JP7072456B2 - Operation method and operation system of coagulation processing equipment - Google Patents

Description

The present invention relates to an operation method and an operation system of a coagulation treatment facility used for solid-liquid separation treatment in water purification treatment, industrial water treatment, sewage treatment, wastewater treatment, etc. The present invention relates to an operation method and an operation system that automates the setting of operation conditions such as a rate.

The coagulation treatment equipment used in water purification treatment, wastewater treatment, etc. is treated by adding a coagulant, a coagulation aid, and a pH adjuster (hydrochloric acid, sodium hydroxide aqueous solution, etc.) to the water to be treated (raw water or wastewater). Aggregate flocs are produced from suspended substances (turbidity) in water. It is necessary to set the amount of chemicals such as coagulant to be added according to the water quality of the water to be treated. Therefore, the sample water collected from the water to be treated is subjected to a coagulation test by the same process as the actual coagulation treatment equipment. , The optimum amount of chemicals to be added is determined based on the results of the aggregation test. The jar test is a typical example of the coagulation test. In the jar test, chemicals such as a flocculant are added to the sample water in a beaker, stirred and allowed to stand, and the supernatant water after standing is collected. The turbidity and chromaticity are measured, and the turbidity and chromaticity of the filtered water are also measured by filtering the sample water remaining in the beaker. In practice, for example, 3 to 10 jar testers that can stir and stand for multiple beakers at the same time are used, and different amounts of chemicals are added to each beaker containing sample water. Perform a jar test in parallel with the sample water in the beaker. Then, the amount of chemicals actually charged in the coagulation treatment facility is determined based on which of the plurality of beakers achieved the target water quality value and showed the best result.

The water quality of the water to be treated can change, but if the amount of change in water quality is small, the set value obtained from the jar test can be used as it is, or the set value can be changed according to the change in water quality. The amount of chemicals added can be adjusted. Further, it is possible to prepare a plurality of setting values based on the result of the jar test and select one of the setting values according to the water quality. However, if the water quality of the water to be treated changes significantly, the set value based on the result of the jar test performed earlier cannot be used, and the jar test is performed again to search for the optimum value of the chemical input amount. There is a need to.

Several techniques have been proposed for automatically controlling the amount of chemicals injected in the coagulation processing equipment. Regarding the amount of the inorganic coagulant added in the coagulation treatment device for coagulating and precipitating the activated sludge, Patent Document 1 has a configuration in which the inorganic coagulant is charged so that the surface charge of the activated sludge in the aeration tank is in a neutralized state. It is disclosed. However, the method described in Patent Document 1 is limited to the treatment of specific activated sludge and requires a means for measuring surface charge, which complicates the equipment configuration. In addition to the inorganic flocculant, it is necessary to add a polymer flocculant, which requires a process to determine the optimum value of the chemical charge by a jar test. Regarding the coagulation treatment device for water purification treatment, Patent Document 2 describes the turbidity of raw water and the supernatant liquid when the coagulant is injected into the turbidity classification treated water obtained by classifying the turbidity of the raw water with a rotary filter. It is disclosed that the turbidity of the floc classification-treated water obtained by injecting the flocculant into the raw water and then classifying the water is used to determine the injection amount of the flocculant. However, the method described in Patent Document 2 requires a rotation filter or the like, which complicates the equipment configuration, and when the water quality of the water to be treated changes significantly, it is necessary to perform a jar test in the end.

Japanese Unexamined Patent Publication No. 2014-91055 Japanese Unexamined Patent Publication No. 2011-67776

The operating conditions of the coagulation treatment equipment, especially the amount of chemicals injected and the injection rate, are determined based on the results of a jar test on the sample water collected from the water to be treated, but when the properties of the water to be treated change. You need to run the jar test again and set it again. Since it takes a certain amount of time to carry out the jar test, the coagulation processing equipment will be operated under non-optimal operating conditions until the chemical injection amount is reset based on the jar test results. There is a concern that the equipment installed after the coagulation treatment equipment will be adversely affected. It is desired to shorten the time for operating the coagulation processing equipment under suboptimal operating conditions.

When the optimum value of the chemical input amount is obtained by the jar test, the trial and error method is used, so that the jar test is repeatedly executed until a state determined to be the optimum aggregation state is obtained. Therefore, it is important to select the initial conditions of the jar test, and if the jar test is started under appropriate initial conditions, the time required to obtain the optimum value of the chemical input amount can be shortened. Skilled workers can select appropriate initial conditions to reduce the number of jar test trials, but when inexperienced workers perform jar tests, the optimum operating conditions for the coagulation processing equipment should be selected. It takes a lot of time to repeat the jar test to set it.

An object of the present invention is to provide an operation method and an operation system of a coagulation treatment equipment capable of quickly adapting the operating conditions of the coagulation treatment equipment to the water quality after the change even when the water quality of the water to be treated fluctuates. To provide.

The operation treatment method of the present invention is an operation method of a coagulation treatment device that performs a coagulation treatment of the water to be treated, and when a part of the water to be treated is branched to perform a coagulation test according to the actual treatment in the coagulation treatment device. As the initial condition of, the test condition obtained by searching the database accumulating the water quality condition, the test condition and the result of the aggregation test conducted in the past by the current water quality condition is used.

The operation treatment system of the present invention is an operation system that controls the operation of the coagulation treatment device that performs the coagulation treatment of the water to be treated, and performs a coagulation test on the test water in which a part of the water to be treated is branched. Using the database that stores the water quality conditions, test conditions and results of the coagulation test conducted in the past for the test equipment and one or more coagulation treatment equipment, and the test conditions obtained by searching the database according to the current water quality conditions. It has a control device for causing a cohesion test device to perform a cohesion test.

According to the present invention, a database accumulating water quality conditions, test conditions and results for coagulation tests conducted in the past for one or more coagulation treatment devices that may be different from the target coagulation treatment device is used. Since the test conditions are acquired from the database using the current water quality conditions when the aggregation test is to be performed, the test conditions considered to be optimal for the current water quality conditions can be obtained. By performing this coagulation test using these test conditions, even if the water quality of the water to be treated fluctuates, the operating conditions of the coagulation treatment equipment can be quickly adapted to the changed water quality.

It is a figure which shows the structure of the coagulation processing apparatus of one Embodiment of this invention. It is a flowchart which shows the process of setting an operating condition.

Next, a preferred embodiment of the present invention will be described. FIG. 1 shows the configuration of a coagulation processing apparatus according to an embodiment of the present invention. This coagulation treatment device performs a coagulation treatment by adding a coagulant or the like to the water to be treated, and is provided on the admixture tank 10 for adding and mixing the coagulant to the water to be treated and on the downstream side of the admixture tank 10. The coagulation tank 20 is provided on the downstream side of the coagulation tank 20 to form flocs by adding a coagulation aid to the water to be treated to which the coagulant is added, and the water to be treated on which the flocs are formed is treated. It is provided with a processing device 30 for performing. The treatment device 30 is, for example, a settling tank, a levitation tank, or the like, and discharges the treated water from the coagulation treatment device. Further, the coagulation processing device includes an automatic jar tester 41 for executing a jar test and a control device 42 for controlling the entire operation of the coagulation processing device. The control device 42 is connected to the database 43. The control device 42 is configured by, for example, a programmable logic controller (PLC) or a microcomputer.

In the pipe that supplies the water to be treated to the mixing tank 10, the temperature sensor 51 that measures the temperature of the water to be treated, the turbidity sensor 52 that measures the turbidity of the water to be treated, and the flow rate of the water to be treated are measured. A flow sensor 53 is provided. The turbidity sensor 52 may be a sensor that measures SS (suspended solid) or hue, not the turbidity of the water to be treated. Further, the pipe for supplying the water to be treated may be provided with a pH sensor 54 for measuring the pH of the water to be treated supplied to the mixing tank 10.

The mixing tank 10 is provided with a stirring device 12 driven by a motor 11 to agitate the water to be treated in the mixing tank 10 and a pH sensor 13 for measuring the pH of the water to be treated in the mixing tank 10. Further, the mixing tank 10 is supplied with water to be treated and a flocculant, and as a pH adjuster, acids such as hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), and carbon dioxide (CO ₂ ) and sodium hydroxide (NaOH) are supplied. ), Calcium hydroxide (Ca (OH) ₂ ), sodium carbonate (Na ₂ CO ₃ ) and other alkalis are being injected. An acidic pH adjuster such as hydrochloric acid is referred to as an acid side pH adjuster, and an alkaline pH adjuster such as sodium hydroxide is referred to as an alkaline side pH adjuster. The measured values of the sensors 13, 51 to 54 are sent to the control device 42.

The coagulation tank 20 is provided with a stirring device 22 that is driven by a motor 21 to stir the water to be treated in the coagulation tank 20.

A turbidity sensor 31 for measuring the turbidity of the treated water is provided in the pipe of the treated water discharged from the treatment equipment 30. The turbidity sensor 31 may be a sensor that measures SS or hue instead of turbidity, or may be a sensor that simultaneously measures turbidity and hue. The pipe of the treated water may be further provided with a pH sensor 32 for measuring the pH of the treated water. The measured values of the sensors 31 and 32 are sent to the control device 42.

The automatic jar tester 41 is a coagulation test device, and the water to be treated branched from the pipe of the water to be treated is supplied, and at the same time, a coagulant, an acid side pH adjuster, an alkaline side pH adjuster and a coagulation aid are supplied. Then, the jar test is automatically performed according to the test conditions instructed by the control device 42. The automatic jar tester 41 has a camera for photographing the formation state of flocs in the water to be treated and a sensor for measuring the water quality of the water to be treated after the jar test, for example, turbidity (may be SS or hue). It is equipped with a sensor for measurement, and sends the image captured by the camera and the measured value by the sensor to the control device 42 as a test result. The automatic jar tester 41 may include a pH sensor, in which case the measured value by the pH sensor is also sent to the control device 42.

Next, the database 43 will be described. In the present embodiment, the database 43 is constructed on a computer such as a server that may be provided separately from the control device 42, and may be the same or different from one or more coagulation processing devices. It accumulates information on past jar tests conducted on. The control device 42 and the database 43 are connected by a communication line or the like. In FIG. 1, the control device 42 and the database 43 are provided on a one-to-one basis, but in reality, agglomeration processing devices provided at each of a plurality of locations separated from each other are connected to a single database 43. are doing. The database 43 is queried for setting test conditions when the jar test is performed in the coagulation processing device, and the water quality conditions and test conditions (particularly the injection amount of chemicals and the like) when the jar test is performed in each coagulation processing device. It accumulates the results of the jar test (especially the aggregated state). Therefore, it is preferable that each coagulation processing apparatus connected to the database 43 transmits the water quality condition, the test condition, and the result of the jar test at that time to the database 43 each time the jar test is executed. By sharing one database 43 with a plurality of coagulation treatment devices, the optimum test conditions for each water quality in a wide range of the water quality of the water to be treated are accumulated in the database 43. As a result, when the water quality of the water to be treated fluctuates greatly and deviates from the allowable range threshold value, an appropriate test based on the results of past jar tests is performed by searching the database 43 based on the fluctuating water quality. The condition can be easily obtained as a reference value for executing a new jar test. Further, in order to search for the initial conditions of the jar test when the coagulation treatment apparatus is newly provided, the database 43 can be used to obtain the initial conditions suitable for the water quality conditions.

Next, the control device 42 will be described. The control device 42 controls the entire coagulation processing device based on the measurement results of the sensors 13, 31, 32, 51 to 54. In the coagulation treatment apparatus shown in FIG. 1, the injection amount (or injection rate) of the coagulant, the injection amount (or injection rate) of the coagulation aid, and the injection of the pH adjusters on the acid side and the alkaline side are controlled. It is controlled by the device 42. The stirring conditions of the stirring devices 12 and 22 are also controlled by the control device 42 by solving the motors 11 and 21. The pH in the mixing tank 10 is maintained at a value set in the operating conditions by feedback control of the injection of the pH adjuster by the control device 42 based on the measured value by the pH sensor 13.

Further, the control device 42 has a function of communicating with the database 43, sets test conditions in the automatic jar tester 41 to execute a jar test, receives a test result from the automatic jar tester 41, and performs aggregation processing based on the received test result. It has a function to set the operating conditions of the device. The test conditions set in the automatic sol tester 41 include an injection amount of a coagulant, a coagulation aid, a pH adjuster, a stirring time, a standing time, and the like. In the present embodiment, the best one is selected from the test results of the jar test and reflected in the actual operation of the coagulation processing apparatus, but as described later, even if the operating conditions are automatically set. Alternatively, the operating conditions may be set with the confirmation of the operator.

In the present embodiment, the data server 43 is searched as the test condition of the jar test when the coagulation treatment apparatus is installed and operated for the first time, or as the test condition of the jar test to be performed when the water quality of the water to be treated changes significantly, for example. Use what is obtained by doing. Therefore, the control device 42 has a function of requesting an initial value (at the time of the first jar test) and a reference value (when the water quality condition changes significantly) from the data server 43 and acquiring the initial value or the reference value from the database 43. .. Specifically, the database 43 is searched using the current water quality conditions grasped by the measured values from the sensors 13, 31, 32, 51 to 54, and the initial values or the initial values are considered to be optimal for the current water quality conditions. Get the test condition which is a reference value. Then, the automatic jar tester 41 is made to execute the jar test based on the acquired test conditions. At this time, a probabilistic statistical analysis is performed on the data in the database 43, and a plurality of test conditions are acquired in the order in which the success probability is expected to be high as the jar test to be performed this time, and the actual jar test is passed. Until, the acquired test conditions may be applied sequentially and the jar test may be repeatedly executed. Further, when a passing value exists in the database 43 regarding the injection rate of the aggregating agent and the aggregating aid in a certain turbidity (or SS, chromaticity) range, the minimum value Min and the maximum value Max are acquired, and (1). ) Average value Ave1 between the minimum value Min and the maximum value Max, (2) Average value Ave2 between the average value Ave1 and the maximum value Max, (3) Maximum value Max, (4) Mean value between the average value Ave2 and the minimum value Min. The execution order of the jar test may be determined in the order of the value Ave3 and (5) the minimum value Min, and the jar test may be executed until the actual jar test is passed.

The water quality conditions used for searching the database 43 include SS (or turbidity or hue) of the water to be treated, pH of the water to be treated, water temperature of the water to be treated, SS (or turbidity or hue) of the treated water, and treatment. At least one of the pH of the target water is used. In order to increase the amount of data stored in the database 43 and obtain more reliable results, in the present embodiment, the control device 42 performs the test results (water quality conditions and) every time the jar test is executed. It is highly preferable to send the test conditions) to the database 43.

Next, the operation method of the coagulation processing apparatus of this embodiment will be described.

Conventionally, when determining the operating conditions in a coagulation treatment device having a mixing tank or a coagulation tank, an appropriate operating condition is searched for by manually performing a jar test on the water to be treated so that the operating conditions are satisfied. The settings of each device were changed. For example, for pH, a target setting value is input to the programmable logic controller so that feedback control is performed for the pH of the admixture tank, and the setting of the coagulant and coagulation aid is also changed in the device to adjust the injection rate. Was.

On the other hand, in this embodiment, although the configuration of the part to be aggregated and the configuration of various sensors are not changed as compared with the conventional one, the jar test performed by humans on the water to be treated is performed. The series of steps in is automated, and the test conditions for the jar test can be set automatically. Operating conditions can be automatically determined based on the results of automated jar tests and equipment settings can be changed. As a result, in the present embodiment, it becomes possible to automatically respond to changes in the water quality of the water to be treated even when the administrator is absent, and it can be expected to avoid fatal treatment failure troubles.

FIG. 2 is a flowchart showing a process of setting operating conditions in the coagulation processing apparatus of the present embodiment. When the operation of the coagulation treatment device is started, the control device 42 first confirms the water quality of the water to be treated by using various sensors in step 101, and in step 102, the water quality of the water to be treated is a predetermined threshold value. To determine if it deviates from. If the water quality is within the threshold range, the control device 42 causes the automatic jar tester 41 to execute the jar test according to the test conditions currently set in step 103, and receives the test result. In step 104, the control device 42 determines whether the test result is acceptable or not. If the test is not passed in step 104, the control device 42 changes the test conditions of the jar test according to the preset fluctuation range and priority in step 105, and again performs the jar test on the automatic jar tester 41. Run and receive test results. After executing step 105, the process returns to step 104.

On the other hand, when the water quality of the water to be treated deviates from the threshold value in step 102, the control device 42 obtains the result of the jar test for the water to be treated close to the water quality of the current water to be treated from the database 43 in step 106. The test condition corresponding to the result showing a good aggregation state is called, the automatic jar tester 41 is made to execute the jar test based on the called test condition, and the test result is received. When the test result is received, the process proceeds to step 104.

In the coagulation processing apparatus of the present embodiment, when the operating conditions are set based on the result of the jar test, the operating conditions are automatically set without the intervention of the operator, or the operation is performed based on the result of the jar test. After determining the conditions, the operator can select whether to actually set the operating conditions in the coagulation processing device after approval. Therefore, if the test result is passed in step 104, the control device 42 determines the new operating conditions of the coagulation processing device (for example, the injection amount of the coagulant or the coagulation aid, the pH value) based on the test result. , Stirring conditions, etc.), and in step 111, it is determined whether the current setting reflection method is automatic (automatic) or semi-automatic (semi-automatic). If it is auto, the process proceeds to step 113 as it is. In the case of semi-automatic mode, in step 112, the control device 42 presents a new operating condition to the operator via a display device (not shown) or the like, and the operator accepts the input from the operator. It is determined whether or not the setting change due to the new operating condition is approved. If the setting change is approved, the process proceeds to step 113, and if the setting change is not approved, the process proceeds to step 105.

In step 113, the control device 42 sets a new operating condition based on the jar test in the coagulation processing device. After that, the control device 42 determines in step 114 whether or not the water quality of the treated water deviates from the threshold value, proceeds to the process in step 105 if it deviates, and if it does not deviate, the periodic start condition in step 115. Is satisfied. In the coagulation treatment apparatus of the present embodiment, even when the change in water quality of the water to be treated is not detected, a jar test is periodically performed in order to confirm whether the coagulation treatment can be performed under the optimum conditions. The process of step 115 confirms whether or not it is time to execute the periodic jar test. If the periodic start condition is satisfied, the process proceeds to step 103 and the periodic start condition is not satisfied. Occasionally, the treatment shifts to step 101 for continued monitoring of water quality fluctuations in the water to be treated.

In the treatment shown in FIG. 2, in steps 102 and 114, a single threshold value is used for detecting the fluctuation of the water quality in the water to be treated and the treated water, respectively. However, a plurality of threshold values are used in the determination of each water quality, and depending on which threshold value is deviated, for example, "a jar test is executed by changing the test conditions according to a preset fluctuation range and priority" or "database". You may choose one of "Run a jar test using the test conditions obtained by searching for 42". As a result, when the inflow water quality fluctuates significantly, the test conditions can be changed significantly and the jar test can be executed, so that the length of time during which the settings do not match and the processing becomes defective can be shortened.

According to the coagulation processing apparatus of the present embodiment described above, it is possible to perform highly accurate automatic operation and shorten the length of time for processing failure as compared with the conventional condensation processing apparatus advocating automatic control. can.

10 Mixing tank 20 Coagulation tank 30 Processing equipment 41 Automatic jar tester 42 Control device 43 Database

Claims (8)

It is an operation method of the coagulation treatment device that performs the coagulation treatment of the water to be treated.
As an initial condition when a part of the water to be treated is branched and a coagulation test is performed according to the actual treatment in the coagulation treatment apparatus, a database accumulating water quality conditions, test conditions and results for the coagulation test conducted in the past. Using the test conditions obtained by searching for the current water quality conditions ,
When the quality of at least one of the water to be treated or the treated water deviates from the threshold value, the aggregation test is performed to reset the operating conditions of the aggregation treatment apparatus.
A plurality of threshold values for water quality are set, and depending on which threshold value is deviated, the test conditions are changed according to the preset fluctuation range and priority, and the aggregation test is executed, or the database is searched and obtained. A method of operating a coagulation processing apparatus, wherein either the coagulation test is performed using the set test conditions or the coagulation test is performed . The operation method according to claim 1, wherein the water quality condition, the test condition, and the result are transmitted to the database and stored each time the aggregation test is performed in the aggregation processing apparatus. The operation method according to claim 1 or 2, wherein the operating conditions of the coagulation processing apparatus are set based on the latest coagulation test results each time the coagulation test is performed in the coagulation processing apparatus. The operation method according to any one of claims 1 to 3, wherein the database is provided in common for a plurality of coagulation processing devices. With at least one of suspended solids, turbidity and hue as a suspension index, the water quality conditions are the suspension index of the water to be treated, the pH of the water to be treated, the water temperature of the water to be treated, and the suspension of the treated water. The operation method according to any one of claims 1 to 4 , which comprises one or more items selected from the turbidity index and the pH of the treated water. It is an operation system that controls the operation of the coagulation treatment device that performs the coagulation treatment of the water to be treated.
An aggregation test device that performs an aggregation test on the water under test in which a part of the water to be treated is branched,
A database accumulating water quality conditions, test conditions, and results of coagulation tests conducted in the past for one or more coagulation treatment devices.
A control device that causes the aggregation test device to perform an aggregation test using the test conditions obtained by searching the database according to the current water quality conditions.
Have,
When the quality of at least one of the water to be treated or the treated water deviates from the threshold value, the control device causes the aggregation test device to perform the aggregation test and resets the operating conditions of the aggregation treatment device.
A plurality of threshold values for water quality are set, and whether the control means executes the aggregation test by changing the test conditions according to the preset fluctuation range and priority according to which threshold value is deviated. An operating system that selects whether to perform the aggregation test using the test conditions obtained by searching the database . The operation system according to claim 6 , wherein the control device transmits the water quality condition, the test condition, and the result to the database each time the aggregation test is performed by the aggregation test device. The operation system according to claim 6 or 7 , wherein the control device sets the operating conditions of the coagulation processing device based on the result of the latest coagulation test each time the coagulation test is performed.

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