JP5473560B2 - Water purification automatic continuous monitoring device and continuous water purification system monitoring system using the same - Google Patents

Description

  The present invention relates to a water quality monitoring / control system for a water purification process of a water purification plant, and more particularly to crisis management of water treatment in general at a water purification plant.

In general, water treatment plants take raw water from water sources such as rivers and reservoirs, pass through unit processes of coagulation, flock formation, sedimentation, filtration and sterilization to remove suspended solids and colloids from the treated water and remove bacteria, etc. It is detoxified and supplied as tap water.
As described above, in the water purification treatment, a method of combining the coagulation sedimentation treatment and the filtration treatment is widely adopted.
In a general water treatment flow in a water purification plant, a water treatment chemical such as a flocculant is injected in a mixing pond, stirred and mixed with a rapid stirrer, etc., and then passed through a flock formation pond, a chemical sedimentation pond, and a rapid filtration pond. After that, the turbidity of the treated water is controlled to 0.1 degrees or less that the Ministry of Health, Labor and Welfare teaches in Non-Patent Document 1. The total required time (total residence time) of the flow is usually about 6 hours.

Recently, there have been frequent outbreaks of microplankton due to eutrophication in tap water sources throughout the country. Since microplankton leaks from the rapid filtration pond and increases the turbidity of the filtered water to 0.1 ° C. or more, the water utility is struggling to take countermeasures.
The Ministry of Health, Labor and Welfare is instructing management of filtered water turbidity of 0.1 degrees or less (see Non-Patent Document 1) as a response to infection caused by cryptosporidium generated through tap water. Management of filtered water turbidity at or below 0.1 degrees is positioned as the most important water quality management item.

However, because current scientific knowledge cannot predict the occurrence of microplankton in advance, the water utility monitors the turbidity change of the filtered water continuously day and night, and when the filtered water turbidity increases. For the first time, only measures such as strengthening the pre-flocculating agent and injecting the post-flocculating agent were taken.
Since time delays occur in such on-site responses, water utilities are taking safety measures such as cohesion strengthening as a precautionary measure based on the small movement of filtered water turbidity. Currently.

However, such a response causes an irrational mass injection of the flocculant and also causes a filtered water turbidity leak accident caused by a delay in judgment time, especially at night. It is also.
In order to solve these problems, a continuous jar tester is used to measure treated water corresponding to the water quality after the floc formation pond using the polymer flocculant, and there is a method for convenient handling based on the results. It has been proposed (Patent Document 1).

However, in the water quality evaluation test of the implementation facility, it is necessary to evaluate not only the treatment using the polymer flocculant but also the filtration treatment.
However, the production of a miniaturized rapid filtration column has various problems in terms of supporting the filtration layer and preventing short-circuit flow along the periphery of the filtration layer, and it is difficult to simulate the filtration device of the implementation. For this reason, several methods have been proposed (Patent Documents 2 to 4).
However, since these conventional methods do not measure the water quality after filtration, they do not sufficiently correspond to the filtered water turbidity after being treated in the rapid filtration basin of the implementation facility, and are still satisfactory. It was not possible to monitor.

JP 63-162007 A JP 2002-253904 A JP 54-93848 A JP-A-5-146608

Ministry of Health, Labor and Welfare Notification “Cryptosporidium Guidelines for Water Supply” (2007)

  The continuous monitoring device of the present invention has all the functions after the floc formation pond in the water purification facility of the implementation, and the facility has been miniaturized, and the time until measurement of filtered water turbidity is implemented. 1/6 to 1/12 of 1 hour to 30 minutes or less, and based on the results obtained there, the change in filtered water turbidity of the implementation facility is predicted more than 5 hours ago However, by optimizing the timing of cohesion strengthening, the problem is to eliminate the delay in response at the implementation facility.

  That is, the present invention is a purified water having a floc formation pond unit, a chemical sedimentation basin unit with an inclined plate settling device, a rapid filtration basin unit, and a turbidity monitoring unit in which the equipment after the floc formation pond in the water purification facility of the implementation is miniaturized. This is an automatic continuous monitoring system. The residence time to the floc formation pond unit and the chemical sedimentation basin unit with inclined plate is about 20 minutes, and the total residence time including the rapid filtration basin unit is about 30 minutes to less than 1 hour (turbidity) Monitoring device).

  In order to make the total residence time from floc formation to filtration within 1 hour, the development of a small filtration device that does not impair the function, in addition to the improvement of the existing agglomeration, floc formation and sedimentation equipment The present invention has been completed by solving each of these problems. Moreover, the continuous control system of the water purification process which can respond rapidly to a water quality change is completed by using the continuous monitoring apparatus of this invention.

  The water purification automatic continuous monitoring device of the present invention has all the functions after the floc formation pond in the water purification facility of the implementation, and the equipment is downsized. A water purification treatment automatic continuous monitoring apparatus having a unit, a rapid filtration pond unit, and a turbidity monitoring unit for precipitated water and filtrate. The time required for water treatment from flock formation to filtration is 1/6 to 1 / By shortening to about 12, the state of the water purification treatment can be monitored at an early stage (invention of claim 1).

  The chemical sedimentation basin unit with an inclined plate settling device in the automatic continuous monitoring system for water purification treatment of the present invention comprises an inclined plate settling device, a settling tank, and an overflow tank equipped with a bypass wall, and an inclined plate settling device portion is inclined. It can be exchanged with an inclined plate settling device with a different plate pitch, and the settling tank has an automatic mud discharge device at the bottom, and a sludge preventive device for sludge outflow prevention at the bottom sludge reservoir, bypassing the overflow tank By making the upper part of the wall a smooth inclined structure, the turbidity of the precipitated water is less than 1.0 degree (invention of claim 2).

The rapid filtration pond unit in the automatic continuous monitoring system for water purification treatment of the present invention is a small filtration column, and is provided with a non-land prevention baffle for eliminating unevenness caused by water introduction in cascade. A fixed support plate for supporting the filtration layer is provided in the lower part.
Furthermore, it has an automatic washing function based on the time setting or the water level setting of the water level meter, and the turbidity of the filtered water is set to 0.05 degrees or less (invention of claim 3).

The water purification treatment automatic continuous monitoring device of the present invention has a floc formation pond unit, a chemical sedimentation basin unit with an inclined plate settling device and a rapid filtration basin unit formed of a transparent material, and the state inside each unit is visually observed from the outside. This is an observable structure (the invention of claim 4).
The floc formation pond unit in the water purification automatic continuous monitoring apparatus of the present invention has a plurality of agitators, and these agitators can adjust the rotation speed independently of each other according to the water quality change of the raw water (claims) (5 invention)

The turbidity monitoring unit in the water purifying automatic continuous monitoring device of the present invention is provided with a turbidimeter or a turbidimeter and a fine particle counter. (Invention of claim 6)
The continuous monitoring device of the water purification process of the present invention comprises the water purification automatic continuous monitoring device of any one of 1 to 6 above, a chemical injection equipment unit including a flocculant, a chlorine agent, powdered activated carbon, and a rapid stirrer in the preceding stage. It consists of a water mixing unit and a water quality monitoring unit equipped with a water quality meter including a turbidity meter and a residual chlorine meter. It is equipped with all the functions of the water purification facility at the facility, and the facility is downsized and filtered from the intake of raw water. The water purification treatment state can be monitored at an early stage by shortening the time required for the entire water purification process from 1/6 to 1/12 of the implementation facility (invention of claim 7).

  The continuous control system of the water purification process of the present invention is based on the information on the precipitated water turbidity and filtered water turbidity obtained from any one of the water purification automatic continuous monitoring devices of 1 to 6 above, and the cause of the water purification treatment failure is minute. It is determined whether or not the filtration trouble is caused by plankton, and when it is judged that the filtration trouble is caused by microplankton, the flocculant is automatically injected in the coagulation treatment step after the implementation (the invention of claim 8).

  According to the present invention, the retention time corresponding to the water treatment from floc formation to filtration in the water purification automatic continuous monitoring device is set to a short time of 1 hour or less, thereby rationalizing the use of the flocculant in the implementation facility, proper The risk management capability in the water purification process is dramatically improved.

FIG. 1 shows a water purification process in a general water purification plant. Before the water treatment chemical injection step in the water purification plant of the present invention and the stirring step in the mixing pond are completed by the water purification treatment automatic continuous monitoring device of the present invention. It shows that it is a device for guiding a part of treated water. FIG. 2 shows each unit of the water purifying automatic continuous monitoring apparatus of the present invention. FIG. 3 shows an inclined plate settling device in a chemical sedimentation basin unit with an inclined plate settling device. FIG. 4 shows a chemical sedimentation basin unit with an inclined plate sedimentation device. FIG. 5 is a schematic diagram showing the action of the bypass wall in the overflow tank. FIG. 6 shows the water introduction position of the continuous monitoring device for the water purification process. FIG. 7 shows a flowchart of the continuous monitoring device for the water purification process. FIG. 8 shows a flowchart of the continuous control system of the water purification process. Fig. 9 shows the measured residence time of the device. FIG. 10 shows the measurement result of the sediment water turbidity of the water purification automatic continuous monitoring system. FIG. 11 shows the measurement results of the filtered water turbidity of the water purification process automatic continuous monitoring device. FIG. 12 shows changes in the number of filtered water particles and the number of raw water picoplankton in the implementation facility.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a water purification process automatic continuous monitoring apparatus and a water purification process continuous monitoring system using the same will be described with reference to the accompanying drawings.
The present invention aims to reduce the residence time corresponding to water treatment from floc formation to filtration in a water purification automatic continuous monitoring system to a short time within 1 hour, particularly impairing the treatment performance as a rapid filtration basin. In addition, it is a water purification automatic continuous monitoring device that makes it possible to shorten the residence time.
In addition, without impairing a processing function, it is aiming at 0.05 degree | times whose filtration water turbidity in the normal time after processing with a rapid filtration basin unit is equivalent to an implementation facility.

As shown in Fig. 1, the general water treatment process at a water treatment plant is that raw water is taken into a landing well from a water source such as a river or a reservoir, and a pH adjusting agent, an oxidizing agent, and a flocculant are used as water treatment chemicals in the mixing pond. After being injected, stirred and mixed with a rapid stirrer, etc., it is sent to a clean water basin through a flock formation pond, a chemical sedimentation pond, and a rapid filtration pond.
The continuous control system of the water purification process of the present invention leads to a part of the pretreated water after the water treatment chemical injection step and the stirring step are completed in the water purification facility of the above implementation to the water purification automatic continuous monitoring device of the present invention. Based on the information from the turbidity monitoring unit of the monitoring device, the raw water chemical injection control in the implementation facility is performed.

And, as shown in FIG. 2, the water purifying automatic continuous monitoring device of the present invention is characterized in that it measures the quality of water after filtration, unlike the conventional monitoring device. It enables monitoring corresponding to the filtrate turbidity after being treated in the filter basin.
The filtration column used in the rapid filtration pond unit newly developed in the present invention has been improved several times in order to shorten the residence time in the rapid filtration pond unit, and the improvements are described below. To do.

First, the water introduction to the filtration column adopts a cascade method in consideration of the scale of the device, but in that case, when unfiltered water falls on the water surface, the sand layer surface is disturbed, and the filtration performance is affected. There was a problem forming the land.
Therefore, in the present invention, as shown in 13 of FIG. 2, it is one of the features that the problem of the unevenness is improved by providing an obstruction prevention device on the water falling surface of the filtration column. It is.

In addition, the rapid filtration basin unit needs to be periodically cleaned to become clogged with operation.For this purpose, a fixed support plate is provided at the bottom of the filtration column so that the backwash process can be easily performed, and time setting or An automatic cleaning function based on the water level setting of the water level gauge is provided.
Furthermore, since the function as a monitoring device stops at the time of cleaning, it is necessary to make the periodic cleaning interval as long as possible, and extending the periodic cleaning interval has also been a conventional problem.

For this reason, in order to remove the fine solid matter of the precipitated water introduced into the rapid filtration basin unit, in the present invention, a chemical precipitation with a floc formation pond unit and an inclined plate settling device installed in the preceding stage of the rapid filtration basin unit is performed. Some improvements will be made to the pond unit.
Usually, in a chemical sedimentation basin, an inclined plate sedimentation device is installed to ensure sedimentation efficiency. The specifications of this settling device depend on the quality of raw water and the injection rate of the coagulant, but the conventional device only has a settling device with a fixed specification, and it is not a specification that responds immediately to the conditions of the raw water. It was.

In particular, in a monitoring device that targets a filtered water turbidity of 0.05 degrees, it is necessary to set the target turbidity of a chemical sedimentation basin unit with an inclined plate settling device to less than 1.0. It was necessary to improve the specifications of the settling device. For this reason, in the chemical sedimentation basin unit with an inclined plate settling device of the present invention, the inclined plate settling device with different inclined plate pitches shown in FIG. 3 can be replaced according to the quality of raw water and the coagulant injection rate. It is.
Moreover, in the conventional chemical sedimentation site, sludge discharge amount and discharge interval vary depending on raw water quality and water treatment conditions. Since the function as a monitoring device stops when sludge is discharged, the extension of the sludge discharge interval is an issue, and when restarting after the sludge is discharged, the treatment becomes unstable and the turbid matter flows out to the filtration pond. Since it also becomes a factor which impairs the function as a device, there is a problem to be improved as a new device.

  In order to cope with the above problem, in the chemical sedimentation basin unit with an inclined plate sedimentation device of the present invention, the sludge flow prevention device shown in FIG. 4 is installed in the sedimentation tank, and the turbid matter flows out to the filtration unit. In addition, the upper part of the bypass wall of the overflow tank has a smooth inclined structure as shown in FIG. 5, so that even if fine flocs that could not be removed by sediment flow out, the flocs will not break down and disperse more finely. Designed to be

Even in the floc formation pond unit, it is possible to effectively form flocs and reduce the load on the filtration device by adopting a configuration in which multiple agitators can adjust the rotation speed independently of each other according to the raw water quality It has a simple structure.
The turbidity monitoring unit monitors the treated water of both precipitated water and filtered water, and the turbidimeter alone may be used as a monitoring means, but more accurate by using a turbidimeter and fine particle counter together. Monitoring is possible.

  The water purification treatment automatic continuous monitoring device of the present invention includes a floc formation basin unit, a chemical sedimentation basin unit with an inclined plate sedimentation device, and a rapid filtration basin unit, which are formed of a transparent material that can be visually observed. The processing status such as the status and the sedimentation status can be visually confirmed, and the operating status of the water purification automatic continuous monitoring device of the present invention can be explained to an outside visitor in an easy-to-understand manner.

  In actual water treatment plants, coagulant, chlorinating agent, and powder activity are injected into the raw water in a form corresponding to the raw water quality that changes from time to time, so that the water treatment is thorough. However, especially when it is raining, when the raw water quality changes abruptly, injection control with a flocculant or the like may not be in time, and a water treatment accident may occur. Moreover, even in normal times, an unexpected water treatment accident may be caused due to a problem such as a flocculant injection machine.

  In the continuous monitoring device of the water purification process of the present invention, a chemical injection equipment unit containing a flocculant, a chlorinating agent and powdered activated carbon, a mixing pond unit equipped with a rapid stirrer, and turbidity in the previous stage of the water purification automatic continuous monitoring device By installing a water quality monitoring unit equipped with a water quality meter including a total chlorine meter and a residual chlorine meter, an appropriate injection rate of water treatment chemicals for sudden changes in raw water quality can be fed forward to the water treatment facility to prevent water treatment accidents. It is possible. In addition, since this monitoring device shortens the total water purification process time from 1/6 to 1/12 of the implementation facility, it is possible to detect in advance the occurrence of defects such as the flocculant injector at the implementation facility, It is possible to expand and prevent water treatment accidents.

Currently, water treatment plants in various regions are suffering from the leakage of microplankton into filtered water. The characteristic of turbidity disturbance caused by microplankton is that only the turbidity of filtered water increases (0.1 degree or more) under the same conditions as in normal times. This is because the contribution rate of microplankton to turbidity increases with filtered water. Control of filtered water turbidity of 0.1 degree or less is the most important current tap water treatment management as a countermeasure against Cryptosporidium.
The continuous water purification process monitoring system of the present invention can reduce the total water purification process time from 1/6 to 1/12 of the facility and monitor the turbidity of precipitated water and filtered water. Change in turbidity can be detected before turbidity failure occurs at the facility. Since microplankton can be removed by a flocculant (post-flocculant) at the front stage of the rapid filtration basin, automatic control of the post-flocculant injection enhancement for the detected turbidity abnormality is automatically controlled. The continuous monitoring system can prevent an increase in the turbidity of filtered water at the implementation facility.

As described above, the present invention is based on the new development of a floc formation pond unit, a chemical sedimentation basin unit with an inclined plate sedimentation device, and a rapid filtration pond unit that does not impair the function of sedimentation and filtered water turbidity monitoring units. The water treatment automatic continuous monitoring device with a total residence time corresponding to the treatment process from flock formation to filtration within 1 hour and the water treatment automatic continuous monitoring device are provided with units corresponding to the previous treatment steps. The present invention relates to a continuous monitoring device for the added water purification process, and further relates to a continuous control system for the water purification process using the water purification automatic continuous monitoring device.

Size, width 1,450mm x depth 900mm x height 1,300mm
Material: Frame; SS400, water tank; Transparent PVC
Specific examples of processing results are shown below.
FIG. 9 shows the residence time of the apparatus after adding potassium chloride to the water purification automatic continuous monitoring apparatus. The total residence time of the device (up to the filtrate turbidimeter) that can be calculated from the amount of treated water in the device is about 30 minutes, but the peak appearance time of potassium chloride in filtered water is about 30 minutes as shown in FIG. The device has been proved to have the prescribed performance.

FIG. 10 shows a monitoring result by the water purification automatic continuous monitoring apparatus when macroalgae are occurring. Precipitation water turbidity shows a target value of 1 degree or more and varies greatly, but this is due to macroalgae. The filtered water turbidity in the same period shown in FIG. 11 also greatly exceeds 0.1 degree.
However, the turbidity of the precipitated water and the filtrated water both decreased from July 16 and showed target values of less than 1 degree and less than 0.05 degree, respectively. The cause of this decrease is that cohesion strengthening was performed at the implementation facility. It shows that the monitoring apparatus of the present invention can properly reproduce the water treatment status of the implementation facility.

FIG. 12 shows a change in the number of filtered water particles (particles having a picoplankton size) and a change in the number of raw water picoplanktons in the implementation facility. In contrast to the change in the number of raw water picoplankton, the number of filtered water particles changes with a delay of about 6 hours, which is the residence time of the implementation facility.
The counting of picoplankton requires microscopic observation, and it takes a long time to obtain the counting result, but the number of filtered water particles in the implementation can be used as an alternative index for picoplankton.
Therefore, based on the relationship between the change in turbidity of the monitoring device of the present invention and the change in the number of particles in the implementation facility, it indicates that it is possible to optimize the water purification process early based on the continuous control system of the water purification process of the present invention. It is.

The present invention is a water purification process automatic continuous having a floc formation pond unit, a chemical sedimentation basin unit with a sloping plate sedimentation device, a rapid filtration basin unit, and a turbidity monitoring unit for sedimentation water and filtered water. It is a type monitoring device, and the water treatment time from floc formation to filtration can be monitored at an early stage by shortening the time required for water treatment from 1/6 to 1/12 of the implementation facility. The use of chemicals can be rationalized and optimized, and preventive detection such as coagulation failure can be performed, so that the crisis management ability in the water purification process is dramatically improved.

1 Flock formation pond unit 2 Stirrer
3 Chemical sedimentation basin unit with inclined plate settling device 4 Tilted plate settling device 5 Tilted plate pitch 6 Sludge 7 Sludge prevention device for sludge outflow prevention 8 Automatic drainage device
DESCRIPTION OF SYMBOLS 9 Overflow tank 10 Detour wall 11 Rapid filtration pond unit 12 Turbidity monitoring unit 13 Intrusion prevention device 14 Filter sand 15 Fixed support plate 16 Water level meter

Claims (7)

Floc formation pond unit, chemical sedimentation basin unit with sloping plate settling device, rapid filtration basin unit, sedimentation water and filtered water that have all the functions after the floc formation pond in the actual water purification equipment and that have been downsized. A water purification automatic continuous monitoring device having a turbidity monitoring unit of
The chemical sedimentation basin unit with an inclined plate settling device consists of an inclined plate settling device, a settling tank, and an overflow tank with a bypass wall, and the inclined plate settling device can be replaced with an inclined plate settling device with a different inclined plate pitch. The sedimentation tank has an automatic mud drainage device at the bottom, and a sludge preventive device for sludge outflow prevention in the lower sludge reservoir, and the upper part of the bypass wall of the overflow tank has a smooth inclined structure. Is a chemical sedimentation basin unit with an inclined plate sedimentation device that makes the turbidity of the sedimentation water less than 1.0 degree,
A water purification treatment automatic continuous monitoring apparatus characterized in that the water treatment treatment state can be monitored early by shortening the time required for water treatment from flock formation to filtration to about 1/12 to 1/12 of the implementation facility. The rapid filtration basin unit is a small filtration column, which is guided by a cascade system, and has a non-land flow prevention device for eliminating unevenness, a fixed support plate that supports the filtration layer, and a time setting or water level meter. an automatic cleaning function based on the water level setting, water treatment automatic continuous monitor of claim 1, the turbidity of the filtered water, characterized in that 0.05 degrees or less. The water purification treatment automatic continuous according to claim 1 or 2 , wherein the flock formation pond unit, the chemical sedimentation basin unit with an inclined plate sedimentation device, and the rapid filtration basin unit are formed of a transparent material that can be visually observed. Type monitoring device. The said floc formation pond unit has a some agitator, and those agitators can adjust a rotation speed mutually independently according to raw | natural water quality, The one in any one of Claims 1-3 characterized by the above-mentioned. Clean water treatment automatic continuous monitoring device. The said turbidity monitoring unit is equipped with a turbidimeter or a turbidimeter, and a fine particle counter, The water purifying automatic continuous monitoring apparatus in any one of Claims 1-4 characterized by the above-mentioned. And one of water treatment automatic continuous monitoring system according to claim 1-5, flocculants, pesticides, and chemical injection equipment unit containing powdered activated carbon, a mixing basin unit equipped with a rapid stirrer, a turbidimeter, residual chlorine The water quality monitoring unit has a water quality meter including a meter, has all the functions of the water purification facility on the facility, and has reduced the size of the facility to carry out the total water purification process time required from the intake of raw water to filtration. A continuous monitoring device for a water purification process, characterized in that the state of the water purification treatment can be monitored at an early stage by shortening from 1/6 to 1/12. Based on the information on the precipitated water turbidity and filtered water turbidity obtained from the water purification automatic continuous monitoring device according to any one of claims 1 to 5 , it is determined whether or not the cause of the water purification treatment failure is a filtration failure due to microplankton. A continuous control system for a water purification process that automatically injects a coagulant in a post-coagulation treatment step after the implementation when it is determined that the filtration trouble is caused by microplankton.

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