JPS58202003A - Method for restoring capacity of ion exchange membrane type electrodialytic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for restoring the performance of an ionotransverse transverse electrodialysis device.

Conventional ion exchange membrane electrodialysis technology has been widely used industrially, including for concentrating seawater, deoxidizing food products such as milk, sugar syrup, and soybean oil, and deoxidizing fruit juice. These devices 1
Generally, performance gradually deteriorates with long-term use. At this point, the voltage of the translucent nail increases, the direct current efficiency decreases, and the rate of confusion at one time in history is extremely low. It also reduces the selective permeation performance of the air-permeable VR pupil that incorporates an ion-exchanging 4!S membrane that protects the body from water. When electrodialysis is applied to Daizensui #4Ni with just a slight filtration process, the filtration process, humins, and other organic substances in the treated water #4Ni are removed by dialysis. If it is brought into the equipment, that is, the dialysis room, and deposited, it not only reduces the performance of the %Fr1f!, but also increases the indoor pressure. Due to the increase in dialysis equipment, troubles such as a single wave of #liquid from the dialysis machine may occur.

Conventionally, when performance deteriorates, including the troubles mentioned above, the dialysis machine is dismantled, the dialysis chamber components, i.e., ion exchange membranes, gaskets, spacers, etc., are manually cleaned, and the necessary chemical solutions are removed. After processing, etc., it was assembled into P+ and put into use. For this reason, when it comes to ion-exchange membrane electroporation needles that are used in seawater production in China, disassembly and reassembly are usually carried out once every three weeks [... to three months]. It didn't turn out to be a problem. Due to the time required for this, the operating rate of these boss dialysis systems is usually limited to 6° to 9°.

As mentioned above, this invention was made for the purpose of reducing the reduction in operation rate caused by low-quality water, and for example, in the salt production industry from seawater. This makes it possible to reduce the disassembly and reassembly time of the acid dialysis machine from 6 months to 7 years or more. This is extremely good news for the industries that use it.

That is, the gist of the present invention is to repair the ion-exchange membrane electrodialysis equipment used to supply dialysis to an ion-exchange membrane electrodialysis equipment whose performance has deteriorated due to use. It's a method.

Previously, the performance of ion exchange h! has decreased with use. 4
There was no denying the fact that cleaning at Cangshan improved its performance. However, these leading proposals feared that the performance would deteriorate due to acid exposure in the ion machine, and as shown in the graphs shown in the graphs, low-armpit (tt.
Irresistibility is 0. They were dazzled by the flatness of performance around the 2-degree range and developed the established theory that low-grade acids should be used. Of course, it is true that point 1j, which uses high-grade acid, was useful for preventing corrosion of equipment and for dangerous lines.

However, according to the results of research by the present defenders, the use of 1 liter of thick acid of 3 or more, preferably 4 or more,
It breaks the conventional theory and atones for the shortcomings of the gods who were taught in Shirinjuku, bringing about technological benefits that are worthy of being worshiped.

That is, according to the invention, several thousand ion-exchange membranes and gaskets attached to them were assembled by hand, and the enormous labor of cleaning and assembling them was also required. When closed l&#1
It was shrunk to a width of 4R, and the ion-exchange membrane was shortened to 1.5 mm in width after disassembly, hand-washing, and assembly. Therefore, according to the present invention group, the seedlings of the plant roots that are used in large numbers in the Kamekikome Ur device are thick (for those who are involved in the industry, etc. .

In addition, seawater, the water from the flash water plant, and the selection of monovalent ions used in the destruction of the tributary wall of the land T Kansui Kan's water power plant]? In general, the connectivity of the permselective performance is short, and the performance is low due to contamination of the permeation. As previously reported, the rate of selective permeability that can be recovered by the combined feeding treatment is surprisingly greater than by conventional hand washing.

In the acid treatment in the invention, the period of supplying acid to the partial air dialysis apparatus is not limited to a certain time. Therefore, it is best to supply the diaphragm at regular intervals, such as 3 to 30 days, and to prevent the rate of increase in the voltage required for dialysis, the increase in pressure when the solution to be treated is supplied to the dialysis room, and other performance deterioration. Based on the measured factors, performance recovery processing can be performed in response to the rate of change.

In general, acid can be supplied simultaneously by switching to the supply line of the solution to be treated and introducing it into the pulp carrier.In some cases, a high-strength acid is injected into the slightly treated solution, and the I solution W& is added to 3N. It is also possible to supply the acid to the dialysis room with the acid concentration above. In addition, the supplied acid solution contains UA, and the reason is obvious.
do not have. The soap used is rice and mineral acid.
h I! e+gin is used, but among these, hydrochloric acid is also advantageous.

The time for supplying the melt can be determined on a case-by-case basis, but in general, it is best to stop the supply after 0% of the initial M force gθ~lθ, and then restart the aeration analysis of 1 gg to be treated. good. Also, acid (Ji, 1 when equipped with Toru IFjT at the time of supply...
You can leave the current on, or you can interrupt the stream and supply a stream.

Furthermore, the acid is applied to the concentration room and (or RJ) dilution room in the dialysis room, but we use spam water that contains many non-M8 substances, such as seawater, natural water from rivers, lakes, and marshes. In this case, it is preferable to supply the acid to the dialysis chamber in which the liquid to be treated is directly supplied to at least the buttocks.

Boss dialysis equipment to which the present invention may be applied is sometimes inconsistent;
The ion exchange membranes incorporated in these electrodialysis devices are not limited to any type (such as ordinary cation exchange membranes and whisper ion exchange membranes). Membrane Teru.

In the meantime, if we cut down the ion cross-legs that have given selective permeability to the monovalent 1a ion and (or J/'i Because of their large size, when these ion exchange membranes are applied to a magnetic dialysis device in which silk is incorporated, the young fruits of the present invention exhibit ten+ effects.Among them, Table 11! In the case of a tonki dialysis device using a monovalent kanone selectively permeable cation exchange membrane in the form of a monovalent kanone attached thereto, the upper piping molecule Kame Kanao/Waterbath Kei is added to the dialysis room following the acid cap treatment of the present invention. By supplying VC, it is possible to increase the performance of monovalent selectivity to almost 100%.
Although it is unclear whether the effect of the present invention on the change in valence selectivity is due to the negative effect, the effect is completely surprising.

The following examples demonstrate the effects of the present invention.

Example 1 Cation exchange membrane Neocelli CIM (@Sulfone Mfi & manufactured by Sanso i!8) and anion exchange membrane Neocepta ^IO-
3 (Tokuyama-4 grade ammonium type) and thickness Q,
3u(7)-:fmuifsk')to(effective M41r/!
5.2m x Kog! ;car) and oblique M14#!
Stacks ′fI-
Electrodialysis tank TS-C type (in-mount #I) attached with a tightening plate
The rise in pressure drop in the dialysis room was measured over a certain period of time by continuously supplying seawater using a dialysis chamber.

#1 in the dialysis room regarding pressure drop or increase in the dialysis room.
An acidic solution was provided, and the young fruits were observed.

μf acid supply for 1 hour, 6es/sec at /7~20C
It circulated at a flow rate of

In addition, the pressure loss ratio was calculated using the following formula.

Table 1 and Figure 1 VC show the acid concentration and pressure drop recovery ratio.

As is clear from the graph, acid a? ! Strength: 3 normal or higher Table I Comparative Example 9 The same operation as in Example 1 was carried out by changing the type of acid solution. The results are shown in Table 1 and Figure 2.

6 n From the above results, pressure loss L due to acid n@! It can be seen that although there are some differences in the amount of damage, the effect increases in a flying manner from 3N or higher.

Seawater AM was carried out using a TS-2 electrodialyzer (manufactured by Tokuyama Sotatsu) in the same manner as in Example.

A new version of the cation exchange membrane Neosepta CIM (sulfonic acid type cation exchange membrane manufactured by Tokuyama Soda and Neosegta-10KS (quaternary ammonium type anion exchange membrane manufactured by Tokuyama Soda) and a membrane that has already been used for seawater concentration for one year) A selective treatment agent for imparting selective permeability to heptavalent ions was used.For the nocyandia, a 0-formalin polycondensate was used. Add water, mix SL, and send b crn/sec to the electrodialysis room.
Pump circulation was carried out for 1 hour at a flow rate of . Electrodialysis was then performed. Table 11 shows the relationship between the *** treatment before the selection treatment and the concentration of the acid solution and the pure salt rate after the selection treatment.

In addition, if the membrane used is specified as having been hand-washed, it means that the surface layer was coated with a 6-moleaceous substance, which was rubbed with a sludge and washed with water.Example q The same operation as in Example 3 was carried out.

The acid treatment solution was changed. The results are shown in Table ■.

Table ■ Example S Ion exchange membrane σ Neosegota C1, l, -5T (Tokuyama 1-cleft sulfonic acid type cation exchange membrane) and Neosegta^C5 (
A quaternary ammonium type anion exchange membrane (manufactured by Tokuyama Soda) was used. As a selective treatment agent, polyethylene liquid/(molecular weight approximately 30,000) 200θ:Jpm m solution was used.
An Hr immersion treatment was performed. Comparisons were made between new membranes and used membranes treated with a selective treatment agent without acid solution treatment, with WI solution treatment, and with water washing and selective treatment. The results are shown in Table ■.

As can be seen from Examples 3 to 5, it can be seen that the ion exchange membrane of the present invention has extremely high selective permselectivity performance recovery power for seven-valent ions.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between acid concentration and performance recovery rate during acid treatment based on Example 1, and Figure 2 is a diagram showing a similar relationship based on Example 1. . Patent applicant Tokuyama Soda Co., Ltd.

Claims (1)

[Scope of claims] 〉1 Performance regeneration force method for dialysis equipment. / The membrane is selectively permeable to monovalent ions (Claim 11). Title @ (method described in paragraph 11. 15+ Supplying i! ii! with salt removal 轡Fl- Claim's promontory method according to paragraph 15.