Circulation-operated reverse osmosis water treatment apparatus

Abstract

The present invention relates to a circulation-operated reverse osmosis water treatment apparatus for circulating and operating raw water by filtration, the circulation-operated reverse osmosis water treatment apparatus comprising: an inlet unit; a pumping unit; a filtering unit; a treated water outlet unit; a first concentrated water discharge unit; a first recovery unit; a second concentrated water discharge unit; and a second recovery unit. Accordingly, the present invention circulates or forcibly discharges the concentrated water to primarily recover and secondarily recover and reprocess the concentrated water when producing the treated water so as to mix and dilute the concentrated water with the supply water at a predetermined ratio or produce the treated water without discharging the concentrated water during operation. The present invention automatically discharges only the water in a filter container when a set time or water quality is reached, thereby enabling economical, high-efficiency, high-recovery operation without deterioration of the performance of the filter or reverse osmosis membrane.

Description

Circulating reverse osmosis water treatment plant

[0001] The present invention relates to a circulating reverse osmosis water treatment device, and more particularly, to a circulating reverse osmosis water treatment device that filters raw water by reverse osmosis.

[0002] In general, in the field of water treatment that purifies sewage water or wastewater (hereinafter referred to as “wastewater” for convenience), produced water is obtained by filtering pollutants in the wastewater using a membrane.

[0003] A membrane is a special membrane made of a material that is suitable for not only general filtration that separates undissolved particles by selectively allowing specific components to pass through, but also for separating and removing suspended substances such as colloids and fine particles in wastewater, and even for separating dissolved substances in liquid or mixed gases.

[0004] Depending on their performance, these separation membranes are divided into microfiltration membranes (MF), ultrafiltration membranes (UF), nanofiltration membranes (NF), reverse osmosis membranes (RO), ion exchange membranes (IE), electrodialysis membranes (ED), gas separation / PV membranes (GAS), and hemodialysis membranes, and are appropriately selected depending on the intended use.

[0005] In addition, membranes can be classified into spiral-wound, hollow-fiber, tubular, plate & frame, hollow-fiber, and monolithic modules depending on their shape.

[0006] There are various operation methods for water treatment processes using separation membranes as described above, but there are problems such as it is difficult to minimize membrane contamination and load when treating high-concentration wastewater or concentrating pollutants or materials to be recovered, the recovery rate is low, resulting in low efficiency, and the need to reprocess the concentrated water.

[0007] In addition, the low recovery rate in water treatment processes using membranes requires a relatively large amount of power to supply a large amount of raw water compared to the amount of produced water, which may increase the operating cost of water treatment.

[0008] In recent years, the importance of reusing treated wastewater discharged from wastewater treatment plants has grown. Accordingly, reusing treated wastewater is becoming mandatory, and water quality standards for reused water are being established.

[0009] The method of producing recycled water can be constructed based on various water treatment processes that can appropriately remove pollutants contained in wastewater treatment water to suit the intended use.

[0010] However, the treatment of concentrated water generated in the water treatment process is emerging as a new problem. Concentrated water is water that is not included in reusable water and is concentrated with pollutants such as solutes and suspended substances.

[0011] This concentrated water must be reprocessed and discharged to meet discharge water quality standards, depending on its quality, or disposed of through costly waste disposal procedures. The amount of concentrated water generated is known to reach approximately 20-30% of the influent treated water volume. Therefore, the costs of concentrated water treatment and disposal can be a significant economic burden in wastewater treatment and reuse, significantly reducing the economic efficiency of recycled water production methods.

[0012] As described above, reverse osmosis equipment divides feedwater, concentrated water, and treated water into a fixed ratio. This is because reverse osmosis equipment is used to purify or separate inorganic ions. Therefore, a certain amount of concentrated effluent must be discarded to prevent large amounts of ionic substances from precipitating and depositing on the filter (membrane) surface due to concentration.

[0013] In addition, in the case of a two-array or three-array configuration, fouling contamination by fine particles occurs in the front-side filter or reverse osmosis membrane, and scale contamination due to ion concentration occurs in the back-side filter or reverse osmosis membrane.

[0014] This causes uneven contamination of the filters within the filter container, making efficient management and maintenance difficult. Furthermore, the constant discharge of a constant volume of concentrated water during operation leads to significant economic burdens, such as quantitative loss of supply water and increased power costs, as well as the need for additional concentrated water reprocessing processes and handling issues related to increased concentrated water discharge.

[0015] The present invention has been devised to solve the above-mentioned conventional problems, and the purpose of the present invention is to provide a circulating reverse osmosis water treatment device that can first recover concentrated water during the production of treated water, second recover it, and circulate it for reprocessing, or forcibly discharge it to mix and dilute it with the supply water at a certain ratio, or produce treated water without discharging concentrated water during operation, and automatically discharge only the water in the filter container when a set time or water quality is reached, thereby enabling economical, high-efficiency, high-recovery operation without deterioration of the performance of the filter or reverse osmosis membrane.

[0016] In addition, the present invention provides a circulating reverse osmosis water treatment device that improves the flow rate within the filter container by recovering all of the concentrated water without discharging it during operation, thereby suppressing scale attachment on the filter surface due to concentration polarization, and reduces the quantitative loss of the supply water by discharging only water within the filter container when the concentration exceeds the saturation concentration, thereby improving the durability of the filter or reverse osmosis membrane and extending its lifespan, and improving economic efficiency by reducing the capacity reduction of the pretreatment facility and operating maintenance costs.

[0017] In addition, the present invention was developed to solve problems such as increased operating costs, including a shortened lifespan of filters, by minimizing contamination caused by quantitative loss of supply water due to discharge of concentrated water compared to produced water and an imbalance of filters or reverse osmosis membranes accompanying the arrangement configuration, and to provide a circulating reverse osmosis water treatment device that eliminates quantitative loss of supply water and improves the efficiency of filters or reverse osmosis membranes in the arrangement configuration by recovering all of the concentrated effluent generated during operation without using it in a separate reprocessing process or by diluting a certain ratio of the concentrated effluent with raw water, thereby enabling high-efficiency, high-recovery operation.

[0018] In order to achieve the above object, the present invention provides a circulating reverse osmosis water treatment device that treats raw water by filtration in a circulating manner, comprising: an inlet (10) through which raw water is supplied; a pumping unit (20) installed downstream of the inlet (10) to pump and inject raw water; a filtration unit (30) installed downstream of the pumping unit (20) to filter and treat the raw water; a treated water discharge unit (40) connected to one side downstream of the filtration unit (30) to discharge treated water treated in the filtration unit (30); a first concentrated water discharge unit (50) connected to the other side downstream of the filtration unit (30) to discharge concentrated water treated in the filtration unit (30); It is characterized by including a first recovery unit (60) which is connected to one side downstream of the first concentrated water discharge unit (50) and the upstream side of the pumping unit (20), respectively, to selectively recover the concentrated water discharged from the first concentrated water discharge unit (50) and supply it to be circulated to the filtration unit (30); a second concentrated water discharge unit (90) which is connected to the other side downstream of the first concentrated water discharge unit (50) and discharges the concentrated water treated in the first concentrated water discharge unit (50); and a second recovery unit (100) which is connected to the downstream side of the second concentrated water discharge unit (90) and the upstream side of the pumping unit (20), respectively, to selectively recover the concentrated water discharged from the second concentrated water discharge unit (90) and supply it to be circulated to the filtration unit (30).

[0019] In addition, the present invention is characterized in that it further includes a blower connected to the inlet (10) and blowing air according to the pressure difference between the upstream and downstream of the filter (30).

[0020] The blower of the present invention is characterized by including a first blower (70) connected to one side of the inlet (10) and blowing outside air when the pressure difference between the upstream and downstream of the filter (30) is within a predetermined range; and a second blower (80) connected to the other side of the inlet (10) and blowing compressed air when the pressure difference between the upstream and downstream of the filter (30) is equal to or greater than a predetermined value.

[0021] The inlet (10) of the present invention is characterized by including: a supply pipe for introducing and supplying raw water; a supply automatic valve installed on one side of the supply pipe for controlling whether or not to supply raw water; a raw water pressure gauge installed on one side of the supply pipe for measuring the pressure of the raw water; a first water quality measuring device installed on one side of the supply pipe for measuring the water quality of the raw water; a second water quality measuring device installed on the other side of the supply pipe for measuring the water quality of the raw water; a potential analyzer installed on the other side of the supply pipe for measuring the raw water by a potential difference; a water quality analyzer installed on the other side of the supply pipe for analyzing the water quality of the raw water; and a silica analyzer installed on the other side of the supply pipe for measuring the contamination level of the raw water.

[0022] The pumping unit (20) of the present invention is characterized by including: a supply pump that pumps and injects raw water; a pump controller that is connected to one side of the supply pump and controls the pumping of the supply pump; a pumping pressure gauge that is installed downstream of the supply pump and measures the pumping pressure of the raw water; and a differential pressure measuring unit that is installed between the upstream of the filtering unit (30) and the first concentrated water discharge unit (50) and measures the differential pressure.

[0023] The above-described treated water discharge unit (40) of the present invention is characterized by including: an discharge pipe through which treated water discharges; a treated water quality measuring device installed on one side of the discharge pipe to measure the water quality of the treated water; and a treated water flow rate measuring device installed on one side of the discharge pipe to measure the flow rate of the treated water.

[0024] The first concentrated water discharge unit (50) of the present invention is characterized by including: an 11th discharge pipe through which concentrated water is discharged; a 12th discharge pipe branched off at one end downstream of the 11th discharge pipe and discharging concentrated water to the outside; an 11th automatic valve installed at one end of the 12th discharge pipe and controlling whether concentrated water is discharged; and a first concentrated water pressure gauge installed at one end of the 12th discharge pipe and measuring the pressure of concentrated water.

[0025] The first recovery unit (60) of the present invention is characterized by including: a first recovery pipe for recovering concentrated water; a twelfth automatic valve installed on one side of the first recovery pipe for controlling whether or not to recover concentrated water; a first control valve installed on one side of the first recovery pipe for controlling the recovery amount of concentrated water; a second concentrated water pressure gauge installed on one side of the first recovery pipe but upstream of the twelfth automatic valve for measuring the pressure of concentrated water; a concentrated water flow rate meter installed on the other side of the first recovery pipe for measuring the flow rate of concentrated water; a concentrated water quality meter installed on the other side of the first recovery pipe for measuring the water quality of concentrated water; and a third concentrated water pressure gauge installed on the other side of the first recovery pipe but upstream of the concentrated water flow rate meter for measuring the pressure of concentrated water.

[0026] The second concentrated water discharge unit (90) of the present invention is characterized by including: a 21st discharge pipe through which concentrated water is discharged; a 22nd discharge pipe branched off at one end downstream of the 21st discharge pipe and discharging concentrated water to the outside; a 21st automatic valve installed at one end of the 21st discharge pipe and controlling whether concentrated water is discharged; a 22nd automatic valve installed at one end of the 22nd discharge pipe and controlling whether concentrated water is discharged; a second storage tank installed at the 21st discharge pipe but downstream of the 21st automatic valve and temporarily storing concentrated water; and a 21st concentrated water pressure gauge installed at one end of the 2nd storage tank and measuring the pressure of concentrated water.

[0027] The second recovery unit (100) of the present invention is characterized by including: a second recovery pipe for recovering concentrated water; a 23rd automatic valve installed on one side of the second recovery pipe for controlling whether or not to recover concentrated water; a recovery pump installed downstream of the 23rd automatic valve for pressurizing the recovered concentrated water; a second filter installed downstream of the recovery pump for filtering concentrated water; and a 24th automatic valve installed downstream of the second filter for controlling whether or not to discharge concentrated water.

[0028] As described above, the present invention provides an effect that enables the production of treated water without discharging concentrated water during operation by first recovering concentrated water during the production of treated water, second recovering it, and then circulating or forcibly discharging it for reprocessing, mixing and diluting it with the supply water at a certain ratio, and automatically discharging only the water in the filter container when the set time or water quality is reached, thereby enabling economical, high-efficiency, high-recovery operation without deterioration of the performance of the filter or reverse osmosis membrane.

[0029] In addition, by recovering all of the concentrated water without discharging it during operation, the flow rate inside the filter container is improved, thereby suppressing scale attachment on the filter surface due to concentration polarization, and by discharging only water inside the filter container when the concentration exceeds the saturation concentration, the quantitative loss of the supply water is reduced, thereby improving the durability of the filter or reverse osmosis membrane and extending its lifespan, and providing the effect of improving economic efficiency by reducing the capacity of the pretreatment facility and reducing the operation and maintenance costs.

[0030] In addition, in order to solve problems such as increased operating costs, such as a shortened lifespan of filters, by minimizing contamination caused by the quantitative loss of supply water due to the discharge of concentrated water compared to the produced water and the imbalance of filters or reverse osmosis membranes accompanying the arrangement configuration, the concentrated effluent generated during operation is not used in a separate reprocessing process or by diluting a certain ratio of concentrated effluent with raw water, but rather by recovering and using all of the concentrated effluent, thereby eliminating the quantitative loss of supply water and improving the efficiency of filters or reverse osmosis membranes in the arrangement configuration, providing the effect of enabling high-efficiency, high-recovery operation.

[0031] Figure 1 is a schematic diagram showing an example of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0032] Figure 2 is a schematic diagram showing another example of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0033] Figure 3 is a schematic diagram showing the first circulation process of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0034] Figure 4 is a schematic diagram showing a blowing process of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0035] Figure 5 is a schematic diagram showing a secondary circulation process of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0036] Figure 6 is a schematic diagram showing a concentrated water discharge process of a circulating reverse osmosis water treatment device according to one embodiment of the present invention.

[0037] <Explanation of symbols for the main components of the drawing>

[0038] 10: Inlet 20: Pumping section

[0039] 30: Filtration section 40: Treated water outlet section

[0040] 50: 1st concentrated water discharge section 60: 1st recovery section

[0041] 70: First blower 80: Second blower

[0042] 90: Second concentrated water discharge unit 100: Second recovery unit

[0043] Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the attached drawings.

[0044] FIG. 1 is a schematic diagram showing an example of a circulating reverse osmosis water treatment device according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing another example of a circulating reverse osmosis water treatment device according to an embodiment of the present invention, FIG. 3 is a schematic diagram showing a primary circulation process of a circulating reverse osmosis water treatment device according to an embodiment of the present invention, FIG. 4 is a schematic diagram showing a blowing process of a circulating reverse osmosis water treatment device according to an embodiment of the present invention, FIG. 5 is a schematic diagram showing a secondary circulation process of a circulating reverse osmosis water treatment device according to an embodiment of the present invention, and FIG. 6 is a schematic diagram showing a concentrated water discharge process of a circulating reverse osmosis water treatment device according to an embodiment of the present invention.

[0045] As shown in FIGS. 1 and 2, the circulating reverse osmosis water treatment device according to the present embodiment comprises an inlet (10), a pumping unit (20), a filtering unit (30), a treated water outlet (40), a first concentrated water discharge unit (50), a first recovery unit (60), a blower unit (70, 80), a second concentrated water discharge unit (90), and a second recovery unit (100), and is a circulating reverse osmosis water treatment device that treats raw water by filtration in a circulating manner.

[0046] The inlet (10) is an inlet means through which raw water is supplied, and is composed of a supply pipe (11), an automatic supply valve (12), a raw water pressure gauge (13), a first water quality measuring device (14), a second water quality measuring device (15), a potential measuring device (16), a water quality analyzer (17), and a silica analyzer (18).

[0047] The supply pipe (11) is a pipe member that supplies raw water by introducing it, and is connected downstream from a raw water storage tank or supply source that stores various raw waters such as wastewater, sewage water, and water supply, to supply the raw water.

[0048] The automatic supply valve (12) is a valve member installed on one side of the supply pipe (11) to control whether raw water is supplied, and is composed of a differential pressure flow control valve to selectively control whether raw water is supplied to the filter unit (30).

[0049] The raw water pressure gauge (13) is a measuring member installed on one side of the supply pipe (11) to measure the pressure of the raw water. It is composed of a PT (PRESSURE TRANSMITTER) and measures the supply pressure of the raw water to control the process pressure of the treatment process by filtration of the raw water to be maintained constant.

[0050] The first water quality measuring device (14) is a measuring device installed on one side of the supply pipe (11) to measure the quality of raw water, and is composed of a TDS (Total Dissolved Solid) measuring device to measure the contamination level of raw water during water treatment.

[0051] The second water quality measuring device (15) is a measuring device installed on the other side of the supply pipe (11) to measure the quality of raw water. It consists of a TDS (Total Dissolved Solid) measuring device installed downstream of the confluence of the raw water and the recovered concentrated water, and measures the contamination level of the mixed water of the raw water and the concentrated water during water treatment.

[0052] The potential measuring device (16) is a measuring member installed on the other side of the supply pipe (11) to measure the raw water by the potential difference, and is composed of an ORP (Oxidation Reduction Potential) measuring device installed downstream of the confluence of the raw water and the recovered concentrated water, and measures the oxidation-reduction potential of the mixed water of the raw water and the concentrated water during water treatment.

[0053] The water quality analyzer (17) is a measuring device installed on the other side of the supply pipe (11) to analyze the water quality contamination of raw water. It is composed of a TOC (Total Organic Carbon) analyzer installed downstream of the confluence of the raw water and the recovered concentrated water, and measures the water quality contamination of the mixed water of the raw water and the concentrated water during water treatment.

[0054] The silica analyzer (18) is a measuring device installed on the other side of the supply pipe (11) to measure the contamination level of raw water. It is composed of a SiO2 (silicon dioxide; silica) measuring device installed downstream of the confluence of the raw water and the recovered concentrated water, and measures the contamination level of the mixed water of the raw water and the concentrated water during water treatment.

[0055] The pumping unit (20) is a pumping means installed downstream of the inlet unit (10) to pump and inject raw water, and is composed of an inlet pipe (21), a supply pump (22), a pump controller (23), a pumping pressure gauge (24), and a differential pressure measuring unit (25).

[0056] The input pipe (21) is a pipe member that is connected between the downstream of the supply pump (22) and the upstream of the filtering unit (30) to input raw water by pumping, and supplies various raw waters such as wastewater, sewage water, and water supply to the filtering unit (30).

[0057] The supply pump (22) is an input member that pumps and inputs raw water, and supplies various raw waters such as wastewater, sewage water, and water supply to the filter unit (30) by pumping of the supply pump (22).

[0058] The pump controller (23) is a controller that is connected to one side of the supply pump (22) and controls the pumping of the supply pump (22). It is composed of a VFD (Variable frequency drive) inverter and starts the motor of the supply pump (22) using a voltage proportional to the frequency.

[0059] The pumping pressure gauge (24) is a measuring member installed downstream of the supply pump (22) to measure the pressure of the raw water. It is composed of a PT (PRESSURE TRANSMITTER) and measures the pumping pressure of the raw water to control the pumping pressure of the treatment process by filtration of the raw water to be maintained constant.

[0060] The differential pressure measuring device (25) is a measuring device installed between the upstream of the filtration unit (30) and the first concentrated water discharge unit (50) to measure the differential pressure. By measuring the pressure difference between the raw water and the concentrated water, the filtration pressure is controlled by controlling whether or not the blower blows to the filtration unit (30) so as to maintain the filtration pressure of the treatment process by filtration of the raw water constant.

[0061] In addition, it is preferable that the operation of the supply pump (22) of the pumping unit (20) is stopped when the difference between the pressure measured by the pumping pressure gauge (24) downstream of the pumping unit (20) and the pressure measured by the third concentrated water pressure gauge (67) of the first recovery unit (60) is equal to or greater than the set value.

[0062] The filter unit (30) is a filtering means installed downstream of the pumping unit (20) to filter raw water and is composed of a filter (31), a filter check valve (32), and an automatic filter valve (33).

[0063] The filtration filter (31) is composed of an osmotic membrane or nanofilter in which multiple filtration membranes are installed in a row inside a pressure vessel, and in particular, the arrangement method of this filtration unit (30) is largely divided into a single-array method, a double-array method, and a third-array method depending on the arrangement method, and the single-array method is mainly used in household water purifiers, small-capacity water treatment devices, and seawater desalination. In the case of seawater desalination, the single-array method is used due to the high salt concentration of seawater, and a large amount of concentrated water, that is, about 50% of the supply water, is discharged.

[0064] Therefore, the 2-array method and the 3-array method are selectively used in cases of medium and large capacity, and are determined according to the water quality and pretreatment method of the raw water. It is preferable that the composition ratio of the 2-array pressure vessel be 2:1, and that the composition ratio of the 3-array pressure vessel be 4:2:1.

[0065] In addition, it is possible that the filtration filter (31) of this filtration unit (30) is composed of one or more filter groups in which multiple filtration filters are connected in multiple stages, such as the 11th to 14th filtration filters (31a, 31b, 31c, 31d) as shown in Fig. 2. It is also possible that one or more of these filter groups are arranged in series or in parallel.

[0066] The filtration check valve (32) is a valve member that is installed on one side of the filtration pipe connected to the downstream side of the filtration filter (31) and is installed upstream of the treated water discharge port (40) to control the direction of discharge of the treated water, and controls the discharge of the treated water in one direction only to the outside.

[0067] In addition, it is also possible that these filtration check valves (32) are each composed of one or more check valve groups connected in series to multiple filtration filters, such as the 11th to 14th filtration filters (31a, 31b, 31c, 31d), such as the 11th to 14th check valves (32a, 32b, 32c, 32d) as shown in FIG. 2.

[0068] The automatic filtration valve (33) is a valve member that is installed on the other side of the filtration pipe connected to the downstream side of the filtration filter (31) and controls whether or not to supply air. When the differential pressure increases upstream and downstream of the filtration filter (31), the differential pressure is controlled by the air blown from the blower to maintain the filtration pressure, thereby selectively controlling whether or not to supply air to the filtration unit (30).

[0069] The treated water discharge unit (40) is a treated water discharge means that is connected to one side downstream of the filtration unit (30) and discharges the treated water treated in the filtration unit (30), and is composed of an discharge pipe (41), a treated water quality measuring device (42), and a treated water flow measuring device (43).

[0070] The outlet pipe (41) is a pipe member through which treated water flows out from one side downstream of the filtration unit (30), and the treated water filtered by the reverse osmosis membrane or nano filter in the filtration unit (30) flows out.

[0071] The treated water quality measuring device (42) is a measuring device installed on one side of the discharge pipe (41) to measure the water quality of the treated water, and is composed of a TDS (Total Dissolved Solid) measuring device installed downstream of the filtration unit (30) to measure the contamination level of the treated water discharged during water treatment.

[0072] The treated water flow meter (43) is a measuring member installed on one side of the discharge pipe (41) to measure the flow rate of treated water, and is composed of an FT (FLOW TRANSMITTER) installed downstream of the filtration unit (30) to measure the flow rate of treated water discharged during water treatment, thereby maintaining the discharge amount of treated water constant.

[0073] The first concentrated water discharge unit (50) is connected to the other side downstream of the filtration unit (30) and is a primary concentrated water discharge means that discharges the concentrated water treated in the filtration unit (30) primarily by gravity without power, and is composed of an 11th discharge pipe (51), a 12th discharge pipe (52), an 11th automatic valve (53), and a 1st concentrated water pressure gauge (54).

[0074] The 11th discharge pipe (51) is a pipe member through which concentrated water is discharged from the other side downstream of the filtering unit (30). It is connected to the other side downstream of the filtering unit (30) and the concentrated water filtered by the reverse osmosis membrane or nano filter in the filtering unit (30) is discharged.

[0075] The 12th discharge pipe (52) is a pipe member that branches off from one side downstream of the 11th discharge pipe (51) and discharges the concentrated water to the outside, and a portion of the concentrated water filtered by the reverse osmosis membrane or nano filter in the filtration unit (30) is selectively discharged to the outside.

[0076] The 11th automatic valve (53) is a valve member installed on one side of the 12th discharge pipe (52) to control whether or not to discharge the concentrated water. It is composed of a differential pressure flow control valve and selectively controls whether or not to discharge the concentrated water initially to the outside.

[0077] The first concentrated water pressure gauge (54) is a measuring member that is installed on one side of the 12th discharge pipe (52) to measure the pressure of the concentrated water, and is composed of a PT (PRESSURE TRANSMITTER) to measure the discharge pressure of the concentrated water and control the discharge pressure of the concentrated water to keep it constant.

[0078] The first recovery unit (60) is a recovery means that is connected to the downstream of the first concentrated water discharge unit (50) and the upstream of the pumping unit (20) to selectively recover the concentrated water discharged from the first concentrated water discharge unit (50) and supply it to the filtration unit (30), and is composed of a first recovery pipe (61), a 12th automatic valve (62), a first control valve (63), a concentrated water quality meter (64), a concentrated water flow meter (65), a second concentrated water pressure gauge (66), a third concentrated water pressure gauge (67), a first check valve (68), and a gate valve (69).

[0079] The first recovery pipe (61) is a pipe member for recovering the concentrated water, and is connected between the downstream of the first concentrated water discharge unit (50) and the upstream of the pumping unit (20). The concentrated water discharged from the filtering unit (30) is combined with the raw water downstream of the inlet unit (10) without being discharged to the outside, and is reprocessed in the filtering unit (30) to circulate and reprocess without discharging the concentrated water.

[0080] The 12th automatic valve (62) is a valve member installed on one side of the first recovery pipe (61) to control whether or not to recover the concentrated water, and is composed of a differential pressure flow control valve to selectively control whether or not to recover the concentrated water.

[0081] The first control valve (63) is a valve member installed on one side of the first recovery pipe (61) to control the amount of concentrated water recovered. It is composed of a solenoid valve and controls the amount of concentrated water recovered by mixing with raw water and being reprocessed.

[0082] The concentrated water quality measuring device (64) is a measuring device installed on the other side of the first recovery pipe (61) to measure the water quality of the concentrated water. It is composed of a TDS (Total Dissolved Solid) measuring device installed downstream of the filtration unit (30) and measures the contamination level of the concentrated water that is selectively recovered during water treatment, mixed with raw water, and then reprocessed and circulated.

[0083] The concentrated water flow meter (65) is a measuring member installed on the other side of the first recovery pipe (61) to measure the flow rate of concentrated water, and is composed of an FT (FLOW TRANSMITTER) installed downstream of the filtration unit (30). It measures the flow rate of concentrated water that is selectively recovered during water treatment, mixed with raw water, and then reprocessed and circulated, thereby maintaining the recovered amount of concentrated water constant.

[0084] The second concentrated water pressure gauge (66) is a measuring member that is installed on the other side of the first recovery pipe (61) and upstream of the concentrated water flow meter (65) to measure the pressure of the concentrated water. It is composed of a PT (PRESSURE TRANSMITTER) and measures the discharge pressure of the concentrated water to maintain the discharge pressure of the concentrated water constant.

[0085] The third concentrated water pressure gauge (67) is a measuring member that is installed on one side of the first recovery pipe (61) and upstream of the 12th automatic valve (62) to measure the pressure of the concentrated water, and is composed of a PT (PRESSURE TRANSMITTER) to measure the recovery pressure of the concentrated water and control the recovery pressure of the concentrated water to keep it constant.

[0086] In this way, when the difference between the pressure measured by the pumping pressure gauge (24) of the pumping unit (20) and the pressure measured by the second concentrated water pressure gauge (66) of the first recovery unit (60) is equal to or greater than the set value, the pressure of the mixed water of the raw water and the concentrated water rises higher than the pressure of the concentrated water, thereby lowering the efficiency of membrane filtration treatment by reverse osmosis or nanofilter, so it is desirable to stop the operation of the pumping unit (20).

[0087] The first check valve (68) is a valve member installed on one side of the first recovery pipe (61) and downstream of the first control valve (63) to control the flow direction of the concentrated water, and controls the concentrated water to flow in one direction only to the confluence between the inlet (10) and the pumping unit (20).

[0088] The gate valve (69) is a valve member installed on one side of the first recovery pipe (61) and downstream of the first control valve (63) to control the amount of concentrated water recovered. When mixed with the raw water of the inlet (10), the gate valve (69) controls the flow rate of the concentrated water so as to control the amount of concentrated water recovered according to various conditions such as the water quality or hydraulic pressure of the raw water.

[0089] The blower (70, 80) is a blower means that is connected to the inlet (10) and blows air according to the pressure difference between the upstream and downstream of the filter (30), and is composed of a first blower (70) that blows outside air and a second blower (80) that blows compressed air.

[0090] The first blower (70) is a blower member that is connected to one side of the inlet (10) and blows outside air when the pressure difference between the upstream and downstream of the filter (30) falls within a predetermined range, and is composed of a first blower pipe (71), a blower (72), a blower controller (73), a first blower pressure gauge (74), a first air volume measuring device (75), and a first blower automatic valve (76).

[0091] The first blower pipe (71) is a pipe member that blows outside air to the filtering unit (30), and is connected to the supply pipe (11) of the inlet unit (10) to blow outside air when the pressure difference between the upstream and downstream of the filtering unit (30) is greater than 2.0 bar and less than 3.0 bar.

[0092] The blower (72) is a blower means installed on one side of the first blower pipe (71) to provide blowing air, and is composed of blowing equipment such as an air blower or blowing fan to provide blowing power by bringing in outside air.

[0093] The blower controller (73) is a control means that is connected to one side of the blower (72) and controls the blower (72) blowing air. It is composed of a VFD (Variable Frequency Drive) and controls the blower (72) to maintain the blowing pressure of the outside air constant.

[0094] The first blower pressure gauge (74) is a measuring member installed on the other side of the first blower pipe (71) to measure the blower pressure, and is composed of a PT (PRESSURE TRANSMITTER) to measure the blower pressure of the outside air and control the blower pressure of the outside air to maintain it constant.

[0095] The first air volume measuring device (75) is a measuring member that is installed on the other side of the first blower pipe (71) and downstream of the first blower pressure gauge (74) to measure the blown air volume, and is composed of an FT (FLOW TRANSMITTER) installed downstream of the first blower section (70) to measure the blown air volume of the outside air blown to the filter section (30) and maintain the blown air volume of the outside air constant.

[0096] The first blower automatic valve (76) is a valve member installed on the other side of the first blower pipe (71) to control whether or not to blow outside air, and is composed of a differential pressure flow control valve to selectively control whether or not to blow outside air.

[0097] The second blower (80) is a blower member that is connected to the other side of the inlet (10) and blows compressed air when the pressure difference between the upstream and downstream of the filter (30) is greater than a predetermined value, and is composed of a second blower pipe (81), a compressor (82), a second blower pressure gauge (83), a second air volume measuring device (84), and a second blower automatic valve (85).

[0098] The second blower pipe (81) is a pipe member that blows compressed air to the filtering unit (30), and is connected to the supply pipe (11) of the inlet unit (10) to blow compressed air when the pressure difference between the upstream and downstream of the filtering unit (30) is 3.0 bar or more.

[0099] The compressor (82) is a compression member installed on one side of the second blower pipe (81) to provide compressed air, and is composed of compression equipment such as an air compressor to compress outside air to form compressed air.

[0100] The second blower pressure gauge (83) is a measuring member installed on the other side of the second blower pipe (81) to measure the blower pressure, and is composed of a PT (PRESSURE TRANSMITTER) to measure the blower pressure of compressed air and control the blower pressure of compressed air to maintain it constant.

[0101] The second air volume measuring device (84) is a measuring member that is installed on the other side of the second blower pipe (81) and downstream of the second blower pressure gauge (83) to measure the blown air volume, and is composed of an FT (FLOW TRANSMITTER) installed downstream of the second blower section (80) to measure the blown air volume of compressed air blown to the filter section (30) and maintain the blown air volume of the compressed air constant.

[0102] The second blower automatic valve (85) is a valve member installed on the other side of the second blower pipe (81) to control whether compressed air is blown, and is composed of a differential pressure flow control valve to selectively control whether compressed air is blown.

[0103] The second concentrated water discharge unit (90) is a secondary concentrated water discharge means that is connected to the other side downstream of the first concentrated water discharge unit (50) and discharges the concentrated water treated in the first concentrated water discharge unit (50) secondarily using gravity without power, and is composed of a 21st discharge pipe (91), a 22nd discharge pipe (92), a 21st automatic valve (93), a 22nd automatic valve (94), a second storage tank (95), and a 21st concentrated water pressure gauge (96).

[0104] The 21st discharge pipe (91) is a pipe member through which concentrated water is discharged from the other side downstream of the first concentrated water discharge unit (50), and is connected to the other side downstream of the first concentrated water discharge unit (50) so that concentrated water discharged from the first concentrated water discharge unit (50) is selectively discharged.

[0105] The 22nd discharge pipe (52) is a pipe member that branches off from one side downstream of the 21st discharge pipe (91) and discharges the concentrated water to the outside, and a portion of the concentrated water discharged from the first concentrated water discharge unit (50) is selectively discharged to the outside.

[0106] The 21st automatic valve (93) is a valve member installed on one side of the 21st discharge pipe (91) to control whether or not to discharge the concentrated water. It is composed of a differential pressure flow control valve to selectively control whether or not to discharge the concentrated water for a second time.

[0107] The 22nd automatic valve (94) is a valve member installed on one side of the 22nd discharge pipe (92) to control whether or not to discharge the concentrated water. It is composed of a differential pressure flow control valve and selectively controls whether or not to discharge the concentrated water to the outside for a second time.

[0108] The second storage tank (95) is installed in the 21st discharge pipe (91) and is installed downstream of the 21st automatic valve (93) as a storage means for temporarily storing the concentrated water discharged in the first place. The concentrated water discharged in the first place is temporarily stored and discharged to the outside in the second place or recovered in the second place and circulated.

[0109] The 21st concentrated water pressure gauge (96) is a measuring member installed on one side of the second storage tank (95) to measure the pressure of the concentrated water, and is composed of a PT (PRESSURE TRANSMITTER) to measure the secondary discharge pressure of the concentrated water and control the secondary discharge pressure of the concentrated water to maintain it constant.

[0110] The second recovery unit (100) is a recovery means that is connected to the downstream of the second concentrated water discharge unit (90) and the upstream of the pumping unit (20), and selectively recovers the concentrated water discharged secondarily from the second concentrated water discharge unit (90) and supplies it to the filter unit (30) for circulation, and is composed of a second recovery pipe (101), a 23rd automatic valve (102), a recovery pump (103), a second filter (104), a 24th automatic valve (105), and a second check valve (106).

[0111] The second recovery pipe (101) is a pipe member that recovers the concentrated water for a second time, and is connected between the downstream of the second concentrated water discharge unit (90) and the upstream of the pumping unit (20). The concentrated water discharged from the first concentrated water discharge unit (90) is combined with the raw water downstream of the inlet unit (10) without being discharged to the outside, and is reprocessed in the filtration unit (30) to circulate and reprocess without discharging the concentrated water.

[0112] The 23rd automatic valve (102) is a valve member installed on one side of the second recovery pipe (101) to control whether or not to recover the concentrated water for the second time. It is composed of a differential pressure flow control valve to selectively control whether or not to recover the concentrated water for the second time.

[0113] The recovery pump (103) is installed downstream of the 23rd automatic valve (102) and is a pressurizing member that pressurizes the secondary recovered concentrated water to a low pressure. The secondary recovered concentrated water is pressurized to a low pressure by pumping of the recovery pump (103) and supplied to the filter (30) downstream of the inlet (10) for reprocessing, thereby circulating.

[0114] The second filter (104) is a filter member installed downstream of the recovery pump (103) to filter the secondary recovered concentrated water, and is made of a cartridge filter that is easy to replace so that the secondary recovered concentrated water is filtered and circulated.

[0115] The 24th automatic valve (105) is a valve member installed downstream of the second filter (104) to control the amount of recovered concentrated water. It is composed of a solenoid valve and controls the amount of recovered concentrated water reprocessed in the filtration unit (30).

[0116] The second check valve (106) is a valve member installed on one side of the second recovery pipe (101) and downstream of the 24th automatic valve (105) to control whether or not to discharge the secondary recovered concentrated water, and controls the concentrated water to flow in one direction only to the confluence between the inlet (10) and the pumping unit (20).

[0117] Hereinafter, a water treatment process using a circulating reverse osmosis water treatment device of the present embodiment will be specifically described with reference to the drawings.

[0118] As shown in FIGS. 3 to 6, the water treatment process using the circulating reverse osmosis water treatment device of the present embodiment is a concentrated water treatment process of a circulating reverse osmosis water treatment facility that treats raw water through filtration in a circulating manner, consisting of a primary circulation process, a secondary circulation process, and a concentrated water discharge process.

[0119] In addition, it is also possible for the concentrated water treatment process of this type of circulating reverse osmosis water treatment facility to include a blowing process between the primary and secondary circulation processes.

[0120] The first circulation process is a process of recovering and circulating part or all of the concentrated water by opening the first recovery unit (60) branched from the first concentrated water discharge unit (50) as shown in FIG. 3. Of course, it is also possible to recover all of the concentrated water discharged from the first concentrated water discharge unit (50) by closing the 11th automatic valve (53) of the first concentrated water discharge unit (50) and opening the 12th automatic valve (62) of the first recovery unit (60).

[0121] Specifically, the first control valve (63) installed downstream of the 12th automatic valve (62) is opened to control the opening amount of the first control valve (63) to control the amount of concentrated water to be recovered, and a process for controlling whether the first control valve (63) installed in the recovery section (60) is opened is further provided, so that the opening amount of the first control valve (63) is controlled by PID control (Proportional Integral Derivation Control) to control the amount of concentrated water to be recovered and circulated.

[0122] In addition, a pumping unit (20) installed downstream of the confluence of the inlet (10) where raw water flows in and the first recovery unit (60) where the concentrated water discharged from the filtration unit (30) is first recovered is operated to pump a mixed water of raw water and concentrated water at high pressure and feed it into the filtration unit (30).

[0123] The operating time of the pumping unit (20) is set by measuring the flow rate and pressure of the mixed water of raw water and concentrated water while comparing the operating time of the pumping unit (20) with the service time and the set time, and determining the operating time of the pumping unit (20) as 20 to 60 minutes to control whether or not the pump is operated.

[0124] In addition, it is also possible to control whether or not to operate the pump by analyzing the silica contained in the mixed water of raw water and concentrated water by a silica analyzer (18) installed downstream of the confluence of the inlet (10) where raw water flows in and the first recovery unit (60) where the concentrated water discharged from the reverse osmosis filter (30) is recovered and comparing it with a set value.

[0125] In addition, it is also possible to control whether or not to operate the pump by analyzing the potential difference of the mixed water of raw water and concentrated water by a potential measuring device (16) installed downstream of the confluence between the inlet (10) where raw water flows in and the first recovery unit (60) where the concentrated water discharged from the reverse osmosis filter (30) is recovered, and comparing it with a set value.

[0126] In addition, it is also possible to control the pump by analyzing the contamination level of the mixed water of raw water and concentrated water and comparing it with a set value by a second water quality measuring device (15) installed downstream of the confluence of the inlet (10) where raw water flows in and the first recovery unit (60) where the concentrated water discharged from the filtration unit (30) is recovered.

[0127] In addition, the operation of this pumping unit (20) compares the difference between the pressure measured by the pumping pressure gauge (24) of the pumping unit (20) and the pressure measured by the third concentrated water pressure gauge (67) of the first recovery unit (60) with a set value.

[0128] The blowing process, as shown in Fig. 4, is a process that blows outside air to the filtering unit (30) when the pressure difference between the upstream and downstream of the filtering unit (30) on one side of the inlet (10) is within a predetermined range, and when the pressure difference between the upstream and downstream of the filtering unit (30) is greater than 2.0 bar and less than 3.0 bar, outside air is blown to the filtering unit (30) to forcibly discharge the concentrated water by the outside air.

[0129] This blowing process is performed by opening the 11th automatic valve (53) of the first concentrated water discharge unit (50) and the filtration automatic valve (33) of the filtration unit (30), after the opening set time of the 11th automatic valve (53) and the filtration automatic valve (33) has elapsed, opening the 11th automatic valve (53) of the first concentrated water discharge unit (50) and the first blowing automatic valve (76) of the first blowing unit (70), after the opening set time of the 11th automatic valve (53) and the first blowing automatic valve (76) has elapsed, and then opening the 11th automatic valve (53) and the supply automatic valve (12).

[0130] The following blowing process is a process of blowing compressed air to the filtering unit (30) when the pressure difference between the upstream and downstream of the filtering unit (30) on the other side of the inlet (10) is within a predetermined range. When the pressure difference between the upstream and downstream of the filtering unit (30) is 3.0 bar or more, compressed air is blown to the filtering unit (30) to forcibly discharge the concentrated water by the compressed air.

[0131] The following blowing process is performed by opening the 11th automatic valve (53) of the 1st concentrated water discharge unit (50) and the filtration automatic valve (33) of the filtration unit (30), after the opening set time of the 11th automatic valve (53) and the filtration automatic valve (33) has elapsed, opening the 11th automatic valve (53) of the concentrated water discharge unit (50) and the second blowing automatic valve (85) of the second blowing unit (80), after the opening set time of the 11th automatic valve (53) and the second blowing automatic valve (85) has elapsed, and then opening the 11th automatic valve (53) and the supply automatic valve (12).

[0132] The secondary circulation process is a process of recovering part or all of the concentrated water by opening the second recovery unit (100) branched from the second concentrated water discharge unit (90), as shown in FIG. 5. It is also possible to recover and circulate all of the concentrated water discharged from the second concentrated water discharge unit (90) by closing the 11th automatic valve (53) of the first concentrated water discharge unit (50) and the 12th automatic valve (62) of the first recovery unit (60), opening the 21st automatic valve (93) of the second concentrated water discharge unit (90), closing the 22nd automatic valve (94), and opening the 23rd automatic valve (102) and the 24th automatic valve (105) of the second recovery unit (100).

[0133] Next, the recovery pump (103) installed downstream of the second recovery unit (100) where the concentrated water discharged from the filter unit (30) is recovered is operated to pump the concentrated water stored in the storage tank (95) at low pressure and feed it into the filter unit (30).

[0134] The concentrated water discharge process is a process for discharging all of the concentrated water remaining in the filtration unit (30) after the first circulation process and the second circulation process, as shown in FIG. 6, to the outside. It is of course also possible to discharge all of the concentrated water discharged from the filtration unit (90) together through the first concentrated water discharge unit (50) and the second concentrated water discharge unit (90) by opening the 11th automatic valve (53) of the first concentrated water discharge unit (50), closing the 12th automatic valve (62) of the first recovery unit (60), opening the 21st automatic valve (93) and the 22nd automatic valve (94) of the second concentrated water discharge unit (90), and closing the 23rd automatic valve (102) of the second recovery unit (100).

[0135] This concentrated water discharge process is a discharge step that discharges the concentrated water treated in the filtration unit (30) without power using gravity downstream of the filtration unit (30). If the pressure difference between the upstream and downstream of the filtration unit (30) is 2.0 bar or less, the concentrated water is discharged without power using gravity.

[0136] As described above, according to the present invention, when producing treated water, the concentrated water is first recovered and then recovered a second time to be circulated for reprocessing, or forcibly discharged to be mixed and diluted with the supply water at a certain ratio, or the production of treated water is possible without discharging the concentrated water during operation, and when a set time or water quality is reached, only the water inside the filter container is automatically discharged, thereby providing the effect of enabling economical, high-efficiency, high-recovery operation without deterioration of the performance of the filter or reverse osmosis membrane.

[0137] In addition, by recovering all of the concentrated water without discharging it during operation, the flow rate inside the filter container is improved, thereby suppressing scale attachment on the filter surface due to concentration polarization, and by discharging only water inside the filter container when the concentration exceeds the saturation concentration, the quantitative loss of the supply water is reduced, thereby improving the durability of the filter or reverse osmosis membrane and extending its lifespan, and providing the effect of improving economic efficiency by reducing the capacity of the pretreatment facility and reducing the operation and maintenance costs.

[0138] In addition, in order to solve problems such as increased operating costs, such as a shortened lifespan of filters, by minimizing contamination caused by the quantitative loss of supply water due to the discharge of concentrated water compared to the produced water and the imbalance of filters or reverse osmosis membranes accompanying the arrangement configuration, the concentrated effluent generated during operation is not used in a separate reprocessing process or by diluting a certain ratio of concentrated effluent with raw water, but rather by recovering and using all of the concentrated effluent, thereby eliminating the quantitative loss of supply water and improving the efficiency of filters or reverse osmosis membranes in the arrangement configuration, providing the effect of enabling high-efficiency, high-recovery operation.

[0139] The present invention described above may be implemented in various other forms without departing from its technical spirit or essential characteristics. Therefore, the above embodiments are merely illustrative in all respects and should not be construed as limiting.

[0140] The present invention provides a circulating reverse osmosis water treatment device that filters raw water by reverse osmosis.

Claims

1. A circulating reverse osmosis water treatment device that treats raw water through filtration in a circulating manner. Inlet (10) where raw water is supplied; A pumping unit (20) installed downstream of the above inlet unit (10) to pump and inject raw water; A filtering unit (30) installed downstream of the above pumping unit (20) to filter raw water; A treated water discharge unit (40) connected to one side downstream of the above filter unit (30) and discharging the treated water from the above filter unit (30); A first concentrated water discharge unit (50) connected to the downstream side of the above filter unit (30) and discharging the concentrated water treated in the above filter unit (30); A first recovery unit (60) connected to the downstream side of the first concentrated water discharge unit (50) and the upstream side of the pumping unit (20), respectively, to selectively recover the concentrated water discharged from the first concentrated water discharge unit (50) and supply it to the filter unit (30) for circulation; A second concentrated water discharge unit (90) connected to the other side downstream of the first concentrated water discharge unit (50) and discharging the concentrated water treated in the first concentrated water discharge unit (50); and A circulating reverse osmosis water treatment device characterized by including a second recovery unit (100) which is connected to the downstream of the second concentrated water discharge unit (90) and the upstream of the pumping unit (20), respectively, to selectively recover the concentrated water discharged from the second concentrated water discharge unit (90) and supply it to the filtration unit (30) for circulation.

2. In paragraph 1, A circulating reverse osmosis water treatment device characterized in that it further includes a blower connected to the inlet (10) and blowing air according to the pressure difference between the upstream and downstream of the filter (30).

3. In paragraph 2, The above blower, A first blower (70) connected to one side of the above inlet (10) and blowing outside air when the pressure difference between the upstream and downstream of the filter (30) falls within a predetermined range; and A circulating reverse osmosis water treatment device characterized by including a second blower (80) connected to the other side of the inlet (10) and blowing compressed air when the pressure difference between the upstream and downstream of the filter (30) is greater than a predetermined value.

4. In paragraph 1, The above inlet (10) is A supply pipe that supplies raw water; An automatic supply valve installed on one side of the above supply pipe to control whether raw water is supplied; A raw water pressure gauge installed on one side of the above supply pipe to measure the pressure of the raw water; A first water quality measuring device installed on one side of the above supply pipe to measure the water quality of raw water; A second water quality measuring device installed on the other side of the above supply pipe to measure the water quality of the raw water; A potential analyzer installed on the other side of the above supply pipe to measure raw water by potential difference; A water quality analyzer installed on the other side of the above supply pipe to analyze the quality of raw water; and A circulating reverse osmosis water treatment device characterized by including a silica analyzer installed on the other side of the above supply pipe and measuring the contamination level of raw water.

5. In paragraph 1, The above pumping unit (20) is A supply pump that pumps and injects raw water; A pump controller connected to one side of the above supply pump and controlling pumping of the supply pump; A pumping pressure gauge installed downstream of the above supply pump to measure the pumping pressure of the raw water; and A circulating reverse osmosis water treatment device characterized by including a differential pressure measuring device installed between the upstream of the filter unit (30) and the first concentrated water discharge unit (50) to measure differential pressure.

6. In paragraph 1, The above treatment water outlet (40) is Outflow pipe through which treated water flows out; A treated water quality measuring device installed on one side of the above discharge pipe to measure the water quality of the treated water; and A circulating reverse osmosis water treatment device characterized by including a treated water flow meter installed on one side of the above-mentioned outlet pipe and measuring the flow rate of treated water.

7. In paragraph 1, The above first concentrated water discharge unit (50) is Discharge pipe No. 11 through which concentrated water is discharged; A 12th discharge pipe branched off from one side downstream of the 11th discharge pipe to discharge the concentrated water to the outside; An 11th automatic valve installed on one side of the 12th discharge pipe to control whether to discharge the concentrated water; and A circulating reverse osmosis water treatment device characterized by including a first concentrated water pressure gauge installed on one side of the 12th discharge pipe and measuring the pressure of concentrated water.

8. In paragraph 1, The above first recovery unit (60) is First recovery pipe for recovering concentrated water; A 12th automatic valve installed on one side of the first recovery pipe to control whether or not to recover the concentrated water; A first control valve installed on one side of the first recovery pipe to control the amount of concentrated water recovered; A second concentrated water pressure gauge installed on one side of the first recovery pipe and upstream of the 12th automatic valve to measure the pressure of the concentrated water; A concentrated water flow meter installed on the other side of the first recovery pipe to measure the flow rate of concentrated water; A concentrated water quality measuring device installed on the other side of the first recovery pipe to measure the water quality of the concentrated water; and A circulating reverse osmosis water treatment device characterized by including a third concentrated water pressure gauge installed on the other side of the first recovery pipe and installed upstream of the concentrated water flow meter to measure the pressure of the concentrated water.

9. In paragraph 1, The above second concentrated water discharge unit (90) is Discharge pipe No. 21 through which concentrated water is discharged; A 22nd discharge pipe branched off from one side downstream of the 21st discharge pipe and discharges the concentrated water to the outside; A 21st automatic valve installed on one side of the 21st discharge pipe to control whether or not to discharge the concentrated water; A 22nd automatic valve installed on one side of the 22nd discharge pipe to control whether or not to discharge the concentrated water; A second storage tank installed in the above 21st discharge pipe and downstream of the 21st automatic valve, for temporarily storing concentrated water; A circulating reverse osmosis water treatment device characterized by including a 21st concentrated water pressure gauge installed on one side of the second storage tank and measuring the pressure of concentrated water.

10. In paragraph 1, The above second recovery unit (100) is A second recovery pipe for recovering the concentrated water; A 23rd automatic valve installed on one side of the second recovery pipe to control whether or not to recover the concentrated water; A recovery pump installed downstream of the above 23rd automatic valve to pressurize the recovered concentrated water; A second filter installed downstream of the above recovery pump to filter the concentrated water; and A circulating reverse osmosis water treatment device characterized by including a 24th automatic valve installed downstream of the second filter to control whether to discharge concentrated water.

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