KR200408180Y1 - Membrane filtering water treatment apparatus having pre-treatment selectively controled by the quality of raw water - Google Patents

Abstract

The present invention relates to a membrane filtration advanced processing apparatus including a raw water storage tank, a mixing tank, a coagulation tank, a sedimentation tank, and a membrane system. More specifically, the raw water of the raw water storage tank is directly filtered using an automatic control system. Raw water to Membrane (RM) process, and flocculation to Membrane (FM) process, which are coagulated and precipitated by administering coagulant to raw water in raw water storage tank, can be selectively applied. The present invention relates to a selective pretreatment membrane filtration advanced processing apparatus using automatic control.

The selective pre-treatment membrane filtration advanced processing apparatus using the automatic control according to the present invention is a membrane filtration advanced processing apparatus including a raw water storage tank, a mixing tank, a flocculation tank, a settling tank, and a separation membrane system, wherein the raw water introduced into the raw water storage tank is Raw water storage tank meter installed to measure the turbidity (Ta) and pH in real time, sedimentation tank meter installed to measure the turbidity (Tb) of the membrane feed water flowing out of the settling tank in real time, and a flocculant to be administered to the mixing tank A flocculant injector installed so as to be connected to the mixing tank and one or more agitators and the raw water reservoir meter and the sedimentation tank meter, and collecting measured values and comparing the flocculant injector with a reference value of preset turbidity and pH. Includes automatic control system to selectively control the operation of the stirrer Characterized in that configured.

Membrane filtration, advanced treatment, water treatment, membrane separation, membrane, turbidity, selective pretreatment, algae water, automatic control, effluent

Description

Membrane filtering water treatment apparatus having pre-treatment selectively controlled by the quality of raw water}

1 is a schematic configuration showing a membrane filtration advanced processing apparatus according to the prior art,

2a and 2b is a schematic diagram and photograph showing a membrane module and a membrane system used in the membrane filtration advanced processing apparatus,

Figure 3 is a schematic configuration showing a selective pretreatment membrane filtration advanced processing apparatus according to the present invention,

4 is a schematic configuration diagram showing an automatic control system according to the present invention;

5A and 5B are explanatory views showing a raw water direct membrane filtration (R-M) process and a flocculation sedimentation membrane filtration (F-M) process according to the present invention;

6 is a schematic flowchart illustrating a selective pretreatment membrane filtration advanced treatment method according to the present invention.

**** Description of the symbols for the main parts of the drawings ****

2: raw water storage tank 4: mixing tank

6: flocculation tank 8: precipitation tank

10: membrane system 20: pretreatment process

30: discharged water reuse system 52: raw water reservoir measuring instrument

53: flocculant injector 54, 56: stirrer

58: sedimentation tank measuring instrument 80: automatic control system

The present invention relates to a membrane filtration advanced processing apparatus including a raw water storage tank, a mixing tank, a coagulation tank, a sedimentation tank, and a membrane system. More specifically, the raw water of the raw water storage tank is directly filtered using an automatic control system. By selectively applying Raw Water to Membrane (RM) process and flocculation to Membrane (FM) process, which is subjected to flocculation and coagulation sedimentation by administering coagulant to raw water in raw water storage tank, Regardless of the rapid change of raw water quality, it ensures safe and stable treatment water quality, and if the raw water quality is good, it eliminates the pretreatment process of mixed condensation, not only reducing the operating cost but also automatic control that can achieve unmanned through automation. It relates to a selective pretreatment membrane filtration advanced processing device using.

In recent years, the introduction of advanced water treatment systems has become commonplace as water supply pollution becomes more serious. In addition, it is difficult to secure a new water treatment plant site, and a method of improving an existing old water treatment plant to an advanced water treatment plant is being studied. As one such solution, advanced water treatment processes using membrane filtration have been developed. The advanced water treatment process using membrane filtration has the advantage that it can be easily applied to the existing water treatment process because it is not only easy to operate and maintain, but also compact.

1 is a schematic block diagram showing an example of a membrane filtration advanced processing apparatus according to the prior art. As shown, the membrane filtration advanced processing apparatus 1 is generally composed of a raw water storage tank 2, a mixing tank 4, a coagulation tank 6, a precipitation tank 8, and a membrane system 10. Therefore, the raw water supplied from the raw water treatment tank 2 passes through the mixing tank 4, the coagulation tank 6, and the settling tank 8, and then flows into the separation membrane system 10 in a treated state.

The membrane system 10, as shown in Figure 2a and 2b, is composed of a plurality of membrane modules, the membrane module is preferably an MF membrane (Microfiltration mambrane). This MF membrane has pores small enough to remove most bacteria. In addition, it is also possible to change and install the UF membrane (Ultrafiltration) that can remove the virus in place of the MF membrane. Thus, the membrane system 10 removes harmful substances such as viruses and THMs as well as pathogenic microorganisms such as Giardia and Cryptosporidium contained in raw water.

However, the advanced treatment process (1) using the conventional membrane system has a problem that the operating cost is increased because a large amount of flocculant and energy is used.

It is economically applicable only if the water quality of the raw water is relatively good. In other words, filtering raw water with high concentrations of various organic substances and green algae causes membrane fouling, which shortens the filtration time, reduces the production volume, shortens the life of the membrane, and provides stable treatment water through frequent backwashing. There will be no. Therefore, in the conventional membrane filtration advanced treatment apparatus, a pretreatment process consisting of one or more mixing tanks and agglomeration tanks is placed in front of the membrane system to maintain the water quality of the membrane feed water supplied to the membrane system at a constant level to enable economic treatment.

However, in such a pretreatment process, since a large amount of flocculant and energy is used, there is a problem in that operating costs are increased. In addition, the raw water flowing into the membrane filtration advanced treatment system often changes depending on the season and climate, and the water quality of the raw water also changes rapidly due to rainfall or pollutant leakage. Therefore, a new type of membrane filtration advanced treatment device that can save the cohesive and energy required for the pretreatment by minimizing the operation time of the pretreatment process by minimizing the operation time of the pretreatment process by rapidly responding to the rapidly changing raw water quality. Is required.

The present invention has been made to solve this problem, the main purpose of the present invention is to apply the mixing / flocculation and precipitation process as a pretreatment process of the membrane system, the raw water quality of the raw water supplied from the raw water reservoir and the membrane feed water supplied from the sedimentation tank Depending on the quality of the water, the pretreatment process consisting of the mixing / aggregation and precipitation processes may be performed or omitted to ensure safe and stable treatment regardless of the change in the quality of the raw water, and the mixing / aggregation process may be omitted if the quality of the raw water is good. It is to provide an optional pretreatment membrane filtration advanced processing device that can reduce the operating cost and achieve unmanned through automation.

 In addition, the present invention is a pretreatment consisting of mixing / flocculation and precipitation according to the turbidity (Ta, Tb), pH or algae water of the raw water supplied from the raw water reservoir and the membrane feed water supplied from the sedimentation tank using an automatic control system interlocked with the measuring instrument It is to provide an optional pretreatment membrane filtration advanced treatment apparatus to selectively apply the process.

In addition, the present invention, using an automatic control system interlocked with one or more measuring instruments, if the turbidity (Ta), pH or algae number of the raw water flowing into or supplied from the raw water storage tank is less than the reference value directly blocks the raw water of the raw water storage tank. Raw water direct membrane filtration (RM: Raw water to Membrane) process is carried out. The present invention provides a method for selective pretreatment membrane filtration using an automatic control to selectively apply flocculation to membrane (FM) process.

In order to achieve the object of the present invention, the selective pretreatment membrane filtration advanced processing apparatus using the automatic control according to the present invention, the membrane filtration advanced processing apparatus comprising a raw water storage tank, mixing tank, flocculation tank, sedimentation tank and separation membrane system A raw water storage tank measuring instrument installed to measure in real time the turbidity (Ta) and pH of the raw water introduced into the raw water storage tank, and a sedimentation tank installed to measure the turbidity (Tb) of the membrane feed water flowing out of the settling tank in real time. A measuring device, a flocculant injector installed to administer the flocculant to the mixing tank, one or more agitators and the raw water storage tank measuring device and the sedimentation tank measuring device installed in the mixing tank and the flocculating tank to collect measured values, and set a predetermined turbidity and operation of the flocculant injector and stirrer compared to the reference value of pH It is configured to include an automatic control system for controlling the optional.

In the present invention, the automatic control system further includes an input means for inputting the measured value of the number of birds measured by water quality analysis.

In addition, the automatic control system stops the operation of the flocculant injector and stirrer when the turbidity (Ta) of the raw water measured by the raw water reservoir measuring instrument is 20 NTU or less, or when the pH is 5.6 or more or the number of algae individuals is 10,000 / mL or less. It features.

In addition, the automatic control system is a pretreatment by operating the flocculant injector and stirrer when the turbidity (Tb) of the membrane feed water measured by the sedimentation tank measuring instrument is 10NTU or more, the pH of the raw water is 8.6 or more, or the number of algae individuals 10,000 or mL Characterized in that.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the selective pre-treatment membrane filtration advanced processing apparatus using automatic control according to the present invention.

First, Figure 3 is a block diagram showing a selective pre-treatment membrane filtration advanced processing apparatus using an automatic control according to the present invention. As shown, the selective pre-treatment membrane filtration advanced processing device (hereinafter abbreviated as 'membrane filtration advanced processing device') 100 using automatic control according to the present invention is a mixing tank 4, a plurality of coagulation tank (6) ) And a preliminary treatment device 20 composed of a settling tank 8, a raw water storage tank 2 having a predetermined size installed in front of the pretreatment device 20, and a plurality of separation membrane modules installed at a rear end of the pretreatment device 20. It consists of a membrane system 10 including (12).

In addition, a granular activated carbon filtration process (GAC) is preferably installed at the rear end of the separation membrane system 10. In addition, although not shown, a powder activated carbon contact tank may be further installed between the raw water storage tank 2 and the pretreatment apparatus 20 through a separate channel. And it is preferable that the discharge water reuse system 30 is installed between the separation membrane system 10 and the raw water storage tank 2 through a separate treated water transfer path 31.

On the other hand, the membrane filtration advanced processing apparatus 100 according to the present invention, the raw water storage tank 2 is installed in the raw water storage tank measuring unit 52 for automatically measuring the turbidity (Ta) and pH of the raw water, the settling tank (8) ) Is provided with a sedimentation tank measuring instrument 58 for automatically measuring the turbidity Tb of the membrane feed water.

In the front end of the mixing tank 4, a flocculant injector 53 for administering a flocculant is provided. At this time, the flocculant injector 53 includes a flocculant injection pump for adjusting the amount of flocculant introduced into the mixing tank. The mixing tank 4 and the coagulation tank 6 are provided with agitators 54 and 56, respectively. The stirrers 54 and 56 are equipped with an electric motor.

Subsequently, the membrane filtration advanced processing apparatus 100 according to the present invention is electrically connected to the raw water reservoir measuring instrument 52 and the sedimentation tank measuring instrument 58, and collected through a predetermined reference value and the measuring instruments 52 and 58. Automatic control system 80 for selectively controlling the injection pump of the flocculant injector 53 and the motors of the stirrers 54 and 56 installed in the mixing tank 4 and the flocculation tank 6 by comparing the measured values. It includes more.

Therefore, the membrane filtration advanced processing apparatus 100 according to the present invention is automatically operated according to the quality of raw water measured in real time by the raw water reservoir measuring instrument 52 and the quality of the membrane feed water measured in real time by the sedimentation tank measuring instrument 58. The control system 80 automatically controls the pretreatment device 20. For example, when the concentration of contaminants contained in the raw water supplied from the raw water storage tank 2 is lower than the reference value (that is, good water quality), the automatic control system 80 stops the operation of the pretreatment device 20. Let's do it. On the other hand, when the concentration of pollutants contained in the raw water is higher than the reference value (that is, poor water quality), the automatic control system 80 operates the pretreatment device 20 so that a high concentration of pollutants flow into the membrane system 10. Prevent it.

In addition, the present invention measures the water quality of the membrane feed water supplied from the settling tank 8, when the concentration of the pollutant is less than the reference value (that is, good water quality) to stop the pretreatment device 20, the contaminants of the membrane feed water When the concentration is higher than the reference value (that is, poor water quality), the pretreatment device 20 is executed to prevent membrane contamination by various contaminants such as high concentration organic materials and green algae.

In this way, the present invention is capable of quickly responding to the rapidly changing water quality fluctuation by selectively controlling the pretreatment device 20 based on the water quality measured in the raw water storage tank (2) and sedimentation tank (8) spaced apart in time and space. Membrane contaminants are blocked from entering the membrane system (10).

Subsequently, as shown in FIG. 4, the automatic control system 80 according to the present invention includes a PLC system 84 and an integrated management system 86. The PLC system 84 collects the measured values of turbidity and pH measured in real time by the raw water reservoir measuring instrument 52 and the sedimentation tank measuring instrument 58, compares them with a predetermined reference value through a predetermined automatic operation program, and then preprocesses them. Select the mode automatically. To this end, the PLC system 84 is electrically connected to the raw water reservoir measuring instrument 52 and the sedimentation tank measuring instrument 58, and the coagulant injecting pump and the stirrer motor, and the CPU which stores the automatic operation program and performs a CPU function. And the like.

 And the integrated management system 86 is an input device for inputting the number of birds and other control commands measured through a separate number analysis, a display device for displaying the measured value measured through the instrument to the outside, the trend of the measured value Graphical means for showing a graph and a control unit for controlling them.

Therefore, the automatic control system 80 according to the present invention is a measurement value measured through the raw water reservoir measuring instrument 52 and the sedimentation tank measuring instrument 58, the number of bird subjects input through the input device, and is preset in the PLC system The pretreatment mode can be selected by controlling the coagulant injection pump and the stirrer motor on / off by running an automatic operation program based on the reference value.

5A and 5B are schematic diagrams showing two preprocessing operation modes according to the present invention.

5a is a raw water direct filtration process (R-M: Raw water to Membrane) applied when the quality of raw water is good. At this time, the control factor of the control device according to the present invention is based on the turbidity and pH measured in real time through a measuring instrument. In addition, the present invention can be used as another control factor the number of algae measured through a separate water analysis. In general, it is known that the number of birds and the pH closely correlated, both can be used simultaneously or selectively.

Raw water direct filtration process (RM) according to the present invention has a turbidity (Ta) of the raw water measured by the raw water reservoir measuring instrument 52 is 20 NTU or less, pH of 5.6 or more or the algae of raw water input through the integrated management system 86 Applies when the population is below 10,000 / mL. In this raw water direct filtration process (R-M), the raw water of the raw water storage tank 2 is introduced into the membrane system 10 without a pretreatment process to perform membrane filtration. In this case, the mixing tank 4 and the coagulation tank 6 do not perform the original pretreatment function, but merely serve as a channel through which raw water is transferred. In other words, the coagulant injection pump of the mixing tank 4 and the motors of the stirrers 54 and 56 provided in the mixing tank 4 and the coagulation tank 6 are stopped. On the other hand, the settling tank 8 to reduce the load flowing into the membrane system 10 by sedimenting the particles contained in the raw water. Therefore, the water quality of the raw water measured in the sedimentation tank 8 is more improved than the water quality of the raw water measured in the raw water storage tank 2.

Figure 5b is a flocculation sedimentation filtration process (F-M: Flocculation to Membrane) is selectively applied when the water quality of the raw water fell according to the change of seasons or climate. The flocculation sedimentation filtration process (F-M) is applied when the turbidity (Tb) of the membrane feed water measured by the sedimentation tank meter 58 is 10 NTU or more, the pH of the raw water is 8.6, or the number of algae individuals is 10,000 or more mL / mL. This coagulation sedimentation filtration process (F-M) is introduced into the membrane system 10 after the raw water in the raw water storage tank 2 has undergone both the mixing / flocculation and the pretreatment process of precipitation. In the mixing tank 4, the flocculant is administered through the flocculant injector 53, and in the flocculation tank 6, the agitators 54 and 56 operate to perform the flocculation function. And the settling tank 8 gravity-sets the flocculated floc.

Hereinafter, with reference to Figure 6 will be described a selective pre-treatment membrane filtration advanced processing method using an automatic control according to the present invention.

First, when the turbidity (Ta) of the raw water measured by the raw water reservoir measuring instrument 52 is 20 NTU or less, or the pH is 5.6 or more or the number of algae is 10,000 or mL or less, membrane filtration directly from the membrane system 10 without undergoing a pretreatment process. Raw membrane direct filtration (RM) is performed.

As such, the membrane filtration advanced treatment apparatus 100 according to the present invention can perform the raw water direct filtration process (R-M) in normal times, thereby saving the coagulant and energy. The present invention significantly reduces the maintenance cost compared to the existing water treatment equipment. For example, as shown in the table below, the turbidity of the raw water flowing into the water treatment plant is 10.4 NTU on average, pH is 7.4 and the number of algae is 6,718.

<Table>

division pH Turbidity (NTU) Temperature (℃) Coagulant (KMn0 ₄ ) Consumption (mg / L) Number of bird individuals (dog / mL) maximum 8.9 137.7 24.8 16.3 26,180 at least 6.8 2.6 1.0 3.6 580 Average 7.4 10.4 13.1 4.9 6,718

Results of Analysis of Waterworks Research Institute

Therefore, the membrane filtration advanced processing apparatus 100 according to the present invention will perform most of the operating time by the raw water direct filtration process (R-M). Considering this point, the present invention has an effect of saving 40 to 50% of operating cost compared to a conventional water treatment device.

On the other hand, as shown in Figure 6, such as during the rainfall or during the dry season or algal bloom time is generated a lot of pollutants and algae turbidity (Ta) of the raw water measured in the raw water reservoir measuring instrument 52, or the pH is 5.6 If the number of birds or less than 10,000 / mL or more is carried out coagulation sedimentation filtration process (FM). The flocculation sedimentation filtration process (F-M) is performed even when the turbidity Tb of the membrane feed water measured by the sedimentation tank measuring instrument 58 is 10 NTU or more, the pH of the membrane feed water is 8.6 or more, or the number of algae objects is 10,000 / mL or more.

Therefore, even when the turbidity (Ta) of the raw water measured by the raw water reservoir measuring instrument 52 is 20 NTU or less, when the turbidity Tb of the membrane feed water measured by the sedimentation tank measuring instrument 58 is 10 NTU or more, the flocculation sedimentation filtration process (FM) is performed. do. This takes into account the turbidity that is naturally removed from the settling tank 8 and also limits the turbidity introduced into the membrane system 10 to 10 NTU or less. In addition, when the pH of the feed water is more than pH8.6 or the number of algae is more than 10,000 / mL, the flocculation sedimentation filtration process (F-M) is always performed to prevent the occurrence of membrane fouling or odor by algae. If the pH of the raw water is 5.6 or more and the pH of the membrane feed water is 8.6 or less, the pretreatment process is selected in consideration of turbidity and algal individual water.

As such, the present invention can selectively respond to rapid water fluctuations by selectively switching the pretreatment process using the raw water storage tank measuring instrument 52 and the sedimentation tank measuring instrument 58 spaced at a time and place, and contaminants having high concentrations of contaminants are separated. It can be blocked from entering the system.

Meanwhile, referring to FIG. 3, the granular activated carbon filtration device 40 may be further installed at the rear end of the separation membrane system 10 so as to adsorb contaminants contained in the filtered water. The granular activated carbon filtration device 40 removes taste, smell, disinfection by-products, synthetic organic compounds, and the like contained in the filtered water. The effluent reuse system 30 also includes a plurality of tubular membrane modules. The effluent reuse system 30 increases the recovery rate of the entire water treatment plant by again filtering and recovering the backwashed water discharged from the membrane system 10 and the water contained in the sludge discharged from the washing water or the sedimentation tank 8. For example, the present invention can raise the recovery rate to 99% or more.

As described above, the selective pre-treatment membrane filtration advanced processing apparatus using the automatic control according to the present invention and the method is a mixing / flocculation and sedimentation process according to the water quality of the raw water supplied from the raw water storage tank and the membrane feed water supplied from the sedimentation tank By selectively applying the configured pretreatment process, it is possible to guarantee safe and stable treatment quality regardless of the change of raw water quality, and if the raw water quality is good, it can skip the pretreatment process and reduce operating cost and achieve unmanned through automation. It has an effect.

Claims (5)

In the membrane filtration advanced treatment apparatus including raw water storage tank, mixing tank, flocculation tank, sedimentation tank and membrane system, A raw water storage tank measuring device installed to measure turbidity (Ta) and pH of raw water introduced into the raw water storage tank in real time; A sedimentation tank meter installed to measure the turbidity (Tb) of the membrane feed water flowing out of the settling tank in real time; A coagulant injector installed to administer the coagulant to the mixing tank; At least one stirrer installed in the mixing tank and the coagulation tank; And an automatic control system electrically connected to the raw water reservoir meter and the settling tank meter to collect measured values and to selectively control the operation of the flocculant injector and the stirrer by comparing with measured turbidity and pH reference values. Selective pretreatment membrane filtration advanced processing device using automatic control. The method of claim 1, The automatic control system is an optional pre-treatment membrane filtration advanced processing device using automatic control, characterized in that the apparatus further comprises an input means for inputting the analysis value of the number of birds analyzed by water analysis. The method according to claim 1 or 2, The automatic control system includes a central processing unit electrically connected to a raw water reservoir meter and a sedimentation tank meter, electrically connected to a flocculant injector and agitator of a mixing tank, and performing a memory and a calculation function in which a predetermined automatic operation program is stored. A PLC system comprising; An input device for inputting the number of birds and the control commands analyzed through water analysis, a display device for displaying measured values measured through a measuring instrument, graphic means for showing the trend of measured values, and a control unit for controlling them. Selective pretreatment membrane filtration advanced processing device using an automatic control, characterized in that consisting of an integrated management system comprising a. The method according to claim 1 or 2, The automatic control system performs a raw water direct membrane (RM: Raw water to Membrane) process to directly filter the raw water of the raw water storage tank according to turbidity and pH measured in real time in the raw water storage tank measuring instrument and the sedimentation tank measuring instrument or coagulant to the raw water. Selective pretreatment membrane filtration advanced processing apparatus using automatic control, characterized in that the selective control of the flocculation sedimentation membrane filter (FM: Flocculation to Membrane) process to administer and coagulate precipitate. The method according to claim 1 or 2, The automatic control system stops the operation of the flocculant injector and the stirrer when the turbidity (Ta) of the raw water measured by the raw water reservoir measuring instrument is 20 NTU or less, the pH is 5.6 or more or the number of algae individuals is 10,000 or mL or less, and Selective pretreatment using automatic control, characterized in that the flocculant injector and stirrer are operated when the turbidity (Tb) of the membrane feed water measured by the settling tank meter is 10 NTU or more, the pH is 8.6 or more, or the number of algae is 10,000 or more mL. Membrane filtration advanced processing equipment.

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