1. A method for optimizing the hydrophilicity of an electrode active material, which is applied to capacitive desalination of water, is characterized by comprising the following steps:

providing an electro-adsorption module required by capacitive desalination, wherein the electro-adsorption module is provided with an active electrode made of an active material;

b, improving the surface area of the active electrode to be fully utilized, adding an acid solution into the water for infiltrating the active electrode, wherein the ratio of the acid solution to the water is 1: 10;

c, soaking the active electrode in a mixed solution of acid water for more than 10 hours;

step d: generating hydrophilic groups of the active electrode, inputting electrode pair voltage to 2V-2.5V at two ends of the active electrode, keeping for 20min, and then performing short circuit discharge until the end; in this process, water is required to flow in the electrodes all the time;

step e: inputting reverse electrode pair voltage 2V-2.5V at two ends of the active electrode, maintaining for 20min, and short-circuiting and discharging to end; in this process, water is required to flow in the electrodes all the time;

step f: and e, repeating the operations from the step d to the step e for 2-3 turns till the end.

2. The method for optimizing hydrophilicity of an electrode active material according to claim 1, wherein the acid solution is a hydrochloric acid solution and has a concentration of 28% to 30%.

3. The method for optimizing hydrophilicity of an electrode active material according to claim 1, wherein the active material is activated carbon.

4. The method for optimizing hydrophilicity of an electrode active material according to claim 1, wherein the interval between each round of the step f is 10 min.

5. The method for optimizing hydrophilicity of an electrode active material according to claim 1, wherein the soaking time in the step c is 18 hours.

Background

The electric adsorption technology is a novel water treatment technology which realizes the concentration and separation of ions in water by utilizing the effect of the adsorption of ions on the surface of an electrode. The method has the advantages of simple process flow, good tolerance, low treatment cost and the like, is particularly suitable for the desalination treatment of raw water with complex water quality components such as various sewage and wastewater, and has very important technical support effect on water saving and emission reduction.

The core of the electro-adsorption technology is an electro-adsorption module, which generally comprises an active electrode, a collector electrode, an isolation material, an electrode substrate, a sealing material and the like. When water containing ions flows through the water flow channel formed by the isolating material between the active electrodes, the ions in the water migrate to the anode and the cathode respectively and are adsorbed on the surfaces of the active electrodes under the action of a direct current electric field applied to the active electrodes, so that the ion concentration in the water is greatly reduced, and the product water with low ion content after ion removal treatment is obtained at the electrode water flow outlet. After the active electrode is saturated in adsorption, the applied direct current electric field is removed, and the positive and negative active electrodes are short-circuited at the same time, so that charges on the active electrode are released and neutralized, the attraction to ions is lost, the adsorbed ions return to the water in the water flow channel, concentrated water with high ion concentration is obtained at the water flow outlet of the active electrode, and the active electrode is regenerated to be adsorbed in the next period. The purpose of desalting the water is realized by repeating the steps.

The existing electrode active material has certain hydrophobicity, and meanwhile, the electrode active material is provided with a great number of micro tube holes in the electrode active material, so that water serving as a working medium cannot fully enter the micro tube holes due to the surface tension of the water, the surface area of the active material cannot be fully utilized, the performance of the electrode active material is greatly reduced, and ions in the water cannot be completely absorbed and removed.

Therefore, a process method capable of changing the active electrode material to make it have better hydrophilicity is in need of research.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for optimizing hydrophilicity of an electrode active material, which is used for overcoming the defect of low efficiency of electro-adsorption desalination caused by the fact that the surface area of the electrode active material cannot fully infiltrate the surface hydrophobicity of the medium water and the active material.

In order to solve the above technical problems, the present invention discloses a hydrophilic optimization method of an electrode active material, which is applied to capacitive desalination of water, and comprises:

providing an electro-adsorption module required by capacitive desalination, wherein the electro-adsorption module is provided with an active electrode made of an active material;

b, improving the surface area of the active electrode to be fully utilized, adding an acid solution into the water for infiltrating the active electrode, wherein the ratio of the acid solution to the water is 1: 10;

c, soaking the active electrode in a mixed solution of acid water for more than 10 hours;

step d: generating hydrophilic groups of the active electrode, inputting electrode pair voltage to 2V-2.5V at two ends of the active electrode, keeping for 20min, and then performing short circuit discharge until the end; in this process, water is required to flow in the electrodes all the time;

step e: inputting reverse electrode pair voltage 2V-2.5V at two ends of the active electrode, maintaining for 20min, and short-circuiting and discharging to end; in this process, water is required to flow in the electrodes all the time;

step f: and e, repeating the operations from the step d to the step e for 2-3 turns till the end.

According to an embodiment of the present invention, the acid solution is a hydrochloric acid solution, and the concentration of the hydrochloric acid solution is 28% to 30%.

According to an embodiment of the present invention, the active material is activated carbon.

According to an embodiment of the present invention, the interval between each round in the step f is 10 min.

According to an embodiment of the present invention, the soaking time in the step c is 18 hours.

Compared with the prior art, the invention can obtain the following technical effects:

the hydrochloric acid solution with a certain proportion is introduced into the water, so that the surface tension of the water is greatly reduced, the water can be fully diffused and infiltrated into pipe holes with various apertures of the active material, and the surface area utilization of the active material is increased, so that more working medium water can be accommodated; meanwhile, the electrode pair voltage is input to the electrode to generate oxidation reaction to generate hydrophilic groups, so that the hydrophobic property of the active material is changed, the performance of the electrode active material is finally improved, and the desalting effect is improved.

Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.

Detailed Description

The following embodiments are described in detail with reference to the accompanying drawings, so that the implementation process of the present invention for solving the technical problems and achieving the technical effects by applying technical means can be fully understood and implemented.

The invention discloses a hydrophilic optimization method of an electrode active material, which is applied to capacitive desalination of water and comprises the following steps:

providing an electro-adsorption module required by capacitive desalination, wherein the electro-adsorption module is provided with an active electrode made of an active material;

b, improving the surface area of the active electrode to be fully utilized, adding an acid solution into the water for infiltrating the active electrode, wherein the ratio of the acid solution to the water is 1: 10; in this step, the surface tension of water is decreased by adding an acid solution so that the medium water can be sufficiently diffused into many minute pores of the electrode active material, thereby sufficiently infiltrating the medium water.

C, soaking the active electrode in a mixed solution of acid water for more than 10 hours;

step d: generating hydrophilic groups of the active electrode, inputting electrode pair voltage to 2V-2.5V at two ends of the active electrode, keeping for 20min, and then performing short circuit discharge until the end; in this process, water is required to flow in the electrodes all the time; in this step, in order to change the hydrophobic property of the active material, the electrode is subjected to an oxidation reaction by inputting a direct current to the electrode.

Step e: inputting reverse electrode pair voltage 2V-2.5V at two ends of the active electrode, maintaining for 20min, and short-circuiting and discharging to end; in this process, water is required to flow in the electrodes all the time;

step f: and e, repeating the operations from the step d to the step e for 2-3 turns till the end.

In the invention, the active material can be preferably active carbon, the surface of the active material is provided with countless fine gaps which are divided into macropores, mesopores, micropores and micropores, wherein the diameter of the micropores on the surface of the active carbon is mostly between 2 nm and 50nm, and in the process of electro-adsorption desalination of water, for partial mesopores, most of the micropores and micropores, because the pore diameter is too small, water serving as a working medium cannot fully enter the pores with smaller pore diameter, so that ions in the water cannot be effectively absorbed, and the trouble of low desalination efficiency is caused. The surface tension of the water is greatly reduced by adding the acid solution into the water, the water can be fully diffused and soaked into pipe holes with various apertures of the active material, and the surface area utilization of the active material is increased so as to accommodate more working medium water.

Preferably, the soaking time in the step c is 18 hours, so that the acid solution can enter the surface of the activated carbon electrode sufficiently to absorb the reaction and increase the specific surface area.

In addition, after the surface of the activated carbon is soaked in the acid solution and the specific surface area of the surface pores is maximized, the electrode pair voltage at two ends of the electrode is increased, so that the activated carbon electrode generates an oxidation reaction, hydrophilic groups are generated on the surface of the activated carbon electrode, and the hydrophilic effect of the activated carbon material is improved. Therefore, the active carbon electrode can change the hydrophobic characteristic thereof and accommodate more working medium water, thereby improving the adsorption capacity of charged ions in water and finally improving the desalting effect.

In a preferred embodiment, the acid solution of the present invention is a hydrochloric acid solution, and has moderate acidity and concentration of 28% -30%.

It should be understood that, in the step d, the electrochemical characteristics of the surface of the activated carbon electrode are utilized to remove charged ions in water, so as to purify water, when the voltage value is increased to 2V-2.5V, the activated carbon electrode can generate oxidation reaction, so as to generate hydrophilic groups, and finally, the voltage is reduced, short circuit discharge is performed, so that capacitive desalting work is completed, and the operation is convenient.

Preferably, steps d-e are operated in at least two cycles with 10min intervals, so that the oxidation reaction of the activated carbon electrode is more sufficient to generate enough and sufficient hydrophilic groups.

In conclusion, the hydrochloric acid solution with a certain proportion is introduced into the water, so that the surface tension of the water is greatly reduced, the water can be fully diffused and infiltrated into pipe holes with various apertures of the active material, and the surface area utilization of the active material is increased, so that more working medium water can be contained; meanwhile, the electrode pair voltage is input to the electrode to generate oxidation reaction to generate hydrophilic groups, so that the hydrophobic property of the active material is changed, the performance of the electrode active material is finally improved, and the desalting effect is improved.

The foregoing description shows and describes several preferred embodiments of the invention, but as aforementioned, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.