JP2009045608A - Method for desalination by capacitor using monopolar electrode and bipolar electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of desalinating seawater with a concentration of 35,000 ppm to several hundreds ppm at a low cost in a method for cleaning water by a CDI (continuous deionization) method using electrodes. <P>SOLUTION: With the five of an ion adsorption substance, the cell structure of a flow through capacitor (FTC) 200, the feed of working voltage, the feed of working electric current and a CDI operation as parameters, the optimum values are decided, so as to construct a system. In particular, the values of the voltage and electric current fed to bipolar/monopolar electrodes 215, influencing on the performance of CDI are optimized. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a capacitor structure that uses surface adsorption of ions for water purification. Reduction of total electrolytic substance (TDS) in water with capacitors. Structurally, using monopolar and bipolar electrodes, water is passed through electrodes charged by static electricity to remove ions in the water.

Seawater is most abundant on Earth, but due to the high concentration of salinity and various dissolved substances, it is very difficult to process to the drinking water level. In the desalination business, reverse osmosis pressure (RO) and distillation (multistage flash distillation method--MSF) are the two most common methods. RO is technically stable and commercially accepted, but has a low freshwater yield. In addition, it is weak against surfactants and has a weak point that the temperature range of treated water is narrow. The distillation method such as MSF has the advantage that it is unquestioned regarding the components of the water to be treated, and the accuracy of the treatment is high. However, the biggest disadvantages of these heat treatment methods are the large scale of funds and enormous energy consumption. The electricity consumption of the MSF circulation pump alone is greater than the overall electricity consumption of the RO desalination. Unfortunately, both RO and MSF quantitative technologies result in secondary environmental pollution due to the use of chemicals.
From the viewpoint of energy consumption and secondary contamination, the deionization method (CDI) using a capacitor electrode is superior to RO and MSF as a desalting method. The CDI technique is unquestioned regarding the components of the treated water. Therefore, the CDI method and the MSF method can omit the water pretreatment process. In the case of the RO method, if the pretreatment of water is omitted, the treatment film becomes useless, which is inconvenient. The RO method requires extra pretreatment chemicals and electricity costs, and is expensive to prevent secondary contamination. The CDI method performs ion adsorption with a direct current low voltage. The treated water is passed through a flowing water passing tube made of a capacitor called FTC (Flow Through Capacitor). Ion adsorption at FTC is equivalent to charging a capacitor. Rapidly with less power consumption. In order to produce water of the same conditions, the CDI method requires only one third of the energy consumption compared to the RO method of desalination. Therefore, the CDI method is the most energy-saving among the desalination methods described above. Further, when the FTC saturated with ion adsorption is refreshed, it is only necessary to discharge the capacitor, and at the same time, the electrical energy is recovered by discharging, and various valuable ions can be recovered. Therefore, the CDI method has added value other than the purpose of fresh water production.

The CDI technology itself has been around for 30 years (US Pat. Nos. 3,515,664 and 3,658,674). For the last 20 years, CDI technology has been FTC (through-flow water) type, using carbon aerogel as an ion adsorption medium, and widely advertised in the structure of disk and outer frame. Examples are US Pat. Nos. 5,192,432,5,425,858,6,096,179,6,309,532 and 6,569,298. Metal oxides (US Pat. No. 4,072,596), graphite (US Pat. No. 6,410,128), and activated carbon (US Pat. No. 6,462,935) are also used as adsorption media in FTC. In the ion adsorption medium, activated carbon is most suitable for FTC. The reason is that carbon provides a large surface area at a lower cost. The liquid flow path and pattern in the FTC, which are as important as the adsorption medium, are also determinants of CDI performance. The FTC's disk and outer frame structure have a serpentine flow pattern and an electrode gap of 0.05 mm. To pass the liquid, too long flow paths and narrow clearances are undesirable from a performance point of view. During CDI operation, water pressure drop and contamination inside FTC at reset is inevitable. Furthermore, cylindrical FTC rolls manufactured in concentric circles (US Pat. Nos. '432 and' 935) have difficulty in evenly passing water. Reasons why CDI technology is not common in water treatment include small processing amount, low electrode efficiency, and time required for FTC cell refresh.

In the above description, the electrodes constituting the FTC cell are all monopolar electrodes. In other words, the electrodes used for FTC assembly are directly connected to the power supply. Therefore, the electrode has only one polarity. Either positive or negative. In the FTC in the form of a disk and an outer frame, a large number of positive and negative electrodes of 100 pairs (100 cells) are used and connected in series. If one cell requires an operating voltage of 2 volts, the overall FTC will be over 200 volts, making it a complex and dangerous system for management. There is only one cell in a cylindrical FTC regardless of size. This is because it contains only a pair of positive electrode and negative electrode. Thus, the overall operating voltage of the cylindrical FTC is only 2 volts, and the overall current is proportional to the effective electrode surface area. Based on the theory of general capacitors, existing technologies have tried to increase ion adsorption efficiency by narrowing the gap between electrodes in order to obtain high electrostatic field energy. However, in order to do so, it was necessary to supply a large amount of power with a margin in addition to a narrow electrode gap. In the present invention, in order to obtain an effective and sufficient electrostatic field, a method in which a monopolar electrode and a bipolar electrode are mixed and assembled in an FTC module is adopted to maintain an optimum operating voltage and current. During the desalting process, a constant voltage is sent from the power source to the FTC, while the actual operating current is determined by the constituents of the treated water and the state of ion adsorption. By setting the power supply current constant, the charging rate is limited and the electric field potential is also reduced. Thus, the present invention raises the electric field potential of the FTC cell with a supercapacitor (hereinafter abbreviated as S / C) as an “unlimited” current supplier. In the present invention, a unique proposal has also been made for a flowing water path for increasing the amount of treated water compared to the CDI technology.

The problem to be solved by the present invention is to assemble a through-flow capacitor (FTC) module using a plurality of electrodes and convert seawater into fresh water by ion adsorption. All of the electrodes before passing current through the FTC are the same. That is, there are three types of electrodes (top, middle, and bottom) electrodes. These are connected to a power source. These three electrodes have polarity. If the electrodes at both ends are the positive electrode (negative electrode), the intermediate electrode is the negative electrode (positive electrode). If the two electrodes at both ends are positive, there are a plurality of intermediate electrode plates that can be divided into two sub-groups and share the negative electrode. Each sub-group has the same number of pairs of electrodes consisting of positive and negative electrodes. These intermediate electrodes do not require direct connection with a power source. Due to the voltage applied to the positive electrode and the negative electrode and the electrical conduction of the passing water, the intermediate electrode becomes a negative electrode when its surface becomes a positive electrode. Therefore, each group has a plurality of bipolar electrodes connected. The FTC as a whole is connected in parallel because the two groups have the same poles as the power supply. Since the FTC is considered as an element of one unit, the configuration here can be said to be an intra-element (intra-element) connection of a combination of series and parallel.

The second object of the present invention is to provide the power required for the FTC module and to adsorb many ions in a single pass. If the total operation voltage and the voltage of each FTC cell are known, the number of sub-group bipolar electrodes is determined. For example, if the operating voltage of each cell is 2 volts and the total voltage is 20 volts, nine bipolar electrodes are required between the positive electrode and the negative electrode, forming a total of 10 sets of cells. . The voltage for operating the small group is proportional to the number of electrodes forming the group. This voltage is also the operating voltage of the FTC. This is because sub-groups are connected in parallel. When determining the operating voltage, electrical connections, and the number of bipolar devices required, judge from the needs of the system to be built. On the other hand, there is only one current value for ion adsorption. The reason is that all electrodes in the sub group are connected in series. The total current that drives the FTC is proportional to the number of sub-groups that make up the FTC module. The potential of the electrostatic field created by the monopolar electrode is stronger than that of the bipolar electrode, but the monopolar requires more operating current. For this reason, when making an FCT module, it is very impractical to make it only with a monopolar. Mixing monopolar and bipolar can provide the optimal voltage and current combination. Since large-scale processing is required for industrial use, CDI technology also needs to increase the surface area in the FTC. As a result, the power required for CDI is enormous. In order to economically respond to this power demand, the present invention uses the S / C as a power amplifier to reduce the burden on the main power supply.

In the present invention, optimization of the passing water in the FTC is considered from the viewpoint of hydrodynamics. Several parameters were optimized. Water flow rate, water residence time, water distribution and ease of drainage. The flow path or the opening of the electrode determines the water flow rate and water retention time, which determines the CDI throughput and ion removal rate. Large spaces and large openings increase the amount of water passing through, but the water retention time is too short for ion removal. And the capacitance and electrostatic field potential of FTC are reduced because there are few electrode surfaces. In the present invention, the electrode gap is set to 1 mm or less, the opening with respect to the electrode surface area is set within a range of 7 to 15 percent, and the water flow rate, water residence time, capacitance, and electrostatic field potential are optimally maintained. Next, electrode plates having an opening area of 7 to 15 percent are arranged so that the openings are staggered so that water passing between the plurality of electrode plates meanders. The treated water that passes through is homogeneously mixed. At the same time, the water retention time and electrode contact efficiency are optimized. Since the water path is short and there is no dead space, the rinsing water at the time of FTC refresh easily passes through. Easy and quick FTC refresh can speed up water treatment and minimize the risk of contamination of the treated water.

Furthermore, the present invention uses S / C to realize energy saving and operating time of CDI operation. Since the desalination process during CDI operation is equivalent to charging the FTC cell, a refresh of CDI operation is achieved by discharging the saturated FTC cell this time. At this time, energy is released so that it can be recovered. This energy can be directly charged into a supercapacitor connected in parallel with the FTC. At least 30 percent of the power consumed in desalting can be recovered by FTC refresh, and is the best medium for S / C to be charged regardless of the scale of recovered power. In order to promote the refresh of the FTC, the working time of the CDT process can be improved by charging a plurality of S / Cs. As long as the potential of the S / C is lower than that of the saturated FTC, the remaining energy of the FTC cell automatically moves to the S / C in a few seconds. At the same time, the adsorbed ions automatically leave the FTC cell and the ionized material is present with the rinse water and may be recovered later or easily discarded.

FIG. 1 shows a concentric hole formed in a titanium plate coated with activated carbon for ion adsorption. Regardless of the size of the plate, the present invention drills holes equal to 5 to 20 percent of the surface area, preferably 7 to 15 percent area. This method provides the best performance. The diameter of the holes, the number of holes, and the number and spacing of the rings depend on the treatment capacity (treatment amount and treated water purity). By using a mathematical model, the opening pattern is determined by application.
FIG. 2 shows another best opening pattern. Two types of opening patterns of the electrode 1 and the electrode 2 are basic elements of the FCT module of the present invention. The FTC module stacks electrodes 1 and 2 alternately. Since the opening patterns of these electrodes are located at positions where they do not overlap with each other, the cell constituted by two electrodes is shaped to block the opening pattern of each electrode. There is a capacitance that performs ion adsorption / desorption of CDI operation in a space that is not an opening portion of two electrodes facing each other. Therefore, if each electrode has many openings, the processing capability of the FTC cell becomes small. In the present invention, an open area of 7 to 15 percent of the plate is considered optimal.

As shown in FIG. 3, when assembling the FTC module, a plurality of electrodes 1 and 2 are stacked and concentric holes are formed with the same distance between the electrodes. In FIG. 3, when the stacked electrodes are viewed from above, they are stacked so that their concentric holes do not overlap. Therefore, the treated water passing through the hole which is the opening passes through the FTC in a zigzag manner. The passing water mixes well in the FTC cell and becomes uniform toward the outlet. Furthermore, since the water travels in a mixed manner in all directions, the electrode is in sufficient contact with the water. The spacing between adjacent rows of holes should be set appropriately. The reason is that the distance determines the passage distance of water, and determines the passage rate, the holding time, and the ease of rinsing the electrode during refresh. (Although omitted in FIG. 3) All the outer extensions of the electrode 1 and the electrode 2 are set with O (O) rings to seal the ends of the electrodes. This O-ring is made of rubber, EPDM (Ethylene Propylene Diene Monomer), silicon, urethane, polypropylene (PP), etc., and has a thickness of 0.6 millimeters or 1 millimeter. The outer diameter is larger than the electrode diameter, and the inner diameter is smaller than the electrode diameter. The difference between the outer diameter and the inner diameter is the width of the O-ring. The plate of the FTC module is made of titanium, and the electrode is prepared with a thickness of 0.3 mm or more so that it can correspond to any chemical liquid. If the chlorine content of the treated water is low, inexpensive grade 316, 314, 304, etc. stainless steel may be used.

A plurality of electrodes 1 and 2 are stacked vertically to form a portable FTC module as shown in FIG. If 21 electrodes 1 and 2 are used (collectively indicated by reference numeral 215 in the figure), the first and 21st sheets, that is, the uppermost and lowermost electrodes, are the positive electrodes. The eleventh sheet is a negative electrode. (The poles may be opposite to each other.) Although not shown in FIG. 4, these three electrode plates are provided with terminals and connected to the corresponding poles of the external power source. As shown in FIG. 4, the tip electrode is connected to the positive electrode of the power source, and the intermediate electrode is connected to the negative electrode. These three electrodes become a positive electrode and a negative electrode as denoted by reference numerals 201 and 202, and form a monopolar electrode. Therefore, the FTC module 200 is composed of two sub-groups having the same number of electrodes. In each sub-group, a pair of positive and negative monopolar electrodes, two at the tip and bottom, and nine electrodes with electrode 1 and electrode 2 opening patterns in between were stacked alternately. There is no intermediate electrode in physical contact with the main power supply, but one side is charged to the positive electrode and the other side is charged to the negative electrode due to the charging of the tip electrode and the treated water passing through the electrode. . As a result, the intermediate electrode is connected in series as a bipolar electrode, and has a configuration of two monopolar electrodes and nine bipolar electrodes. In terms of electrical connection, the FTC module 200 has two sub groups. The sub group has 11 electrodes connected in series, and the two sub groups share a central monopolar electrode and are connected in parallel. It connects with the negative electrode 202 and the positive electrode 201 (FIG. 4). Other numbers of electrodes are possible. Similarly, the number of monopolar electrodes of the FTC module can be increased and various sub-groups connected in series can be configured, both long and short. If the number of electrodes connected in series is increased, the operating voltage must be high, but the operating current may be low. On the other hand, when the electrodes are connected in parallel, the operating current is high, but the operating voltage is low. In the parallel type, the electrodes are monopolar and each electrode is connected to a power source. As the number of points connected to the power supply increases, the material becomes more bulky and the system becomes more complicated. By making the FTC module a mixture of mono and bi, balanced operating voltage, operating current, manufacturing cost, system size, etc. can be obtained.

The FTC module uses 21 O-rings and 21 spacers with 21 electrodes (215), fixed in a sandwich, and then fixed with the upper PP plate (211) and the bottom PP plate (213). There is no need for a sealed enclosure. The upper metal ring 209 and the bottom metal ring (not shown) are sandwiched between the bar 205 and the nut 207. A pipe connected to the FTC is connected to the water receiving port 220 and the outlet 240. Check the FTC module for water leaks and electrical shorts. Three legs 260 come out of the bottom of the FTC and can be placed independently on the floor. Nylon, polypropylene (PP), urethane, etc. 0.5mm to 0.8mm mesh, screen, lattice, net, etc., and placed as an O-ring adjacent to each electrode as a spacer, electrical short Prevent the treated water passage channel.

The FTC module of FIG. 4 can be integrated into a compact three-fold performance system by connecting a plurality of, for example, three units (however, omitting legs and upper and lower pipes in this case). Any number of modules is possible depending on demand. The FTC module can be connected in series or in parallel as in the existing RO membrane system, and can be configured in any way as a turn key system. In the three-unit connection system, each module has an electrode lead as shown in FIG. 4, but the treated water passes through three FTCs in series. The passing water passes through the FTC in series, but the operating voltage applied to the three FTCs is in parallel. Therefore, the operating voltage is one type. The same is true regardless of the number of FTCs. By charging the FTC modules in parallel, the total operating voltage can be reduced.

In the desalination process of the CDI process, the FTC system becomes saturated due to ion adsorption. Therefore, an FTC refresh operation is required. The most economical method is to discharge the adsorbed ions to the power tank. As described in US Pat. Nos. 6,580,598, 6,661,643 and 6,795,298, CDI operation is repeated charging and discharging of the FTC module. During desalting, the DC power supply charges the FTC and this time it is discharged during refresh. At this time, the power is turned off and no current is received. In the present invention, at least 30 percent of the energy required for desalting can be recovered at the time of refresh. When converting 1 ton of seawater (concentration 35,000 ppm) to fresh water (concentration 250 ppm), CDI technology consumes about 1 kilowatt hour (kWh) of electrodes. Therefore, for desalted CDI operations with more than 10,000 tons per day, the total power is significant. S / C is considered optimal as an energy recovery device during refresh. Compared with the FTC cell, the S / C has a much smaller resistance (ESR is small), so it feels as if it is short-circuited when viewed from the FTC cell. In other words, if these are connected in parallel, the hungry S / C will be instantly charged from the saturated FTC cell. The charging speed is fast, and in a few seconds, more than 90 percent of the saturated cell energy is transferred. Little energy remains in the FTC and appears at low voltage. Since the voltage accumulated in the FTC is a good indicator of the amount of ions adsorbed on the electrode, the lower voltage means that the FTC energy has moved to S / C and the refresh was successful. is there. In the present invention, the FTC refresh takes several seconds, unlike the several hours of the existing technology. The rinse water used for discharging and refreshing the saturated FTC passes through the FTC, and the FTC is ready for the next ion adsorption. In addition, all saturated FTCs are discharged to S / C, and FTC refresh is facilitated.

A further reason that S / C is the best medium for recovering energy from saturated FTC is that energy recovery is direct and there is no need to convert energy. In this process, no mechanical or chemical treatment is required. Further, S / C has a very long life, and the collection system is simple and inexpensive. There are other methods, for example LC circuits and RO pumps. The LC circuit uses an inductor, a capacitor, and a noise-producing flywheel, and the motor and generator are used together. The RO pump uses the difference in water pressure. All of these have energy losses during energy conversion. The recovery by S / C can be performed rapidly and without energy conversion and without loss. There is another approach to recycle the residual energy of saturated FTC (PCT / US 2001-016406). Through electrical arrangement, the residual energy is transferred from the saturated FTC to another FTC that requires energy. The residual energy of the saturated FTC is often inadequate for desalting, so that the desalting process is also inadequate. In fact, S / C not only provides two important functions for CDI operation, but is also optimal for high power supply. This is especially true for industrial scale. Water treatment with thousands of CMD for industrial use. If the surface area required for the FTC module is expressed in square meters, if the desalting current density is 20 mA / cm ² , an electrode surface area of 1 m ² requires a current of 200 amperes. An S / C with an internal resistance (ESR) of 10 milliohms at 15 volts x 40 farads can supply a peak current of 200 amps for 2 seconds. When constantly receiving 20 amperes from the power supply, 200 amperes can be continuously and stably supplied by using the two S / Cs. In this power supply system, each S / C discharges only energy effective for driving, that is, energy at the initial stage of discharge. After one S / C discharges effective energy, the other S / C immediately takes over the discharge, and at the same time, the S / C that has finished the initial initial discharge is recharged. Since the depth of the S / C discharge is shallow and the energy from the power source is high, the S / C module is quickly fully charged. In the next cycle, the two S / C modules alternate between charging and discharging roles and repeat this process as long as the load device is needed. The two S / Cs repeatedly discharge and charge alternately and continuously flow a consistent peak current is called CD swing. Since the CD swing is set so as to release only effective energy, the effect of using energy is high.

FTC in the desalination process may not necessarily use energy from the power source without waste, but in order to perform ion removal without failure in CDI operation, it is better to make the supply current larger than too small. . Similar to a general electric capacitor, the FTC cell also has an initial charge rate that is very fast, slowly becoming fully charged as it approaches full, and the rate of ion adsorption decreases early when it approaches saturation and early. Therefore, the current during charging of the FTC cell is a measure of the ion adsorption rate. When the CDI process is performed at a constant voltage, the current is limited by the progress of ion adsorption on the surface of the FTC electrode. This is the actual operating current consumption. That is, it may be different from the current supplied from the power source. A high current may be passed through the FTC to facilitate ion removal. However, preparing hundreds of amps of power for large-scale water treatment is extremely uneconomical. Therefore, the present invention can propose a compact power supply system with low cost and high energy efficiency by using S / C and its application, that is, CD swing. The CDI process desalinates water using an electrostatic field in the FTC cell. In addition to the ion-adsorbing material, FTC architecture, and voltage, current supply greatly affects performance. In the following two examples, it is shown that the result is not always expected depending on the setting in the water treatment with the FTC module of the present invention.

As Example 1, 21 activated carbon coated titanium plates are stacked to assemble an FTC unit and sealed in a plastic case. Each plate is 10 centimeters in diameter and has the opening pattern of FIGS. The effective area of one side of these electrode plates is about 66.7 square centimeters. Since the FTC unit has 20 cells inside, the layer effective surface area of one unit is 1,334 square centimeters. Five units are connected in series to allow water to pass through, but each unit has terminals at the top and bottom, and each receives current independently. Therefore, each FTC unit is composed of 19 bipolar electrodes sandwiched between a pair of positive and negative electrodes. In order to charge 5 FTC units in parallel, the 10 electrical terminals are first divided into two groups, each group having 5 terminals. One group external power supply is connected to the positive electrode, and the other group is connected to the negative electrode.

In order to remove coarse particles in the treated water, after filtering with a paper filter, 2 liters of seawater with a TDS concentration of 36,600 ppm is passed through a system connected to 5 FTCs at a rate of 600 milliliters per minute. The power supply system is a combination of a DC power supply and two S / Cs (15 volts x 40 farads). In FIG. 5, the result of TDS when seawater passes the system once is shown by two curves. One measured TDS data 5 times every 200 milliliters and 2 times every 500 milliliters. Another curve shows ion removal from collection to collection. The data was recorded in Table 1.
The third column in Table 1 is the TDS concentration, and the fourth column is the TDS removal rate extracted from the raw seawater. The ion removal rate was calculated by comparing the TDS of the raw seawater with the TDS concentration at the time of collection. As can be seen from Table 1 and FIG. 5, the first 200 milliliters of seawater passed through changed to 785 ppm of water, and the ion removal rate was 97.86 percent. Ions accumulated in the FTC unit, and in the second round, the TDS jumped 10 times and the ion removal rate dropped sharply. This shows that FTC rapid charging and rapid ion absorption occurred. At the same time, it can be said that the FTC electrode surface rapidly became saturated and the desalting effect was weakened. The total surface area of the five FTC units is 6,670 square centimeters. During the desalting process, the DC power supply voltage applied to the FTC remained at 40 volts, so each cell was operating at 2 volts DC. The current was set at 40 amps, but the operating current was recorded as 8.5 amps. Therefore, it was 340 watts of power consumed in the desalination of Table 1. With other settings, for example, 20 amps and 30 amps, good results as shown in Table 1 are not obtained. (Data not shown.) In this experiment, when current is passed through five FTCs, a current of 30 amperes or more may be required initially. Therefore, desalting should be performed by setting the setting to 30 amperes or more. Table 1 demonstrates that the present invention clearly has high performance. This is a result without water pretreatment with chemicals. On the other hand, in this test, water was passed only once. However, it is possible to further purify the water by repeating a plurality of times and circulating the water. Increasing the number of FTCs has the same effect.

As a second example, the FTC module of FIG. 4 is created. 21 electrodes are stacked vertically. Three electrodes, that is, the first, eleventh, and twenty-first sheets are monopolar electrodes, and the first and twenty-first sheets are connected to the positive electrode of the power source, and the eleventh sheet The eye is connected to the negative electrode. That is, there are nine bipolar electrodes connected in series between the positive electrode and the intermediate negative electrode. All electrodes are 10 cm diameter stainless steel with an activated carbon coating finish and have the opening pattern of FIGS. Each electrode has an effective surface area of 267 square centimeters on one side and a total effective surface area of an FTC module consisting of 20 cells is 5,340 square centimeters. 30 volts x 10 amps from a DC power supply and a power system consisting of two S / Cs (15 volts x 40 farads) are passed through the FTC module. 10 liters of tap water with a TDS concentration of 114 ppm is circulated in the FTC at 2.4 liters per minute. The purpose is to remove the hardness. The TDS of the treated water was measured at a certain time as shown in Table 2. FIG. 6 shows the data.
Compared with the case of the seawater of Example 1, tap water has little ion content. In the case of water with a low ion content, the rate of ion adsorption is slow and the operating current is as low as 2.6 amperes. During this process, the FTC cell is not in a saturated state. In fact, the TDS measurement in Table 2 can be said to be a dynamic mode. This is because the measured TDS data of the circulating water changes with time. As processing proceeds further, that is, as time elapses, the water becomes cleaner. The ion removal rate is also improved. The third column of Table 2 shows the concentration over time of the measurement compared to the initial TDS concentration. If 80 ppm is soft water suitable for beverages, the system produced 10 liters of soft water in just 5 minutes. This is equivalent to a single pass process.

Arrangement of holes for passing treated water in FTC electrode plate Arrangement of holes for passing the treated water provided in the FTC electrode plate. Arranged alternately with the above plate holes. The treated water passes meandering over the two electrode plates. A monopolar electrode and a bipolar electrode were mixed and combined. FTC unit. TDS curve. Five sets of FTC modules (diameter 10 centimeters) connected in series with 20 VDC. Desalination by passing seawater through the module once. TDS curve. Five sets of FTC modules (diameter 10 centimeters) connected in series with 20 VDC. Produces soft water by passing tap water through a single module.

Claims (4)

As a component of a flow-through capacitor (FTC) for water treatment:
(1) at least one monopolar electrode;
(2) At least one bipolar electrode.
(3) An opening portion formed in the monopolar electrode and the bipolar electrode.
(4) O-rings attached to all the above monopolar electrodes and bipolar electrodes (5) Spacers attached to all the above monopolar electrodes and bipolar electrodes (6) At least one DC power source;
(7) At least one supercapacitor;
(8) At least one controller (controls the DC power supply and super capacitor). The mechanism in which the monopolar electrode in the flowing water capacitor (FTC) according to claim 1 is physically connected to both poles of the DC power supply. 2. A mechanism in which the bipolar electrode in the flowing water capacitor (FTC) according to claim 1 is not physically connected to the DC power source. In the flowing water type capacitor (FTC) according to claim 1, 7 to 15 percent of the total surface area of the monopolar electrode and the bipolar electrode is set as the opening portion.