JP4512993B2 - Water treatment equipment - Google Patents

Description

  The present invention relates to an apparatus for removing and purifying an organic substance from water containing the organic substance, and in particular, an apparatus used for purifying industrial wastewater containing an organic substance such as an organic solvent discharged from various factories, research facilities, etc. About.

  Conventionally, as an apparatus for removing harmful organic substances from water and purifying it, an exchangeable adsorption apparatus using an adsorbent such as activated carbon has been widely used. That is, it is a simple treatment apparatus that allows water containing an organic substance to flow through a tank filled with an adsorbent such as activated carbon and efficiently removes harmful organic substances in water by the adsorbent. However, the exchangeable adsorption device continues to adsorb toxic organic substances for a certain period of time, and if the adsorption capacity of the adsorbent reaches saturation, it can be continuously replaced by replacing it with a new one or removing the adsorbent from the device and regenerating it once. In addition, 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. Organic materials could adversely affect the health of workers. In order to solve such a problem, it is conceivable to extend the replacement cycle by using a large amount of adsorbent, but it is inevitable to enlarge the apparatus and invest in the equipment. In addition, although it has been studied to improve the adsorption ability such as appropriately hydrophobizing the surface of the activated carbon as an adsorbent (see, for example, Patent Document 1), it is effective in removing a trace amount of harmful substances. However, it is not a fundamental solution when it is required to treat a large amount of harmful organic substances with high efficiency, and it is not satisfactory particularly when used in laboratories and factories. In addition, the conventional purification apparatus has a problem that the toxic substance adsorption performance changes between the start of use of the adsorbent and before the end of use (immediately before the replacement of the adsorbent), and the purification process cannot be stably performed. .

JP-A-9-77508

  The present invention has been made against the background of the problems of the prior art, achieves continuous purification of water, basically eliminates the need for replacement of the adsorbent, and can remove a large amount of harmful organic substances with high efficiency and stability. It is an object to provide a processing apparatus.

As a result of intensive studies in order to solve the above problems, the present inventors have finally completed the present invention. That is, the present invention is (1) an apparatus for purifying water by adsorbing and removing an organic substance from water containing an organic substance, wherein the water containing the organic substance is passed through the adsorption element and the organic substance is passed through the adsorption element. A water treatment apparatus characterized by alternately performing an adsorption process for adsorbing water and a desorption process for desorbing an organic substance adsorbed on the adsorption element by passing a high-temperature heating gas through the adsorption element; 2) The water treatment apparatus according to (1) above, wherein the adsorbent contained in the adsorbing element is activated carbon and / or zeolite, and (3) the adsorbing element has a honeycomb structure. (1) to (3), wherein the water treatment device according to (1) or (2), (4) the adsorption element is subjected to water repellent treatment with fluorine, silicon, or a hydrocarbon compound. Water treatment equipment, (5) water containing organic substances Desorption, which is a subsequent step of the adsorption step of passing an adsorbing element to adsorb an organic substance on the adsorbing element, and desorbing the organic substance adsorbed on the adsorbing element by passing a high-temperature heated gas through the adsorbing element The water treatment device according to any one of (1) to (4) above, wherein (6) the gas flow is provided. The water treatment device according to any one of (1) to (5), wherein the water generated in the purge step for removing water in the adsorption element is returned to the inlet of the water treatment device. .

  The water treatment apparatus according to the present invention can remove a large amount of harmful organic substances continuously with high efficiency, and basically does not require the replacement of the adsorbent. There is an advantage that harmful organic substances can be removed.

  The water treatment apparatus according to the present invention includes an adsorption process facility for allowing water containing an organic substance to flow through an adsorption element and adsorbing the organic substance to the adsorption element, and a high-temperature heating gas to flow through the adsorption element. It is preferable that the water treatment apparatus includes a desorption process facility for desorbing the organic substance adsorbed on the adsorption element, and alternately performs such a 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 having a structure in which the adsorbing element can rotate and the part of the adsorbing element that adsorbs the organic substance in the adsorption process moves to the desorption process by the rotation of the adsorbing element. .

  Hereinafter, a water treatment apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 2 is an example of a preferred embodiment of the present invention. The water treatment apparatus illustrated in FIG. 2 has an adsorption region 23 of the adsorption element 22 formed in the columnar shape illustrated in FIG. 3 or the cylindrical shape illustrated in FIG. And an adsorbing step of adsorbing and removing the organic substance by the adsorbent and discharging it as purified water.

  On the other hand, it is preferable that the adsorption element 22 has a purge process in which the adsorption element 22 rotates and is sent to the purge region 24 to remove water droplets remaining on the adsorption element surface by gas flow. This is because removal of water droplets with an air stream facilitates desorption of harmful organic substances by heating. Although the desorption process described later may be performed simultaneously by using the purge gas as a high-temperature heating airflow, it is preferable to separate the purge process and the desorption process from the viewpoint of energy cost.

  The water removed here contains an organic substance and may be accumulated and incinerated. However, it is preferable to return to the raw water containing the organic substance at the inlet of the apparatus from the return line 25. This is because the number of steps can be omitted and this method is efficient.

  Further, the adsorption element 22 is rotated, and a desorption process is performed in which the adsorbed harmful substance is desorbed by heating the adsorption element with a heating gas in the desorption region 26 after the purge process and is regenerated so that the adsorption can be performed again. It is preferable to have. This is because after the harmful organic substance is desorbed by heating, it can be continuously moved to the adsorption step. Gases containing organic substances generated by the desorption process are used in general gas processing equipment such as direct combustion equipment, catalytic combustion equipment, thermal storage type combustion equipment, etc. and solvent recovery equipment using activated carbon fibers. Can be processed.

  By continuously repeating the above-described adsorption process → purge process → desorption process, the apparatus can economically adsorb and remove organic substances from water containing organic substances. By such continuous adsorption-heat desorption, it is possible to remove and remove harmful organic substances in water at low cost, stably and with high capacity, and to prevent generation of algae and the like.

The structure of the adsorbing element according to the present invention is not particularly limited, and may be one filled with a granular material, one made of a fibrous material into a non-woven fabric, or the like. It is particularly preferred to have By adopting a honeycomb-like structure, pressure loss is extremely low compared to granular and fibrous forms, the processing capacity can be increased, clogging due to solids such as dust is less likely to occur, and furthermore, gas is not removed in the purge process. This is because even when water droplets on the surface of the adsorption element are removed by circulation, the water droplets can be easily removed.

  Although the operation of the adsorption element according to the present invention is preferably continuous, it may be intermittent operation in consideration of the amount of harmful organic substances to be removed, the amount of treated water, and the like. This is because, under the condition that the amount of harmful organic substances or the amount of treated water is small, it is not required that the operation is continuous, and the operation cost can be reduced.

  The adsorbent used in the present invention is not particularly limited, but activated carbon or zeolite is preferable because of its excellent ability to adsorb harmful organic substances in water. Among them, zeolites include hydrophilic zeolite and hydrophobic zeolite, and hydrophobic zeolite is more preferable. This is because hydrophobic zeolite has a low water adsorption rate due to its high Si / Al ratio (molar ratio) compared to hydrophilic zeolite, and can adsorb organic substances preferentially over water. This is because the adsorption performance of the substance is more excellent. Hydrophobic zeolite has a remarkably high heat-resistant temperature and can use heated air at a higher temperature in the desorption process, and can be applied even to organic substances that have high molecular weight and can be desorbed only at high temperatures with high boiling points. It also has the effect of becoming.

  The adsorbing element used in the apparatus according to the present invention is preferably water-repellent treated with fluorine, silicon, or a hydrocarbon compound. By performing such a treatment, the energy required for the latent heat of vaporization during the heat treatment in the desorption process can be reduced, desorption of harmful organic substances can be facilitated, and organic matter is given priority over water. This is because a harmful substance such as a solvent is selectively adsorbed and the adsorbing performance is improved. A particularly preferred treating agent is fluorine.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
The evaluation was performed by the following method.
(Organic substance removal effect)
Raw water containing 20 ppm of toluene was supplied at a flow rate of ³ m ³ / min with water at a temperature of 25 ° C., and the toluene concentration at the outlet of each water treatment apparatus after 10 hours and 500 hours of operation was measured.
(Toluene concentration evaluation)
Analysis and measurement were performed by gas chromatography.

〔Example〕
Contains 50% by weight of ZSM-5 type hydrophobic zeolite having an Si / Al ratio (molar ratio) of 1000, an average pore size of 5.5 mm, and a specific surface area of 400 m ² / g as an adsorbent, and tetrafluoride as a water repellent. Raw water is supplied to a water treatment apparatus containing an adsorption element containing 25 wt% of an ethylene resin and having a diameter of 450 mmΦ divided into an adsorption region, a purge region, and a desorption region and having a cylindrical honeycomb structure with a thickness of 450 mm and a weight of 20 kg. Introduced.

180 ° C. air was used as a heating gas in the desorption process of the water treatment apparatus, and the desorption air flow was 1 m ³ / min. In the purge process, air was flowed at 0.3 m ³ / min. Further, the rotation speed of the adsorption element was rotated at a cycle of 2 RPH.

  The water purified by the water treatment apparatus of this example had a toluene concentration of 1 ppm or less after 10 hours and after 500 hours. Since adsorption and desorption are performed continuously, processing is stable and highly efficient with no performance degradation.

[Comparative Example]
Raw water was introduced into a water treatment apparatus of an exchange type adsorption system in which 50 kg of cylindrical coconut shell activated carbon having an average pore diameter of 16 mm, a specific surface area of 1000 m ² / g and a packing density of 450 g / l was packed in a 0.11 m ³ adsorption layer.

  The water purified by the water treatment device of this comparative example had a toluene concentration of 1 ppm or less after 10 hours, but after 500 hours, the toluene concentration was 20 ppm, the same as the inlet, and was treated stably and with high efficiency. I could n’t do it. This is because, unlike the example, the comparative example does not continuously perform adsorption and regeneration by an operation of only adsorption, so that the adsorption capacity of the adsorbent immediately reaches saturation.

  The water treatment apparatus of the present invention is a treatment apparatus that realizes continuous purification of water, basically eliminates the need for replacement of the adsorbent, and can remove a large amount of harmful organic substances with high efficiency and stability. It is possible to omit the adsorbent replacement work without the need to reduce costs, achieve stable removal of harmful substances, and ensure the safety of workers, and can be used in a wide range of fields such as laboratories and factories, contributing to the industry. It is great to do.

Illustration of honeycomb structure A water treatment apparatus using a columnar honeycomb-structured adsorption element, which is an example of a preferred embodiment of the present invention. Example of cylindrical honeycomb device Example of cylindrical honeycomb device

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Raw water introduction line 22 Adsorption element 23 Adsorption area 24 Purge area 25 Return line 26 Desorption area 31 Concentrated gas 32 Desorption heating gas 33 Raw water 34 Purified water 35 Cylindrical honeycomb 36 Rotation direction 37 Desorption zone 38 Adsorption zone 40 Desorption heating gas 41 Raw water 42 Purified water 43 Cylindrical honeycomb 44 Direction of rotation 45 Flow piping 46 Honeycomb mounting metal box

Claims (5)

An apparatus for purifying water by adsorbing and removing an organic substance from water containing an organic substance, wherein an adsorption step of passing the water containing the organic substance through the adsorption element and adsorbing the organic substance to the adsorption element; A purge process for removing water on the surface of the adsorption element by flowing a gas through the adsorption element after the adsorption process, and a high-temperature heated gas is passed through the adsorption element after the purge process to be adsorbed by the adsorption element. A water treatment apparatus characterized by continuously repeating a desorption process for desorbing organic substances . The water treatment apparatus according to claim 1, wherein the adsorbent contained in the adsorption element is activated carbon and / or zeolite . The water treatment apparatus according to claim 1, wherein in that the suction element has a honeycomb-like structure. The water treatment apparatus according to any one of claims 1 to 3 , wherein the adsorption element is subjected to water repellent treatment with fluorine, silicon, or a hydrocarbon compound . 5. The apparatus according to claim 1 , wherein the water generated in the purge step of removing water on the surface of the adsorption element by the gas flow is returned to the inlet of the water treatment device. Water treatment equipment .

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