JP2013111553A - Water treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treatment system capable of decreasing the regenerating energy quantity of an adsorption element and improving a heat recovery efficiency while keeping the adsorption performance to decrease the regenerating energy of the adsorption element as a problem to be solved.SOLUTION: The water treatment system which purifies water by adsorbing and removing an organic compound from the water containing the organic compound, includes: a water treatment apparatus in which an adsorption process in which a water containing the organic compound is passed through the adsorption element including an active carbon fiber with a fiber diameter of 21-40 μm and a toluene adsorption capacity of 200-750 mg/g to adsorb the organic compound onto the adsorption element, and a desorption process in which a high temperature heated gas is passed through the adsorption element to make desorption of the organic compound adsorbed onto the adsorption element to exhaust the desorbed gas containing the organic compound, are alternatively repeated; and a combustion apparatus for decomposing the organic compound in the desorption gas generated in the desorption process of the water treatment apparatus and exhausting the treated gas.

Description

  The present invention relates to an apparatus for removing and purifying organic compounds from water containing organic compounds, and in particular, an apparatus used for purifying industrial wastewater containing organic compounds such as organic solvents discharged from various factories and research facilities. It is about.

  Conventionally, as an apparatus for purifying water containing an adsorbent such as an organic compound, an exchangeable adsorption apparatus using a replaceable adsorption element made of an adsorbent such as activated carbon has been widely used. In the exchangeable adsorption device, water containing an adsorbent is introduced into a tank filled with an adsorbent, and the adsorbent adsorbs the adsorbent to remove the adsorbate contained in the water. .

However, the exchangeable adsorption device continues to adsorb the adsorbed material for a certain period of time, and if the adsorption capacity of the adsorbent reaches saturation, it is necessary to replace it with a new one, or to remove the adsorbent from the device once and regenerate it continuously. Furthermore, unlike the purification of air, the purification of water is unavoidable for the growth of microorganisms, and the life of the adsorbent may be shortened. .
Further, the conventional purification apparatus has a problem that the adsorption performance changes between the start of use of the adsorbent and before the end of use, and the purification process cannot be stably performed.

  Patent Document 1 describes a water treatment apparatus that can continuously purify water containing an adsorbed substance such as an organic compound and basically does not require replacement of an adsorbent. In this water treatment apparatus, an adsorption process in which water containing an adsorbed substance is caused to flow through an adsorbing element containing activated carbon fibers to adsorb the adsorbing object, and then a high-speed gas is applied to the adsorbing element that adsorbs the adsorbing object. A purge (dehydration) process for removing adhering water adhering to the adsorbing element by ventilating, and a desorption process for regenerating the adsorbing element by desorbing the adsorbed material adsorbed on the adsorbing element by ventilating high-temperature heated gas Is performed continuously.

  Moreover, in the water treatment system of patent document 2, the desorption gas containing the organic compound discharged | emitted at the time of reproduction | regeneration of the water treatment apparatus of patent document 1 is passed through a combustion apparatus, and the organic compound is decomposed | disassembled.

  In the water treatment apparatus of Patent Document 1, as the regeneration energy of the adsorption element, in addition to the desorption of the adsorbed object adsorbed on the adsorption element, the desorption of water adsorbed on the adsorption element and the adhesion remaining on the surface of the adsorption element The energy required to supply the heated gas used for water drying is required. Therefore, if the adhering water can be dehydrated and removed with high efficiency, the regeneration energy of the adsorption element can be reduced.

  Further, in the water treatment apparatus of Patent Document 1, as the regeneration energy of the adsorption element, electric energy used for a blower or a blower that is a heating gas supply means is applied, but the pressure of the adsorbent contained in the adsorption element When the loss is high, a lot of electric energy is used for supplying air. Therefore, if an adsorbent with a low pressure loss can be used as the adsorbing element, the regeneration energy of the adsorbing element can be reduced.

  Further, in the water treatment system of Patent Document 2, when the regeneration efficiency of the water treatment device is improved, the amount of gas used for regeneration is small, so that the combustion device can be downsized or the gas in the gas after regeneration can be reduced. Since the concentration of the organic compound increases and the processing gas temperature of the combustion apparatus rises, it becomes easy to recover heat.

JP 2008-188493 A JP 2008-188492 A

  The present invention has been made with the object of reducing the regeneration energy of the adsorption element, and is capable of reducing the amount of regeneration energy of the adsorption element while maintaining the adsorption performance, thereby improving the heat recovery efficiency. The problem is to provide a system.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, the present invention has the following configuration.

1. A water treatment system for purifying water by adsorbing and removing organic compounds from water containing organic compounds,
An adsorption step in which water containing an organic compound is passed through an adsorption element containing activated carbon fibers having a fiber diameter of 21 to 40 μm and a toluene adsorption capacity of 200 to 750 mg / g to adsorb the organic compound to the adsorption element; A water treatment device that alternately repeats a desorption step of passing a high-temperature heating gas through the element to desorb an organic compound adsorbed on the adsorption element and discharging a desorption gas containing the organic compound;
A combustion apparatus for decomposing an organic compound in the desorption gas generated in the desorption process of the water treatment apparatus and discharging the treatment gas;
Having water treatment system.
2. 2. The water treatment system according to 1, further comprising a dehydration step of removing moisture adhering to the surface of the adsorption element by passing a high-speed gas through the adsorption element before the desorption process of the water treatment apparatus.
3. 3. The water treatment system according to 2 above, wherein moisture adhering to the surface of the adsorbing element is returned before the adsorbing element and is adsorbed by the adsorbing element again.
4). The aeration apparatus for removing aeration gas containing water by contacting a gas with water, and treating the water containing the organic compound after treating the water containing the organic compound. 4. The water treatment system according to any one of 1 to 3 introduced into 1.
5. 5. The water treatment system according to any one of 1 to 4, wherein the aeration gas discharged from the aeration apparatus is mixed with a desorption gas discharged from the water treatment apparatus 1 and introduced into the combustion apparatus.
6). The water treatment system according to any one of the above 1 to 5, wherein the treatment gas discharged from the combustion device is subjected to heat exchange, and the heated gas of the water treatment device is preheated.
7). A phenolic fiber obtained by spinning and curing a mixture in which the activated carbon fiber is a phenol resin mixed with at least one compound selected from the group consisting of fatty acid amides, phosphate esters, and celluloses. 7. The water treatment system according to any one of 1 to 6 above, which is an activated carbon fiber obtained by carbonization / activation.

  According to the water treatment system of the present invention, the amount of regeneration energy of the adsorption element of the water treatment device can be reduced, and the combustion efficiency of the combustion device can be improved.

It is an example of one form of the preferable water treatment system of this invention. It is an example of one form of the preferable water treatment apparatus of this invention. It is an example of one form of the preferable water treatment system of this invention. It is an example of one form of the preferable combustion apparatus of this invention.

  FIG. 1 shows an example of a preferred embodiment of the present invention, which is a water treatment system mainly including a water treatment device and a combustion device.

  The water treatment apparatus of the present invention includes an adsorption process in which water containing an organic compound is passed through an adsorption element to adsorb the organic compound in the adsorption element, and a high-temperature heated gas is passed through the adsorption element to the adsorption element. The water treatment apparatus includes a desorption process for desorbing an adsorbed organic compound, and alternately performs the process. This is because the processing can be continuously performed by adopting such a structure.

  A more preferable apparatus structure is a water treatment apparatus in which the adsorption element is divided into several parts, and the adsorption process and the desorption process are switched by a damper or the like, and the adsorption and desorption are continuously performed. A water treatment apparatus having a structure in which the adsorbing element can rotate and the part of the adsorbing element that adsorbs the organic compound in the adsorption process moves to the desorption process by the rotation of the adsorbing element is also a preferable apparatus structure.

  As shown in FIG. 2, the water treatment apparatus of the present invention may have a dehydration step of removing the adhering water remaining on the surface of the adsorption element after the organic compound adsorption step by flowing high-speed gas from the piping line L8. preferable. This is because the organic compound can be easily desorbed by heating by removing the adhering water with an air stream.

  Furthermore, it is preferable to return the removed water droplets to the raw water containing the organic compound at the inlet of the apparatus from the return line L9 shown in FIG. This is because the number of steps can be omitted and this method is efficient.

  The adsorbing element of the present invention preferably has a desorption step in which a harmful substance adsorbed by heating the adsorbing element with a heated gas is desorbed and regenerated so that it can be adsorbed again after the dehydration step. This is because the organic compound can be desorbed by heating and then the adsorption process can be continued. The desorption gas containing the organic compound generated in the desorption process is processed by a combustion apparatus such as a direct combustion apparatus, a catalytic combustion apparatus, or a regenerative combustion apparatus.

  The combustion apparatus is an apparatus that decomposes an organic compound in a gas generated by a desorption process of the water treatment apparatus. The treatment format is not particularly limited, but a direct combustion device that directly oxidizes and decomposes gas at a high temperature of 650 to 800 ° C., a catalytic combustion device that performs catalytic oxidation reaction of gas using a catalyst, and oxidative decomposition, It may be a regenerative direct combustion apparatus or a regenerative catalytic combustion apparatus that recovers heat using a heat accumulator and directly oxidatively decomposes economically. This is because such an apparatus can decompose organic compounds with high efficiency and continuously.

  As shown in FIG. 3, the combustion is performed by bubbling the waste water before the water treatment device with an aeration device to volatilize and remove organic compounds in the water, and mixing the aeration gas discharged after bubbling with the desorption gas. You may make it the structure made to decompose | disassemble with an apparatus. By adopting such a configuration, it is possible to reduce the load of the organic compound on the water treatment apparatus, and to reduce the apparatus size and improve the combustion efficiency of the combustion apparatus.

  As shown in FIG. 4, the process gas discharged from the combustion device is subjected to heat exchange via a heat exchange device or the like, and is used for preheating the combustion device or preheating the heated gas of the water treatment device. Also good. This is because by adopting such a configuration, it is possible to reduce energy required for heating the gas in these apparatuses.

  By such continuous adsorption-heat desorption-decomposition, organic compounds in water can be removed at a low cost, stably and safely with high capacity.

  The adsorbing element according to the present invention may be in the form of powder, granule, honeycomb structure, etc., but is an activated carbon fiber in terms of performance. In other words, activated carbon fiber has micropores on the surface and a fibrous structure, so it has high contact efficiency with water, especially the adsorption rate of organic compounds in water is high, and removal is extremely high compared to other structures. It is because efficiency can be expressed.

  The activated carbon fiber used in the present invention has a fiber diameter of 21 to 40 μm. This is because, when the fiber diameter is 22 μm or more, the pressure loss of the adsorption element when the heated gas is ventilated can be reduced, the amount of water adhering to the fiber surface can be reduced, and the desorption efficiency can be improved. On the other hand, if the fiber diameter exceeds 40 μm, the above-described effect of improving the desorption efficiency can be expected, but the contact efficiency between the substance to be adsorbed in water and the adsorbing element decreases due to the increase in the fiber diameter. Decreases.

  As the phenol fiber which is a precursor of the activated carbon fiber used in the present invention, a mixture obtained by mixing a phenol resin with at least one compound selected from the group consisting of fatty acid amides, phosphate esters and celluloses is spun. And phenolic fibers obtained by curing. By mixing the compound, the phenolic fiber having a thick fiber diameter not mixed with the compound has a low tensile elongation and it is difficult to produce a nonwoven fabric. The problem that the activated carbon fiber nonwoven fabric has low tensile strength can be solved, and an activated carbon fiber nonwoven fabric having high tensile strength can be obtained.

  The phenol fiber used in the present invention is obtained by spinning a mixture obtained by mixing a phenol resin with at least one compound (compound) selected from the group consisting of fatty acid amides, phosphate esters, and celluloses. Phenol fiber is preferably used.

  As the phenol resin, a novolac type phenol resin obtained by reacting phenols and aldehydes in the presence of an acidic catalyst, or a resol type phenol obtained by reacting phenols and aldehydes in the presence of a basic catalyst Examples thereof include resins, various modified phenolic resins, and mixtures thereof.

  In the present invention, it is preferable to use a novolac type phenol resin or a resol type phenol resin. A phenol resin may be used individually by 1 type, and may use 2 or more types together.

  The fatty acid amides used as a blend in the present invention means a non-polymer having a structure in which one or more hydrogen atoms bonded to the nitrogen atom of ammonia or amine are substituted with an acyl group. A primary amide in which two atoms are bonded, a secondary amide in which one hydrogen atom is bonded to the nitrogen atom, a tertiary amide in which no hydrogen atom is bonded to the nitrogen atom, a lactam, and one molecule Includes those having two or more amine nitrogen atoms. Therefore, the “fatty acid amides” in the present invention are different from polymers such as so-called aliphatic polyamides typified by nylon-6 and nylon-6,6. “Fatty acid amides” are also referred to as fatty acid amides.

  Among the above fatty acid amides, primary amides and secondary amides are preferred, primary amides are more preferred, saturated fatty acid monoamides, unsaturated, from the viewpoints of handleability, stability or spinnability of the raw material mixture. Fatty acid monoamides are particularly preferred.

“Phosphoric acid” of the phosphoric acid esters used as a compound in the present invention is a general term for various oxo acids generated by hydrolysis of tetraphosphorus decaoxide (P ₄ O ₁₀ ). Including acid (diphosphoric acid), triphosphoric acid, tetraphosphoric acid, metaphosphoric acid and the like.

  In the present invention, the “phosphate esters” mean those in which one or more of —OH in phosphoric acid is substituted with a group represented by the following general formula (1) (phosphate esters) or salts thereof.

[Wherein R ¹³ is a hydrocarbon group having 4 or more carbon atoms which may have a hetero atom (atom other than carbon and hydrogen), AO is an oxyalkylene group having 2 to 4 carbon atoms, n Is the average number of moles added and represents a number from 0 to 100. ]

  As phosphate esters, since mechanical strength is likely to increase particularly when a large-diameter phenolic fiber is used, at least one of —OH in orthophosphoric acid is substituted with the group represented by the above formula (1). (Orthophosphoric acid ester) or a salt thereof is preferred.

  Examples of the phosphate ester salt include alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of phosphate esters. Phosphate esters may be used alone or in combination of two or more.

  Examples of celluloses used as a blend in the present invention include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and the like. Cellulose may be used independently or may use 2 or more types together.

  The activated carbon fiber used in the present invention is obtained by carbonizing and activating the phenolic fiber as a precursor.

The physical properties other than the above of the activated carbon fiber used in the present invention are not particularly limited, but the BET specific surface area is 900 to 2000 m ² / g, the pore volume is 0.4 to 0.9 cm ³ / g, Those having an average pore diameter of 14 to 18 mm are preferred. When the BET specific surface area is less than 900 m ² / g, the pore volume is less than 0.4 cm ³ / g, and the pore diameter is less than 14 mm, the adsorption amount of the organic compound becomes low, the BET specific surface area exceeds 2000 m ² / g, When the pore volume exceeds 0.9 cm ³ / g and the pore diameter exceeds 18 mm, the pore diameter increases, so that the adsorption ability of the organic compound decreases, the strength of the adsorption element decreases, Costs are high and not economical.

  Thus, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Hereinafter, the present invention will be described in more detail with reference to examples. The characteristics shown in the examples were measured by the following methods.

(BET specific surface area)
The BET specific surface area was measured by measuring the amount of nitrogen adsorbed on the sample when the relative pressure was raised in the range of 0.0 to 0.15 in the atmosphere of the boiling point of liquid nitrogen (-195.8 ° C), and a BET plot. Was used to determine the surface area (m ² / g) per unit mass of the sample.

(Pore volume)
The pore volume was measured by a nitrogen gas adsorption method at a relative pressure of 0.95.

(Average pore diameter)
The average pore diameter was determined by the following formula.
dp = 40000 Vp / S (where dp: average pore diameter (径))
Vp: pore volume (cc / g)
S: BET specific surface area (m ² / g)

(Toluene adsorption capacity)
The toluene adsorption capacity was measured by the method defined in JIS K1477.

(Organic compound concentration)
The concentration of organic compounds in the water at the inlet / outlet of the apparatus and in the gas was analyzed and measured by gas chromatography.

(Equilibrium adsorption amount)
The equilibrium adsorption amount (q ^* ) was determined by measuring the 50% breakthrough time and using the following equation.
q ^* (mg / g) = organic compound supply amount × 50% breakthrough time / adsorbent weight

(Adsorption band thickness)
The adsorption band thickness (10% Za) was determined by the following formula by measuring the breakthrough time for breakthrough by 10%.
10% Za = (50% breakthrough time−10% breakthrough time) × 2 / (50% breakthrough time)

(Moisture content)
The amount of adhering moisture was determined by the following equation by measuring the weight of the adsorbent after the dehydration operation.
Adhesive water content (g / g) = Adsorbent weight after dehydration operation (g) / Adsorbent weight in absolute dryness (g)

(Average pressure loss of adsorbent)
The average pressure loss of the adsorbent was determined by measuring the pressure at the inlet / outlet of the apparatus during the dehydration and desorption operations with a manostar cage and calculating the average value of the pressure at the inlet / outlet of the apparatus by the following formula.
Pressure loss of adsorbent (kPa) = apparatus inlet pressure (kPa) −apparatus outlet pressure (kPa)

(Blower power)
The blower power was obtained by the following formula.
Blower power (W) = air volume (m ³ / min) × inlet pressure (kPa) /6120/9.81/0.7×10 ⁶

[Example 1]
1000 parts by weight of phenol, 733 parts by weight of formalin 733 parts by weight and 5 parts by weight of oxalic acid were charged into a reaction vessel equipped with a reflux condenser, heated from room temperature to 100 ° C. over 40 minutes, and further reacted at 100 ° C. for 4 hours. Then, the mixture was heated to 200 ° C., dehydrated and concentrated, and then cooled to obtain a novolac type phenol resin.

  475 kg of the above-mentioned novolak type phenol resin and 25 kg of behenamide are charged into a biaxial kneader (high-speed biaxial continuous mixer), kneaded (melted and mixed) at 150 ° C., cooled to room temperature, and light yellow transparent A block-like product was obtained. In addition, behenic acid amide (BNT-22H) manufactured by Nippon Seika Co., Ltd. was used as the behenic acid amide.

  Next, this block-like product is coarsely pulverized and melted at 200 ° C. using a melt spinning apparatus (grid melter type), and the melt obtained by the melting has a pore diameter of 0.1 mm maintained at 170 ° C., A yarn was obtained by spinning (melt spinning) at a spinning speed of 75 m / min while maintaining a constant discharge rate from a spinneret with L / D = 3 and 10 holes.

  The obtained yarn was cut into a length of 70 mm, placed in a container, immersed in an aqueous solution of 14% by mass hydrochloric acid and 8% by mass formaldehyde for 30 minutes at room temperature, heated to 98 ° C. in 2 hours, and further 98 Curing was performed by holding at 2 ° C. for 2 hours.

  Subsequently, after taking out the hardened | cured material obtained from the said container and fully washing with water, neutralization was performed for 30 minutes at 60 degreeC with 3 mass% ammonia aqueous solution. Thereafter, it was thoroughly washed with water again and dried at 90 ° C. for 30 minutes to obtain a phenolic fiber having a single fiber fineness of 11 dtex, a fiber length of 70 mm, and no fiber crimp.

Using the obtained phenol-based fiber, a back and front treatment was performed with a needle punch machine under the conditions of a needle density of 500 / inch ² , a needle depth of 12 mm (back) and 7 mm (front) to obtain an ACF nonwoven fabric precursor, The precursor is heated from normal temperature to 890 ° C. for 30 minutes in an inert atmosphere (nitrogen atmosphere) and carbonized, and then activated for 100 minutes at a temperature of 890 ° C. in an atmosphere containing 12% by mass of water vapor. A nonwoven fabric composed of activated carbon fibers having a diameter of 24 μm, an average pore diameter of 14 mm, a BET specific surface area of 1650 m ² / g, a total pore volume of 0.7 cm ³ / g, and a toluene adsorption capacity of 490 mg / g was obtained.

Two adsorbing elements with an absolute dry weight of 200 g having a thickness of 150 mm and a thickness of 150 mm using the obtained activated carbon fiber non-woven fabric were prepared and installed in the damper-switching water treatment apparatus of FIG. ? Raw water containing dioxane was introduced at a water linear velocity of 2.8 cm / min. As a result of confirming the change over time in the outlet concentration at that time, as shown in Table 1, the adsorption band thickness (Za 10%) was 40 mm, and the equilibrium adsorption amount (q ^* ) was 300 mg / g, which was a good adsorption performance. .

  Next, 30 ° C. air was blown for 5 minutes at a wind speed of 35 cm / s as a gas for the dehydration process of the water treatment apparatus, and water adhering to the adsorption element was purged away. At that time, the amount of adhering water was 2.4 g / g.

  Next, 120 degreeC air was ventilated by the wind speed of 35 cm / s as heating gas in a desorption process. At that time, the average pressure loss of the adsorbent was 3.8 kPa. The blower power was 25W.

Next, the gas generated in the desorption process was introduced as a raw gas into a catalytic combustion apparatus in which a platinum catalyst was installed at a space velocity (SV) of 40000 h ⁻¹ and a combustion temperature of 300 ° C. This catalytic combustion apparatus has a configuration in which the processing gas and the raw gas are heat-exchanged by a heat exchanger having a heat exchange rate of 60% to preheat the raw gas, and then the temperature is raised by an electric heater. When the treatment gas concentration was measured, it was a good decomposition performance of 1 ppm or less. Moreover, it was 355 degreeC when the process gas temperature was measured. At that time, the required power of the electric heater was 150 W or less.

[Comparative Example 1]
A monofilament fineness of 5.6 dtex, a fiber length of 70 mm, a phenolic fiber (Kinei Chemical Industry Co., Ltd., Kynol KF-0570) without fiber crimp is used, and a needle density of 500 / inch ^{2 is obtained} by a needle punch machine. The ACF nonwoven fabric precursor was obtained by performing backside treatment under conditions of needle depth 12 mm (back) and 7 mm (front), and the precursor was heated from normal temperature to 890 ° C. over 18 minutes in an inert atmosphere, and carbonized. Next, activation was performed for 60 minutes at a temperature of 890 ° C. in an atmosphere containing 12% by mass of water vapor, a fiber diameter of 17 μm, an average pore diameter of 14 mm, a BET specific surface area of 1650 m ² / g, a total pore volume of 0.7 cm ³ / g, A nonwoven fabric made of activated carbon fibers having a toluene adsorption capacity of 490 mg / g was obtained.

Two adsorbing elements with an absolute dry weight of 200 g having a thickness of 150 mm and a thickness of 150 mm using the obtained activated carbon fiber non-woven fabric were prepared and installed in the damper-switching water treatment apparatus of FIG. ? Raw water containing dioxane was introduced at a water linear velocity of 2.8 cm / min. As a result of confirming the change over time in the outlet concentration at that time, as shown in Table 1, the adsorption band thickness (Za 10%) was 40 mm, and the equilibrium adsorption amount (q ^* ) was 300 mg / g, which was a good adsorption performance. .

  Next, air at 30 ° C. was blown for 5 min at a wind speed of 56 cm / s as a gas for the dehydration process of the water treatment apparatus, and moisture adhering to the adsorption element was purged away. At that time, the amount of adhering water was 2.4 g / g.

  Next, air at 120 ° C. was blown at a wind speed of 56 cm / s as a heating gas in the desorption process. At that time, the average pressure loss of the adsorbent was 9.5 kPa. The blower power was 101 W, and 4 times or more electric power was required as compared with Example 1.

Next, the gas generated in the desorption process was introduced as a raw gas into a catalytic combustion apparatus in which a platinum catalyst having the same apparatus configuration as that of the example was installed at a space velocity (SV) of 40000 h ⁻¹ and a combustion temperature of 300 ° C. When the treatment gas concentration was measured, it was a good decomposition performance of 1 ppm or less. Moreover, it was 335 degreeC when the process gas temperature was measured. In that case, the electric power required of the electric heater is 400 W or more, and 2.6 times or more of electric power is required.

  The water treatment system of the present invention is a treatment system that realizes continuous purification of water containing organic compounds, basically eliminates the need for replacement of adsorbents, and can efficiently remove a large amount of the organic compounds with high efficiency. Therefore, it is a system that can be used in a wide range of laboratories, factories, etc. It is important to contribute to the industry.

DESCRIPTION OF SYMBOLS 100 Water treatment apparatus 110 1st process tank 111 Adsorbent 120 2nd process tank 121 Adsorbent 200 Combustion apparatus 210 Heat exchanger 211 Heat exchanger 220 Combustion furnace 300 Aeration apparatus 311 Aeration pipe L1-L15 Piping line V101-V112 Valve

Claims (7)

A water treatment system for purifying water by adsorbing and removing organic compounds from water containing organic compounds,
An adsorption step in which water containing an organic compound is passed through an adsorption element containing activated carbon fibers having a fiber diameter of 21 to 40 μm and a toluene adsorption capacity of 200 to 750 mg / g to adsorb the organic compound to the adsorption element; A water treatment device that alternately repeats a desorption step of passing a high-temperature heating gas through the element to desorb an organic compound adsorbed on the adsorption element and discharging a desorption gas containing the organic compound;
A combustion apparatus for decomposing an organic compound in the desorption gas generated in the desorption process of the water treatment apparatus and discharging the treatment gas;
Having water treatment system.   The water treatment system according to claim 1, further comprising a dehydration step of removing moisture adhering to the surface of the adsorption element by passing a high-speed gas through the adsorption element before the desorption process of the water treatment apparatus.   The water treatment system according to claim 2, wherein moisture adhering to the surface of the adsorption element is returned before the adsorption element and is adsorbed by the adsorption element again.   The aeration apparatus for removing aeration gas containing water by contacting a gas with water, and treating the water containing the organic compound after treating the water containing the organic compound. The water treatment system in any one of Claims 1-3 introduce | transduced into.   The water treatment system according to any one of claims 1 to 4, wherein the aeration gas discharged from the aeration apparatus is mixed with a desorption gas discharged from the one water treatment apparatus and introduced into the combustion apparatus.   The water treatment system according to any one of claims 1 to 5, wherein the treatment gas discharged from the combustion device is subjected to heat exchange to preheat the heating gas of the water treatment device.   A phenolic fiber obtained by spinning and curing a mixture in which the activated carbon fiber is a phenol resin mixed with at least one compound selected from the group consisting of fatty acid amides, phosphate esters, and celluloses. The water treatment system according to any one of claims 1 to 6, which is an activated carbon fiber obtained by carbonization and activation.