JP2010022960A - Water treatment apparatus and water treatment method for organofluorine compound-containing water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment apparatus and a water treatment method which enables the decomposition and removal of organofluorine compounds at a low cost even if the concentration of the organofluorine compounds is low and the amount of water to be treated is large. <P>SOLUTION: Organofluorine compound-containing water is treated in two steps. In a first step, decomposition products generated by decomposing the organofluorine compound-containing water by nanobubbles are adsorbed by fixed activated carbon 32, 33, 34. In a second step, decomposition products generated by decomposing low concentration organofluorine compounds in the treated water treated in the first step are adsorbed by fluidized activated carbon 67. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water treatment apparatus and a water treatment method for water containing an organic fluorine compound. In particular, the present invention relates to a water treatment apparatus and a water treatment method for water containing an organic fluorine compound that are preferably used for decomposing and removing perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).

  As with dioxins, environmental pollution of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) as organic fluorine compounds is becoming a problem internationally.

  Organic fluorine compounds are chemically stable substances. The organic fluorine compounds are widely used as industrial materials such as various surfactants and antireflection films in semiconductor production because they have excellent properties from the viewpoints of heat resistance and chemical resistance.

  However, since the organic fluorine compound is a chemically stable substance, it is difficult to be decomposed by microorganisms. In addition, since it is difficult to be decomposed by microorganisms, it will cause environmental pollution if released into the environment.

  For example, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) as the organic fluorine compound are concerned about the influence on the ecosystem because the decomposition in the ecosystem does not proceed. That is, the above-mentioned perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are chemically stable and therefore require a high temperature of about 1000 ° C. or higher for thermal decomposition. In order to avoid this decomposition method, it is extremely difficult to decompose by treatment with conventional microorganisms or conventional photocatalysts.

  Against such a background, conventionally, there are a combustion method and a high-pressure supercritical method as the treatment of water containing refractory organic fluorine compounds such as PFOS and PFOA. Here, as described above, since extremely high temperatures are indispensable for the combustion method, fuel is consumed to promote global warming.

  In addition, the organic fluorine compound concentration in the wastewater containing organic fluorine compounds discharged from semiconductor factories is low at the ppb level, while the amount of wastewater is several tens to several hundred tons per day. There are a lot of current situations.

  Here, the prior art can be applied only when the concentration of the organic fluorine compound is high and the amount of wastewater is small, and specifically, there is a problem that it can be applied only when the amount of wastewater is at most several tons per day.

  In addition, in the treatment of river water and lake water, the concentration of organic fluorine compounds in river water and lake water is even lower than in the case of drainage, and the amount of water is much higher, so the use of conventional methods is virtually impossible. It is.

  Here, conventionally, as a method of using nanobubbles, there is one described in Japanese Patent Application Laid-Open No. 2004-121962.

  This method utilizes characteristics such as a decrease in buoyancy of nanobubbles, an increase in surface area, an increase in surface activity, generation of a local high-pressure field, a surface active action by realizing electrostatic polarization, and a bactericidal action. More specifically, the interrelation between them improves the adsorption function of dirt components, the high-speed cleaning function of the object surface, and the sterilization function, and various objects are cleaned with high functionality and low environmental load. , Purifying polluted water.

  Moreover, as a utilization method and apparatus of nanobubble, there exist some which are described in Unexamined-Japanese-Patent No. 2003-334548 (patent document 2).

  In this method, a part of the liquid is decomposed and gasified in the liquid, and ultrasonic waves are applied in the liquid to generate nanobubbles.

  Moreover, as an apparatus for treating waste liquid using ozone microbubbles, there is one described in JP-A-2004-321959 (Patent Document 3).

  In this apparatus, ozone microbubbles are vented into the waste liquid in the treatment tank through the opening of the gas blowing pipe, and the waste liquid is processed.

However, even if it is referred to the above-mentioned literature etc., even if nanobubbles can decompose organic fluorine compounds, it is not known at all, and a method in which organic fluorine compounds can be decomposed and removed by a method that can be used industrially However, the current situation is that it is not known.
JP 2004-121962 A JP 2003-334548 A JP 2004-321959 A

  As an organic fluorine compound decomposition method, even an international conference considers that there is only a method of incineration at 1000 ° C. or higher. When trapped, the bond between carbon and fluorine, which is a chemical structural formula in the organic fluorine compound, is stable and therefore does not decompose even in strong acids. In addition, there is an activated carbon adsorption system for the purification of general treated water, but activated carbon absorbs all organic matter and easily breaks through if there is organic matter in the treated water. It must be replaced frequently and the running costs associated with the replacement of activated carbon are very high. Therefore, the efficiency is very poor, and the adoption of the activated carbon adsorption method is economically problematic.

  In such a background, highly stable organofluorine compounds have been released into the environment, have traveled around the world, and have been concentrated in all living organisms around the world. For example, organic fluorine compounds are also detected in polar bears, seals, and whales, causing international environmental pollution.

  Therefore, it is very significant to provide an apparatus and a method capable of decomposing and removing an organic fluorine compound by a low-cost industrially available method.

  In such a background, as described above, organic fluorine compound-containing wastewater discharged from each factory, river water, and lake water have a low concentration of organic fluorine compounds, but the amount of treated water is large. In the combustion method and the high-pressure supercritical method, it is impossible to treat the organic fluorine compound for economic reasons. Further, the combustion method and the high-pressure supercritical method are expensive in terms of construction costs and running costs, and are not suitable for the treatment of organic fluorine compounds.

  Therefore, the problem of the present invention is to provide a water treatment apparatus and an organic fluorine compound-containing water capable of decomposing and removing the organic fluorine compound at low cost even when the concentration of the organic fluorine compound is low and the amount of water to be treated is large. It is to provide a water treatment method.

In order to solve the above problems, the water treatment device of the present invention is:
A first nanobubble generator;
A second nanobubble generator;
Carbon and fluorine decomposition products generated by decomposing the organic fluorine compound in the organic fluorine compound-containing water containing the organic fluorine compound by nanobubbles discharged from the first nanobubble generator and using the nanobubbles A pre-disassembly part to be removed;
The first treated water treated in the preceding decomposition unit is introduced, the nano bubbles from the second nano bubble generator are discharged, and the organic fluorine compound in the first treated water is decomposed by the nano bubbles. And a post-stage decomposition section for removing a decomposition product of carbon and fluorine generated by the above.

  According to the present invention, nanobubble bubbles are discharged into and mixed with organic fluorine compound-containing water in two stages, and the bond between carbon and fluorine in the organic fluorine compound is decomposed using the oxidizing power of radicals possessed by the nanobubbles. Low molecular weight carbon and fluorine decomposition products can be gasified and ventilated in two stages. That is, the strong carbon-fluorine bond is decomposed in the first stage, and the remaining low-molecular-weight carbon and fluorine decomposition products can be further gasified and removed in the liquid phase in the second stage. .

  A radical (also called a free radical) is an atom, molecule, or ion having an unpaired electron. Since radicals are usually highly reactive, as soon as they are generated, they undergo oxidation-reduction reactions with other atoms and molecules to become stable molecules and ions. From this, the radical has a strong oxidizing power, decomposes a strong bond between carbon and fluorine, lowers the molecular weight of the compound of carbon and fluorine, and can be further gasified. Nanobubbles generated by a nanobubble generator have a radical, that is, oxidizing power, that is much stronger than microbubbles or micronanobubbles.

In addition, this inventor confirmed the component of the gasified decomposition product by advanced analysis (GC-MS). Specifically, the gasification generated as a result of the decomposition was collected by an altitude measuring device, and the components were confirmed. Examples of the gasified decomposition products include CF ₃ (CF ₂ ) _n H (where n = 3,4,5,6) (one type of PFC gas = a gas called perfluorocarbon = a greenhouse gas). And CF ₃ (CF ₂ ) _m COOCH ₃ (where m = 5, 6).

In one embodiment,
Each of the first nanobubble generator and the second nanobubble generator has three gas-liquid mixed gas shearing portions connected in series.

  According to the said embodiment, since each nano bubble generator has three gas-liquid mixed-gas shearing parts, it can generate a large amount of nano bubbles.

In one embodiment,
Each of the front stage decomposition part and the rear stage decomposition part consists of an upper part and a lower part located vertically below the upper part,
Nanobubbles from the first nanobubble generator are discharged to the lower part of the front stage decomposition unit, and nanobubbles from the second nanobubble generator are discharged to the lower part of the rear stage decomposition unit,
The upper part of the preceding stage decomposition part has an adsorption processing part for adsorbing the gas of the decomposition product generated by the decomposition of the organic fluorine compound at the lower part of the previous stage decomposition part,
The upper part of the latter decomposition part has an adsorption treatment part for adsorbing the gas of the decomposition product generated when the organic fluorine compound is decomposed in the lower part of the latter decomposition part.

  According to the above-described embodiment, the gas generated by decomposing the organic fluorine compound with nanobubbles at the lower part can be adsorbed at the upper part in the former decomposition part, and the organic substance with the nanobubbles at the lower part in the latter decomposition part. Gas generated by decomposing the fluorine compound can be adsorbed at the top.

In one embodiment,
A pre-stage upper air supply unit for supplying air to the upper part of the pre-stage decomposition unit;
A pre-stage lower aeration section for aeration of liquid present in the lower portion of the pre-stage decomposition section;
A rear lower aeration unit for aerating liquid existing in the lower part of the rear decomposition unit.

  Examples of the air supply unit include a fan and a blower.

  According to the above embodiment, fresh air can be supplied to the upper part of the front decomposition unit by the upper air supply unit, and as a result, the vapor pressure near the water surface of the front decomposition unit is not saturated, and the organic fluorine compound Degradation can be accelerated. In addition, by aeration of the liquid in the front lower aeration section and the rear lower aeration section, the decomposition product gas generated in the liquid can be efficiently removed.

In one embodiment,
The adsorption treatment unit of the pre-stage decomposition unit has an activated carbon storage unit and activated carbon stored in the activated carbon storage unit,
The said adsorption | suction process part of the said back | latter stage decomposition | disassembly part has a sprinkling part which sprinkles the water containing activated carbon.

  According to the said embodiment, the organic substance in a liquid can be adsorption-treated with the said activated carbon. Moreover, since the activated carbon which flows in a liquid is used in the latter stage decomposition part where the density | concentration of a decomposition product is low, in the latter stage decomposition part, a decomposition product can be efficiently adsorbed.

In one embodiment,
Each of the first nanobubble generator and the second nanobubble generator is
A gas-liquid mixing circulation pump;
A first gas shearing section having an electric needle valve for controlling the passage of gas;
A second gas shearing part;
A third gas shearing portion.

  According to the above embodiment, microbubbles can be generated in the first gas shearing part, some nanobubbles can be generated in the second gas shearing part, and finally a large amount of nanobubbles can be generated in the third gas shearing part. it can.

In one embodiment,
The amount of air passing through the electric needle valve of each of the first nanobubble generator and the second nanobubble generator is 1.2 liters / minute or less.

  According to the above embodiment, a large amount of nanobubbles can be generated. If the amount of air is more than necessary, nanobubbles are hardly generated.

In one embodiment,
The first gas shearing portion of each of the first nanobubble generator and the second nanobubble generator has an elliptical shape or a perfect circular shape, and an inner surface of each first gas shearing portion has two or more grooves. .

  According to the embodiment, since the inner surface of each first gas shearing portion has two or more grooves, the swirling turbulence of the fluid in the microbubble generating portion can be controlled. In addition, air can be sheared stably, and a large amount of microbubbles can be generated.

In one embodiment,
The depth of the groove is 0.3 mm to 0.6 mm, and the groove width of the groove is within 0.8 mm.

  According to the above embodiment, the swirling turbulent flow of the fluid in the microbubble generator can be controlled more precisely.

In one embodiment,
In the gas-liquid mixing circulation pump of each of the first nanobubble generator and the second nanobubble generator, the cross-section of the discharge pipe of the gas-liquid mixing circulation pump is more than the cross-section of the suction pipe of the gas-liquid mixing circulation pump. small.

  According to the above embodiment, air can be stably sheared and nanobubbles can be generated efficiently.

In one embodiment,
Each of the gas-liquid mixing and circulation pumps of the first nanobubble generator and the second nanobubble generator takes in gas after the output of the gas-liquid mixing and circulation pump reaches the maximum value.

  If air is initially introduced into the gas-liquid mixing circulation pump, it may cause cavitation and damage the pump. Here, cavitation is a phenomenon in which a low-pressure part of a liquid (water, etc.) flowing at high speed is vaporized, a vapor pocket is created in a very short time, and collapses and disappears in a very short time. That means.

  According to the above embodiment, the gas-liquid mixing circulation pump is configured to take in the gas after the output of the gas-liquid mixing circulation pump reaches the maximum value. Will not occur and the pump will not be damaged.

In one embodiment,
Each of the gas-liquid mixing and circulation pumps of the first nanobubble generator and the second nanobubble generator takes in gas after 60 seconds from the operation of the gas-liquid mixing and circulation pump.

  According to the said embodiment, after the output of a gas-liquid mixing circulation pump reaches the maximum, gas can be taken in. This is because it takes less than 60 seconds for the gas-liquid mixing circulation pump to reach its maximum output.

In one embodiment,
In the first gas shearing portion of each of the first nanobubble generator and the second nanobubble generator, the incident angle of the gas inflow tube with respect to the side surface of the microbubble generating portion is approximately 18 °.

  According to the above embodiment, in the nanobubble generator, air can be sheared stably and a large amount of micro-nanobubbles can be generated.

In one embodiment,
The thickness of the first gas shearing part of each of the first nanobubble generator and the second nanobubble generator is 6 mm or more and 12 mm or less.

  According to the above embodiment, loss of kinetic energy can be suppressed, and microbubbles can be generated stably and efficiently.

In one embodiment,
The upper part of the latter stage decomposition part has an activated carbon filling part that fills with water containing activated carbon, while the lower part of the latter stage decomposition part has a lower stage aeration part that performs aeration.

  According to the above embodiment, the decomposition product generated by the decomposition can be adsorbed by the activated carbon at the upper part of the former decomposition part, and the liquid in the latter decomposition part is activated by aeration at the lower part of the latter decomposition part. be able to. Moreover, according to the said embodiment, activated carbon can be made into a fluid state by the aeration of the said lower part of the said latter decomposition | disassembly part, and the contact with the trace amount organic fluorine compound in activated water and activated carbon can be increased. .

In one embodiment,
The lower part of the rear decomposition part has a slope having a slope of 30 ° or more with respect to the horizontal plane in a state where the bottom surface of the lower part is spread in a substantially horizontal direction.

  According to the said embodiment, the activated carbon whole quantity can be made into a fluid state effectively by installation of an inclined wall. And the contact efficiency of activated carbon and to-be-processed water can be enlarged.

In one embodiment,
The lower rear aeration part is
With the blower,
The activated carbon suction part is connected to the blower and communicates with the lower part of the rear decomposition part, and the activated carbon filling part is positioned above the air diffusion diffuser in the vertical direction. Has a tube,
The upper part of the latter stage decomposition part has a watering part for watering the water containing activated carbon,
The liquid sucked through the activated carbon suction pipe is sent to the watering unit by an activated carbon watering pump.

  According to the above embodiment, the activated carbon flowing in the rear decomposition unit is sucked by the activated carbon suction pipe connected to the activated carbon water spray pump, and the activated carbon can be sprinkled from the upper part of the second adsorption box. It can be adsorbed with activated carbon sprinkling product gas.

  In the present invention, when the decomposed material is removed by ventilation in two stages, for example, the fan is removed by ventilation in the first stage, and the air discharged from the blower is removed in the second stage. Usually, the blower is used for air agitation in the water tank, and those skilled in the art do not have the idea of using the blower for removing gas of decomposition products in the water tank. The present inventor has discovered that the use of flowing activated carbon enables efficient removal of decomposition products using air discharged from a blower.

In one embodiment,
Install the total organic carbon meter at the lower part of the latter decomposition part,
Based on the concentration of the previous organic carbon in the lower part of the rear decomposition unit measured by the total organic carbon meter, the rotational speeds of the motor of the blower and the motor of the activated carbon watering pump are controlled.

  According to the embodiment, since the total organic carbon meter is installed in the lower part of the rear decomposition unit, the water quality deteriorates in the lower part of the rear decomposition unit when the total organic carbon amount is high. In this case, in the electric motors of both the activated carbon watering pump and the blower, the activated carbon can be brought into a more discrete flow state by increasing the rotation speed. Therefore, the total organic carbon content concentration can be reduced, and the removal rate of cracked gas can be improved. Needless to say, when the total organic carbon content concentration is low, the removal rate of the cracked gas increases.

In one embodiment,
A chemical oxygen demand meter is installed at the lower part of the latter stage decomposition section,
Based on the chemical oxygen demand measured by the chemical oxygen demand meter, the rotational speeds of the blower motor and the activated carbon water pump are controlled.

  According to the embodiment, since the chemical oxygen demand meter is installed at the lower part of the rear decomposition unit, the water quality is reduced when the chemical oxygen demand is high at the lower part of the rear decomposition unit. In this case, the activated carbon can be brought into a more discrete flow state by increasing the rotation speed in both the activated carbon watering pump and the blower motor. Therefore, the chemical oxygen demand concentration can be reduced and the removal rate of the cracked gas can be improved. Needless to say, when the chemical oxygen demand concentration is low, the removal rate of the cracked gas increases.

In one embodiment,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone gas, while the gas introduced from the electric needle valve of the second nanobubble generator is air.

  According to the above embodiment, ozone gas nanobubbles can be generated. Here, since the ozone nanobubble has a strong oxidizing action, the organic fluorine compound can be strongly oxidized and decomposed.

In one embodiment,
The gas introduced from the electric needle valve of the first nanobubble generator is oxygen, while the gas introduced from the electric needle valve of the second nanobubble generator is air.

  According to the above embodiment, oxygen gas nanobubbles can be generated. Here, since the oxygen nanobubble has stronger oxidizing power than the nanobubble made of air, the organic fluorine compound can be strongly oxidized and decomposed.

In one embodiment,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone, and the gas introduced from the electric needle valve of the second nanobubble generator is ozone.

  According to the above-described embodiment, ozone nanobubbles having a strong oxidizing action are used in two stages, so that the organic fluorine compound can be strongly oxidized and decomposed.

In one embodiment,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone, while the gas introduced from the electric needle valve of the second nanobubble generator is oxygen.

  According to the above embodiment, the organic fluorine compound can be efficiently and oxidatively decomposed efficiently by the strong oxidizing action of ozone nanobubbles in the first stage and by the oxygen nanobubbles in the second stage. The reason why the nanobubbles in the first stage are ozone nanobubbles is that the concentration of the organic fluorine compound is higher in the first stage than in the second stage.

In one embodiment,
The activated carbon housed in the activated carbon housing part of the preceding stage cracking part is zeolite, and the activated carbon present in the water sprinkled from the watering nozzle of the latter stage cracking part is zeolite.

  According to the said embodiment, an organic substance can be adsorb | sucked efficiently to a zeolite and purification of to-be-processed water can be performed efficiently.

Moreover, the water treatment method of the organic fluorine compound-containing water of the present invention comprises:
Nanobubbles are discharged and mixed into organic fluorine compound-containing water containing an organic fluorine compound, and the bond between carbon and fluorine is decomposed in the organic fluorine compound by the oxidizing power of radicals possessed by the nanobubble. Produce a decomposition product of carbon and fluorine with a molecular weight smaller than the molecular weight of the fluorine compound,
The decomposition product of carbon and fluorine is gasified and removed.

  According to the present invention, an organic fluorine compound can be efficiently decomposed and removed.

In one embodiment,
The organic fluorine compound-containing water contains at least one of perfluorooctane sulfonic acid and perfluorooctanoic acid.

  According to the embodiment, at least one of harmful perfluorooctane sulfonic acid and perfluorooctanoic acid can be decomposed and removed.

  Representative examples of the hardly decomposable organic fluorine compound are PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid).

  The Stockholm Convention, an international treaty, discusses whether the use of PFOS (perfluorooctane sulfonic acid) is completely prohibited or allowed with restrictions. A conclusion will be made at the international conference in May 2009 in Geneva.

  Under such circumstances, if the present invention capable of realizing the detoxification technology is reported at an international conference in October 2008, internationally, on the condition that PFOS can be sufficiently managed without affecting the environment, There is a possibility that the use of PFOS may be permitted with restrictions in domestic law. For this reason, this invention has very important significance.

In one embodiment,
The decomposition product generated by decomposing the organic fluorine compound in the water containing the organic fluorine compound with nanobubbles is adsorbed with fixed activated carbon,
Thereafter, the organic fluorine compound is decomposed by the nanobubbles, and the decomposition product is decomposed by the nanobubbles in the first treated water after the decomposition product is adsorbed by the fixed activated carbon. Is adsorbed with activated carbon fluidized in the first treated water.

  According to the above embodiment, the activated carbon fixed in the first stage having a high decomposition product concentration is used, while the activated carbon flowing in the second stage in which the decomposition product concentration is low is used. Can be decomposed and removed.

In one embodiment,
Activated carbon is added to the organic fluorine compound-containing water, and the activated carbon is brought into a fluid state by aeration and stirring.

  According to the above embodiment, since the activated carbon flows in the organic fluorine compound-containing water by aeration and stirring, the frequency of contact between the trace amount of the organic fluorine compound and the activated carbon in the water to be treated can be increased. Therefore, the decomposed gas can be efficiently adsorbed on the activated carbon and removed.

In one embodiment,
The organic fluorine compound in the organic fluorine compound-containing water is decomposed into the above decomposed product with nanobubbles, and the decomposed product is gasified with a fan to perform the first treatment,
The organic fluorine compound in the organic fluorine compound-containing water after the first treatment is decomposed into the decomposition products with nanobubbles, and the decomposition products are removed using air discharged from a blower.

  According to the embodiment, the decomposed product can be efficiently removed.

  According to the water treatment device and the water treatment method of water containing an organic fluorine compound of the present invention, the organic fluorine compound can be efficiently decomposed and removed.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram of a water treatment apparatus according to a first embodiment of the present invention.

  This water treatment apparatus includes the raw water tank 2, a pre-stage decomposition adsorption unit 83 as a pre-stage decomposition unit, and a post-stage decomposition adsorption unit 84 as a post-stage decomposition unit.

  Into the raw water tank 2, the organic fluorine compound-containing water that has passed through the inflow pipe 1 flows. Here, examples of the organic fluorine compound-containing water include organic fluorine compound-containing wastewater discharged from each factory, general river water and general lake water containing a small amount of organic fluorine compound.

  The raw water tank 2 is provided with a raw water pump 3. The raw water pump 3 transfers the organic fluorine compound-containing water to the first decomposition part water tank 63 of the pre-stage decomposition adsorption part 83.

  The said front | former decomposition | disassembly adsorption part 83 has the decomposition product gas adsorption part 21 as an upper part, and the 1st decomposition part water tank 63 as a lower part. On the other hand, the post-stage decomposition adsorption part 84 includes a second adsorption box 58 as an upper part and a second decomposition part water tank 75 as a lower part. The first decomposition part water tank 63 and the second decomposition part water tank 75 communicate with each other through the outlet water pipe 36, and the first decomposition part water tank 63 is processed by the front decomposition adsorption part 83 from the first decomposition part water tank 63 to the second decomposition part water tank 75. The first treated water flows in.

  By operating the raw water pump 3, the water to be treated is transferred and introduced into the first decomposition unit water tank 63. The inside of the first decomposition unit water tank 63 is agitated by the water flow 15 of the raw water pump 3 and the nanobubble flow 13 discharged from the third gas shearing part 12 of the first nanobubble generator 61.

  The decomposed gas adsorbing part 21 that is the upper part of the preceding stage decomposition part adsorbing part 83 has the fan 17 as the former stage upper air supply part and the first adsorption box 64, and the first adsorption box 64 includes the exhaust chimney 35, It has an upper outlet 24, an intermediate outlet 23, and a lower outlet 22. A first nanobubble generator 61 is installed outside the first decomposition unit water tank 63, which is the lower part of the preceding decomposition adsorption unit 83. The first nanobubble generator 61 and the first decomposition part water tank 63 communicate with each other through the water pipe 9, and the nanobubbles are introduced into the first decomposition part water tank 63 through the water pipe 9. Yes. PFOS, PFOA, etc. in the organic fluorine compound-containing water introduced into the first decomposition part water tank 63 are oxidatively decomposed by nanobubbles discharged from the nanobubble generator 61.

  PFOS, PFOA, and the like are considered to be chemically stable substances. More generally, it is considered that a compound having a structure having carbon and fluorine cannot be decomposed by a conventional method. However, the present inventor has discovered that even these stable substances can be decomposed by the oxidation action of the radicals generated by the nanobubbles over time using the nanobubbles. Since radicals are usually highly reactive, they have the property of causing an oxidation reaction with other atoms and molecules as soon as they are generated, resulting in stable molecules and ions.

  Next, the mechanism of the first nanobubble generator 61 will be described in detail. The first nanobubble generator 61 includes a gas-liquid mixing / circulation pump 5, a first gas shearing unit 6, a second gas shearing unit 8, a third gas shearing unit 12, an electric needle valve 11, and connecting them. It is made up of piping.

  Nanobubbles are generally manufactured through a first stage and a second stage.

  In the first stage, in the first gas shearing section 6, the pressure is controlled hydrodynamically, the gas is sucked from the negative pressure forming part, and the sucked gas and water are caused to move at a high speed to move the negative pressure part. To generate microbubbles. Briefly, it is easier to understand. Water and air are effectively self-mixed and dissolved, and pumped to produce microbubble cloudy water.

  Next, in the second stage, in the second gas shearing portion 8 and the third gas shearing portion 12, air and water are subjected to high-speed fluid motion to form a negative pressure portion, and useful substance-containing microbubbles are generated. . The microbubble cloudy water produced | generated in the 1st step is introduce | transduced into the 2nd gas shearing part 8 and the 3rd gas shearing part 12 through a water piping, and a nanobubble is generated from a microbubble by shearing as fluid motion.

  Hereinafter, the first stage and the second stage will be described in more detail.

(First stage)
The gas-liquid mixing circulation pump 5 used in the first nanobubble generator 61 is a high-lift pump having a lift of 40 m or higher (that is, a high pressure of 4 kg / cm ² ). That is, the gas-liquid mixing / circulation pump 5 having the first gas shearing portion 6 is a high-lift pump and has a stable torque of two poles (the pump has two poles and four poles, and two poles The pump has a stable torque.)

  Further, the gas-liquid mixing circulation pump 5 needs to control the pressure. This pressure control is performed, for example, by controlling the rotational speed of the high-lift pump with a rotational speed controller (generally called an inverter). By generating a pressure suitable for the purpose by controlling the rotation speed of the pump, microbubbles with a bundled bubble size can be manufactured.

  Next, the mechanism of microbubble generation in the gas-liquid mixing circulation pump 5 having the first gas shearing part 6 will be described. In the first gas shearing section 6, in order to generate microbubbles, a mixed-phase swirling flow of liquid and gas is generated, and a gas cavity that is swirled at a high speed is formed at the center of the first gas shearing section 6. Next, the hollow portion is thinned into a tornado shape with pressure to generate a rotating shear flow that swirls at a higher speed. Air as a gas in this hollow portion (in some cases, ozone, carbon dioxide gas, nitrogen gas, oxygen gas may be used, but in the present invention, only air is used, but other gases may be selected depending on the purpose). Is automatically supplied using negative pressure (negative pressure). Further, the multiphase flow is rotated while cutting and grinding. This cutting / pulverization occurs due to the difference in the swirling speed of the gas-liquid two-phase fluid inside and outside in the vicinity of the apparatus outlet. The rotational speed of this turning is 500 to 600 revolutions / second.

  That is, in the first gas shearing part 6, by controlling the pressure hydrodynamically, the gas is sucked from the negative pressure forming part, and the high pressure pump moves the fluid at high speed to form the negative pressure part. Substance-containing microbubbles are generated. In a first stage, microbubble cloudy water is produced by effectively self-mixing and dissolving water and air with a high-lift pump and pumping in a first stage.

  The operation of the gas-liquid mixing circulation pump 5 is controlled by a signal from a sequencer (not shown). The internal shape of the first gas shearing portion 6 is generally an ellipse, and more preferably a true circle. In this case, the shearing effect can be maximized. Furthermore, the interior is mirror finished to reduce internal friction. Further, a groove having a groove depth of 0.3 mm to 0.6 mm and a groove width of 0.8 mm or less is provided in the first gas shearing part 6 in order to control the swirling turbulent flow of the fluid.

(Second stage)
The microbubbles generated by the gas-liquid mixing / circulation pump 5 having the first gas shearing part 6 are pumped to the second gas shearing part 8 through a water pipe. The second gas shearing part 8 and the third gas shearing part In the part 12, the pipe size is further reduced after the first stage. In this way, the fluid is caused to move at a high speed, and the fluid flow is narrowed in a tornado shape to generate a rotating shear flow that swirls at a higher speed. In this way, nanobubbles are generated from microbubbles, and at the same time, an ultra-high temperature limit reaction field is generated.

  The reason why the second gas shearing portion 8 and the third gas shearing portion 12 are installed is to generate a larger amount of nanobubbles, and the gas shearing portion is configured in three stages. This is because a larger amount of nanobubbles can be generated than in the case of one stage.

  That is, when an extremely high temperature extreme reaction field is formed, a high temperature and high pressure state is locally generated, an unstable free radical (also called a radical) is generated, and heat is generated at the same time. Each of the second gas shearing portion 8 and the third gas shearing portion 12 is generally made of stainless steel and has an elliptical shape, preferably a perfect circle. The second gas shearing portion 8 and the second gas shearing portion 12 have small holes, and the discharge port diameter is optimally 4 mm to 9 mm.

  Next, “high-speed fluid motion” in the first stage will be described.

  In the first gas shearing section 6, “high-speed fluid motion” is performed in order to generate microbubbles.

  In detail, first, a wing called a pump impeller is rotated at an ultra high speed. In this way, a mixed-phase swirling flow of liquid and gas is generated, and a gas cavity that is swirled at a high speed is formed at the center of the first gas shearing portion 6.

  Next, this hollow portion is thinned into a tornado shape by pressure to generate a rotating shear flow that swirls at a higher speed. Air (gas, ozone, carbon dioxide gas, nitrogen gas, oxygen gas) may be supplied to the cavity, and the mixed phase flow supplied with gas as the rotating shear flow may be cut and pulverized. Rotate while. This cutting / pulverization occurs due to the difference in the swirling speed of the gas-liquid two-phase fluid inside and outside in the vicinity of the apparatus outlet. The rotation speed is 500 to 600 rotations / second.

  If the metal constituting the first gas shearing portion 6 is thin, vibration is generated by operating the gas-liquid mixing and circulating pump 5, and this vibration is transmitted to the outside by propagation. That is, a portion of the fluid kinetic energy is lost as vibration energy, which reduces the required high velocity fluid motion, ie, the energy of the high speed swirl and the shear energy. This phenomenon can be effectively suppressed when the thickness of the metal constituting the first gas shearing portion 6 falls within the range of 6 mm to 12 mm.

  Next, “shearing as a fluid motion” will be described.

  The microbubbles generated by the gas-liquid mixing circulation pump 5 having the first gas shearing part 6 are pumped to the second gas shearing part 8 and the third gas shearing part 12 through a water pipe. At this time, in the second gas shearing portion 8 and the third gas shearing portion 12, the pipe size is further reduced after the first stage, and the flow of the fluid is reduced at high speed and in a tornado shape, Generates a rotating shear flow that swirls at higher speeds.

  Next, the “negative pressure forming portion” will be described. The “negative pressure forming portion” is generated due to the difference in the swirling speed of the gas-liquid two-phase fluid inside and outside in the vicinity of the apparatus outlet. As described above, the rotational speed of this turning is 500 to 600 revolutions / second.

  Next, the “negative pressure part” will be described.

  The “negative pressure part” refers to an area in the gas / liquid mixture where the pressure is smaller than the surrounding area.

  The above is the mechanism of the first nanobubble generator 61.

  In addition, the set of the gas-liquid mixing circulation pump 5, the 1st gas shearing part 6, the 2nd gas shearing part 8, and the 3rd gas shearing part 12 which comprises the 1st nanobubble generator 61 fundamentally is marketed. Any manufacturer can use it. For example, a product (specific product name: Bavidas HYK type) manufactured by Kyowa Kikai Co., Ltd. can be used.

  Here, three types of bubbles will be described.

  First, a normal bubble (bubble) refers to a bubble that rises in the water and eventually disappears by blowing off the bread on the surface.

  In contrast, microbubbles are fine bubbles having a diameter of 50 microns (μm) or less, which are reduced in water and eventually disappear (completely dissolved).

  On the other hand, nanobubbles are bubbles that are smaller than microbubbles (100 to 200 nm with a diameter of 1 micron or less) and can exist in water forever.

  Micro-nano bubbles are bubbles in which micro-bubbles and nano-bubbles are mixed.

  The first nanobubble generator 61 discharges nanobubbles into the first decomposition unit water tank 63 to form the nanobubble flow 13. Then, the formed nanobubble flow 13 and the water flow 15 which is the discharge water from the raw water pump 3 merge to form a large water flow, and the water to be treated in the first decomposition unit water tank 63 is agitated by this water flow. To do.

Then, the water to be treated in the first decomposition unit water tank 63 is agitated, whereby the organic fluorine compound (PFOS, PFOA, etc.) in the water to be treated is decomposed by the oxidizing action of the nanobubble radicals, and the low molecular organic It becomes a fluorine compound (CF ₃ (CF ₂ ) 3H and many others). In addition, low molecular weight organic fluorine compounds (CF ₃ (CF ₂ ) 3 H and many others) are gasified and rise to near the water surface of the first decomposition unit water tank 63.

  The inventor has discovered the following phenomenon.

That is, if the state of the gas phase near the water surface of the first decomposition unit water tank 63 is a saturated vapor (a state where both gas-liquid phases coexist or a state where saturated vapor exists), the organic fluorine compound in the treated water (PFOS, PFOA, etc.) are hardly decomposed and changed to low molecular weight organic fluorine compounds (many such as CF ₃ (CF ₂ ) 3H) even if nanobubbles are present. That is, the decomposition product gas 38 is hardly generated.

Conversely, if the state of the gas phase near the water surface of the first decomposition unit water tank 63 is not a saturated vapor (a state in which both gas-liquid phases coexist), the decomposition gas 38 is often generated, organic fluorine compound in the for-treatment water (PFOS, PFOA, etc.), with the nanobubbles exists, changes are oxidatively decomposed in the organic fluorine compound of low molecular _{(CF 3} (CF ₂₎ 3H like many).

  In the first embodiment, as shown in FIG. 1, fresh air is constantly introduced from the suction port 16 into the lower part of the first adsorption box 64 by the fan 17. It is possible to avoid the state of a nearby gas phase from becoming a saturated vapor (a state in which both gas-liquid phases coexist).

Therefore, the organic fluorine compounds (PFOS, PFOA, etc.) in the water to be treated can be effectively decomposed, and a large number of low molecular organic fluorine compounds, such as CF ₃ (CF ₂ ) 3H, produced as a result of the decomposition can be continuously added. It can be gasified into a decomposed gas 38 and can be adsorbed by the lower activated carbon 32, the intermediate activated carbon 33 and the upper activated carbon 34 filled in the first adsorption box 64.

The organic fluorine compound (PFOS, PFOA, etc.) in the water to be treated is discharged from the blower 71 as the front lower aeration unit and the rear lower aeration unit through the air pipe 70 and is discharged from the air diffuser 85. Even in the aerated state after forming 86, it is oxidatively decomposed and changed into a low molecular weight organic fluorine compound (a large number of CF ₃ (CF ₂ ) 3H, etc.) as in the operation of the fan 17. The ventilation removal by the air discharged from the blower 71 exhibits the same effect as the ventilation removal by the fan 17. And by the ventilation removal by both, decomposition | disassembly of organic fluorine compounds, such as PFOS and PFOA, is accelerated | stimulated significantly.

  The lower activated carbon 32, the intermediate activated carbon 33, and the upper activated carbon 34 are accommodated in a lower activated carbon accommodating container 29, an intermediate activated carbon accommodating container 30, and an upper activated carbon accommodating container 31, respectively. As the lower activated carbon 32, the intermediate activated carbon 33, and the upper activated carbon 34, for example, Kuraray Chemical Co., Ltd. granular activated carbon trade name Kuraray Coal (for gas phase) can be used. The lower activated carbon 32, the intermediate activated carbon 33, the upper activated carbon 34, the lower activated carbon storage container 29, the intermediate activated carbon storage container 30, and the upper activated carbon storage container 31 constitute an adsorption processing section.

  As an alternative to the activated carbon in the lower activated carbon 32, the intermediate activated carbon 33, and the upper activated carbon 34, various adsorbing substances are conceivable. Depending on the type and concentration of the organic fluorine compound, zeolite may be suitable.

  The lower activated carbon storage container 29, the intermediate activated carbon storage container 30, and the upper activated carbon storage container 31 respectively have a lower fixed hole base 26, an intermediate fixed hole base 27, and an upper fixed hole. It is installed on the base 28. The activated carbon containing containers 29, 30, and 31 and the fixed hole bases 26, 27, and 28 have a large number of small holes so that the generated gas efficiently contacts the activated carbon.

  Activated carbon in a breakthrough state, that is, at the end of its life, is taken out from the lower outlet 22, the intermediate outlet 23, and the upper outlet 24, which are the respective outlets, in the storage container, and replaced with new activated carbon. It has become.

  Since the lower outlet 22, the intermediate outlet 23, and the upper outlet 24 are all in a flanged state, the activated carbon container can be easily taken out by loosening the bolt and removing the lid. The used activated carbon is brought into a cement factory and is effectively used as fuel sludge.

  In addition, the lower part of the pre-stage decomposition part adsorption part 83 is comprised from the large 1st decomposition part water tank 63 and the small scale water tank 37 correctly. The water tank 37 simply serves as a water storage tank in which the suction pipe 44 of the second nanobubble generator 73 is installed.

  The water to be treated that has exited the water tank 37 is introduced into a second decomposition section water tank 75 that is a lower part of the post-stage decomposition adsorption section 84. The rear stage decomposition adsorption unit 84 includes a second adsorption box 58 having an upper second exhaust chimney 59 and a second decomposition unit water tank 75 which is a lower part. A blower 71 is installed outside the second decomposition unit water tank 75, and the air from the blower 71 is discharged into the second decomposition unit water tank 75 by discharging it through the air pipe 70 and the air diffusion pipe 69. The activated carbon 67 is made to flow. As the activated carbon 67, for example, Kuraray Chemical Co., Ltd. granular activated carbon trade name Kuraray Coal (for liquid phase) can be adopted.

  Since the activated carbon 67 has a specific gravity greater than 1, the aerated air at a level at which the activated carbon 67 does not settle is indispensable because the activated carbon 67 sinks to the second decomposition unit water tank bottom 68 when weak aeration occurs.

The aerated air at a level at which the activated carbon 67 does not settle has an air amount of 50 m ³ / hour / m ³ or more per tank capacity. The amount of air flows while the activated carbon 67 does not settle, and at the same time, the decomposition gas (PFC gas = perfluorocarbon gas) of the trace amount of organic fluorine compound in the water is surely moved to the water surface, and a large amount Can be ventilated with air.

  An activated carbon suction pipe 43 is installed on the upper part of the air diffusion pipe 69. When the sprinkling pump 41 is operated, the activated carbon 67 in a state of flowing with the aeration air of the diffusion pipe 69 is sucked from the activated carbon suction pipe 43, passes through the water pipe 55, and is a mixture of the water to be treated and the activated carbon 67. However, water is sprayed from the watering nozzle 56 as a watering part. The sprinkling nozzle 56 and the mixture of the water to be treated sprinkled from the sprinkling nozzle 56 and the activated carbon 67 constitute an adsorption processing unit.

When the activated carbon 67 is sprinkled from the upper water spray nozzle 56 of the second adsorption box 58, a small amount of organic fluorine compound (CF ₃ (CF ₂ ) 3H or the like) that is a decomposition product of a small amount of PFOS or PFOA as a small amount of organic fluorine compound. Many) are adsorbed.

  The reason why the second decomposition unit water tank 75 has the inclined wall 66 is that the activated carbon 67 is naturally settled and collected near the diffuser tube 69 from which aerated air is discharged. By doing in this way, activated carbon 67 can be efficiently flowed with aeration air. The configuration of the second nanobubble generator 73 is exactly the same as that of the first nanobubble generator 61, and the mechanism of nanobubble generation is also the same.

  That is, a set of the gas-liquid mixing circulation pump 45, the first gas shearing portion 46, the second gas shearing portion 48, and the third gas shearing portion 52 that basically constitute the second nanobubble generator 73 is commercially available. However, in the present embodiment, specifically, a product of Kyowa Kikai Co., Ltd. (specific product name: Bavidas HYK type) is used as the first nanobubble generator. The same as 61 is adopted.

  In the apparatus of this embodiment, the treated water becomes treated water 74 and is discharged out of the system. On the other hand, the exhaust as a gas also becomes the second processing gas 60 and is discharged out of the system. In addition, as the activated carbon 67 which flows in the 2nd decomposition | disassembly part water tank 75, the spherical activated carbon brand name Kuraray Coal of Kuraray Chemical Co., Ltd. is employable, for example.

  According to the water treatment apparatus of the first embodiment, since the organic fluorine compound is decomposed using the oxidizing power of the nanobubbles, the decomposition product having a reduced number of carbon atoms can be gasified.

  Moreover, according to the water treatment apparatus of the first embodiment, the gas as the decomposition product is constantly removed from the liquid phase and the liquid phase (water surface) surface, so the organic fluorine compound is converted into the nanobubble of the organic fluorine compound. It can be decomposed efficiently using the oxidizing power.

  Further, according to the water treatment apparatus of the first embodiment, activated carbon that adsorbs decomposition products is adsorbed with activated carbon in a fixed state in the first stage where the concentration of decomposition products is high, while the concentration of decomposition products is low. In the second stage, since the adsorption treatment is performed with the activated carbon in the water sprinkled state, the effect of removing the organic fluorine compound can be remarkably improved. In particular, the present inventor can significantly improve the catalytic action of the activated carbon by bringing the activated carbon into a fluid state in the second stage, and remove the substance even if the concentration of the substance to be removed is low. It was discovered that the substances to be removed can be efficiently adsorbed and removed.

  Moreover, according to the water treatment apparatus of the said 1st Embodiment, it has the 1st decomposition part water tank 63 and the 2nd decomposition part water tank 75 which introduce | transduces the liquid from the 1st decomposition part water tank 63, and both water tanks Since the nanobubble generator is installed and the activated carbon is allowed to flow in the second decomposition unit water tank 75, the treatment effect of the organic fluorine compound can be remarkably improved.

  Moreover, according to the water treatment apparatus of the first embodiment, the second stage decomposition adsorption part 84 for treating the primary treated organic fluorine compound-containing water is divided into the second adsorption box 58 that is the upper part and the second adsorption box 58 that is the lower part. The decomposition part water tank 75 is configured, and the lower part is configured to flow activated carbon as a decomposition part using nanobubbles, and the upper part is sprinkled with activated carbon so that a gas as a decomposition product is adsorbed to the activated carbon. Therefore, the processing efficiency of the organic fluorine compound can be remarkably improved.

  Moreover, according to the water treatment apparatus of the first embodiment, PFOA and PFOS in water containing organic fluorine compounds such as PFOS and PFOA are decomposed by utilizing the oxidizing power of nanobubbles, so that a strong bond between carbon and fluorine is obtained. And most of the carbon number of the decomposition product can be 4, 5, 6 or 7. Moreover, the gas as a decomposition product can be rendered harmless by adsorption treatment with two-stage activated carbon. This has been confirmed by a study in which the gas components of the decomposition products are collected on activated carbon and subjected to advanced analysis (GC-MS = gas chromatograph mass spectrometry).

(Second Embodiment)
FIG. 2 is a schematic diagram of a water treatment apparatus according to a second embodiment of the present invention.

  The water treatment device of the second embodiment is the water treatment device of the first embodiment in which the gas sucked into the first nanobubble generator 161 is ozone, and the gas sucked into the first nanobubble generator 61 is air. And different.

  In the water treatment device of the second embodiment, the same reference numerals are assigned to the same components as those of the water treatment device of the first embodiment, and the description thereof will be omitted. Moreover, in the water treatment apparatus of 2nd Embodiment, it abbreviate | omits description about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

  In the second embodiment, the gas automatically sucked into the first nanobubble generator 161 is ozone gas, while the gas automatically sucked into the second nanobubble generator 73 is air.

  Ozone gas has more oxidizing power than air. Here, in the second embodiment, ozone nanobubbles can be discharged from the first nanobubble generator 261, so that the organic fluorine compound, which is a control substance in the water to be treated, can be more efficiently oxidized and decomposed.

  The water treatment apparatus according to the second embodiment is excellent for purifying organic fluorine compound-containing water having a high concentration. When purifying the organic fluorine compound-containing water having a high concentration, the water treatment apparatus of the second embodiment uses ozone gas as a gas in the first nanobubble generator 61, and the high concentration organic fluorine compound-containing water with a strong oxidizing power, Decomposes oxidatively. The remaining trace amount of organic fluorine compound-containing water is oxidatively decomposed with air nanobubbles by introducing air into the second nanobubble generator 73.

  Compared with ozone, ozone nanobubbles have a short duration in which ozone stays in water, while maintaining an oxidizing power as long as one month or longer. In addition, ozone has oxidizing power and oxidizing power by radicals that generate nanobubbles. Therefore, ozone nanobubbles having both properties have a synergistic effect, and the oxidizing power is remarkably improved. An object such as a high concentration organic fluorine compound can be oxidatively decomposed.

(Third embodiment)
FIG. 3 is a schematic diagram of a water treatment apparatus according to a third embodiment of the present invention.

  The water treatment device of the third embodiment is such that the gas sucked into the first nanobubble generator 261 is oxygen, and the gas sucked into the first nanobubble generator 61 is air. And different.

  In the water treatment device of the third embodiment, the same reference numerals are assigned to the same components as the components of the water treatment device of the first embodiment, and description thereof is omitted. Moreover, in the water treatment apparatus of 3rd Embodiment, it abbreviate | omits description about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

  In the third embodiment, the gas automatically sucked into the first nanobubble generator 261 is oxygen, whereas the gas automatically sucked into the second nanobubble generator 73 is air.

  Oxygen is more oxidizing than air. Here, in the second embodiment, since the oxygen nanobubbles can be discharged from the first nanobubble generator 361, the organic fluorine compound that is the control substance in the water to be treated can be more efficiently oxidized and decomposed.

  In addition, unlike ozone, oxygen is less harmful to living organisms, but because it has a function to activate living organisms, treated water after removal of organic fluorine compounds is used for breeding microorganism cultures and seafood. In this case, it is preferable to use oxygen nanobubbles rather than air nanobubbles or ozone nanobubbles. However, oxygen gas has a drawback that the running cost is higher than air.

(Fourth embodiment)
FIG. 4 is a schematic view of a water treatment device according to a fourth embodiment of the present invention.

  In the water treatment apparatus of the fourth embodiment, the first nanobubble generation is that the gas sucked into the first nanobubble generator 361 is ozone and the gas sucked into the second nanobubble generator 373 is ozone. The gas sucked by the machine 61 is air, and the gas sucked by the second nanobubble generator 73 is different from the water treatment apparatus of the first embodiment, which is air.

  In the water treatment device of the fourth embodiment, the same reference numerals are assigned to the same components as those of the water treatment device of the first embodiment, and the description thereof will be omitted. Moreover, in the water treatment apparatus of 4th Embodiment, it abbreviate | omits description about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

  In the fourth embodiment, the gas automatically sucked into the first nanobubble generator 361 is ozone, and the gas automatically sucked into the second nanobubble generator 373 is ozone.

  According to the water treatment apparatus of the fourth embodiment, ozone nanobubbles having a strong oxidizing action can be generated in two stages. Therefore, the decomposition efficiency of the organic fluorine compound can be remarkably improved by the ozone nanobubbles generated in these two stages.

(Fifth embodiment)
FIG. 5 is a schematic diagram of a water treatment device according to a fifth embodiment of the present invention.

  In the water treatment apparatus of the fifth embodiment, the first nanobubble generation is that the gas sucked into the first nanobubble generator 461 is ozone, and the gas sucked into the second nanobubble generator 473 is oxygen. The gas sucked by the machine 61 is air, and the gas sucked by the second nanobubble generator 73 is different from the water treatment apparatus of the first embodiment, which is air.

  In the water treatment device of the fifth embodiment, the same reference numerals are assigned to the same components as those of the water treatment device of the first embodiment, and the description thereof will be omitted. Moreover, in the water treatment apparatus of 5th Embodiment, it abbreviate | omits description about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

  According to the water treatment device of the fifth embodiment, since ozone gas has an oxidizing power rather than air, the first stage ozone discharged from the first nanobubble generator 461 compared to the first embodiment. Nanobubbles can strongly oxidatively decompose a control substance such as an organic fluorine compound in the water to be treated.

  Whereas ozone lasts for a short time in water, ozone nanobubbles can maintain an oxidizing power as long as one month or longer. In addition, because ozone has oxidizing power and oxidizing power due to radicals that generate nanobubbles, ozone nanobubbles synergistically enhance oxidizing power, and target substances such as high-concentration organic fluorine compound-containing water in treated water Can be efficiently oxidized and decomposed.

  On the other hand, the second nanobubble generator 73 generates oxygen nanobubbles. In the second stage, oxygen nanobubbles that are more oxidizing than air are produced to oxidatively decompose trace amounts of organic fluorine compounds.

(Sixth embodiment)
FIG. 6 is a schematic view of a water treatment device according to a sixth embodiment of the present invention.

  In the water treatment device of the sixth embodiment, the same reference numerals are assigned to the same components as those of the water treatment device of the first embodiment, and the description thereof will be omitted. Moreover, in the water treatment apparatus of 6th Embodiment, description is abbreviate | omitted about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

  In the water treatment apparatus of the sixth embodiment, a TOC meter 576 (total organic carbon meter) is installed on the upper portion of the second decomposition unit water tank 75 in the latter decomposition adsorption unit 584. In addition, a TOC controller 78 and a sequencer 79 are installed outside the lower part of the rear decomposition adsorption unit 584.

  According to the water treatment device of the sixth embodiment, since it has the TOC meter 576, the TOC controller 78, and the sequencer 79, it is reasonable to use these devices based on the water quality of the rear-stage decomposition adsorption unit 584. You can drive.

  In the sixth embodiment, the TOC meter 576 inspects the TOC concentration of the post-stage decomposition adsorption unit 584, and if the TOC concentration increases by a predetermined concentration or more, the TOC meter (total organic carbon meter) 576 to the TOC controller 78. In addition, the program of the sequencer 79 increases the number of rotations of the motors of the blower 71 and the watering pump 41, thereby increasing the amount of air discharged from the air diffusion pipe 69 and “active carbon and water from the watering nozzle 56. The mixture 72 '' of the second is increased, and the TOC concentration of the second decomposition unit water tank 75 can be lowered.

(Seventh embodiment)
In the water treatment device of the seventh embodiment, the same reference numerals are assigned to the same components as those of the water treatment device of the first embodiment, and the description thereof will be omitted. Moreover, in the water treatment apparatus of 7th Embodiment, it abbreviate | omits description about the effect and modification which are common in the water treatment apparatus of 1st Embodiment, The structure and effect | action different from the water treatment apparatus of 1st Embodiment are omitted. Only the effects and modifications will be described.

In the seventh embodiment,
In the water treatment apparatus of the seventh embodiment, a COD meter 80 (chemical oxygen demand meter) is installed above the second decomposition unit water tank 75 in the post-stage decomposition adsorption unit 684. Further, a COD controller 81 and a sequencer 79 are installed outside the lower part of the rear decomposition adsorption unit 684.

  According to the water treatment device of the seventh embodiment, since it has the COD meter 80, the COD controller 81, and the sequencer 79, it is reasonable to use these devices based on the water quality of the downstream decomposition adsorption unit 684. You can drive.

  In the sixth embodiment, the COD meter 80 inspects the COD concentration of the post-stage decomposition adsorption unit 684, and if the COD concentration increases by a predetermined concentration or more, the COD meter (total organic carbon meter) 80 changes to the COD controller 81. In addition, the program of the sequencer 79 increases the number of rotations of the motors of the blower 71 and the watering pump 41, thereby increasing the amount of air discharged from the air diffusion pipe 69 and “active carbon and water from the watering nozzle 56. This increases the mixture 72 ′ of the second decomposition unit water tank 75 so that the COD concentration in the second decomposition unit water tank 75 can be lowered.

(Test results)
Hereinafter, the performance of the water treatment apparatus of the present invention will be shown as an example by test results using the water treatment apparatus of the first embodiment.

(Experimental result)
This inventor manufactured the water treatment apparatus of 1st Embodiment. Here, the capacity of the raw water tank 2 is 0.3 m ³ , the capacity of the first decomposition part water tank 63 is about 1.0 m ³ , the capacity of the second decomposition part water tank 75 is about 1.5 m ³ , and the decomposed gas. The capacity of the suction part 21 was about 1.5 m ³ , and the capacity of the second suction box 58 was about 1.0 m ³ .

  The first decomposition unit water tank 63 is provided with Kuraray Chemical Co., Ltd., granular activated carbon trade name Kuraray Coal GA (for gas phase), and the second decomposition part water tank 75 is provided with granular material of Kuraray Chemical Co., Ltd. Activated carbon trade name Kuraray Coal KW (for liquid phase) was placed.

  In addition, as the first nanobubble generator 61 and the second nanobubble generator 73, the HYK type of Kyowa Kikai Co., Ltd., in which the motors of the gas-liquid mixing circulation pump 5 and the gas-liquid mixing circulation pump 45 are each composed of 3.7 kW. Each was used.

  Moreover, sirocco fan CLF5-RS type 0.75KW made by Teral Co., Ltd. was selected as the fan 17 for constantly supplying fresh air to the decomposed gas adsorbing portion 21.

  Further, as a blower 71 for discharging air to the first decomposition part water tank 63 and the second decomposition part water tank 75, a root blower ARH32 type 0.75 KW made by Shin Meiwa Kogyo Co., Ltd. was used.

  Then, the organic fluorine compound-containing water is introduced into the raw water tank 2 of the water treatment device, and is installed outside the first nanobubble generator 61 and the decomposed gas adsorbing part 21 installed in the first decomposition part water tank 63. A certain fan 17 was operated, and then the second nanobubble generator 73 installed in the second decomposition unit water tank 75 and the blower 71 installed outside the second decomposition unit water tank 75 were operated.

  The operation was started, and the concentration of the treated water 74 at the outlet of the raw water tank 2 and the second decomposition section water tank 75 after 12 days was compared.

  In addition, it has been confirmed that the same effect as this test can be obtained even when the test is performed with other materials and conditions such as activated carbon, nanobubble generator, volume of each tank, pump, blower and the like.

[Table 1] (Liquid phase analysis results)

[Table 2] (Processing gas analysis results)

(Consideration of analysis results)
According to the water treatment apparatus of the present invention, as shown in Table 1, the concentration of the treated water 74 can be drastically reduced in the liquid phase PFOS as compared with the concentration of the raw water tank 2. Quantitatively, a removal rate of 90% can be achieved.

  Further, the concentration of the liquid phase total fluorine amount in the treated water 74 can be remarkably lowered, the fluorine compound can be decomposed efficiently, and the decomposition product can be released into the gas phase.

  Moreover, according to the water treatment apparatus of the present invention, as shown in Table 1, since sulfate ions were confirmed, PFOS in the liquid phase can be efficiently decomposed.

  Further, according to the water treatment apparatus of the present invention, as shown in Table 2, since the PFOS concentration in the gas phase is very low, PFOS is not scattered as mist but is decomposed. Therefore, according to the water treatment apparatus of the present invention, PFOS can be efficiently decomposed.

  Moreover, according to the water treatment apparatus of the present invention, as shown in Table 2, no decomposition products such as perfluorocarbon are detected as decomposition products. Therefore, these harmful substances can be adsorbed on the activated carbon of the adsorbent (the decomposed gas adsorbing portion 21 and the activated carbon of the second adsorption box 58) and reliably processed.

  In addition, the present inventor has conducted a number of various tests in addition to the above test, and has confirmed that all the inventions described in the claims have the excellent effects described above. .

  Below, some of these tests will be disclosed and the items that can be confirmed from those tests will be described.

[Table 3] (Results of liquid phase analysis)

  Table 3 is an apparatus according to an embodiment, and shows the analysis result of the first decomposition unit water tank 63 as a liquid phase when the gas phase air is replaced with a fan or when the liquid phase is aerated. It is.

  As shown in Table 3, at the concentration after 6 days, the PFOS concentration rapidly decreased to 1/10 or less. In addition, the total amount of fluorine such as PFOS is decreased, and sulfate ions generated by decomposition of PFOS are increased.

  For this reason, when the gas phase air is replaced with a fan or the liquid phase is aerated, the decomposition of PFOS can be promoted remarkably.

[Table 4]

  Table 4 is a test result showing an analysis result of the first exhaust chimney 35 of the decomposed gas adsorbing part 21 as a gas phase (when the decomposed gas adsorbing part 21 is not filled with activated carbon).

As shown in Table 4, the liquid phase PFOS is not scattered in the gas phase as mist. Further, the liquid phase PFOS is decomposed and changed to CF ₃ (CF ₂ ) 3 H, CF ₃ (CF ₂ ) 4 H, or the like.

Therefore, if the decomposed CF ₃ (CF ₂ ) 3H, CF ₃ (CF ₂ ) 4H, etc. can be removed, PFOS can be efficiently removed. In the present invention, these decomposed substances can be adsorbed and removed by activated carbon, so that PFOS can be efficiently removed.

[Table 5]

  Table 5 is a table showing analysis results of the exhaust chimney 35 of the decomposition product gas adsorption unit 21 as a gas phase (when the decomposition product gas adsorption unit 21 is filled with activated carbon).

As shown in Table 5, the liquid phase PFOS is not scattered in the gas phase as mist. Moreover, from the results in Table 4, the liquid phase PFOS is decomposed and changed to CF ₃ (CF ₂ ) 3H, CF ₃ (CF ₂ ) 4H, etc. This indicates that the activated carbon can be almost completely adsorbed and removed. Therefore, the organic fluorine compound-containing water can be oxidatively decomposed with nanobubbles, and the gasified decomposition product can be adsorbed with activated carbon, and PFOS, PFOA, and the like as the hardly decomposable organic fluorine-based compounds can be reliably rendered harmless.

[Table 6]

  Table 6 shows that the first decomposition unit as the liquid phase when the gas-phase air is not replaced with a fan, that is, when the air is to be replaced, the fan is not installed, or the liquid phase is not aerated. It is a table | surface which shows the analysis result of the water tank 63. FIG.

  This test was performed by preventing the replacement of the gas phase air in the first decomposition part water tank 63 by closing the upper opening of the first decomposition part water tank 63 with a glass plate.

  As shown in Table 6, the PFOS concentration is not decreased in this test. Further, the total fluorine amount such as PFOS has not decreased. Further, free sulfate ions generated by the decomposition of PFOS have not increased.

  Therefore, it can be seen from this result that PFOS cannot be decomposed unless gas phase air is replaced, and that the decomposition of PFOS does not proceed unless the vapor of the saturated PFOS decomposition product is removed.

  According to the present invention, in the second decomposition unit water tank 75, since aeration is performed by a blower that discharges a large amount of air, it is possible to prevent the saturation state due to the decomposition product of PFOS, and to decompose PFOS. It is possible to proceed without ventilation by a new fan.

  Therefore, as is clear from the above description, according to the present invention, the organic fluorine compound-containing water is oxidized and decomposed with nanobubbles, and the gasified decomposition product is adsorbed with, for example, activated carbon. PFOS, PFOA, etc. as organic fluorine compounds can be reliably rendered harmless.

It is a schematic diagram of the water treatment apparatus of 1st Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 2nd Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 3rd Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 4th Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 5th Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 6th Embodiment of this invention. It is a schematic diagram of the water treatment apparatus of 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inflow piping 2 Raw water tank 3 Raw water pump 4 Suction piping 5 Gas-liquid mixing circulation pump 6 1st gas shearing part 7 Water piping 8 2nd gas shearing part 9 Water piping 10 Air piping 11 Electric needle valve 12 3rd gas shearing part 13 Nano bubble flow 14 Water piping 15 Water flow 16 Suction port 17 Fan 18 Discharge duct 19 Duct flange 20 Disassembly part
21 Decomposed gas adsorbing part 22 Lower outlet 23 Intermediate outlet 24 Upper outlet 25 Water surface 26 Lower fixed hole base 27 Intermediate fixed hole base 28 Upper fixed hole base 29 Lower activated carbon storage container 30 Intermediate activated carbon storage Container 31 Upper activated carbon storage container 32 Lower activated carbon 33 Middle activated carbon 34 Upper activated carbon 35 First exhaust chimney 36 Outlet water piping 37 Water tank 38 Decomposed gas 39 Flow of fresh air 40 Inclined wall 41 Sprinkling pump 42 Water piping 43 Activated carbon suction piping 44 Suction piping 45 Second gas-liquid mixing circulation pump 46 First gas shearing portion 47 Water piping 48 Second gas shearing portion 49 Water piping 50 Air piping 51 Electric needle valve 52 Third gas shearing portion 53 Nano bubble flow 54 Water flow 55 Water piping 56 Sprinkling nozzle 57 Claw flange 58 Second adsorption box 59 Second exhaust Projection 60 Second processing gas 61,161,261,461 First nanobubble generator 62 Water flow 63 First decomposition section water tank 64 First adsorption box 65 First processing gas 66 Inclined wall 67 Activated carbon 68 Second decomposition section water tank bottom 69 Scattering Trachea 70 Air piping 71 Blower 72 Mixture of activated carbon and water 73,373,473 Second nanobubble generator 74 Treated water 75 Second decomposition water tank 77 Signal line 78 TOC (total organic carbon) controller 79 Sequencer 80 COD (chemical (Oxygen demand) meter 81 COD (chemical oxygen demand) controller 82 Decomposition gas 83 First-stage cracking adsorption part 84,584,684 Second-stage cracking adsorption part 85 Aeration pipe 86 Bubble 576 TOC meter (total organic carbon meter)

Claims (29)

A first nanobubble generator;
A second nanobubble generator;
Carbon and fluorine decomposition products generated by decomposing the organic fluorine compound in the organic fluorine compound-containing water containing the organic fluorine compound by nanobubbles discharged from the first nanobubble generator and using the nanobubbles A pre-disassembly part to be removed;
The first treated water treated in the preceding decomposition unit is introduced, the nano bubbles from the second nano bubble generator are discharged, and the organic fluorine compound in the first treated water is decomposed by the nano bubbles. A water treatment apparatus comprising: a post-stage decomposition unit that removes a carbon and fluorine decomposition product generated by the above. The water treatment apparatus according to claim 1,
Each of said 1st nano bubble generator and said 2nd nano bubble generator has three gas-liquid mixed-gas shearing parts connected in series, The water treatment apparatus characterized by the above-mentioned. The water treatment device according to claim 1 or 2,
Each of the front stage decomposition part and the rear stage decomposition part consists of an upper part and a lower part located vertically below the upper part,
Nanobubbles from the first nanobubble generator are discharged to the lower part of the front stage decomposition unit, and nanobubbles from the second nanobubble generator are discharged to the lower part of the rear stage decomposition unit,
The upper part of the preceding stage decomposition part has an adsorption processing part for adsorbing the gas of the decomposition product generated by the decomposition of the organic fluorine compound at the lower part of the previous stage decomposition part,
The water treatment apparatus according to claim 1, wherein an upper portion of the rear decomposition unit includes an adsorption treatment unit that adsorbs a gas of the decomposition product generated when the organic fluorine compound is decomposed in the lower part of the rear decomposition unit. The water treatment apparatus according to claim 3,
A pre-stage upper air supply unit for supplying air to the upper part of the pre-stage decomposition unit;
A pre-stage lower aeration section for aeration of liquid present in the lower portion of the pre-stage decomposition section;
A water treatment apparatus comprising: a rear lower aeration unit for aerating liquid existing in the lower portion of the rear decomposition unit. The water treatment apparatus according to claim 3 or 4,
The adsorption treatment unit of the pre-stage decomposition unit has an activated carbon storage unit and activated carbon stored in the activated carbon storage unit,
The water treatment apparatus, wherein the adsorption treatment unit of the latter decomposition unit has a watering unit for spraying water containing activated carbon. In the water treatment device according to any one of claims 1 to 5,
Each of the first nanobubble generator and the second nanobubble generator is
A gas-liquid mixing circulation pump;
A first gas shearing section having an electric needle valve for controlling the passage of gas;
A second gas shearing part;
A water treatment device comprising a third gas shearing portion. The water treatment device according to claim 6,
The water treatment apparatus characterized in that the amount of air passing through the electric needle valve of each of the first nanobubble generator and the second nanobubble generator is 1.2 liters / minute or less. The water treatment apparatus according to claim 6 or 7,
The first gas shearing portion of each of the first nanobubble generator and the second nanobubble generator has an elliptical shape or a perfect circular shape, and an inner surface of each first gas shearing portion has two or more grooves. The water treatment apparatus characterized by the above-mentioned. The water treatment apparatus according to claim 8,
The depth of the said groove | channel is 0.3 mm-0.6 mm, and the groove width of the said groove | channel is less than 0.8 mm, The water treatment apparatus characterized by the above-mentioned. The water treatment device according to any one of claims 6 to 9,
In the gas-liquid mixing circulation pump of each of the first nanobubble generator and the second nanobubble generator, the cross-section of the discharge pipe of the gas-liquid mixing circulation pump is more than the cross-section of the suction pipe of the gas-liquid mixing circulation pump. A water treatment apparatus characterized by being small. In the water treatment apparatus of any one of Claim 6 to 10,
Each of the gas-liquid mixing and circulation pumps of the first nanobubble generator and the second nanobubble generator performs gas intake after the output of the gas-liquid mixing and circulation pump reaches a maximum value. Water treatment equipment. The water treatment device according to any one of claims 6 to 11,
Each of the gas-liquid mixing and circulation pumps of the first nanobubble generator and the second nanobubble generator takes in gas after 60 seconds from the operation of the gas-liquid mixing and circulation pump. Water treatment equipment. The water treatment device according to any one of claims 6 to 12,
In the first gas shearing part of each of the first nanobubble generator and the second nanobubble generator, an incident angle of the gas inflow pipe with respect to the side surface of the microbubble generating part is approximately 18 °. apparatus. The water treatment apparatus according to any one of claims 6 to 13,
A water treatment apparatus, wherein the thickness of the first gas shearing portion of each of the first nanobubble generator and the second nanobubble generator is 6 mm or more and 12 mm or less. The water treatment apparatus according to any one of claims 3 to 14,
The upper part of the latter stage decomposition part has an activated carbon filling part filled with water containing activated carbon, while the lower part of the latter stage decomposition part has a latter lower part aeration part for performing aeration. The water treatment device according to claim 15, wherein
The said lower part of the said latter stage decomposition | disassembly part has the slope which has an inclination of 30 degrees or more with respect to a horizontal surface in the state which the bottom face of the lower part has spread in the substantially horizontal direction. The water treatment device according to claim 15 or 16,
The lower rear aeration part is
With the blower,
The activated carbon suction part is connected to the blower and communicates with the lower part of the rear decomposition part, and the activated carbon filling part is positioned above the air diffusion diffuser in the vertical direction. Has a tube,
The upper part of the latter stage decomposition part has a watering part for watering the water containing activated carbon,
The water treatment apparatus according to claim 1, wherein the liquid sucked by the activated carbon suction pipe is sent to the watering section by an activated carbon watering pump. The water treatment apparatus according to claim 17,
Install the total organic carbon meter at the lower part of the latter decomposition part,
A water treatment apparatus characterized by controlling the rotational speed of the blower motor and the activated carbon watering pump motor based on the lower organic carbon concentration in the lower part of the rear decomposition unit measured by the total organic carbon meter. The water treatment device according to claim 17,
A chemical oxygen demand meter is installed at the lower part of the latter stage decomposition section,
A water treatment apparatus that controls the rotational speed of the blower motor and the activated carbon water spray pump motor based on the chemical oxygen demand measured by the chemical oxygen demand meter. The water treatment device according to claim 6,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone gas, while the gas introduced from the electric needle valve of the second nanobubble generator is air. Processing equipment. The water treatment device according to claim 6,
The gas introduced from the electric needle valve of the first nanobubble generator is oxygen, while the gas introduced from the electric needle valve of the second nanobubble generator is air. Processing equipment. The water treatment device according to claim 6,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone, and the gas introduced from the electric needle valve of the second nanobubble generator is ozone. Water treatment equipment. The water treatment device according to claim 6,
The gas introduced from the electric needle valve of the first nanobubble generator is ozone, while the gas introduced from the electric needle valve of the second nanobubble generator is oxygen. Processing equipment. The water treatment apparatus according to claim 5,
The water treatment apparatus according to claim 1, wherein the activated carbon accommodated in the activated carbon accommodating part of the preceding decomposition unit is zeolite, and the activated carbon present in the water sprayed from the watering nozzle of the latter decomposition part is zeolite. Nanobubbles are discharged and mixed into organic fluorine compound-containing water containing an organic fluorine compound, and the bond between carbon and fluorine is decomposed in the organic fluorine compound by the oxidizing power of radicals possessed by the nanobubble. Produce a decomposition product of carbon and fluorine with a molecular weight smaller than the molecular weight of the fluorine compound,
A method for water treatment of water containing an organic fluorine compound, wherein the decomposition product of carbon and fluorine is gasified and removed. In the water treatment method of the organic fluorine compound containing water of Claim 25,
The water treatment method for organic fluorine compound-containing water, wherein the organic fluorine compound-containing water contains at least one of perfluorooctanesulfonic acid and perfluorooctanoic acid. In the water treatment method of the organic fluorine compound containing water of Claim 25 or 26,
The decomposition product generated by decomposing the organic fluorine compound in the water containing the organic fluorine compound with nanobubbles is adsorbed with fixed activated carbon,
Thereafter, the organic fluorine compound is decomposed by the nanobubbles, and the decomposition product is decomposed by the nanobubbles in the first treated water after the decomposition product is adsorbed by the fixed activated carbon. Is adsorbed with activated carbon that has been flowed into the first treated water. In the water treatment method of the organic fluorine compound containing water of any one of Claim 25 to 27,
A water treatment method for organic fluorine compound-containing water, wherein activated carbon is added to the organic fluorine compound-containing water, and the activated carbon is brought into a fluidized state by aeration and stirring. In the water treatment method of the organic fluorine compound containing water of any one of Claim 25-28,
The organic fluorine compound in the organic fluorine compound-containing water is decomposed into the above decomposed product with nanobubbles, and the decomposed product is gasified with a fan to perform the first treatment,
The organic fluorine compound in the organic fluorine compound-containing water after the first treatment is decomposed into the decomposition product with nanobubbles, and the decomposition product is removed using air discharged from a blower. A method for water treatment of water containing an organic fluorine compound.

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