JP2011121026A - Water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply treated water having a predetermined treated water quality even if deterioration of the water quality of treating water or performance lowering of an ultraviolet irradiation device occurs. <P>SOLUTION: The water treatment apparatus forms a circulation path 5 that includes a circulation tank 3, an oxidation means 1 including an oxidant feed device 9 and the ultraviolet irradiation device 10, and a pump 4. The apparatus includes a control means 18 repeatedly performing a water feed process to the circulation tank 3, a circulation process of operating the oxidation means 1 and pump 4 and circulating the treating water in the circulation path 5 after the water feed process, and a water sending process of sending the treated water in the circulation tank 3 to a treated water tank 8 after the circulation process; and a sensor 17 detecting an organic matter concentration of the treated water in the circulation path 5. The control means 18 shifts the circulation process to the water sending process when the organic matter concentration detected by the sensor 17 is lowered below a set value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water treatment apparatus for treating water to be treated containing an organic substance.

  Conventionally, an oxidant supply device that supplies an oxidant to the water to be treated, an ultraviolet oxidizer that irradiates the water to be treated with an ultraviolet ray, and a circulation tank are formed to form organic water in the water to be treated by photooxidation. A water treatment apparatus for circulating treatment is known from Patent Document 1 and the like.

  In this conventional water treatment device, if the quality of the water to be treated is deteriorated or the performance of the ultraviolet irradiation device is deteriorated, a predetermined quality of treated water cannot be obtained.

JP 2003-340472 A

  The problem to be solved by the present invention is to supply treated water having a predetermined treated water quality even when the quality of the water to be treated is deteriorated or the performance of the ultraviolet irradiation device is deteriorated.

  The present invention has been made to solve the above problems, and the invention according to claim 1 includes a circulation path including a circulation tank, an oxidizing means including an oxidant supply device and an ultraviolet irradiation device, and a pump. A water treatment apparatus that circulates and treats water to be treated containing organic matter, the water supply step of storing a predetermined amount of water to be treated in the circulation tank, and the step that is performed after the water supply step, the oxidizing means And a circulation treatment step of operating the pump to circulate the water to be treated in the circulation path to oxidize, and a water supply step of feeding the treated water in the circulation tank to the treated water tank after the circulation treatment step. Repetitive control means, and a sensor for detecting the organic matter concentration of the treated water in the circulation path, and the control means is configured to perform the circulation treatment process when the organic matter concentration detected by the sensor becomes a set value or less. It is characterized by shifting to the water supply step from.

  According to invention of Claim 1, since the organic substance density | concentration of the treated water in the said circulation path becomes below a preset value, since it transfers to the said water feeding process, the water quality of to-be-processed water deteriorates or the said ultraviolet irradiation Even if the performance of the apparatus deteriorates, treated water of a predetermined water quality can be supplied.

  The invention according to claim 2 is characterized in that, in claim 1, the ultraviolet irradiation device comprises an ultraviolet lamp and is continuously operated during the water supply process, the circulation treatment process and the water supply process. .

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, since the ultraviolet lamp is not turned on and off in a short time, the life of the ultraviolet lamp can be extended. .

  Invention of Claim 3 is comprised in Claim 2 so that the part containing the said oxidation means and the said pump of the said circulation path may make a part of water supply path from the said circulation tank to the said treated water tank, In the water feeding step, the treated water in the circulation tank is fed to the treated water tank while being subjected to an oxidizing action by the oxidizing means by the operation of the pump.

  According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, the treated water fed to the treated water tank is further oxidized by the ultraviolet irradiation device during the water feeding process. The treated water quality can be further improved.

  Further, the invention according to claim 4 is the invention according to claim 2, wherein the oxidation means is disposed in a treated water supply path for supplying treated water to the circulation tank, and the circulation path is connected to the treated water supply. A part of the path is included so as to include the oxidation means, and the water to be treated is sent to the circulation tank while being subjected to the oxidizing action by the oxidation means in the water supply step.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 2, since the treated water can be oxidized during the water supply step, the treated water can be treated in a predetermined quality in a short time. There is an effect that it can be.

  According to this invention, even if the water quality of to-be-processed water deteriorates or the performance of an ultraviolet irradiation device falls, the treated water of a predetermined treated water quality can be supplied.

It is a figure explaining schematic structure of Example 1 of the present invention. It is a flowchart figure explaining the principal part of the control procedure of the Example 1. FIG. It is a figure explaining the water supply process of the Example 1. FIG. It is a figure explaining the circulation process process of the Example 1. FIG. It is a figure explaining the water supply process of the Example 1. FIG. It is a figure explaining schematic structure of Example 2 of the present invention. It is a figure explaining the water supply process of the Example 2. FIG. It is a figure explaining the circulation process process of the Example 2. FIG. It is a figure explaining the water supply process of the Example 2. FIG.

  Next, an embodiment of the water treatment apparatus of the present invention will be described. Embodiment of this invention is implemented suitably for the water treatment apparatus which processes the to-be-processed water containing organic substance.

  This embodiment will be specifically described. The water treatment apparatus of this embodiment forms a circulation path including a circulation tank, an oxidizer, and a pump, and circulates water to be treated containing organic matter (which can be referred to as organic pollutants). is there. The oxidizing means includes an oxidizing agent supply device that supplies (also referred to as addition) an oxidizing agent into the water to be treated and an ultraviolet irradiation device that irradiates the water to be treated with ultraviolet rays.

  And a water supply step of storing a predetermined amount of water to be treated in the circulation tank, and a step performed after the water supply step, wherein the water to be treated is circulated in the circulation path by operating the oxidation means and the pump. And a control means for repeatedly performing a circulatory treatment step for oxidizing and a water supply step for feeding the treated water in the circulation tank to the treated water tank after the circulatory treatment step.

  The circulation treatment step is preferably configured to start during the water supply step, that is, when a certain amount of water to be treated is stored in the circulation tank. Thereby, compared with what does not start the said circulation treatment process in the middle of the said water supply process, the water quality of to-be-processed water can be reduced to a setting value in a shorter time.

  Further, this embodiment includes an organic substance concentration sensor that detects an organic substance concentration of the treated water in the circulation path, and the control means performs the circulation process when the detected organic substance concentration by the organic substance concentration sensor becomes a set value or less. It is comprised so that it may transfer to the said water supply process from a process.

  In the water treatment apparatus of this embodiment, the control means repeatedly performs the water supply step, the circulation treatment step, and the water supply step in this order. In the circulation treatment step, the organic matter contained in the water to be treated in the circulation tank is oxidized and decomposed by oxidation called so-called photooxidation (or accelerated oxidation) by the oxidation means. Since the mechanism of photo-oxidation is known, its description is omitted here.

  When decomposition of the organic matter in the water to be treated progresses due to photo-oxidation and the organic matter concentration detected by the organic matter concentration sensor becomes a set value or less, the control means ends the circulation treatment step and proceeds to the water supply step. Transition. The treated water stored in the circulation tank is sent to the treated water tank, and the quality of the treated water is maintained at a predetermined value.

  In this embodiment, preferably, the ultraviolet irradiation device is composed of an ultraviolet lamp and is continuously operated during a series of repeated processes, that is, during the water supply process, the circulation treatment process, and the water supply process. (Continue ON).

  By continuously operating the ultraviolet lamp in this way, it is possible to extend the life of the ultraviolet lamp that shortens the life when turned on and off in a short time.

  In the embodiment in which such an ultraviolet lamp is continuously operated, the position of the oxidizing means is not limited to a specific one, but preferably the following two forms are used.

  In a 1st form, the part containing the said oxidation means and the said pump of the said circulation path is comprised so that a part of water supply path from the said circulation tank to the said treated water tank may be made. The order of the oxidizing means and the pump is arranged so that the oxidizing means is on the downstream side of the pump. And at the time of the said water supply process, by the drive of the said pump, the treated water in the said circulation tank is sent to the said treated water tank, receiving the oxidation effect | action by the said oxidation means. The oxidizing agent supplying means constituting the oxidizing means is controlled (ON-OF control or proportional control) so that the concentration of organic matter in the water to be treated circulating in the circulation path is not more than a set value. A “road” can be referred to as a line.

  According to the first aspect, since the treated water fed to the treated water tank is further subjected to photo-oxidation treatment by the oxidizing means during the water feeding step, the water quality is higher than the water quality at the end of the circulation treatment step. Water can be supplied to the treated water tank.

  In the second embodiment, the oxidation means is disposed in a treated water supply path for supplying treated water to the circulation tank, and the circulation path includes a part of the treated water supply path. To include the oxidation means. And at the time of the said water supply process, to-be-processed water is supplied to the said circulation tank, receiving the oxidation effect | action by the said oxidation means.

  According to the second aspect, since the water to be treated sent to the circulation tank is oxidized by the oxidation means during the water supply step, the water to be treated is compared with a device that is not oxidized during the water supply step. Can be made to have a predetermined treated water quality in a short time.

Here, the component which comprises the water treatment apparatus of embodiment of this invention is demonstrated. The treated water supplied to the circulation tank is preferably wastewater used in various apparatuses (for example, wastewater obtained after sludge treatment), but contains organic matter at a high concentration even if it is not wastewater. Raw water may be used.

  The oxidizing agent supply device and the ultraviolet irradiation device of the oxidizing means are preferably arranged close to each other and configured as a single oxidizing device, but may be arranged at separate positions. Moreover, the preferable order of an oxidizing agent supply means and an ultraviolet irradiation device is the order of an oxidizing agent supply means and an ultraviolet irradiation means along the flow direction of to-be-processed water.

The oxidizer supply device adds an oxidizer such as hypochlorous acid (NaOCL), hydrogen peroxide (H ₂ O ₂ ), ozone, etc. to the water to be treated, and oxidizes organic substances in the water to be treated to produce COD. (Chemical
It reduces oxigen demand (chemical oxygen demand) value or TOC (Total Organic Carbon) value.

  The ultraviolet irradiation device irradiates the water to be treated with ultraviolet rays, that is, electromagnetic waves in a relatively short wavelength (100 to 400 nm) region, and preferably uses a low-pressure mercury lamp as a light source for ultraviolet irradiation.

  The circulation tank is not limited to a tank having a specific structure, and includes a water level sensor that detects the amount of water to be treated.

  The circulation pump is not limited to one having a specific structure, and one having a capacity corresponding to the amount of water to be treated per unit time circulating in the circulation path is selected.

  The organic substance concentration sensor is a sensor that detects the organic substance concentration of the water to be treated, and can detect an ultraviolet ray transmittance and output it as a COD converted value. The organic substance concentration sensor can be provided in a component such as the circulation path and a circulation tank included in the circulation path, but is preferably provided in the circulation tank.

  The said control means controls the said water supply process, the said circulation process process, the said water supply process, etc. based on the control procedure memorize | stored beforehand. Specifically, the control means inputs signals from the organic substance concentration sensor, the water level sensor, etc., and controls the circulation pump and various valves. The control procedure includes a procedure for shifting from the circulation processing step to the water feeding step when the organic matter concentration by the organic matter concentration sensor becomes a set value or less.

  Hereinafter, Example 1 of the water treatment apparatus of this invention is described in detail based on drawing. FIG. 1 is a diagram illustrating a schematic configuration of the first embodiment, FIG. 2 is a flowchart illustrating a main part of a control procedure of the first embodiment, and FIG. 3 is a water supply of the first embodiment. FIG. 4 is a diagram for explaining the circulation processing step of the first embodiment, and FIG. 5 is a diagram for explaining the water supply step of the first embodiment.

  The water treatment apparatus according to the first embodiment forms a circulation path 5 including an oxidation means 1, a first valve 2 including an electric valve, a circulation tank 3, and a pump 4, and circulates organic matter in the water to be treated. It is configured to do. The water supply path 7 is branched from the upstream side of the first valve 2 in the circulation path 5. This water supply path 7 is for supplying treated water to the treated water tank 8 and has a second valve 6 made of an electric valve.

  One end of the oxidizer 1 is connected to the downstream side (discharge side) of the pump 4, and the other end is connected to the branch portion of the water supply path 7, that is, between the first valve 2 and the second valve 6. Thus, a part of the circulation path 5 including the pump 4 and the oxidizing means 1 constitutes a part of the water supply path 7, that is, also serves as a part.

  Moreover, the oxidation means 1 is comprised including the oxidizing agent supply apparatus 9 which supplies an oxidizing agent in to-be-processed water, and the ultraviolet irradiation device 10 which irradiates an ultraviolet-ray with respect to to-be-processed water, and it is in the flow direction of to-be-processed water. Along with this, the oxidizing agent supply device 9 → the ultraviolet irradiation device 10 is provided.

  In the first embodiment, the oxidant supply device 9 is a device that injects hypochlorous acid, and has a configuration in which the injection amount can be controlled. The injection amount is controlled by measuring the organic substance concentration in the water to be treated by the organic substance concentration sensor 17 to be described later, and setting the organic substance concentration to a set value or less. Moreover, the ultraviolet irradiation device 10 uses the thing of the well-known structure using the ultraviolet lamp which consists of a low pressure mercury lamp as a light source.

  And the to-be-processed water supply path 12 which supplies to-be-processed water from the to-be-processed water tank (it can call a raw | natural water tank) 11 to the said circulation tank 3 by a gravity difference or a pump (illustration omitted) is connected. The treated water supply path 11 includes a third valve 13 made of an electric valve. Reference numeral 14 denotes a water to be treated inflow passage where the water to be treated flows into the water tank 11 to be treated.

  The treated water tank 8 includes a treated water supply path 15 that supplies treated water to the treated water utilization facility in response to a request from the treated water utilization facility (not shown). The treated water supply passage 15 is provided with a pump (not shown) that is operated in response to the request.

  The circulation tank 3 is provided with a water level sensor 16. The water level sensor 16 can detect an abnormally low water level LL, a lower limit water level L (> LL) of the water level control range, an upper limit water level H (> L) of the water level control range, and an abnormally high water level HH (> H). It is configured.

  An organic substance concentration sensor 17 for detecting the organic substance concentration of the water to be treated is provided on the downstream side of the oxidation means 1 in the circulation path 5. The organic substance concentration sensor 17 uses a known sensor that applies light to sample water, measures the absorbance of visible light and ultraviolet light, and outputs the measured value as a COD converted value.

  The pump 4, the first valve 2, the second valve 6, and the third valve 13 are controlled based on a control procedure stored in advance by a controller 18 that inputs signals from the water level sensor 16 and the organic matter concentration sensor 17. The

  The control procedure includes a water supply step for storing a predetermined amount of water to be treated in the circulation tank 3, and the water to be treated is circulated in the circulation path 5 by operating the oxidizer 3 and the pump 4 after the water supply step. In this order, there is included a procedure in which a circulation treatment step for oxidation treatment and a water feeding step for feeding treated water in the circulation tank 3 to the treated water tank 8 after this circulation treatment step are repeated in this order. And in this treatment procedure, the procedure of continuously operating the ultraviolet irradiation means 10 during the water supply step, the circulation treatment step and the water supply step, and when the detected organic matter concentration by the organic matter concentration sensor 17 is below a set value, And a procedure for shifting from the circulation process to the water supply process. The set value is set according to the request of the facility for using treated water, and is, for example, COD: 30 mg / L. An example of this processing procedure is shown in FIG.

  Next, the operation of the water treatment apparatus according to the first embodiment will be described with reference to the drawings. In FIGS. 3 to 5, the black-painted valve is closed, and the non-black-painted valve is open. With reference to FIG. 2, when an operation switch (not shown) is turned on to operate the water treatment apparatus of the first embodiment, it is determined to be turned on in processing step S <b> 1 (hereinafter, processing step SN is simply referred to as SN). To S2. In S2, the ultraviolet irradiation device 10 is activated (ON), and the process proceeds to the next water supply step after a predetermined time has elapsed. Thus, the reason why the ultraviolet irradiation device 10 is operated before the water supply process is started is that it takes time until the ultraviolet lamp is stabilized.

(Water supply process)
In this water supply process S3, first, as shown in FIG. 3, the controller 18 opens the first valve 2 and the third valve 13 and closes the second valve 6. In the initial state, the water level of the circulation tank 3 is LL or less, and the treated water in the treated water tank 11 is supplied to the circulating tank 3 through the treated water supply path 12.

  When the water level in the circulation tank 3 becomes L or more, the pump 4 is driven and the oxidant supply device 9 is activated (ON). As a result, a circulation process similar to the circulation process S5 described later is started. Here, description of the circulation process is omitted.

  When the water level in the circulation tank 3 is equal to or higher than H, that is, it is determined that a predetermined amount of water to be treated is stored, YES is determined in S4, and the water supply step S3 is terminated. And it transfers to the circulation process process of S5 shown in FIG.

(Circulating process)
In the circulation processing step S5, the controller 18 opens the first valve 2 and closes the second valve 6 and the third valve 13. The operation of the pump 4 and the oxidation means 1 is continued from the water supply step S2. The oxidant supply device 9 is controlled so that the organic matter concentration in the for-treatment water measured by the organic matter concentration sensor 17 is equal to or less than a set value.

  As a result, the water to be treated stored in the circulation tank 3 is oxidized and decomposed by the photooxidation by the oxidation means 3 while containing organic substances while circulating in the circulation path 5. As a result, the organic matter concentration in the for-treatment water is lowered. This decrease in concentration is detected by the organic substance concentration sensor 17, and when the detected value is equal to or less than the set value, YES is determined in S6, and the circulation processing step S5 is terminated. And it transfers to the water supply process shown in FIG.

(Water supply process)
In this water feeding step S7, the controller 18 opens the second valve 6, closes the first valve 2 and the third valve 13, operates the pump 4, and continues the operation of the ultraviolet irradiation device 10 of the oxidation means 1, The operation of the oxidant supply device 9 is stopped.

  As a result, the water to be treated whose organic substance concentration stored in the circulation tank 3 is equal to or lower than the set value, that is, the treated water, is supplied to the treated water tank 8 through a part of the circulation path 5 including the oxidation means 1 and the water supply path 7. Is done. At the time of this water feeding step S6, the treated water in the circulation tank 3 is fed to the treated water tank 8 while receiving the photo-oxidation action by the oxidizing means 3. As a result, the treated water in the treated water tank 8 is treated water with high water quality having an organic substance concentration lower than the set value.

  When the water level of the circulation tank 3 becomes L or less, YES is determined in S8, the water feeding step S7 is terminated, and the process proceeds to S9. Unless it is determined in S9 that the operation switch is OFF, the above-described water supply step S3, circulation processing step S5 and water supply step S7 are repeated.

  If it is determined in S9 that the operation switch is OFF, the process proceeds to S10 and a stop process S step 10 is performed. In the stop processing step S10, energization to the oxidizing means 3, the pump 4, and the valves 2, 6, 13 is stopped. Note that the determination in S9 is also performed during the water supply process S3, the circulation process S5, and the water supply process S7.

According to the first embodiment configured as described above, when the organic substance concentration detected by the organic substance concentration sensor 17 is equal to or lower than the set value, the circulation process step 4 is terminated and the process proceeds to the water supply process S7. Even if the water quality deteriorates or the performance of the ultraviolet irradiation device 10 deteriorates, the quality of the treated water sent to the treated water tank 8 can be maintained at the set value. Further, since the water to be treated is circulated, the capacity of the oxidation means 3 can be minimized.

  Moreover, according to this Example 1, since the ultraviolet lamp which comprises the ultraviolet irradiation device 10 is continuously operated during water supply process S3, circulation process S5, and water supply process S7, the lifetime of an ultraviolet lamp is lengthened. Can do.

  Further, at the time of the water supply step S7, the treated water sent to the treated water tank 8 is subjected to the oxidizing action by the oxidizing means 3, so that treated water having a higher quality than the water quality at the end of the circulating treatment step S5 is supplied to the treated water tank 8. can do.

  Next, a second embodiment of the water treatment apparatus of the present invention will be described in detail with reference to the drawings. FIG. 6 is a diagram illustrating a schematic configuration of the second embodiment, FIG. 7 is a diagram illustrating a water supply step S3 of the second embodiment, and FIG. 8 is a circulation processing step S5 of the second embodiment. FIG. 9 is a diagram for explaining the water feeding step S7 of the second embodiment. In FIGS. 7 to 9, the black-painted valve is closed, and the non-black-painted valve is open. In the following description of the second embodiment, the description will focus on the configuration different from that of the first embodiment, and the same configuration is denoted by the same reference numeral and the description thereof is omitted.

  In the second embodiment, the configuration of the water treatment circuit is different from that of the first embodiment shown in FIG. 1 in that the oxidation means 1 supplies the water to be treated to the circulation tank 3 as shown in FIG. 12 and the circulation path 5 is configured to include the oxidation means 1 by including a part of the treated water supply path 12. And at the time of water supply process S3, it is the point which comprises so that to-be-processed water may be sent to the circulation tank 3, receiving the oxidation effect | action by the oxidation means 1. FIG.

  In other words, the circulation path 5 is formed in the order of the oxidation means 1, the circulation tank 3, the pump 4, and the first valve 2, and the oxidation means 1 is disposed at a location that becomes the treated water supply path 12 and the circulation path 5. . A part of the circulation path 5 including the pump 4 also serves as the water supply path 7.

  The control procedure by the controller 18 is basically as shown in FIG. 2, but in the first embodiment, as described above, the circulation treatment process is started in the middle of the water supply process S3. In contrast, the second embodiment is different in that the circulation process S5 is not started in the middle of the water supply process S3, and the circulation process S5 is started after the water supply process S3 is completed. The reason why the circulation process is not started in the middle of the water supply process S3 is that when the first valve 2 is opened and the pump 4 is operated in the middle of the water supply process S3, the supply of water from the treated water tank 11 to the circulation tank 3 is hindered. Because it is.

  According to the second embodiment, the water to be treated sent to the circulation tank 3 is oxidized by the oxidation means 1 at the time of the water supply step S3, so that the water to be treated is not oxidized at the time of the water supply step. The treated water can have a predetermined treated water quality in a short time. Since other operations and effects are the same as those of the first embodiment, description thereof is omitted.

DESCRIPTION OF SYMBOLS 1 Oxidation means 3 Circulation tank 4 Pump 5 Circulation path 8 Treated water tank 9 Oxidant supply device 10 Ultraviolet irradiation means 17 Organic substance concentration sensor (sensor)
18 Controller (control means)

Claims (4)

A water treatment device that circulates treated water containing organic matter by forming a circulation path including a circulation tank, an oxidizer including an oxidant supply device and an ultraviolet irradiation device, and a pump,
A water supply process for storing a predetermined amount of water to be treated in the circulation tank, and a process performed after the water supply process, wherein the oxidation means and the pump are operated to circulate the water to be treated in the circulation path for oxidation. A control means for repeatedly performing a circulating treatment step to be treated, and a water feeding step for feeding the treated water in the circulation tank to the treated water tank after the circulating treatment step;
A sensor for detecting the organic matter concentration of the treated water in the circulation path,
The said control means is made to transfer to the said water supply process from the said circulation process process, when the organic substance density | concentration detected by the said sensor becomes below a setting value, The water treatment apparatus characterized by the above-mentioned.   The water treatment apparatus according to claim 1, wherein the ultraviolet irradiation device includes an ultraviolet lamp and is continuously operated during the water supply step, the circulation treatment step, and the water supply step. A portion including the oxidation means and the pump of the circulation path is configured to form a part of a water supply path from the circulation tank to the treated water tank,
3. The water treatment apparatus according to claim 2, wherein during the water feeding step, the treated water in the circulation tank is fed to the treated water tank while being subjected to an oxidizing action by the oxidizing means by the operation of the pump. . The oxidation means is disposed in a treated water supply path for supplying treated water to the circulation tank,
The circulation path is configured to include the oxidation means by including a part of the treated water supply path,
The water treatment apparatus according to claim 2, wherein the water to be treated is sent to the circulation tank while being subjected to an oxidizing action by the oxidizing means during the water supply step.

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