KR101502052B1 - System and method for treating water including measuring of algae - Google Patents

Abstract

The present invention relates to a water treatment system and method including algae measurement. An embodiment of the present invention provides a water treatment method including algae measurement including a step in which raw water to be treated flows into a water treatment system, a step in which the raw water flowing into the water treatment system is turned into treated water through pretreatment for a membrane filtration process, a step in which the concentration of the blue-green algae and diatoms contained in the pretreated treated water is measured, a step in which a flocculant is supplied to the treated water to be mixed and impurities containing the blue-green algae is flocculated and precipitated as sludge by the flocculant, a step in which produced water is generated while a mixture of the flocculant and the treated water is filtered through a filtering membrane, a step in which part of the produced water is supplied to the filtering membrane to be backwashed, and a step in which NaOCl is supplied to the produced water supplied to the filtering membrane during the backwashing so that the diatoms are removed by the NaOCl, in which the amount of supply of the flocculant supplied during the sludge precipitation is controlled in accordance with blue-green algae concentration change and the amount of supply of the NaOCl supplied during the NaOCl supply is controlled in accordance with diatoms concentration change based on the blue-green algae and diatoms concentration data measured during the measurement step.

Description

FIELD OF THE INVENTION The present invention relates to a water treatment system and method,

The present invention relates to a water treatment system and method comprising algae measurements.

Most rivers currently in the country are constructed with dams or boats, which increases the amount of time that water in the upper reaches of rivers is staying, and the amount of water that is generated in rivers due to climate change, This trend is increasing every year.

In a water purification plant for water treatment of river water and supplying water for daily use, production water is produced based on coagulation sedimentation process using coagulant and membrane filtration process. At this time, the algae contained in the raw water may adhere to the filtration facility to cause biological fouling or cause a bad smell. Therefore, in order to obtain high quality production water, algae contained in the raw water must be removed .

The types of algae contained in the raw water are very diverse, and the characteristics of the algae species vary, so it is effective to change the treatment method depending on the species of algae. However, conventional water treatment facilities do not consider algae species, such as being treated according to a consistent treatment method regardless of algae species, and it is difficult to efficiently remove the algae species according to the characteristics of algae contained in the source water have.

In addition, conventionally, in removing the algae during water treatment, the operator is empirically added with an additive for algae elimination, or a certain amount is added periodically. It was impossible to add the additive in accordance with the algae concentration, There is a problem that the amount is supplied more than necessary or is insufficiently supplied in comparison with the concentration of the algae, so that the economic efficiency is lowered and the quality of the produced water is lowered.

In addition, the concentration of the algae changes frequently during the day according to the temperature change, and the treatment efficiency is not good because the algae can not actively cope with the concentration change.

An embodiment of the present invention is to provide a water treatment system and method including algae measurement capable of controlling the water treatment process according to the concentration of algae species in real time in response to the change in species concentration of algae.

According to an aspect of the present invention, there is provided a water supply system including: a raw water supply unit for storing and supplying raw water requiring water treatment; A pretreatment unit for pre-treating the raw water supplied from the raw water supply unit with treated water; An algae detecting unit for measuring in real time the concentration of cyanobacteria and diatoms included in the treated water transferred from the pretreatment unit; A mixing unit for mixing the treated water with a flocculant; A coagulant supply unit for supplying the coagulant to the mixing unit; A filtration unit for filtering the mixture mixed in the mixing unit with a filtration membrane to obtain production water; A production water storage part for storing the produced water filtered by the filtration part and supplying the produced water to an external use place; A NaOCl supply unit supplying a part of the produced water from the produced water storage unit to the filtration unit as reverse osmosis water through a backwash line connecting the production water storage unit and the filtration unit and supplying NaOCl to the backwash line; And a control unit for controlling the amount of coagulant supplied to the coagulant supply unit and the amount of NaOCl supplied to the NaOCl supply unit. The control unit receives the concentration data of the cyanobacteria and the diatoms detected by the algae detecting unit, A water treatment system may be provided that includes an algae measurement that adjusts the amount of coagulant supplied to the NaOCl supply unit and adjusts the NaOCl supply amount of the NaOCl supply unit in accordance with the change in the concentration of the diatom.

According to another aspect of the present invention, there is provided a water supply system comprising: a raw water supply unit for storing and supplying raw water requiring water treatment; A pretreatment unit for pre-treating the raw water supplied from the raw water supply unit with treated water; An algae detecting unit for measuring in real time the concentration of cyanobacteria and diatoms included in the treated water transferred from the pretreatment unit; A mixing unit for mixing the treated water with a flocculant; A coagulant supply unit for supplying the coagulant to the mixing unit; An agglomeration sedimentation portion in which the impurities contained in the mixture mixed in the mixing portion are agglomerated by the agglutinating agent and precipitated as sludge; An activated carbon supplying unit for supplying activated carbon to at least one of the flocculating and sedimenting unit and the mixing unit; A filtration unit for filtrating the mixture supplied from the flocculation and sedimentation unit into a filtration membrane to obtain production water; A production water storage part for storing the produced water filtered by the filtration part and supplying the produced water to an external use place; A NaOCl supply unit supplying a part of the produced water from the produced water storage unit to the filtration unit as reverse osmosis water through a backwash line connecting the production water storage unit and the filtration unit and supplying NaOCl to the backwash line; And a control unit for controlling the amount of coagulant supplied to the coagulant supply unit, the amount of activated carbon supplied to the activated carbon supply unit, and the supply amount of NaOCl supplied to the NaOCl supply unit. The control unit receives the concentration data of the cyanobacteria and the diatoms, A water treatment system may be provided that includes an algae measurement that adjusts the amount of activated carbon supplied to the activated carbon supply unit according to the concentration change of the cyanobacteria and adjusts the amount of NaOCl supplied to the NaOCl supply unit according to the concentration of the diatom.

In addition, the control unit may be provided with a water treatment system including algae measurement for increasing the supply amount of activated carbon when the concentration of the cyanobacteria is higher and increasing the supply amount of NaOCl when the concentration of the diatoms is higher.

The control unit compares the concentration of the diatoms contained in the treated water with the concentration of the cyanobacteria. The control unit determines the algae species having the highest concentration as the dominant species and sets them as the control target. When the algae are determined to be the dominant species, , And when the diatoms are judged to be the dominant species, a water treatment system including algae measurement for controlling the supply amount of NaOCl according to the diatom concentration can be provided.

A control valve for controlling a flow path of the drain water discharged after being filtered by the filtration unit; And an activated carbon recovery unit connected to the control valve for recovering at least a part of the activated carbon contained in the effluent water supplied from the control valve and returning it to the coagulated sedimentation unit.

The control valve is controlled by the control unit, and the control unit controls the control valve so that the discharge water discharged from the filtration unit is supplied to the activated carbon recovery unit only when the cyanobacteria are the dominant species. Can be provided.

The water treatment system may further include algae measurement, further comprising a cross flow line connecting the flocculation pre-sediment part and the filtration part, wherein filtration is performed in the filtration part while the treatment water flows in a cross flow manner.

In addition, a step of introducing raw water requiring water treatment into a water treatment system; Treating the raw water flowing into the water treatment system into pretreatment water for membrane filtration; Measuring the concentration of cyanobacteria and diatoms contained in the pretreated treated water; Supplying and mixing a flocculant to the treated water, and causing the flocculant to aggregate impurities including cyanobacteria to settle as sludge; Producing a water mixture by filtering the mixture of the flocculant and the treatment water through a filtration membrane; Supplying a part of the produced water to the filtration membrane and backwashing it; And supplying NaOCl to the production water supplied to the filtration membrane in the backwashing step and removing diatoms by the NaOCl, wherein the concentration of the cyanobacteria based on the concentration data of the cyanobacteria and diatoms measured in the measuring step There is provided a water treatment method comprising controlling the supply amount of the coagulant supplied in the step of precipitating the sludge according to the change and controlling the supply amount of NaOCl supplied in the step of supplying the NaOCl according to the concentration change of the diatom .

A step of introducing raw water requiring water treatment into a water treatment system; Treating the raw water flowing into the water treatment system into pretreatment water for membrane filtration; Measuring the concentration of cyanobacteria and diatoms contained in the pretreated treated water; Supplying and mixing activated carbon to the treated water, and adsorbing the cyanobacteria contained in the treated water to the activated carbon; Producing a water mixture by filtering the mixture of activated carbon and the treated water through a filtration membrane; Supplying a part of the produced water to the filtration membrane and backwashing it; And supplying NaOCl to the production water supplied to the filtration membrane in the backwashing step and removing diatoms by the NaOCl, wherein the concentration of the cyanobacteria based on the concentration data of the cyanobacteria and diatoms measured in the measuring step And controlling the supply amount of the activated carbon supplied in the adsorption step according to the change and controlling the supply amount of NaOCl supplied in the removing step according to the concentration change of the diatom.

In addition, if the concentration of cyanobacteria measured in the measuring step is increased, the supply amount of activated carbon supplied in the adsorption step is increased, and when the concentration of the diatomic measured increases, the amount of NaOCl supplied from the removing step is increased A water treatment method may be provided.

In addition, when the concentration of diatoms and cyanobacteria measured in the measurement step are compared with each other, the two kinds of algae species having the highest concentration are judged as dominant species and set as the control target. When the cyanobacteria are judged as dominant species, A water treatment method may be provided that includes controlling the amount of activated carbon supplied and controlling the amount of NaOCl supplied according to the concentration of diatoms when the diatoms are determined to be the dominant species.

In the case of a dominant species of cyanobacteria, a water treatment method including the measurement of algae in which NaOCl is supplied according to the diatom concentration when the concentration of the diatom is higher than a predetermined reference value and NaOCl is not supplied when the concentration of the diatom is lower than the reference value Can be provided.

In addition, a water treatment method including algae measurement in which diatoms are dominant species, activated carbon is supplied according to the concentration of cyanobacteria when the concentration of cyanobacteria is higher than a predetermined reference value, and no activated carbon is supplied when the concentration of cyanobacteria is lower than the reference value Can be provided.

When the concentration of cyanobacteria measured in the measuring step is within the range of 0 to 15 mg / m ³ , 50 ppm of activated carbon is supplied, and when the concentration of cyanobacteria is within the range of 15 to 25 mg / m ³ , 100 ppm of activated carbon is supplied, If within mg / m ³ range can be supplied to the activated carbon 200 ppm, and provides a water treatment method including the birds measured for supplying the activated carbon 300 ppm or more when 100 mg / m ^3.

When the concentration of diatom measured in the measurement step is within the range of 0 to 15 mg / m ³ , NaOCl is supplied at 5 ppm in the backwash, and when the concentration is within the range of 15 to 25 mg / m ³ , 10 ppm of NaOCl is supplied at the backwash , 25 and not less than 100 mg / m ³ range backwash when the NaOCl 20 ppm feed and, 100 mg / m ³ within the case can be provided with a water treatment method including the birds measured 30 ppm for supplying the backwash when NaOCl.

In addition, the step of generating the produced water may include a method of treating water including algae measurement in which the treated water flows while flowing in a cross flow manner.

According to the embodiment of the present invention, there is an effect that the additive to be added for eliminating algae can be efficiently supplied.

In addition, it is advantageous in that the concentration of algae is measured in real time and the result of the measurement is reflected in the water treatment control, thereby improving the treatment efficiency by actively coping with the change in the concentration of algae in real time.

1 is a view showing a water treatment system including algae measurement according to a first embodiment of the present invention.
2 is a view showing a water treatment system including algae measurement according to a second embodiment of the present invention.
3 is a view of a water treatment system including algae measurement according to a third embodiment of the present invention.
FIG. 4 is a flowchart illustrating a process of controlling the supply amount of additives according to algae concentration in the water treatment method using the water treatment system shown in FIGS. 2 and 3. FIG.
FIG. 5 is a graph showing a result of testing the water treatment system shown in FIGS. 1 to 3. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

There are various kinds of algae contained in raw water, but they can be divided into cyanobacteria and diatom algae. Diatoms are widely distributed plankton in water and seawater, all of which are characterized by a single-celled, siliceous hard shell. In addition, cyanobacteria are allotted to photosynthetic bacteria with chlorophyll, and are characterized by a single nucleus-free cell. Diatoms predominate mainly in spring, autumn and winter, where water temperature is relatively low, and cyanobacteria flourish in summer, where water temperature is relatively high. These diatoms cause clogging of the filter paper during membrane filtration, and the cyanobacteria cause a bad odor by generating the cyanobacteria due to Geosmin, 2-MIB and the like.

In the method of removing algae according to the embodiments of the present invention, the amount of the additive supplied for algae removal varies depending on the species of algae. In the case of removing diatoms, the production water is supplied to the filter membrane in reverse, NaOCl is injected to destroy the diatomaceous cells attached to the filtration membrane during backwashing. To remove the cyanobacteria, coagulant is added to remove the coagulated sediment, like other foreign substances. Alternatively, the activated carbon may be supplied instead of the flocculant to adsorb and remove the cyanobacteria on the activated carbon. The reason for this removal is that, in the case of diatoms, the substances contained in the cells are innocuous to the human body, so there is no serious problem even if the cells are destroyed. However, in case of the cyanobacteria, when the cells are destroyed, toxic substances are secreted, Or adsorbed on activated carbon to be removed.

Hereinafter, a specific configuration of a water treatment system including algae measurement according to a first embodiment of the present invention will be described with reference to FIG. 1 is a view showing a water treatment system including algae measurement according to a first embodiment of the present invention.

Referring to FIG. 1, the water treatment system 10 including algae measurement according to the first embodiment of the present invention includes a raw water supply unit 101 for drawing raw water from a river or the like into the system, An algae detection unit 103 for detecting the type and concentration of algae contained in the treated water pretreated in the pretreatment unit 102, a supply unit 103 for supplying the treated water from the pretreated treated water and the flocculant supply unit 105 A filtration unit 106 for filtering the mixed liquid mixed in the mixing unit 104 through a membrane filtration process and a filtration unit 106 for transferring the produced water produced by the filtration unit 106 to the outside A part of the produced water is supplied from the production water storage part 108 and the production water storage part 108 to the filtration part 106 and the filtration membrane of the filtration part 106 is backwashed, And a NaOCl supply unit 107 for supplying NaOCl. The control unit 110 may control the supply amount of the coagulant supplying unit 105 and the NaOCl supplying unit 107 according to the type and concentration of the algae detected through the algae detecting unit 103.

The raw water supply unit 101 may receive and store the raw water required for water treatment from a river or the like, and may control the flow rate of the raw water required for the water treatment and transfer the raw water to the pretreatment unit 102.

The pretreatment unit 102 may be configured to perform a pretreatment process of the membrane filtration process on the supplied raw water, and the pretreatment process may be performed to remove impurities and foreign substances in the raw water to protect various devices constituting the system and the filtration membrane For example, an auto-strainer filtering device. At this time, the strainer diameter of the auto strainer may be 500 μm. Hereinafter, the raw water flow from the pretreatment in the pretreatment unit 102 to the filtration in the filtration unit 106 will be defined as treated water.

The algae detecting unit 103 may be configured to measure the concentration of various algae contained in water flowing in real time, and can measure the concentration of underwater algae by quantitative analysis using six spectral groups. As the bird detection unit 103, a commercial bird detection unit may be used. The detailed operation principle of the bird detection unit 103 is well known in the art, so that a detailed description thereof will be omitted.

The mixing unit 104 may be configured to receive the treated water from the algae detecting unit 103 and mix it with the flocculant supplied from the flocculant supply unit 105. The mixing unit 104 may be composed of a mixer including an agitator or an in-line mixer. In addition, in the case of an in-line mixer, the mixing efficiency can be improved, the installation area can be reduced, and the amount of medicine and power consumption can be reduced.

The coagulant supply unit 105 may supply a predetermined amount of coagulant to the mixing unit 104, and the coagulant supplied may be, for example, PACl (Poly Aluminum Chloride). The coagulant supplied to the mixing unit 104 may be mixed with the treated water to form sludge with the cyanobacteria and other impurity particles to form the sludge, and the remaining treated water may be transferred to the filtration unit 106.

The filtration unit 106 may be subjected to a membrane filtration process in which the treatment water is passed through the filtration membrane to filter the impurities present in the water and produce water. In the membrane filtration process using the filtration membrane, many pores formed in the filtration membrane are clogged by the impurities when the operation period has elapsed, so it is necessary to regularly clean the filtration membrane to restore its permeability. For this purpose, continuous air cleaning of the filtration membrane, backwashing by filtration cycle, and cyclic maintenance cleaning using acid or alkaline chemicals are performed in parallel. When the algae detecting unit 103 detects that the concentration of diatoms causing clogging in the raw water is high, it is possible to destroy and disrupt the cells of the diatomite by injecting NaCl in an appropriate amount suitable for the measurement concentration of the diatoms.

The filtration unit 106 may include, for example, an MF membrane as a filtration membrane, and it is possible to filter the treated water passing through the MF membrane by pressure difference between membranes capable of maintaining a pressure or a vacuum state to produce water. The generated production number can be transferred to the production number storage unit 108 or stored or transferred to an external use place.

The filtration unit 106 and the product water storage unit 108 may be connected to the backwash line 12 and the backwash line 12 may be connected to the filtration unit 106 in order to periodically backwash the filtrate (foreign matter) The production water can be periodically transferred from the production water storage part 108 to the filtration part 106 to back up the filtration membrane. At this time, a predetermined amount of NaOCl can be supplied from the NaOCl supply unit 107 to the backwashing line 12 to remove diatoms that are attached to the filtration membrane and cause clogging of the membrane. Concentrated water filtered while produced water in the filtration unit 106 can be discharged to the outside through the discharge port 109.

The supply amount of the additive supplied from the coagulant supply unit 105 and the NaOCl supply unit 107 can be controlled by the control unit 110 and the control unit 110 can control the supply amount of the additive In real time.

For this purpose, the control unit 110 may be a small built-in computer, for example, and may include a program, a memory, and a data processing unit including a CPU. The program receives the algae detection signal from the algae detecting section 103 and controls the supply amount of the flocculant in the flocculating agent supply section 105 according to the concentration change of the algae on the basis of the algae flow detecting signal and adjusts the NaOCl supply amount of the NaOCl supplying section 107 Gt; and / or < / RTI > The program may be stored in a storage medium such as a computer storage medium such as a flexible disk, a compact disk, a hard disk, and an MO (magneto optical disk), and installed in the control unit 110.

The control unit 110 can perform a control operation based on the data on the concentration of the algae detected by the algae detecting unit 103. [ Specifically, when the algae detecting unit 103 transmits the data of the diatoms and the cyanobacteria in real time to the control unit 110, the controller 110 controls the amount of the coagulant supplied to the coagulant supplying unit 105 according to the concentration of the cyanobacteria And the NaOCl supply amount of the NaOCl supply unit 107 can be adjusted according to the change of the diatom concentration. For example, when the concentration of diatoms contained in the treated water is increased, the NaOCl supply unit 107 is controlled to increase the supply amount of NaOCl required for removing diatoms, and when the concentration of the cyanobacteria is increased, The flocculant supply unit 105 can be controlled to increase the flocculant supply amount.

In addition, the control unit 110 can identify a dominant bird species, that is, a dominant species among diatoms and cyanobacteria, and select the target as a control target. For example, when the concentration of the diatoms contained in the treated water is higher than that of the cyanobacteria, the control unit 110 determines that the diatoms are dominant and sets the target as a control target to increase the supply amount of NaOCl, Is higher than the diatomic concentration, the control unit 110 can determine the cyanobacteria as the dominant species and set the control target to increase the supply amount of the coagulant.

As described above, the water treatment system 10 according to the present embodiment monitors the concentration of algae changing in real time and controls the water treatment process so as to increase the supply amount of the additive for removing the dominant species with the dominant species having the relatively high concentration as the control target (Coagulant, NaOCl) for selectively removing the dominant species can be effectively removed, and thus the supply amount of the additive supplied for removing algae can be economically managed.

Hereinafter, a water treatment system including algae measurement according to a second embodiment of the present invention will be described with reference to FIG. 2 is a view showing a water treatment system including algae measurement according to a second embodiment of the present invention.

The water treatment system 10 'according to the second embodiment of the present invention further includes an aggregate sedimentation part 112 and an activated carbon supply part 114 to more effectively perform removal of cyanobacteria than the first embodiment And therefore, differences from the first embodiment will be mainly described, and common descriptions and reference numerals will be used in common.

In the water treatment system 10 according to the first embodiment described above, the flocculant supplied from the flocculant supply unit 105 is mixed with the treated water in the mixing unit 104, and other impurities as well as the cyanobacteria are sludgeized and precipitated and removed . However, since the supply amount of the coagulant is controlled to be changed according to the concentration of the cyanobacteria, when the concentration of the cyanobacteria is lowered and the content of the other impurities is increased, the amount of the coagulant supplied is controlled to decrease according to the concentration of the cyanobacteria. And other impurities other than cyanobacteria are not properly treated.

In addition, since the coagulant such as PACl has a small particle size, when a large amount of coagulant particles are used, the coagulant particles that have not yet aggregated are prevented from adhering to the filtration membrane for the filtration process included in the filtration unit 106, It is necessary to reduce the amount of the coagulant used in the water treatment as much as possible because it may cause the occurrence of inorganic fouling.

In order to solve the problem of the first embodiment, this embodiment is proposed. Referring to FIG. 2, the water treatment system 10 'according to the second embodiment may further include an activated carbon supply part 114 for supplying activated carbon in addition to the flocculant supply part 105 for removal of cyanobacteria. The activated carbon supply unit 114 can control the supply amount of the activated carbon according to the change in the cyanobacteria concentration.

The water treatment system 10 'according to the present embodiment further includes a flocculation and sedimentation unit 112 connected to the mixing unit 104 and having a mixture of the flocculant and the treatment water mixed and precipitated in the mixing unit 104 And the activated carbon supply part 114 can be configured to supply the activated carbon to the flocculation sediment part 112. The activated carbon supply unit 114 may be configured to supply the activated carbon to the mixing unit 104 instead of the flocculation and sedimentation unit 112 and to simultaneously supply activated carbon to the mixing unit 104 and the flocculation and sedimentation unit 112 .

The flocculation sedimentation unit 112 may include a reaction tank and may be connected to the mixing unit 104 to supply the mixed mixture in the mixing unit 104 to the flocculation sedimentation unit 112. The mixture supplied in the flocculation sedimentation section 112 causes flocculation and sedimentation reaction and can sufficiently provide the time required for flocculation and sedimentation as compared with the first embodiment including only the mixing section 104, It can be done better.

There is no limitation on the type and shape of the activated carbon supplied from the activated carbon supply unit 114, but Powdered Active Carbon (PAC) may be supplied as an example. The activated carbon supply unit 114 may be connected to the control unit 110 so that the supply amount of the activated carbon can be controlled by the control unit 110.

The control unit 110 may be configured to receive the change in the concentration of the cyanobacteria from the algal detection unit 103 and to control the amount of activated carbon supplied to the activated carbon supply unit 114 in accordance with the concentration change of the cyanobacteria, Can be kept constant regardless of the change in the concentration of the cyanobacteria or can be controlled depending on the content of the impurities. To this end, a sensor (not shown) for measuring the content of impurities removed by the flocculant except the cyanobacteria may be additionally provided.

As described above, in the water treatment system 10 'according to the second embodiment, the supply amount of the activated carbon supplied from the activated carbon supply part 114 is controlled according to the concentration change of the cyanobacteria, and the amount of the flocculant supplied to the flocculant supply part 105 is changed The supply amount of the coagulant can be reduced to suppress the inorganic fouling of the filtration membrane and the effect of reducing the coagulant supply cost can be obtained.

In the present embodiment, the system configuration including both the activated carbon supply unit 114 and the flocculant supply unit 105 will be described as an example, but the flocculant supply unit 105 may be omitted. In this case, other contaminants other than cyanobacteria are also removed by activated carbon, so that the concentration of other contaminants other than cyanobacteria can be reflected in the control of the amount of activated carbon supplied. If the coagulant supply unit 105 is omitted, the coagulant is not supplied at all in the water treatment process of the system, so that the occurrence of the inorganic fouling of the filtration membrane due to the coagulant can be completely prevented.

Hereinafter, a water treatment system including algae measurement according to a third embodiment of the present invention will be described with reference to FIG. 3 is a view of a water treatment system including algae measurement according to a third embodiment of the present invention.

The water treatment system 10 '' according to the third embodiment of the present invention is different from the second embodiment in that the cross flow line 14, the control valve 116 and the activated carbon recovery section 118 are further added Since the second embodiment differs from the second embodiment, differences from the second embodiment will be mainly described, and common descriptions and reference numerals will be used in common.

3, in the water treatment system 10 '' according to the third embodiment, the flocculation sedimentation unit 112 and the filtration unit 106 can be used not only by the existing line through which the process water flows but also by the cross flow line 14 Can be additionally connected. Existing lines other than the cross flow line 14 may be referred to as full flow filtration lines.

When the treated water is supplied to the filtration unit 106 through the entire filtration line, most of the influx of the treated water is filtered, and the filtration system, which is a filtration system that intermittently discharges the substance to be removed captured by the filtration membrane together with a small amount of washing water, -end. < / RTI > In addition, when the treated water is supplied through the cross flow line 14, the treated water flows at a constant flow rate parallel to the surface of the filtration membrane so that the cross-flow, which is a method of filtering while suppressing the accumulation of impurities on the membrane surface, ) Method. ≪ / RTI > To this end, a flow control valve (not shown) may be provided in the full flow filtration line and the cross flow line 14, and the flow control valve may be controlled by the controller 110 in the opening amount.

The coagulant supplied to the coagulating sedimentation unit 112 coagulates together with the cyanobacteria and the impurities to form sludge. At this time, the coagulant which has not formed the sludge is flowed to the filtration unit 106 together with the treated water, do. This results in wasting the flocculant, which results in lowered flocculant utilization and increased expense.

In order to prevent such a problem, when the concentration of the cyanobacteria is low, the control unit 110 allows the treated water to be delivered through the full-volume filtration line to be filtered by the full-volume filtration system. When the concentration of the cyanobacteria becomes high, The treatment water may be passed through the cross flow line 14 to increase the recycling rate of the coagulant introduced into the filtration unit 106 so as to be controlled to be filtered by the cross flow method. Thereby, the utilization ratio of the flocculant is increased and the effect of reducing the cost can be achieved.

When the concentration of cyanobacteria in the raw water is increased, the amount of activated carbon is increased. In this case, the amount of activated carbon abandoned together with the effluent water is increased due to excessive supply of activated carbon, thereby increasing the waste of activated carbon .

In order to solve such a problem, the water treatment system 10 " includes a control valve 116 for changing the flow path of the drain water discharged through the discharge port 109, and an activated carbon contained in the drain water, And an activated carbon recovery unit (118) for carrying the recovered activated carbon.

The control valve 116 may be connected to the discharge port 109 so that the discharge water may be discharged directly to the outside or may be configured to be controlled by the control unit 110 so as to set the flow path of the discharge water to flow to the activated carbon recovery unit 118 . The control valve 116 may be, for example, a three-way valve, but the spirit of the present invention is not limited by the type of the control valve 116.

The control unit 110 can control the control valve 116 such that some or all of the discharged water is supplied to the activated carbon recovery unit 118. In particular, when the activated carbon supply amount of the activated carbon supply unit 114 increases, So that the waste water can be controlled to be supplied to the recovery unit 118. For example, when the concentration of cyanobacteria is higher than the concentration of diatoms, the control unit 110 supplies the effluent water to the activated carbon recovery unit 118 only when the cyanobacteria are the dominant species. When the diatomaceous species is the dominant species, The valve 116 can be controlled.

The activated carbon recovery unit 118 may recover at least a portion of the activated carbon contained in the effluent water supplied through the control valve 116 and return it to the coagulated sedimentation unit through the activated carbon recovery line 16. The activated carbon recovery unit 118 is a general device for recovering activated carbon from sludge having impurities adsorbed on activated carbon, and its operation mode is well known in the art, so a detailed description thereof will be omitted.

As described above, the water treatment system 10 " according to the present embodiment is effective in recovering at least a part of the activated carbon supplied for removal of cyanobacteria and recycling it, thereby making it possible to economically use the activated carbon, have. Also, the activated carbon recovery unit 118 is operated only when the concentration of the cyanobacteria is high and the supply amount of the activated carbon is large, so that the energy efficiency of the activated carbon recovery unit 118 is high.

A method of performing water treatment using the water treatment system 10, 10 ', 10' 'according to the embodiments of the present invention having the above structure will be described with reference to FIG. 4 and FIG. FIG. 4 is a flow chart for explaining the supply amount control process of the additive according to the algae concentration in the water treatment method using the water treatment system shown in FIG. 2 and FIG. 3, The test result is graph.

The raw water required for water treatment flows into the raw water supply unit 101 from a river or the like and the raw water supply unit 101 can supply the raw water to the pretreatment unit 102 at a predetermined flow rate. In the pretreatment unit 102, raw water supplied may be pretreated for the membrane filtration process, and raw water after the pretreatment, that is, treated water may be transmitted to the algae detecting unit 103.

The algae detecting unit 103 can measure the concentration of each of the algae species of the received treated water and transmit the measured data signal to the controller 110. At this time, the bird species detected by the bird detection unit 103 may be, for example, diatoms and cyanobacteria. The treated water that has passed through the bird detection unit 103 may be transmitted to the mixing unit 104.

The treated water transferred to the mixing unit 104 may be mixed with the flocculant delivered from the flocculant supply unit 105 to cause coagulation sedimentation reaction. In this process, various impurities such as cyanobacteria can aggregate and precipitate to form sludge. The supply amount of the coagulant supplied from the coagulant supply unit 105 can be controlled by the control unit 110.

In addition, in the second and third embodiments, in addition to the coagulant supply unit 105, an activated carbon supply unit 114 is additionally provided, and the activated carbon is supplied from the activated carbon supply unit 114 to the mixing unit 104 and / . Also, as described above, the coagulant supply unit 105 may be omitted in the system configuration. In this case, only the activated carbon may be supplied to the coagulation sedimentation unit 112.

After the sludge is formed through the coagulation sedimentation reaction in the mixing unit 104 or the flocculation sedimentation unit 112, the remaining liquid treated water may be transferred to the filtration unit 106 and may be filtered while passing through the filtration membrane. The concentrated water filtered by the filtration unit 106 can be discharged to the outside through the discharge port 109. The produced water that has passed through the filtration membrane is transferred to and stored in the production water storage unit 108, .

On the other hand, the filtration membrane of the filtration unit 106 can be blocked by debris filtered out as the process is repeated. Especially, when the concentration of the diatoms is high, it can be easily blocked by diatoms. In order to prevent the clogging of the filtration membrane, a part of the produced water can be supplied from the production water storage unit 108 to the filtration unit 106 through the backwashing line 12 periodically as reverse osmosis water, Back washing can be performed. At this time, NaOCl may be supplied from the NaOCl supply unit 107 to the backwash line 12 to which the backwash water is supplied, and NaOCl supplied may destroy the diatomaceous cells and effectively remove the diatoms.

As described above, in the water treatment process, activated carbon and NaOCl may be supplied as treated water, and the supply amount of activated carbon and NaOCl may be controlled by the control unit 110. [ Specifically, when the measured concentration data is measured by the bird detection unit 103 and the measured concentration data is transmitted to the control unit 110, the control unit 110 calculates the concentration of the activated carbon and the NaOCl based on the concentration of the cyanobacteria and the concentration data of the diatoms. The supply amount can be adjusted.

Specifically, referring to FIG. 4, it is possible to determine what species, that is, the dominant species, having higher concentration in the cyanobacteria and the blue algae, are compared with the data obtained through the algal concentration measurement. If it is judged that dominant species of cyanobacteria are dominant, supply amount of activated carbon is set according to the concentration of cyanobacteria, and if it is determined that dominant species is dominant, supply amount of NaOCl can be set according to the concentration of diatom species.

The control unit 110 may determine whether or not to treat the algae species other than the dominant species. If the algae are dominant species, the control unit 110 determines whether the concentration of the diatoms is higher than the reference value. If the concentration is higher than the reference value, And when the concentration is lower than the reference value, the supply of NaOCl can be controlled. Likewise, when the diatom is dominant, the control unit 110 may determine whether the concentration of the cyanobacteria is higher than the reference value, and if the concentration is higher than the reference value, the activated carbon is supplied according to the concentration of the cyanobacteria, .

By controlling the dominant species as a control target, it is possible to economically control the supply amount of activated carbon and NaOCl. In general, diatoms are very prosperous in low spring, autumn and winter with low water temperature, while cyanobacteria are very diminished, and in the summer when water temperature is high, cyanobacteria are very prosperous while diatoms are greatly reduced. The method can be efficient.

However, the control method of the present invention is not limited to a method of selecting a dominant species as a control target, and it is possible to independently remove cyanobacteria and diatoms without selecting a control target. Specifically, it is also possible to independently measure the concentration of cyanobacteria and diatoms to control the supply of both activated carbon and NaOCl according to the concentration of cyanobacteria and diatoms. This control method can be somewhat reduced in terms of the utilization efficiency of activated carbon and NaOCl, but the effect that the control process can be simplified can be achieved.

On the other hand, the amount of activated carbon and NaOCl supplied according to the concentration of cyanobacteria and diatoms can be controlled as shown in Table 1 below.

That is, when the concentration of blue-green algae within 0 ~ 15 mg / m ³ range of the activated carbon is supplied to 50 ppm, and the activated carbon is supplied to 100 ppm when within 15 ~ 25 mg / m ³ range, in the case within 25 ~ 100 mg / m ³ range 200 ppm of activated carbon is supplied, and 300 ppm of activated carbon is supplied when it is 100 mg / m ³ or more. In addition, the concentration of diatoms 0 ~ 15 mg / m ³ range, the backwash when NaOCl is fed 5 ppm case within, and backwash when NaOCl case within 15 ~ 25 mg / m ³ range, the supply 10 ppm, 25 ~ 100 mg / m If within the range of ³ and 20 ppm NaOCl is supplied during backwash, it can be controlled such that during backwash the NaOCl 30 ppm supply not less than 100 mg / m ^3.

The supply amount of activated carbon or NaOCl according to the algae concentration in Table 1 is set to a value at which algaecure removal efficiency becomes maximum with respect to the algae concentration, and can be supported by the experimental result of FIG. The graph of FIG. 5 shows how the membrane permeability of the filtration membrane of the filtration unit 106 changes as the input amount of activated carbon or NaOCl increases depending on the concentration of the algae. The higher the membrane permeability in the graph, the better the filtration is, the higher the production efficiency of the production water, and the better the impurities such as algae are removed.

First, FIG. 5 (a) shows the experimental results of measuring the change in the membrane permeability when the amount of activated carbon is gradually increased while varying the concentration of cyanobacteria. Powder activated carbon (PAC) was used as activated carbon. As shown in the graph, when the concentration of cyanobacteria is 8 mg / m ³ (within the range of 0-15 mg / m ³ ), the membrane permeability becomes maximum when the supply amount of activated carbon is 50 ppm, and 22 mg / m ³ (Within the range of 15 to 25 mg / m ³ ), the membrane permeability is maximized when the amount of activated carbon supplied is 100 ppm, and when the activated carbon supply amount is 65 ppm / m ³ (within the range of 25 to 100 mg / m ³ ) (110 mg / m ³⁾ (100 mg / m ³ or more), the membrane permeability was maximized when the amount of activated carbon supplied was 300 ppm.

FIG. 5 (b) shows the results of an experiment in which the change in membrane permeability was measured when the dosage of NaOCl was gradually increased while the diatom concentration was varied. As shown in the graph, when the diatom concentration is 8 mg / m ³ (within the range of 0 to 15 mg / m ³ ), the membrane permeability is maximized when the supply of NaOCl is 5 ppm, m ³ (within the range of 15 to 25 mg / m ³ ), the membrane permeability is maximized when the supply of NaOCl is 10 ppm at the backwash, and when the backwash is 65 mg / m ³ (within the range of 25 to 100 mg / m ³ ) The membrane permeability was maximized when the supply of NaOCl was 20 ppm and the maximum permeability was at 30 ppm when the backwash was 110 mg / m ³ (100 mg / m ³ or more).

Thus, by adjusting the amount of activated carbon or NaOCl supplied according to the algae concentration as shown in Table 1, it is possible to maximize algae removal efficiency with an excessive supply amount.

The water treatment system and method including algae measurement according to the embodiments of the present invention can economically control the amount of activated carbon or NaOCl added to remove algae. In addition, it is advantageous in that the treatment efficiency is improved by actively coping with the change of the concentration of the algae in real time by measuring the concentration change according to the species of the algae in real time and reflecting the result of measurement in the water treatment control.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. For example, a person skilled in the art can change the material, size and the like of each constituent element depending on the application field or can combine or substitute the embodiments in a form not clearly disclosed in the embodiments of the present invention, Of the range. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, and that such modified embodiments are included in the technical idea described in the claims of the present invention.

10, 10 ', 10'': water treatment system
101: raw water supply unit 102: preprocessing unit
103: Bird detection unit 104: Mixing unit
105: coagulant supply unit 106: filtration unit
107: NaOCl supply unit 108: production water storage unit
109: outlet 110:
112: coagulation sediment part 114: activated carbon supply part
116: Control valve 118: Activated carbon recovery unit

Claims (17)

delete delete delete delete delete delete delete delete delete A step of introducing raw water requiring water treatment into a water treatment system;
Treating the raw water flowing into the water treatment system into pretreatment water for membrane filtration;
Measuring the concentration of cyanobacteria and diatoms contained in the pretreated treated water;
Supplying a flocculant to the treated water;
Supplying activated carbon to the treated water and adsorbing the cyanobacteria contained in the treated water to the activated carbon;
Producing a water mixture by filtering the mixture of activated carbon and the treated water through a filtration membrane;
Supplying a part of the produced water to the filtration membrane and backwashing it; And
Supplying NaOCl to the production water supplied to the filtration membrane in the backwashing step and removing diatoms by NaOCl,
Comparing the concentration of the diatoms and the concentration of the cyanobacteria measured in the measuring step, determining that the bird species having the highest concentration is the dominant species,
In the case where the cyanobacteria are determined to be dominant species, NaOCl is supplied according to the concentration of the diatoms when the concentration of the diatoms is higher than a predetermined reference value while the supply amount of the activated carbon supplied in the adsorption step is adjusted according to the concentration of the cyanobacteria, NaOCl < / RTI > is not supplied when the concentration of < RTI ID = 0.0 >
When the diatoms are judged to be the dominant species, the supply amount of NaOCl supplied at the removing step is controlled according to the measured diatom concentration, and when the concentration of the cyanobacteria is higher than the predetermined reference value, the activated carbon is supplied according to the concentration of the cyanobacteria, Is not supplied with activated carbon when the concentration of the activated carbon is less than the reference value.

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