KR20020071311A - Water purifying method and system thereof - Google Patents

Abstract

PURPOSE: A water purifying method and system thereof is provided, which regenerate ultrafiltration membrane completely by vibration and air pressure, so that the filtration efficiency is enhanced. In the system, various automatic valves and pumps are connected to one power line thus saving operating cost by one third compared to the conventional system. CONSTITUTION: The method comprises the steps of adsorptively removing organic matter or residual chlorine using activated carbon(120); purifying water by primary filtration using micro filtration membrane(130); purify organic matter and undissolved contaminants by secondary filtration using ultrafiltration membrane; removing foreign matter of ultrafiltration membrane by vibration and air pressure; and regenerating the filter by back washing with treated water.

Description

Water Purifying Method and System

TECHNICAL FIELD The present invention relates to a water purification method and a water purification system, and more particularly, to a water purification method and system in which the ultrafiltration membrane is completely regenerated through vibration and air washing to increase efficiency.

Existing apartment water purification system uses ion exchange resin, activated carbon, ultraviolet filter, ozone sterilizer, etc. for the purpose of softening soft water, removing organic substances and microorganisms by ion exchange, adsorption and sterilization. However, these water purifiers are expensive to install the device, there is a disadvantage that excessive water purification without considering the domestic water quality. In other words, in the apartment water purification system, the ground water or the tap water can be filtered to obtain good water quality. Therefore, these systems have low reliability of water purification effect and have difficulty in maintaining water purification material used. In particular, the purified water often causes secondary pollutants due to microbial regrowth or decayed material from the corroded water pipe during transportation to the faucet of each household. Accordingly, even in purified water, microorganisms or sediments were not sufficiently exhibited.

In order to solve this problem, a water purification device using a membrane has recently been developed. As the types of membranes currently being used, reverse osmosis membranes, ultrafiltration membranes, and microfiltration membranes are mainly used. However, the reverse osmosis membrane is expensive because the amount of purified water is small and many modules are used. In addition, ultrafiltration membranes and microfiltration membranes are frequently used for water direct-type household water purifiers, and microfiltration membranes are mainly used for pretreatment due to lower filtration performance than other membranes. The ultrafiltration membrane has excellent functions for removing microorganisms and non-dissolved foreign substances, so it is preferable to use them in a central water purification system, or as the number of modules used decreases due to the small amount of permeated water, the apparatus becomes large and expensive. Recently, there is a tendency to reduce the volume and cost of the apparatus by using a high permeability ultrafiltration membrane device, but also, the disadvantage that the foreign matter affects the membrane performance as the purified water is repeated, so that the water treatment efficiency decreases over time. There was this.

In addition, in the existing water purification system, each line of each automatic valve, pump, etc. is connected to the integrated control unit and is automatically operated. In this case, the system becomes complicated and the manufacturing cost is high.

Accordingly, it is an object of the present invention to provide a water purification method and system in which the ultrafiltration membrane is completely regenerated through vibration and air washing to increase efficiency.

Another object of the present invention is to provide a purification method and system that is economical, easy to control, and does not have interference by connecting all control lines to one existing power line.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the example of the water purification process implemented by the water purification system of this invention.

2 is a view showing a backwashing process of the ultrafiltration membrane device in the water purification system of the present invention.

3 is a schematic diagram of a conventional water purification system control method

4 is a schematic diagram of a water purification system control method of the present invention;

5 is a water permeation amount of the conventional water purification system and water purification system of the present invention

* Explanation of symbols for main parts *

1 to 7 gate valve 11 to 20 flow control valve (globe valve)

21 to 23: check valve 31 to 33: ball valve

41Temperature Indicator

50: Air Compressor

51: Flow Indicating Controller

61 to 65: pressure indicator

71: High Pressure Switch

100: underground reservoir tank 101-106: automatic valve (solenoid valve)

110: circulation pump 120: activated carbon filter

130: precision filtration membrane device 140: ultrafiltration membrane module

141, 142, 143: ultrafiltration membrane 144: ultrafiltration membrane module inlet

145: concentrated water outlet 146, 147: outlet

148: ultrafiltration membrane module 149: ultrafiltration membrane inlet

150: purified water storage tank 160: feed pump

170: UV filter 180: public drinking water

201, 202: Water level regulator (LIC)

Water purification method of the present invention for achieving the above object is adsorptive removal of organic matter, residual chlorine, etc. of raw water using activated carbon; Primary filtration of contaminants using a microfiltration membrane; Microorganisms and insoluble contaminants are purified by secondary filtration with an ultrafiltration membrane; After removing the foreign matter of the ultrafiltration membrane by vibration and air pressure, it is characterized in that it comprises the step of regeneration by backwashing with purified water.

Purification system of the present invention for achieving the above object is activated carbon filter for absorbing and removing organic matter, residual chlorine, etc. of raw water; A microfiltration membrane device directly connected to the activated carbon filter and filtering primary contaminants; An ultrafiltration membrane device connected to the microfiltration membrane device for secondarily filtering microorganisms and insoluble contaminants; And it characterized in that it comprises an air compressor for removing the foreign matter of the ultrafiltration membrane device by vibration and air pressure.

Hereinafter, the present invention will be described in detail.

In general, the water supplied to the apartment is tap water, or the contaminants present in the water as groundwater are mainly iron oxides from the water supply and drain pipes, trihalomethane combined with residual chlorine, and residual aluminum from flocculants used in water purification plants, apartments. Microorganisms, sediments, and foreign substances generated in reservoirs and indoor piping. In addition, groundwater often exceeds the water quality standards such as microorganisms, nitrate nitrogen, hardness. The presence of these contaminants in water results in aesthetically and hygienic poor results. In addition, water purification equipment of apartments that purify poor water quality requires the removal of residual chlorine, which causes bad taste and odor, in addition to foreign substances and microorganisms. If necessary, the hardness should be reduced by using an ion exchange resin or a reverse osmosis system. In addition, the final sterilization process is necessary because the generation of contaminants in the water supply to the faucet is concerned.

With this concept, the present invention installs a water purification system using an activated carbon filter, a microfiltration device, and a high permeability ultrafiltration membrane in an underground reservoir, and installs an ultraviolet filter immediately before being supplied to a common drinking water installed outside, thereby remaining in the tap water. The chlorine is adsorbed and removed from the activated carbon filter, the viable microorganisms from the activated carbon filter are removed from the ultrafiltration membrane, and finally, the microorganisms that may occur during the storage and transport process are finally killed by the ultraviolet filter. Accordingly, the finally treated water does not contain sediments or microorganisms, and there is no bad taste and smell due to residual chlorine. In addition, the ultrafiltration membrane is to remove the foreign matter by vibration and air injection using an air compressor before the backwashing process by the water purification so that foreign matter is not trapped by the purified water. In addition, all the control lines are connected to one power line for easy control and no interference.

It will be described in more detail with reference to the drawings of the present invention. 1 shows a water purification system of the present invention. The raw water supply unit for supplying raw water at a constant flow rate into the system includes an automatic valve 101, a globe valve 11, and a circulation pump 110. Raw water supplied by the circulation pump 110 is transferred to the activated carbon filter 120.

Activated charcoal filter 120 is a filter using activated charcoal having a large surface area of 5 to 150 Å size to maximize the surface area, adsorption and removal of various organic matter, taste, odor, residual chlorine, trihalomethane, pesticides, etc. in water do. Activated carbon filters also feature automatic backwashing. The water treated in the activated carbon filter 120 is sent back to the microfiltration membrane device 130.

The microfiltration membrane is made of α-cellulose material and is formed by molding porous powder and firing at high temperature. Microfiltration membranes remove suspended solids in water by microns, depending on the size of the filter. The first filtered water in the microfiltration membrane device 130 is sent to the ultrafiltration membrane device 140 and the second filtration.

The ultra-permeable ultrafiltration membrane device 140 has fine pores, removes bacteria and viruses that are large molecules of 0.01 μm or more, and also removes turbidity-causing substances and fine suspended matter that have passed through the microfiltration membrane, and passes the mineral components necessary for the human body. It is a membrane device suitable for material removal. The ultrafiltration membrane device of the present invention is made of polysulfone having excellent heat resistance, chemical resistance, chlorine resistance, chemical resistance, durability, and solvent resistance, and has numerous micropores of 0.008 to 0.05 μm, preferably 0.01 μm. It contains a module composed of high permeability bundle special hollow fiber. The size of the membrane is preferably 0.35 to 0.45 mm in inner diameter and 0.5 to 0.6 mm in outer diameter, and is asymmetrical.

Conventional ultrafiltration membranes have problems such as deterioration of specificity due to the active layer present on the surface of the membrane, and low economical efficiency, if the membrane surface is too dense and contaminated a lot, if the chemical cleaning is not performed, the permeate rate is rapidly lowered and the backwashing effect is reduced. There was a disadvantage of deterioration.

Therefore, in the water purification system of the present invention, before using the high permeability ultrafiltration membrane and backwashing with purified water, the air is vibrated by injecting air using the air compressor 50 through the backwashing tube, and the surface of the hollow fiber vibrates. To separate foreign objects. The air compressor 5 is connected to a pressure indicator (not shown) and an air valve (not shown) to control the amount and distribution of air. Subsequently, by removing the residual material and the separated material on the surface of the membrane by washing with purified water, efficient backwashing is possible, and the membrane is not severely contaminated even during long-term operation, and no separate washing process is required. The water filtered in the ultrafiltration membrane device 140 is sent to and stored in the purified water storage tank 150, and when supplied from the purified water storage tank 150 by the ultraviolet filter 170 through the feed pump 160, and finally re- Possible microorganisms are eliminated. The final treated water is to drink through the public drinking water 180.

The system of the present invention is fully automatic. That is, LIC (Level Indicator Control) installed in all automatic valves (101, 102, 103, 104, 105, 106) and underground reservoir and water storage tank by PLC (Program Logic Control) program of the control panel attached to the device. ), Pumps, etc. work together to automate the whole process, and the water purification and backwashing process is repeated according to the given time to keep the membrane surface clean at all times. For example, if you operate the water purification process for 10 hours a day, it is designed to perform automatic backwashing every 1 to 2 minutes. The circulation pump 110 is capable of automatic / manual operation, and in the case of automatic operation, is controlled ON and OFF based on the LIC 202 installed in the purified water storage tank, and at the time of backwashing, a backwash water is secured and a backwashing time is set by a timer. Allow ON and OFF to be controlled. Automatic valves are installed in the raw water inlet 101, the membrane front end 102, the permeate line 103, the drain line 106, the backwash line 104, 105, respectively, and open and close according to the program of the control unit to automate the system. Makes it possible.

In the water purification system of the present invention, the control unit of the automatic valve opening and closing of each water purification step is connected to one power line so that the device cost is low, the control of the transmission and reception is easy, and the control without noise (interference) is achieved. There is a certain characteristic.

Remote control system using power line is divided into transmitter and receiver.

The transmitting side transmits the result of the detection to the input / output control device, which is the control function of the water purification system such as valve and pump of the water purification system, modulates the transmitted signal into PN code, and changes the signal to high frequency to filter And it transmits to the existing power line through the power coupler (Power Coupler).

In addition, the receiving side receives a signal of the transmitting side as a part remotely controlled by the computer terminal, filters and amplifies and demodulates it to a PN code to reproduce the signal sent to the transmitting side. In addition, the process of improving the quality of information before input is performed by eliminating an error control signal caused by noise of a power line.

The operating pressure and the flow rate are adjusted by the FIC 51 and the globe valves 11 to 18 in front of the purified water storage tank. The pressure gauge PI is installed at the front end 63, the drain line 64, and the permeation line 65 of the module, the microfiltration membrane device 62, the front end of the activated carbon filter 61, and the high pressure switch 71 is activated carbon. Installed in front of the filter to prevent damage to the membrane module due to excessive rise in operating pressure. In addition, the flowmeter was installed immediately before the flow through the automatic valve 103 to the purified water storage tank 150 to digitally read.

And, in order to prevent the failure due to the idling of the pump, the water level regulators 201 and 202 are installed in each storage tank so that the system can be opened and closed according to the set value. In addition, the ultrafiltration membrane apparatus installed two sets in parallel, including a spare use, for example.

The operating process is divided into purified water and backwashing. The process is automatically operated by program input and the process can be selected manually by using the clean water / backwash button on the control panel. In addition, the integer and backwash operation time can be arbitrarily selected. When the device is operated again after stopping the device, the operation is performed in the order of backwashing → constant water by permeated water.

If the automatic mode is set, the automatic valve is opened and closed automatically according to the time set by backwashing → water purifying process. The manual valve must be checked for opening and closing. In case of manual operation, operate the valve by opening the automatic valve with the toggle switch. The present invention is based on the total amount of filtration and each operation process is as follows.

1) integer

The flow rate of raw water introduced by the circulation pump includes a globe valve 11 at the front end of the circulation pump, a globe valve 12 installed at the escape pipe of the pump, a globe valve 13 at the front of the activated carbon filter, and a globe valve at the front of the ultrafiltration membrane. Is controlled by

When the water purification process starts, the automatic valves 101, 102 and 103 are opened, the circulation pump 110 is operated to purify the water flowing into the membrane, and the ball valves 31 and 32 are opened in the water purification process. The purified water is collected in the purified water storage tank 150. The pressure applied to the membrane is controlled using a pressure gauge (PI) installed at the front end of the membrane and at the permeation line. In the water purification process, all the filtration is mainly performed, but when the cross flow filtration or the like is performed, the concentrated water is drained through the automatic valve 106.

2) backwash

When the filtration time elapses and the recovery rate of the ultrafiltration membrane decreases, physical manipulation is required to recover the recovery rate. One such operation is backwashing the membrane with treated water.

This process is shown in FIG. Backwashing goes in the opposite direction to the water purification process. If the integer is Out → In of the membrane module, the backwashing is In → Out. If the integer is In → Out, the backwashing is Out → In.

Prior to backwashing with purified water, the air compressor 50 is first subjected to the strength and air washing. Then, the purified water supplied from the purified water storage tank 150 via the automatic valve 104 is a circulation pump 110, automatic valve 105, activated carbon filter 120, microfiltration membrane 130 and automatic valve 105 It is supplied to the ultrafiltration membrane device 140 to backwash the ultrafiltration membrane. The water used for backwash is drained through the automatic valve 106. At this time, the back pressure and the flow rate adjustment are controlled by the gate valves 10, 6, 5 and the globe valves 17, 16. The timer for securing the backwash water serves to store the water required for backwashing in the purified water storage tank 150 by operating the circulation pump for a predetermined time, and the water level of the purified water storage tank 150 is set to LIC even before the set time. The pump is designed to stop automatically when high is reached. When the backwash water securing timer is in operation, the automatic valves 101, 102, 103 are opened and the automatic valves 104, 105, 106 are closed when the circulation pump is in the ON state as in the water purification process. In addition, when the backwash time designation timer is in operation, the automatic valves 101, 102 and 103 are closed and the automatic valves 104, 105 and 106 are opened. The timer for backwashing plays a role of backwashing by operating the circulating pump immediately after the time set for the timer for securing backwashing water for the set time ends.

In the conventional water purification system, the ultrafiltration membrane has to be washed and washed again for chemical use, but in the water purification system of the present invention, the ultrafiltration membrane can be regenerated by performing backwashing with physical vibration and air pressure. . Based on the treatment of 100 tons of water per day, the results of the water purification system immediately after the ultrafiltration membrane and 6 months later before and after the water purification treatment were published in Table 1 below.

Table 1.

Inspection items enemy Purified water immediately after installing ultrafiltration membrane Purified water after 6 months General bacteria (CFU / mL) 4.440 0 0 Escherichia coli (CFU / 50ml) 4.440 0 0 Turbidity (NTU) 3.10 0.10 0.10 Residual Chlorine (mg / ℓ) 1.0 0 0 Hardness (mg / ℓ) 408 8 11 Trihalmethane (mg / l) 0.704 0 0 Phenol (mg / L) 0.035 0 0 Trichloroethane (mg / L) 0.624 0 0 Tetragloethylene (mg / l) 0.203 0 0 Trigloethylene (mg / l) 0.638 0 0 Dichloromethane (mg / L) 0.382 0 0 Benzene (mg / l) 0.189 0 0 Toluene (mg / l) 3.198 0 0 Ethylbenzene (mg / l) 2.133 0 0 Xylene (mg / L) 2.997 0 0 Carbon tetrachloride (mg / l) 0.019 0 0 Malathion (mg / L) 0.8182 0 0 Parathion (mg / L) 0.1379 0 0 Diazinon (mg / L) 0.0905 0 0 Phenithrothione (mg / L) 0.1490 0 0 Carbaryl (mg / L) 0.1992 0 0 Lead (mg / l) 0.6994 0.0422 0.0419 Arsenic (mg / l) 0.2034 0.0123 0.0124

The water purification capacity of the water purification system after backwashing with physical backwashing and purified water was the same within the margin of error compared to the initial use of the ultrafiltration membrane for 6 months. E. coli, chlorine, trihalomethane, phenol, trigloethane, tetragloethylene, trichloroethylene, dichloromethane, benzene, toluene, ethylbenzene, xylene, carbon tetrachloride, malathion, parathion, It contained no phenythrothione or carbaryl and significantly reduced lead and arsenic levels.

In addition, the result of measuring the permeated water amount by the conventional method and the permeate water amount by the method of this invention is shown in FIG. As shown in FIG. 5, the recovery rate was faster and the reduction rate of the permeate amount was smaller than that of the conventional method.

The use of the water purification system of the present invention has the advantage that the lifetime of the expensive ultrafiltration membrane is long and the efficiency of the water purification system is increased. In addition, since each automatic valve, pump, etc. are controlled by one power line, it is easy to control, and there is an advantage that the control is made without noise and the cost is about 1/3 cheaper than the conventional method.

Claims (4)

Adsorption and removal of organic matter, residual chlorine, etc. of raw water using activated carbon; Primary filtration of contaminants using a microfiltration membrane; Microorganisms and insoluble contaminants are purified by secondary filtration with an ultrafiltration membrane; Removing foreign matters of the ultrafiltration membrane by vibration and air pressure; A water purification method comprising the step of regeneration with backwashing with purified water. Activated carbon filters for adsorption and removal of organic matter, residual chlorine, and the like; A microfiltration membrane device directly connected to the activated carbon filter and filtering primary contaminants; An ultrafiltration membrane device connected to the microfiltration membrane device for secondarily filtering microorganisms and insoluble contaminants; And an air compressor for removing foreign matter from the ultrafiltration membrane device by vibration and air pressure. 3. The purified water system according to claim 2, wherein each of the activated carbon filters, the microfiltration membrane device, and the ultrafiltration membrane device is equipped with an automatic valve, and the water purification system includes a control unit for automatically controlling each automatic valve and the air compressor. system. The water purification system according to claim 3, wherein each of the automatic valves and the air compressors is controlled by being connected to the control unit by one power line.