converting it into aluminum fluoride ions as a fluoride salt of calcium aluminate. The method. In addition, as a method of removing the chelating resin of the reduced glucosamine (aminopolyol) type, it is known that the amine-based polyol type chelating getter described in Patent Document 2 and the fluoroacetic acid absorbing agent are used in combination. In the method, or in Patent Document 3, a method of decomposing a fluoroboric acid ion by using an amine-based polyol type chelating resin and evaporating the concentrated treatment liquid is carried out.

However, in the method of Patent Document 1, a large amount of aluminum compound is necessary, and a large amount of sludge is generated, which is related to an increase in the cost of the chemical and the treatment cost of the sludge, and has a problem that the wastewater treatment cost increases. In the method of Patent Document 2, since the fluoride ion and the tetrafluoroboric acid ion are simultaneously absorbed, the purity of the recovered material is lowered, or the hindrance is caused by the absorption of the amine-based polyol type chelating resin. The substance and fluoride ions act, and the rate of absorption of tetrafluoroboric acid ions becomes slow. Further, in the method of Patent Document 3, the decomposition of tetrafluoroboric acid ions is promoted by the absorption of boron in water. However, in this method, the decomposition of the boron fluoride is rate-limited, and there is a problem that rapid removal cannot be performed.

[Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 60-000117

[Patent Document 2] Japanese Patent Laid-Open No. Hei 2-099189

[Patent Document 3] Japanese Patent No. 3915176

In order to solve the problem of the present invention, it is possible to efficiently and efficiently remove such fluorine ions and tetrafluoroboric acid ions at low cost from wastewater containing fluorine ions and tetrafluoroboric acid ions as a fluorine-based substance.

The water treatment method according to the embodiment is a method for treating wastewater containing fluorine ions and tetrafluoroboric acid ions, wherein a calcium-insoluble inorganic substance insoluble in water is added to the wastewater in the reaction tank, and is contained in the wastewater. The first step of converting the fluoride ion into calcium fluoride, and solid-liquid separation of the wastewater containing the calcium fluoride in the solid-liquid separation tank, and removing the calcium fluoride from the wastewater to obtain the first treated water. Step 2. Further, the pH adjustment tank includes a third step of adding a pH adjuster to the first treated water, adjusting a pH of the first treated water to an acidic region, and a hydrophobicity of the first treated water to a filled amine. In the container of the polyol-type chelating resin, the fourth step of obtaining the second treated water is carried out by removing the tetrafluoroboric acid ions from the first treated water.

10,40‧‧‧Water treatment unit

11‧‧‧Reaction tank

111‧‧‧Mixer

12‧‧‧ solid-liquid separation tank

121‧‧‧Filter

122‧‧‧(wrapable) horizontal filter cloth

13‧‧‧pH adjustment tank

131‧‧‧Mixer

14‧‧‧Amino polyol type chelate resin filling tower

16‧‧‧ Container

W0‧‧‧ treated water

W1‧‧1 treatment of water

W2‧‧2 times treated water

R‧‧‧Amino polyol type chelating resin

21~29, 46‧‧‧Pipe

31,32‧‧‧

Fig. 1 is a schematic configuration diagram of a water treatment device according to a first embodiment.

Fig. 2 is a schematic configuration diagram of a water treatment device according to a second embodiment.

(First embodiment)

Fig. 1 is a view showing a schematic configuration of a water treatment device according to the present embodiment. The water treatment device 10 shown in Fig. 1 has a reaction tank 11 for removing fluoride ions of the treated water W0 such as waste water, and a flow side on the lower flow side of the reaction tank 11, and a horizontal surface for the installation surface. The filter 121 divides the internal space into the solid-liquid separation tank (planar filter) 12 of the upper and lower portions 12A and 12B via the filter 121, and is positioned on the flow side below the solid-liquid separation tank 12, in order to carry out the water W0 to be treated. The pH adjustment tank 13 for adjusting the pH of the primary treatment water W1 of the fluoride ion is removed, and the resin column 14 for removing the tetrafluoroboric acid ions remaining in the primary treatment water W1.

The reaction tank 11 is a water-insoluble calcium-containing inorganic substance added to the water W0 to be treated, and a solid-liquid separation tank (planar filter 12) is used to convert fluoride ions contained in the water W to be treated into calcium fluoride. The treated water W0 containing calcium fluoride is subjected to solid-liquid separation, and calcium fluoride is removed from the water W to be treated, in order to obtain a treatment water W1 once. In the pH adjustment tank, a pH adjuster is added to the primary treatment water W1, and in order to adjust the pH of the primary treatment water W1 to an acidic domain, the resin tower 14 is hydrophobic once per treatment water. The treated water W1 absorbs and removes the tetrafluoroboric acid ions, in order to obtain the filling of the treated water W2 twice. A container of an amine polyol type chelating resin.

However, when the filter 121 in the solid-liquid separation tank 12 is level with the installation surface, the direction of the hydrophobic direction and the direction of the gravity of the water W0 to be treated are the same, and the conversion is performed in the reaction tank 11. The layer of the solid substance as the center of the calcium fluoride to be removed is uniformly formed on the filter 121. This calcium fluoride layer functions as a filter layer due to calcium fluoride in the water W0 to be treated which is hydrophobic or hydrophobic, even if there is fine fluorine in the treated water W0. In the case of the calcium precipitate (reaction product), the precipitate may be added and removed.

The filter 121 may be, for example, a filter cloth, a metal mesh, a porous ceramic, a porous polymer or the like. However, the filter cloth is particularly preferable, and for example, a material such as polypropylene, nylon, or polyester is used. Woven, twill weave, plain weave, satin weave, etc. Among them, when a fine filtration membrane (MF membrane) made of a soft filter cloth or a polymer is used, as described below, calcium fluoride formed to remove fluorine ions can be optimally captured.

However, the solid-liquid separation tank 12 of the present embodiment is not limited to the above-described constituents, and may be composed of a general-purpose material.

Further, in the resin column 14, for example, an amine-based polyol type chelating resin R having an average particle diameter of 0.45 to 0.6 mm is filled. The amine-based polyol type chelating resin R is, for example, a chelating resin of N-methylglucamine, and specifically, other Amberlite IRA743 (trade name) of Rohm & Hass Co., Ltd. of Japan, and can be exemplified by Mitsubishi Chemical Corporation of Japan. The company's DIAION CBR-03, CBR-05, or Japan's CHELEST Co., Ltd. CHELESTFIBRE GRY-L.

However, the average particle diameter can be measured, for example, by a laser diffraction method, and specifically, it can be measured by a SALD-3100 type measuring device (trade name) manufactured by Shimadzu Corporation. However, in the following texts in which the "average particle diameter" appears, the specific numerical value is described. Unless otherwise stated, the "average particle diameter" is via the laser diffraction method as described above. Measurer.

The reaction tank 11 and the solid-liquid separation tank 12 are connected to the pipe 22 by the pump 31, and the solid-liquid separation tank 12 and the pH adjusting tank 13 are connected via a pipe 23. However, a pump (not shown) may be provided on the piping 23. Further, the pH adjusting tank 13 and the resin tower 14 are connected via a pipe 24 . Further, pipings 26 and 27 are disposed in the upper portion 12A of the solid-liquid separation tank 12 to constitute each of the washing water supply line and the waste liquid discharge line.

The shape, capacity, material, and the like of the reaction tank 11 are not particularly limited, but it is preferable to have a capacity of at least 15 minutes of the working residence time. In addition, a baffle or the like is provided in the reaction tank 11, and the water to be treated W0 is preferably unsuccinct from the supply port toward the pipe 22.

Further, mixers 111 and 131 are disposed in the reaction tank 11 and the pH adjusting tank 13.

Next, a water treatment method using the water treatment device 10 shown in Fig. 1 will be described. First, in the reaction tank 11, the pipe 21 of the water supply line is supplied with the treated water W0 composed of the wastewater containing fluoride ions and tetrafluoroboric acid ions, and is added to the reaction tank 11 at the same time. By adding a calcium-insoluble inorganic substance insoluble in water, the fluoride ion contained in the treated water W0 in the reaction tank 11 is converted into calcium fluoride. At this time, the water to be treated W0 and the calcium-containing inorganic substance in the reaction tank 11 are mixed via the agitator 111.

In the present embodiment, the "water-insoluble calcium-containing inorganic substance" means a calcium-containing inorganic substance having a solubility in water of 10 g or less (25 ° C) per 1000 ml.

Further, as the calcium-containing inorganic substance, a substance having no hydrate or hydroxyl group is preferred. When a substance having a hydrate or a hydroxyl group has a characteristic of being softer than other substances, it has a condition of plugging a hole of the filter.

Specifically, aragonite, sodium borate, feldspar, omphacite, garnet, scheelite, calcium titanate, calcium iron pyroxene, zoisite, fisheye stone, dolomite, Aluminum fluorogypsum, red curtain stone, carbon strontium stone, raw gypsum, vermiculite, mentholite, calcium plagioclase, diopside, iron ash pyroxene, manganese feldspar, tremolite, rose phosgene, variegated pyroxene, horn Amphibole, ordinary pyroxene, manganese needle soda limestone, Fushan stone, Yijian stone, calcite, vermiculite, Monte stone, Yangqi stone, green curtain stone, oblique vein stone, carbon apatite and other natural ore. Further, a calcium compound obtained by a process of synthesis and formation of calcium carbonate, calcium sulfite, calcium hydroxide, calcium sulfate, calcium titanate or calcium tungstate may be mentioned.

Among the above, calcium carbonate having a small solubility in water or ore having a calcium carbonate as a main component (for example, aragonite, dolomite) is preferable, and in particular, no fluoride ion and tetrafluoroboric acid ion are to be removed. The anionic calcium carbonate is preferred. Excess ion system makes the tree described below The absorption rate of the tetrafluoroboric acid ions in the fat column 14 is lowered, and the removal efficiency of the tetrafluoroboric acid ions is deteriorated.

Further, in the case where calcium chloride is used as the calcium-containing inorganic material, in the treatment of fluoride ions, calcium fluoride may be used in the same manner, but instead, chloride ions are generated in the water to be treated W0. Therefore, there is a problem that corrosion of the piping or the like occurs. In addition, the reason why the suction speed of the resin tower 14 in the subsequent stage is dropped is that the cost of the water treatment method of the present embodiment is increased.

As the above-mentioned calcium-containing inorganic substance, particles having an average particle diameter of 2 to 50 μm are preferably used. When the average particle diameter becomes larger than 50 μm, the surface area of the calcium-containing inorganic material becomes small, and the reaction rate when the above-mentioned fluoride ion is converted into calcium fluoride becomes slow. When the average particle diameter is smaller than 2 μm, the diameter of the produced calcium fluoride becomes small, and the addition of the solid-liquid separation tank 12 as described below becomes difficult.

The calcium-containing inorganic material having the above average particle diameter is suitably classified. When the particle diameter of the obtained calcium-containing inorganic material is larger than the above average particle diameter, it is pulverized by using a ball mill, a Henschel mixer, a roller or the like.

However, when the fluoride ion in the water to be treated W0 is reacted with calcium in the calcium-containing inorganic material to convert it into calcium fluoride in the reaction tank 11, a pH adjuster is added to the reaction tank 11, and the reaction tank 11 is placed in the reaction tank 11. It is preferable that the pH of the treated water W0 is set to 2 to 4. Thereby, the above reaction can be promoted, and the conversion of fluoride ions to calcium fluoride can be promoted. However, in order to do with the pH adjuster added to the pH adjusting tank 13 described later The difference is the case where the pH adjuster to be added to the reaction tank 11 is referred to as "additional pH adjuster".

The above-mentioned additional pH adjuster may be a hydrogen halide or the like in addition to sulfuric acid, nitric acid, an organic acid or hydrogen fluoride. Among them, sulfuric acid is particularly desirable. The sulfuric acid is a sulfate ion in the water to be treated W0, and reacts with the calcium ion of the calcium-containing inorganic substance to become calcium sulfate having a relatively small solubility, thereby solidifying the excess ions.

However, when hydrogen fluoride is used as an additional pH adjuster, fluoride ions are generated, and the fluoride ions are excessive, and the rate of absorption of tetrafluoroboric acid ions in the resin column 14 is lowered to make the tetrafluoroboric acid lower. The removal efficiency of ions is reduced.

Next, by driving the pump 31, the slurry-like treated water W0 containing the produced calcium fluoride is transferred to the filter 121 of the solid-liquid separation tank 12 by the pipe 22, and is drained in the filter. 121. By this, the concentration of the fluoride ion in the primary treated water W1 obtained by the filter 121 is reduced to 30 mg/L, for example, by the addition and removal of most of the calcium fluoride from the slurry-form treated water W0. the following.

Further, in the present embodiment, as described above, the solid-liquid separation tank 12 is formed on the filter 121 by using a flat filter including a filter 121 having a horizontal surface on the installation surface. There is a layer in which the calcium fluoride of the object is removed as a center solid. This layer functions as a filter layer by calcium fluoride in the water W0 to be treated which is hydrophobic after being continuously or continuously, even if there is a precipitation of fine calcium fluoride in the water W0 to be treated. Material (reaction product) In this case, the precipitate may be added and removed.

On the other hand, when a certain degree of filtration is performed, the thickness of the layer formed on the filter 121 is increased and the filtration speed is lowered. When it is in this state, the supply of the water to be treated W0 by the piping 22 is stopped, and the washing water is supplied from the piping 26 of the washing water supply line to flush the solid matter on the filter 121, and then discharged from the waste liquid. The piping 27 discharges the waste liquid containing the concentrated slurry of the solid matter. After that, the water to be treated W0 is transferred to the filter 121 by the pipe 22 to be hydrophobic, and the same is described above, and the calcium fluoride in the water to be treated W0 is added and removed to obtain the treated water W1 once.

However, in order to increase the efficiency of the addition of calcium fluoride in the solid-liquid separation tank 12, it is also possible to add a coagulated polymer to the reaction tank 11, but such a coagulated polymer remains in the treated water W0, and has In the resin column 14 in the subsequent stage, the voids formed between the filled amine-based polyol type chelating resins are clogged, and the life of the resin column 14 is shortened. Further, when a coagulant is used, the cost of the chemical is consumed, and the cost of the sludge for treating the precipitate is increased, so that the water treatment cost in the present embodiment is increased.

Then, the primary treatment water W1 obtained in the solid-liquid separation tank 12 is introduced into the pH adjustment tank 13 through the pipe 23. In this case, a pump is disposed on the pipe 23 as necessary, and the primary treatment water W1 may be introduced into the pH adjustment tank 13 by the pipe 23 by the output force of the pump.

In the pH adjusting tank 13, the pH of the water W1 is treated once When the value is in the neutral range of 6 to 8 when the calcium-containing inorganic substance such as calcium carbonate is added to the reaction tank 11, the pH of the treatment water W1 is added once, and the desired value is Adjust to the acidic range of 2 to 4. This is for the purpose of performing chelation of the tetrafluoroboric acid ion contained in the primary treated water W1 via the amine polyol type chelating resin in the resin column 14 described below.

However, as the above pH adjusting agent, sulfuric acid is preferred. Further, the primary treatment water W1 and the pH adjuster are sufficiently mixed via the agitator 131.

Then, the pump 32 is driven, and the pH-adjusted primary treatment water W1 is introduced into the resin column 14 by the pipe 24, and is hydrophobic in the space between the amine-based polyol-type chelating resins R filled in the resin column 14. . At this time, the amine-based polyol type chelating resin R causes a mismatch reaction with the tetrafluoroboric acid ion contained in the water W to be treated, and the tetrafluoroboric acid ion is introduced as a complex ion to the amine-based polyol type. Chelate the resin to form a complex. As a result, the tetrafluoroboric acid ion in the primary treatment water W1 is absorbed by the amine polyol type chelating resin, and when the tetrafluoroboric acid ion is removed from the primary treatment water W1, the treated water W2 is obtained twice.

However, the secondary treatment water W2 is released from the piping 25 disposed below the resin tower 14 and released to the outside. The water treatment W2 is treated twice as a water resource because it does not contain harmful fluoride ions or tetrafluoroboric acid ions.

As described above, since it is subjected to the conversion reaction in the reaction tank 11 and the recruitment in the solid-liquid separation tank 12, it is introduced into the resin column 14 by itself. The primary treatment water W1 has been removed from the fluoride ion, and the tetrafluoroboric acid ion contained in the primary treated water W1 does not pass through the fluoride ion when the treated water W1 is introduced into the resin column 14 once. The existence of the obstacles. Accordingly, an increase in the absorption rate of the tetrafluoroboric acid ion via the amine polyol type chelating resin R can be achieved.

Further, since the coagulant is not used, the cost of the chemical is not consumed, and the cost of the sludge for treating the precipitate is not generated.

As a result, according to the present embodiment, the fluorine ions and the tetrafluoroboric acid ions can be efficiently and efficiently removed from the water to be treated W0 containing fluorine ions and tetrafluoroboric acid ions at a low cost.

However, the water of the water W1 is treated once in the resin column 14 once, and the rate of absorption of the tetrafluoroboric acid ion by the amine-based polyol type chelating resin R is decreased, and the supply of the treated water W1 is stopped once, and the pipe 28 is supplied. The release liquid is supplied into the resin column 14 to remove the tetrafluoroboric acid which is absorbed by the amine-based polyol type chelating resin. This detachment liquid has no particular problem as long as the inside of the resin column 14 is alkaline, but it is preferably used as an aqueous solution of sodium hydroxide. The wastewater containing the tetrafluoroboric acid ions which are removed by the separation liquid is discharged from the piping 29 from the piping 29 and stored in a waste alkaline tank (not shown).

When the treatment is carried out, the amine-based polyol-type chelating resin filled in the resin column 14 is again supplied to the treated water W1 once by the pipe 24 due to the recovery of the absorbing ability. In the resin column 14, the absorption of the tetrafluoroboric acid ions in the treated water W1 is performed once, and the secondary treated water W2 from which the tetrafluoroboric acid ions are removed can be obtained.

(Second embodiment)

Fig. 2 is a view showing a schematic configuration of a water treatment device according to the embodiment. However, the same or similar components as those of the water treatment device 10 shown in Fig. 1 are denoted by the same reference numerals.

In the water treatment device 40 shown in FIG. 2, the filter 121 in the solid-liquid separation tank 12 is changed to the level of the winding filter 122 by the roller 123, instead of the piping 26 into which the washing water is introduced. The points at which the piping (compressed air supply line) 46 and the container 16 into which the compressed air is introduced are different, and the other configurations are the same as those of the water treatment apparatus 10 shown in Fig. 1 . Accordingly, in the following, the first embodiment will be described with respect to differences in water treatment methods depending on the above-described devices.

However, the above-mentioned "horizontal filter cloth" means that the filter cloth is disposed horizontally with respect to the installation surface of the solid-liquid separation tank 12.

In the present embodiment, the slurry-like treated water W0 containing calcium fluoride converted by the fluoride ions is supplied to the filter cloth 122 of the solid-liquid separation tank 12 via the addition of the calcium-containing inorganic material in the reaction tank 11. on. At this time, the calcium fluoride contained in the water to be treated W0 is added by the filter cloth 122, and a layer on which the calcium fluoride of the object to be removed is centered is formed on the filter cloth 122.

As described above, the above-mentioned layer functions as a filter layer due to calcium fluoride in the water W0 to be treated which is hydrophobic or hydrophobic, even if there is fine fluorination in the treated water W0. In the case of calcium precipitates (reaction products), the precipitates may be supplemented Removed.

However, when the hydrophobic time becomes long and the thickness of the above layer increases, the filtration speed decreases. In such a state, the supply of the water to be treated W0 by the piping 22 is stopped, and the compressed air is supplied from the piping 46 of the compressed air supply line to the filter cloth 122. Thereby, it is possible to promote the hydrophobicity of the filter cloth 122 remaining on the water to be treated W0 on the filter cloth 122, and to lower the moisture content of the layer formed on the filter cloth 122.

The water to be treated W0 which is water-repellent in the filter cloth 122 is sequentially transferred to the pH adjustment tank 13 and the resin tower 14 as the primary treatment water W1. As described in the first embodiment, the tetrafluorocarbon in the treatment water W1 is removed once. Boric acid ion. On the other hand, the filter cloth 122 is lifted by a scraper (not shown) and then scraped off by a scraper (not shown) after lifting the upper surface of the solid-liquid separation tank 12 by a pneumatic cylinder or the like (not shown). The above layer on the filter cloth 122 is housed in the container 16.

However, after the layer of the solid matter having the calcium fluoride on the filter cloth 122 as a center is removed, the roller 123 is rotated to arrange a new filter cloth 122, and the upper portion of the solid-liquid separation tank 12 is returned to the original position. After that, the water to be treated W0 is transferred to the filter cloth 122 by the pipe 22 to be hydrophobic, and the same as described above, the calcium fluoride in the water to be treated W0 is added and removed, and the treated water W1 is obtained once.

In the present embodiment, when the layer of the solid material formed on the filter cloth 122 is washed, the water recovery rate of the treated water W0 is increased because the washing water is not used.

In addition, as in the first embodiment, the import 1 is When the secondary treatment water W1 is applied to the resin column 14, the tetrafluoroboric acid ions contained in the primary treated water W1 are not hindered by the presence of fluoride ions, and the amine-based polyol-type chelating resin R can be obtained. The increase in the absorption rate of tetrafluoroboric acid ions. Moreover, since the coagulant is not used, the cost of the agent is not consumed, and the cost of the sludge for treating the precipitate is not generated.

As a result, according to the present embodiment, the fluorine ions and the tetrafluoroboric acid ions can be efficiently and efficiently removed from the water to be treated W0 containing fluorine ions and tetrafluoroboric acid ions at a low cost.

[Examples] (Example 1)

The test was carried out using the water treatment device 10 shown in Fig. 1 . As the water to be treated W0, a wastewater containing about 1000 mg/L of fluoride ions and about 200 mg/L of tetrafluoroboric acid ions is supplied to the reaction tank, and after adjusting the pH to 3 by sulfuric acid, calcium carbonate having an average particle diameter of 40 μm is used. The powder was added 0.75 times to the fluoride ion by molar ratio, and then mixed by a blender 111 for 15 minutes. Thereafter, the pump 31 was supplied to the solid-liquid separation tank 12 formed of a horizontal filter having a polypropylene filter cloth having a pore size of 10 μm, and subjected to solid-liquid separation. The ion concentration of the treated water W1 was 15 mg/L for fluoride ions and about 180 mg/L for tetrafluoroboric acid ions. In addition, the solid content in water is less than 1 mg/L.

Next, in the pH adjusting tank 13, 1 time via sulfuric acid After the pH of the treated water W1 is adjusted to 3, the resin column 14 which is hydrophobic to the chelating resin (manufactured by Mitsui Chemicals, Inc., trade name (CRB-05)) which is filled with N-methylglucamine having an amine-based polyol The concentration of tetrafluoroboric acid ions discharged from the pipe 25 was analyzed.

When the amount of hydrophobicity SV was changed and the removal performance of tetrafluoroboric acid ions was confirmed, tetrafluoroboric acid ions were not detected until SV40, and a small amount of tetrafluoroboric acid ions were detected in SV50. Therefore, the treatment amount of the water treatment device 10 is clearly SV40 for the resin column 14 described above.

(Comparative Example 1)

The test was carried out in the same manner as in Example 1 except that calcium chloride was used instead of calcium carbonate. However, the particle diameter of the calcium fluoride ion generated at this time is too small to be subjected to solid-liquid separation in the solid-liquid separation tank 12, and a small amount of agglomerated polymer is added to the reaction tank 11 to form an aggregate, followed by filtration. The ion concentration of the treated water W1 was 13 mg/L for fluoride ions and about 180 mg/L for tetrafluoroboric acid ions. In addition, the solid content in water is less than 1 mg/L.

Similarly, when the pH was adjusted with sulfuric acid and then hydrophobic to the resin column 14, tetrafluoroboric acid ions were not detected until SV5, but were detected in SV10. Therefore, the treatment amount of the water treatment device 10 is clearly SV5 for the resin column 14 described above.

(Comparative Example 2)

The treated water W0 is directly supplied to the pH adjusting tank 13, not containing calcium The solid was treated, and when it was hydrophobic to the resin column 14, the tetrafluoroboric acid ion could not be removed until SV2.

The embodiments of the present invention have been described above, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The present invention can be implemented in various other forms, and various omissions, substitutions and changes can be made without departing from the scope of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, and are included in the scope of the invention described herein.

10‧‧‧Water treatment unit

11‧‧‧Reaction tank

111‧‧‧Mixer

12‧‧‧ solid-liquid separation tank

13‧‧‧pH adjustment tank

14‧‧‧Amino polyol type chelate resin filling tower

R‧‧‧Amino polyol type chelating resin

W0‧‧‧ treated water

W1‧‧1 treatment of water

W2‧‧2 times treated water

21~29‧‧‧Pipe

31, 32‧‧‧

131‧‧‧Mixer

121‧‧‧Filter

12A‧‧‧ upper

Claims (10)

A water treatment method is a method for treating wastewater containing fluoride ions and tetrafluoroboric acid ions, characterized by comprising: adding a water-insoluble calcium-containing inorganic substance to the wastewater in a reaction tank, which is contained in the wastewater; The first step of converting the fluoride ion into calcium fluoride, and solid-liquid separation of the wastewater containing the calcium fluoride in the solid-liquid separation tank, and removing the calcium fluoride from the wastewater to obtain the first treated water In the second step, in the pH adjusting tank, a pH adjusting agent is added to the first treated water, a third step of adjusting the pH of the first treated water to an acidic region, and a filling of an amine-based polyol type. In the container of the chelating resin, the first treated water is subjected to hydrophobicity, and the fourth step of the second treated water is obtained by sucking and removing the tetrafluoroboric acid ions from the first treated water. The water treatment method according to the first aspect of the invention, wherein in the first step, an additional pH adjuster is added to the reaction tank to adjust the pH of the wastewater to an acidic domain. The water treatment method according to the first or second aspect of the invention, wherein the solid-liquid separation device is a horizontal filter. The water treatment method according to the first or second aspect of the invention, wherein the calcium-containing inorganic substance is calcium carbonate. The water treatment method according to the first or second aspect of the invention, wherein the pH adjuster is sulfuric acid. The water treatment method according to claim 2, wherein the additional pH adjuster is sulfuric acid. The water treatment method according to the first or second aspect of the invention, wherein the detachment liquid for supplying alkali is contained in the container, and the tetrafluoroboric acid ion which is absorbed and absorbed by the amine-based polyol type chelating resin is removed. The 5th step of the person. The water treatment method according to claim 7, wherein the separation liquid is an aqueous sodium hydroxide solution. A water treatment device for treating wastewater containing fluoride ions and tetrafluoroboric acid ions, characterized by comprising: adding a calcium-insoluble inorganic substance insoluble in water to the wastewater, in order to contain the fluoride contained in the wastewater a reaction tank for converting ions into calcium fluoride, a solid-liquid separation tank for removing the calcium fluoride from the waste water, and a solid-liquid separation tank for obtaining the first treated water, and the first A pH adjusting agent is added to the treated water, and the pH of the first treated water is adjusted to a pH adjusting tank of the acidic region, and the first treated water is made hydrophobic, and the tetrafluoroboric acid is removed from the first treated water. Ion, in order to obtain a container for filling the amine-based polyol type chelating resin of the second treated water. The water treatment device according to claim 9, wherein the solid-liquid separation device is a horizontal filter.