JP2010221173A - Water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment apparatus capable of producing treated water having stable water quality without wasting water. <P>SOLUTION: The water treatment apparatus 1 includes a storage tank 4 for storing water to be treated, an ultraviolet oxidation section 6 for the ultraviolet oxidation treatment of the water to be treated supplied from the storage tank 4 to obtain first treated water, a filtering section 8 installed downstream of the ultraviolet oxidation section 6 for filtering the first treated water to obtain second treated water, a connecting line 12 for connecting the ultraviolet oxidation section 6 to the filtering section 8, and an auxiliary line 14 for connecting the connecting line 12 to the storage tank 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water treatment apparatus, and more particularly, to a water treatment apparatus that performs oxidation treatment by irradiating ultraviolet rays.

  Conventionally, when high-purity water is required, such as a steam boiler or a hot water boiler, water treatment using a filtration device such as a reverse osmosis membrane device using a reverse osmosis membrane has been performed. The reverse osmosis membrane is an artificial semipermeable membrane having ultrafine pores of 0.0001 to 0.0005 microns and selectively transmits only water molecules. The reverse osmosis membrane device selectively utilizes only water as a solvent by applying a pressure higher than the osmotic pressure of the water to be treated by utilizing the property of the reverse osmosis membrane that allows such a solvent to pass but not a solute. Permeate and collect. Therefore, even very fine impurities such as dioxins, heavy metal ions, and viruses dissolved in raw water can be removed.

  By the way, in the conventional water treatment with a filtration membrane, the membrane surface of the filtration membrane is contaminated (fouling) due to an increase in the concentration of organic matter in the raw water and the growth of microorganisms using organic matter as a nutrient source, and the permeability of the filtration membrane is increased. Separation may be reduced. In response to this, for example, there is a water treatment device for preventing fouling of the membrane surface by disposing an ultraviolet oxidation device that irradiates ultraviolet rays to decompose organic substances and sterilize microorganisms in front of the filtration device. It has been proposed (see, for example, Patent Document 1).

JP 2007-69204 A

  However, the bactericidal effect by the ultraviolet oxidation device is generally not sustainable. Therefore, for example, when the water treatment apparatus is stopped, there is a possibility that microorganisms grow in the raw water tank or the connection line during the stop and adhere to the membrane surface at the time of restart. The conventional filtration apparatus including the filtration apparatus described in Patent Document 1 has a problem that so-called biofouling is generated by this repetition, and the permeability and separation performance of the filtration membrane are lowered.

  On the other hand, it is possible to prevent contamination of the membrane surface of the filtration membrane by performing blow processing (drainage treatment) when the filtration device is restarted. However, when the filtration device repeatedly starts and stops, a large amount of water to be treated is drained wastefully, which is not preferable from the viewpoint of resource saving.

  This invention is made | formed in view of the above, Comprising: It aims at providing the water treatment apparatus which can provide the treated water of the stable water quality without waste.

  The water treatment apparatus of the present invention includes a water storage tank for storing the water to be treated, an ultraviolet oxidation unit that oxidizes the water to be treated supplied from the water storage tank with ultraviolet rays to obtain first treated water, and the ultraviolet oxidation A filtration unit that is disposed on the downstream side of the unit to obtain the second treated water by filtering the first treated water, a connection line that connects the ultraviolet oxidation unit and the filtering unit, the connection line, and the water storage And an auxiliary line for connecting the tank.

  Moreover, it is preferable that the said filtration part performs a filtration process in any membrane selected from a reverse osmosis membrane, an ultrafiltration membrane, and a microfiltration membrane.

  Moreover, it is preferable that the to-be-treated water is biologically treated water that has been subjected to biological treatment.

  Moreover, it is preferable that the said to-be-processed water is the water from which the iron content and / or manganese content were removed at least.

  The water treatment method of the present invention includes an ultraviolet oxidation process for obtaining first treated water by oxidizing the treated water supplied from a water storage tank for storing the treated water to obtain a first treated water, and the ultraviolet oxidation process. A filtration treatment step of obtaining the second treatment water by filtering the obtained first treatment water, and the first treatment water obtained by the ultraviolet oxidation treatment step when the filtration treatment step is not executed. And a circulation treatment step for returning to the tank.

  Moreover, it is preferable that the said circulation process process adjusts the flow volume of the said to-be-processed water supplied from the said water storage tank.

  ADVANTAGE OF THE INVENTION According to this invention, the water treatment apparatus which can provide the treated water of the stable water quality without waste can be provided.

It is a flow sheet which shows the water treatment equipment concerning a 1st embodiment of the present invention. It is a flow sheet which shows the water treatment equipment concerning a 2nd embodiment of the present invention. It is a flow sheet which shows the water treatment equipment concerning a 3rd embodiment of the present invention. It is a flow sheet which shows the water treatment equipment concerning a 4th embodiment of the present invention. It is a flow sheet which shows the water treatment equipment concerning a 5th embodiment of the present invention. It is a flow sheet which shows the water treatment equipment concerning a 6th embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[1] 1st Embodiment First, the structure of the water treatment apparatus 1 which concerns on 1st Embodiment is demonstrated. FIG. 1 is a flow sheet showing a water treatment apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 1, the water treatment device 1 includes a biological treatment device 2, a first water storage tank 4 as a water storage tank, and a first water supply line 10 that connects the biological treatment device 2 and the first water storage tank 4. The first water supply pump 3 provided in the first water supply line 10, the ultraviolet oxidation device 6 as an ultraviolet oxidation unit, the second water supply line 11 connecting the first water storage tank 4 and the ultraviolet oxidation device 6, and the second A second water supply pump 5 provided in the water supply line 11, a reverse osmosis membrane device 8 as a filtration unit, a third water supply line 12 as a connection line connecting the ultraviolet oxidation device 6 and the reverse osmosis membrane device 8, and An auxiliary line 14 connecting the three water supply lines 12 and the first water storage tank 4, a prefilter 7 provided in the third water supply line 12, a second water storage tank 9, a reverse osmosis membrane device 8 and a second water storage tank 9. 4th water supply to connect with In-13, and a control unit 15, a.

  The biological treatment apparatus 2 is connected to a source of raw water (not shown). The biological treatment apparatus 2 performs biological treatment, which is a pretreatment for performing advanced treatment, on raw water such as factory wastewater, and generates biological treated water as raw water from the raw water. For example, the biological treatment apparatus 2 decomposes and removes organic substances and oils in the raw water by the action of aerobic microorganisms. In the present embodiment, the biological treatment apparatus 2 performs biological treatment by a membrane separation activated sludge method (MBR; membrane bioreactor).

  The first water storage tank 4 is connected to the downstream side of the biological treatment apparatus 2 via the first water supply line 10. The first water storage tank 4 stores biologically treated water generated by biological treatment by the biological treatment device 2.

  The ultraviolet oxidation device 6 is connected to the downstream side of the first water storage tank 4 through the second water supply line 11. The ultraviolet oxidizer 6 includes three ultraviolet oxidizers 6a, 6b, and 6c arranged in parallel. The second water supply line 11 branches on the upstream side of the ultraviolet oxidation device 6 and is connected to the upstream side of the ultraviolet oxidation devices 6a, 6b, and 6c, respectively.

  The ultraviolet oxidation apparatus 6 includes an ultraviolet lamp (not shown) that irradiates ultraviolet rays, a treatment tank (not shown) in which the ultraviolet lamp is accommodated, and an ozone generation unit (not shown) provided in the treatment tank. Prepare. The treatment tank is formed in a cylindrical shape, and an ultraviolet lamp is accommodated therein. In addition, biologically treated water that is an oxidation target circulates inside the treatment tank. An ozone production | generation part is equipped with the air introduction part which introduces ozonized air to the biological treatment water distribute | circulated inside the processing tank. An ozone production | generation part ozone-converts the air introduce | transduced into a processing tank by irradiating the air introduce | transduced from the outside with an ultraviolet-ray. The ultraviolet oxidation device 6 generates the first treated water by irradiating the biologically treated water with ultraviolet rays while circulating the biologically treated water inside the treatment tank into which the ozonized air is introduced. That is, the ultraviolet oxidizer 6 is configured to perform accelerated oxidation treatment of biologically treated water, decomposes organic substances contained in the biologically treated water, and sterilizes microorganisms.

  The second water supply pump 5 is provided on the upstream side of the branch to the ultraviolet oxidizers 6 a, 6 b, 6 c in the second water supply line 11. The second water supply pump 5 supplies the biologically treated water stored in the first water storage tank 4 to the ultraviolet oxidizers 6a, 6b, 6c.

  The prefilter 7 is provided in the third water supply line 12. The pre-filter 7 is provided on the downstream side of the ultraviolet oxidizers 6a, 6b, and 6c, and mainly removes suspended matter from the first treated water generated by the ultraviolet oxidizers 6a, 6b, and 6c. The third water supply line 12 is provided with a first valve 12a on the upstream side of the prefilter 7 and a second valve 12b on the downstream side. Between the pre-filter 7 and the second valve 12b, one side of the auxiliary line 14 is connected in a form branched from the third water supply line 12. The other side of the auxiliary line 14 is connected to the first water storage tank 4. A circulation valve 14 a is attached to the auxiliary line 14.

  The reverse osmosis membrane device 8 is connected to the downstream side of the second valve 12 b (downstream side of the ultraviolet oxidation device 6) via the third water supply line 12. The reverse osmosis membrane device 8 includes a pressurizing pump 81 provided on the upstream side, and a reverse osmosis membrane module (hereinafter referred to as “RO membrane”) 82 provided on the downstream side. The pressurizing pump 81 pressurizes the first treated water supplied from the ultraviolet oxidizer 6 through the prefilter 7 toward the RO membrane module 82. The RO membrane module 82 includes a large number of RO membranes (not shown), and removes impurities such as dissolved salts with the RO membrane. The reverse osmosis membrane device 8 generates pure water as the second treated water by allowing the first treated water to pass therethrough.

  One side of the fourth water supply line 13 and one side of the concentrated water drainage line 83 are independently connected to the downstream side of the RO membrane module 82. The other side of the fourth water supply line 13 is connected to the second water storage tank 9, and pure water from which impurities have been removed from the first treated water by the RO membrane is passed through the fourth water supply line 13 to the second water storage tank 9. Stored in the water. From the other side of the concentrated water drainage line 83, the concentrated wastewater in which impurities of the first treated water are concentrated by the RO membrane of the RO membrane module 82 is discharged.

  The second water storage tank 9 is connected to the downstream side of the reverse osmosis membrane device 8 via the fourth water supply line 13. The second water storage tank 9 stores the pure water generated by the reverse osmosis membrane device 8.

  The control unit 15 is electrically connected to the biological treatment device 2, the first feed water pump 3, the second feed water pump 5, the ultraviolet oxidation device 6, the first valve 12 a, the second valve 12 b, the circulation valve 14 a, and the reverse osmosis membrane device 8. It is connected. The control unit 15 controls the above-described devices and the like.

  Next, each process performed by the water treatment apparatus 1 according to the first embodiment will be described. The water treatment apparatus 1 according to the first embodiment includes a biological treatment process for performing biological treatment, an ultraviolet oxidation treatment process for performing ultraviolet oxidation treatment, a filtration treatment process for performing filtration treatment, and a circulation treatment step for performing circulation treatment. Prepare.

  The biological treatment process is a process of performing biological treatment by the membrane separation activated sludge method in the biological treatment apparatus 2. The water treatment device 1 generates biologically treated water from raw water by executing a biological treatment process.

  The ultraviolet oxidation treatment step is a step of performing accelerated oxidation treatment by circulating biological treatment water stored in the first water storage tank 4 inside the treatment tank and irradiating ultraviolet rays while introducing ozonized air. The water treatment apparatus 1 produces | generates 1st treated water from biologically treated water by implementing the above-mentioned ultraviolet oxidation process in ultraviolet oxidation apparatus 6a, 6b, 6c.

  In the reverse osmosis membrane device 8, the filtration treatment step is a step of performing filtration treatment of the first treated water by the reverse osmosis membrane. The water treatment device 1 generates pure water from the first treated water by performing the filtration process.

  In the circulation processing step, when the reverse osmosis membrane device 8 is stopped, the biologically treated water stored in the first water storage tank 4 and the first treated water subjected to the oxidation treatment by the ultraviolet oxidation device 6 are used as the second feed water. This is a step of circulating through the line 11, the third water supply line 12 and the auxiliary line 14. At this time, the circulating water is circulated while being subjected to ultraviolet oxidation treatment by the ultraviolet oxidation device 6.

  The water treatment apparatus 1 is configured such that the above-described apparatuses and the like are controlled by the control unit 15 and the above-described processes are executed.

  Next, operation | movement of the water treatment apparatus 1 which concerns on 1st Embodiment is demonstrated concretely with the control in the control part 15. FIG. The first pure water stored in the second water storage tank 9 is appropriately supplied to an external device (not shown). Therefore, the amount of water stored in the second water storage tank 9 decreases according to the amount supplied to the external device. Then, when the amount of water stored in the second water storage tank 9 falls below a predetermined amount of water (predetermined level), an operation request is made to the water treatment device 1.

  When an operation request is made to the water treatment apparatus 1, the control unit 15 activates the biological treatment apparatus 2 to execute a biological treatment process. That is, biologically treated water is generated from raw water. When the biologically treated water is generated, the control unit 15 activates the first water supply pump 3 to store the biologically treated water in the first water storage tank 4.

  When a predetermined amount of biologically treated water is stored in the first water storage tank 4, the control unit 15 stops the biological treatment device 2 and the first water supply pump 3. When the amount of water stored in the first water storage tank 4 falls below a predetermined amount of water (predetermined level), the control unit 15 activates the biological treatment device 2 and the first water supply pump 3 and repeats the above operation.

  Next, the control unit 15 activates the second water supply pump 5 to distribute the biologically treated water to the ultraviolet oxidizers 6a, 6b, and 6c, and activates the ultraviolet oxidizers 6a, 6b, and 6c to perform an ultraviolet oxidation process. Is executed. Specifically, the control unit 15 turns on the ultraviolet lamp and generates ozonized air in the ozone generation unit to generate the first treated water from the biologically treated water.

  Next, the control unit 15 activates the reverse osmosis membrane device 8. When the reverse osmosis membrane device 8 is activated, the reverse osmosis membrane device 8 first operates the pressurizing pump 81. When the pressurizing pump 81 is operated, the supply of the first treated water is started from the ultraviolet oxidizer 6. The first treated water is circulated to the reverse osmosis membrane device 8 via the third water supply line 12.

  At this time, the first valve 12a and the second valve 12b are normally open, and the circulation valve 14a is closed. Therefore, when the pressurizing pump 81 is operated, the first treated water flows through the third water supply line 12 without branching to the auxiliary line 14. However, the circulation valve 14 a is not necessarily fully closed, and the opening degree may be adjusted according to the amount of water supplied to the reverse osmosis membrane device 8. Then, impurities from the first treated water flowing through the third water supply line 12 are removed by the prefilter 7 provided in the third water supply line 12, and then distributed to the reverse osmosis membrane device 8.

  The first treated water circulated through the reverse osmosis membrane device 8 is further circulated to the RO membrane module 82 side by the pressure pump 81. The first treated water circulated to the RO membrane module 82 side is subjected to a filtration process by the RO membrane module 82. That is, pure water generation processing is performed. The first pure water generated by the RO membrane module 82 is pushed out by the pressurizing pump 81 to the fourth water supply line 13 and stored in the second water storage tank 9 through the fourth water supply line 13.

  The controller 15 constantly monitors the amount of water stored in the second water storage tank 9 while the water treatment apparatus 1 is being activated, and operates when the amount of water stored in the second water storage tank 9 falls below a predetermined amount of water (predetermined level). Make a request and repeat the above operation.

  Next, when the amount of water stored in the second water storage tank 9 reaches a predetermined amount of water (predetermined level), the control unit 15 stops the reverse osmosis membrane device 8 and closes the second valve 12b, and the circulation valve 14a. Is released. That is, the process proceeds to the circulation process.

  Here, in the circulation processing step, the control unit 15 closes the second valve 12b and opens the circulation valve 14a. As a result, the first treated water that has been subjected to the accelerated oxidation treatment by the ultraviolet oxidation device 6 is circulated to the auxiliary line 14 that branches from the middle of the third water supply line 12. The first treated water circulated through the auxiliary line 14 is returned to the first water storage tank 4 where it is mixed with the biological treated water. Thus, the first treated water in the circulation treatment step is mixed with the biological treated water to become mixed treated water. Further, the mixed treated water is circulated to the ultraviolet oxidizer 6 by the second feed water pump 5. The mixed treated water oxidized by the ultraviolet oxidizer 6 is returned to the first water storage tank 4 through the auxiliary line 14 again. In the circulation process performed while the reverse osmosis membrane device 8 is stopped, the control unit 15 repeats the above-described operation.

  In the circulation process, the control unit 15 intermittently activates the second water supply pump 5. For example, the control part 15 starts the 2nd water supply pump 5 based on predetermined temperature, or starts the 2nd water supply pump 5 for every predetermined time. For example, the control unit 15 is configured to activate the second water supply pump 5 at a time when at least the entire amount of water stored in the first water storage tank 4 is changed every 60 minutes (time for one turn). Even when the second water supply pump 5 is stopped, if the temperature of the mixed treated water stored in the second water storage tank 9 exceeds a predetermined temperature (for example, 35 ° C.), the second water supply pump 5 is turned off. You may comprise so that it may start. In addition, since an ultraviolet lamp will reach a lifetime in a short period if lighting and extinction are repeated frequently, the irradiation state will be continued even when the 2nd feed pump 5 is stopped during a circulation treatment process.

  In the circulation process, the control unit 15 is configured to be able to adjust the flow rate discharged from the second feed water pump 5 by adjusting the output of the second feed water pump 5. In the present embodiment, the control unit 15 is configured to adjust the discharge output of the second water supply pump 5 and reduce the flow rate through the ultraviolet oxidizer 6 in the circulation processing step.

  In the circulation process, the control unit 15 is configured so that the operator can select the oxidation process performed in the ultraviolet oxidation apparatus 6. For example, it is possible to select composite oxidation treatment (accelerated oxidation treatment) by ultraviolet irradiation and introduction of ozonized air, oxidation treatment by ultraviolet irradiation only (ultraviolet oxidation treatment), and oxidation treatment by only introducing ozonized air (ozone oxidation treatment). It is configured. In addition, in the case where the ultraviolet oxidizer 6 is configured to have a chemical injection unit for injecting an oxidant such as sodium hypochlorite, a combined oxidation treatment by ultraviolet irradiation, ozonized air introduction and oxidant chemical injection (Accelerated oxidation treatment), combined oxidation treatment by ultraviolet irradiation and introduction of ozonated air (accelerated oxidation treatment), combined oxidation treatment by ultraviolet irradiation and oxidant chemical injection (accelerated oxidation treatment), and oxidation treatment by ultraviolet irradiation only ( It is good also as a structure which can select UV oxidation treatment.

  According to the water treatment apparatus 1 according to the first embodiment having the above-described configuration, the following effects can be obtained. The water treatment apparatus 1 according to the first embodiment includes an auxiliary line 14 that can circulate an oxidation treatment target (first treated water or mixed treated water) while the reverse osmosis membrane apparatus 8 is stopped. ing. Therefore, for example, even when the reverse osmosis membrane device 8 is stopped, it is possible to continue the decomposition of organic matter and the sterilization of microorganisms by performing the oxidation treatment by circulating on the auxiliary line 14. This makes it possible to effectively suppress fouling (for example, contamination due to microbial growth) on the membrane surface of the RO membrane. Moreover, unnecessary blow can be reduced by circulating the object to be oxidized. As a result, stable treated water can be provided without waste.

  Further, for example, even when the flow rate of the first treated water flowing through the reverse osmosis membrane device 8 is reduced due to a failure of the ultraviolet oxidation device 6 or the like, the first valve is opened via the auxiliary line 14 by opening the circulation valve 14a. The biologically treated water can be directly drawn into the reverse osmosis membrane device 8 from the 1 water storage tank 4. Therefore, for example, in the reverse osmosis membrane device 8, it is not necessary to take measures against cavitation of the pressurizing pump 81 due to insufficient flow rate or the like. Moreover, the abnormal stop of the reverse osmosis membrane device 8 due to water shortage is reduced.

  In addition, for example, even when the reverse osmosis membrane device 8 is stopped, the object to be oxidized (first treated water or mixed treated water) is circulated to continuously decompose organic substances and sterilize microorganisms. The UV lamp will be lit continuously. Therefore, it is possible to effectively use the energy of the ultraviolet lamp and improve the life of the ultraviolet lamp.

  Further, for example, when the reverse osmosis membrane device 8 is stopped, the object to be oxidized (the first treatment) can be obtained even when the ultraviolet lamp is irradiated (continuous operation) in order to improve the life of the ultraviolet lamp. Water or mixed treated water) is intermittently circulated, so that an increase in the temperature of the object to be oxidized due to irradiation with the ultraviolet lamp can be suppressed. As a result, it is possible to more effectively suppress the growth of microorganisms.

  Further, for example, in the circulation processing step, since the discharge output of the second feed water pump 5 can be adjusted, the discharge flow rate of the second feed water pump 5 can be reduced. As a result, it is possible to realize energy saving in the circulation process.

[2] Other Embodiments Next, other embodiments of the present invention will be described. In other embodiments of the present invention, the description will mainly focus on parts that are different from the first embodiment, the same reference numerals are given to the same components as those in the first embodiment, and description thereof will be omitted. In addition, the description of the first embodiment is appropriately applied to points that are not particularly described in other embodiments. Further, in other embodiments having the same configuration as that of the first embodiment, the same effects as those of the first embodiment are exhibited.

[2-1] Second Embodiment First, a water treatment apparatus 1A according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a flow sheet showing a water treatment apparatus 1A according to the second embodiment of the present invention.

  As shown in FIG. 2, the water treatment apparatus 1A according to the second embodiment includes a microfiltration membrane device 8A disposed on the downstream side of the ultraviolet oxidation device 6 in place of the reverse osmosis membrane device 8. It differs from the water treatment apparatus 1 which concerns on 1 embodiment.

  The microfiltration membrane device 8A has a lower operating pressure required for the filtration process than the reverse osmosis membrane device 8, and therefore does not require the pressurizing pump 81. The microfiltration membrane module (hereinafter referred to as “MF membrane”). Only 82A). The MF membrane module 82A includes a large number of MF membranes (not shown), and removes impurities and the like with a microfiltration membrane. The microfiltration membrane device 8A generates purified water as the second treated water by allowing the first treated water to pass therethrough.

  As described above, the water treatment device 1A according to the second embodiment includes the microfiltration membrane device 8A on the downstream side of the ultraviolet oxidation device 6. Since the microfiltration membrane device 8A can collect a large amount of permeated water, it becomes possible to obtain a large amount of purified water with energy saving. In addition, since the microfiltration membrane device 8A can separate substances having a microfiltration membrane of 0.05 to 10 μm, it can reliably remove suspended substances, bacteria (such as E. coli and general bacteria), and protozoa (such as Cryptosporidium). It becomes possible to remove. Furthermore, also in the water treatment apparatus 1A, as in the first embodiment, fouling of the membrane surface of the MF membrane can be effectively suppressed by the circulation treatment process.

[2-2] Third Embodiment Next, a water treatment apparatus 1B according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a flow sheet showing a water treatment apparatus 1B according to the third embodiment of the present invention. As shown in FIG. 3, the water treatment device 1B according to the third embodiment is provided with an ultrafiltration membrane device 8B instead of the reverse osmosis membrane device 8 on the downstream side of the ultraviolet oxidation device 6. Different from the water treatment apparatus 1 according to the first embodiment.

  The ultrafiltration membrane device 8B has a lower operating pressure required for the filtration process than the reverse osmosis membrane device 8, and therefore does not require the pressurizing pump 81, and the ultrafiltration membrane module (hereinafter referred to as an ultrafiltration membrane " Only 82B). The UF membrane module 82B includes a number of UF membranes (not shown), and removes impurities and the like with the UF membrane. The ultrafiltration membrane device 8B generates purified water as the second treated water by selectively allowing the first treated water to permeate.

  As described above, the water treatment device 1B according to the third embodiment includes the ultrafiltration membrane device 8B on the downstream side of the ultraviolet oxidation device 6. The UF membrane in the ultrafiltration membrane device 8B has a pore size larger than that of the RO membrane and smaller than that of the MF membrane, so that it is not suitable for removing dissolved salts, but it is possible to suitably remove viruses and bacteria. Also in the water treatment apparatus 1B, similarly to the first embodiment, fouling of the membrane surface of the UF membrane can be effectively suppressed by the circulation treatment process.

[2-3] Fourth Embodiment Next, a water treatment apparatus 1C according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flow sheet showing a water treatment apparatus 1C according to the fourth embodiment of the present invention.
As shown in FIG. 4, in the water treatment apparatus 1C according to the fourth embodiment of the present invention, the iron removal manganese removal apparatus 2A is arranged in place of the biological treatment apparatus 2 on the downstream side of the raw water supply source. Different from the water treatment apparatus 1 according to the first embodiment.

  Thus, the water treatment apparatus 1C according to the fourth embodiment includes the iron removal manganese removal apparatus 2A connected to the raw water supply source. The iron removal manganese removal apparatus 2 </ b> A removes iron and manganese components from raw water, and generates water to be treated from raw water such as groundwater. Therefore, the water treatment apparatus 1 </ b> C performs the above-described treatment using the raw water from which iron and manganese components are removed from the raw water, and generates pure water as the second treated water from the first treated water generated from the raw water. It becomes possible. And also in 1 C of water treatment apparatuses, it becomes possible to suppress effectively the fouling of the membrane surface of RO membrane by a circulation treatment process like 1st Embodiment.

[2-4] Fifth Embodiment Next, a water treatment apparatus 1D according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flow sheet showing a water treatment apparatus 1D according to the fifth embodiment of the present invention. As shown in FIG. 5, the water treatment device 1D according to the fifth embodiment of the present invention is provided with a ferrous removal manganese removing device 2A in place of the biological treatment device 2 and in place of the reverse osmosis membrane device 8. Disposing the microfiltration membrane device 8A is different from the water treatment device 1 according to the first embodiment. Specifically, the iron removal manganese removal apparatus 2 </ b> A is connected to the raw water supply source, and the microfiltration membrane apparatus 8 </ b> A is connected to the downstream side of the ultraviolet oxidation apparatus 6 via the third water supply line 12.

  Note that the microfiltration membrane device 8A has the same configuration as that used in the water treatment device 1A of the second embodiment, and a description thereof will be omitted. Moreover, about the iron removal manganese removal apparatus 2A, since it is the structure similar to what was used for the water treatment apparatus 1D of 4th Embodiment, description is abbreviate | omitted.

  As described above, the water treatment device 1D according to the fifth embodiment is configured to include the iron removal manganese removal device 2A connected to the source of raw water and the microfiltration membrane device 8A downstream of the ultraviolet oxidation device 6. ing. Therefore, the water treatment device 1D performs the above-described treatment using the raw water from which raw iron and manganese components have been removed from the raw water such as groundwater, and the second treatment using the microfiltration membrane device 8A from the first treated water generated from the raw water. It becomes possible to produce purified water as treated water. And also in water treatment apparatus 1D, it becomes possible to suppress effectively the fouling of the film surface of MF film | membrane by a circulation process process similarly to 1st Embodiment.

[2-5] Sixth Embodiment Next, a water treatment apparatus 1E according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flow sheet showing a water treatment apparatus 1E according to the sixth embodiment of the present invention. As shown in FIG. 6, a water treatment device 1E according to a sixth embodiment of the present invention is provided with a ferrous removal manganese removing device 2A in place of the biological treatment device 2 and in place of the reverse osmosis membrane device 8. Disposing the ultrafiltration membrane device 8B differs from the water treatment device 1 according to the first embodiment. Specifically, the iron removal manganese removal apparatus 2A is connected immediately below the raw water downstream, and the ultrafiltration membrane apparatus 8B is connected to the ultraviolet oxidation apparatus 6 downstream via the third water supply line 12.

  Since the ultrafiltration membrane device 8B has the same configuration as that used in the water treatment device 1B of the third embodiment, the description thereof is omitted. Moreover, about the iron removal manganese removal apparatus 2A, since it is the structure similar to what was used for the water treatment apparatus 1D of 4th Embodiment, description is abbreviate | omitted.

  As described above, the water treatment device 1E according to the sixth embodiment includes the iron removal manganese removal device 2A connected to the raw water supply source and the ultrafiltration membrane device 8B on the downstream side of the ultraviolet oxidation device 6. Has been. Therefore, the water treatment apparatus 1E performs the above-described treatment using the raw water from which raw iron and manganese components have been removed from the raw water such as ground water, and the first treatment water generated from the raw water uses the ultrafiltration membrane device 8B. 2 It becomes possible to produce purified water as treated water. And also in the water treatment apparatus 1E, it becomes possible to suppress effectively the fouling of the membrane surface of a UF membrane by a circulation treatment process similarly to 1st Embodiment.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment at all, and the technical scope of this invention is not limited to this. For example, in the above embodiment, while the reverse osmosis membrane device 8 is stopped, the second water supply pump 5 is intermittently operated based on a predetermined time. However, the present invention is not limited to this. For example, the structure which makes the 2nd water supply pump 5 operate continuously may be sufficient. By continuously operating the second water supply pump 5 while the reverse osmosis membrane device 8 is stopped, the biologically treated water stored in the first water storage tank 4 can be sterilized at all times, and microorganisms can be propagated continuously. It becomes possible to suppress.

  In addition, in the fourth to sixth embodiments, the iron removal manganese removing apparatus 2A is configured to remove both iron and manganese components from raw water, but the present invention is not limited to this. For example, the iron removal manganese removal apparatus 2A may remove either iron or a manganese component from raw water.

  Moreover, in the said embodiment, although demonstrated using the biological treatment apparatus 2 and the iron removal manganese removal apparatus 2A as an apparatus which performs pre-processing of raw | natural water, the sand filtration apparatus and raw | natural water which remove the suspended solid in raw | natural water It may be configured to use any device selected from an activated carbon filtration device that removes residual chlorine and organic substances, and a soft water device that removes hardness components in raw water.

1, 1A, 1B, 1C, 1D, 1E Water treatment equipment 2 Biological treatment equipment 2A Iron removal manganese removal equipment 4 1st water storage tank (water storage tank)
5 Second water supply pump 6 UV oxidation device (UV oxidation section)
8 Reverse osmosis membrane device (filtration unit)
8A microfiltration membrane device (filtration unit)
8B Ultrafiltration membrane device (filtration unit)
9 Second water storage tank 12 Third water supply line (connection line)
14 Auxiliary line 15 Control unit

Claims (6)

A water storage tank for storing treated water;
An ultraviolet oxidation unit that oxidizes the treated water supplied from the water storage tank with ultraviolet rays to obtain first treated water;
A filtration unit disposed downstream of the ultraviolet oxidation unit and filtering the first treated water to obtain a second treated water;
A connection line connecting the ultraviolet oxidation unit and the filtration unit;
A water treatment apparatus comprising: an auxiliary line for connecting the connection line and the water storage tank.   The water treatment apparatus according to claim 1, wherein the filtration unit performs the filtration treatment with any one selected from a reverse osmosis membrane, an ultrafiltration membrane, and a microfiltration membrane.   The water treatment apparatus according to claim 1, wherein the treated water is biologically treated water that has been subjected to biological treatment.   The water treatment apparatus according to claim 1 or 2, wherein the water to be treated is water from which at least iron and / or manganese has been removed. An ultraviolet oxidation treatment step of performing oxidation treatment with ultraviolet rays on the treated water supplied from a water storage tank for storing the treated water to obtain first treated water;
A filtration treatment step for obtaining a second treated water by filtering the first treated water obtained by the ultraviolet oxidation treatment step;
A water treatment method comprising: a circulation treatment step of returning the first treated water obtained by the ultraviolet oxidation treatment step to the water storage tank when the filtration treatment step is not executed.   The water treatment method according to claim 5, wherein the circulation treatment step adjusts a flow rate of the treated water supplied from the water storage tank.

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