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CN-117466392-B - Ion selective adsorption electrode, micro-electric field adsorption system and application thereof in water softening, sterilization and algae removal

CN117466392BCN 117466392 BCN117466392 BCN 117466392BCN-117466392-B

Abstract

The invention belongs to the technical field of water softening and sterilization, and discloses an ion selective adsorption electrode, a micro-electric field adsorption system and application thereof in water softening, sterilization and algae removal. An ion selective adsorption electrode comprises 5-20% by mass of polycarboxylic acid ion exchange fibers, active carbon, a conductive agent and a binder. The invention takes CCEF modified active carbon as a cathode, under the optimal doping amount, the selectivity coefficients of Ca 2+ and Mg 2+ are respectively 15.0 and 13.5, and the electric adsorption capacity of Ca 2+ is 311 mu mol/g which is far higher than that of an AC electrode. After 50 circles of stability tests, the electric adsorption capacity of Ca 2+ is kept above 85%, and the regeneration capacity is good. The active carbon modified by nano silver is used as an anode, and under the strengthening of an electric field, the inhibition rate of bacteria and microalgae is respectively up to 99% and more than 90%, so that the active carbon has good antimicrobial pollution capability.

Inventors

  • XIAO KAIJUN
  • ZHU ZHONGHAO
  • YI LIZHONG

Assignees

  • 华南理工大学
  • 广东华凯明信科技有限公司
  • 广州洁圣膜技术有限公司

Dates

Publication Date
20260505
Application Date
20231121

Claims (8)

  1. 1. An ion selective adsorption electrode, characterized in that the ion selective adsorption electrode comprises a polycarboxylic acid ion exchange fiber, activated carbon, a conductive agent and a binder; The mass percent of the polycarboxylic acid ion exchange fiber is 10%, the mass percent of the activated carbon is 60% -80%, the mass percent of the conductive agent is 5% -10%, the mass percent of the binder is 5% -10%, and the sum of the mass percent of the components is 100%; The ion selective adsorption electrode is prepared by adopting a coating method, namely adding a proper amount of polycarboxylic acid ion exchange fiber, activated carbon, a conductive agent and a binder into water to disperse into slurry, coating the slurry on a current collector, and drying in vacuum.
  2. 2. The ion selective adsorption electrode of claim 1 wherein the conductive agent is ketjen black or acetylene black; The binder is PTFE, PVDF or Nafion; the current collector is titanium foil, copper foil, aluminum foil, carbon paper, graphite paper or titanium plate.
  3. 3. A micro-electric field adsorption MEFB unit cell, which is characterized by comprising a cathode and an anode, wherein the cathode is the ion selective adsorption electrode according to any one of claims 1-2; the anode is the same as the cathode, or the anode is an active carbon anode doped with nano silver.
  4. 4. The micro electric field adsorption MEFB unit cell according to claim 3, wherein the nano silver doping amount is 0-1wt%.
  5. 5. The micro electric field adsorption MEFB unit cell according to claim 4, wherein the nano silver doped active carbon anode is prepared by a film coating method, and is prepared by adding a proper amount of water into active carbon, a conductive agent, a binder and nano silver to disperse into slurry, coating the slurry on a current collector, and vacuum drying.
  6. 6. A micro-electric field adsorption MEFB system, comprising the cell of any one of claims 3-5, further comprising a conductivity meter, a peristaltic pump, a cyclic adsorption-desorption tank, a desorption tank, and a constant voltage dc power supply.
  7. 7. Use of the micro-electric field adsorption MEFB system of claim 6 for water softening and/or bactericidal and algicidal.
  8. 8. Use according to claim 7, characterized in that the cations in the water comprise calcium ions, magnesium ions, potassium ions, sodium ions; The bacteria are escherichia coli and/or staphylococcus aureus; The applied voltage of the system is 1.0 v-2.0 v.

Description

Ion selective adsorption electrode, micro-electric field adsorption system and application thereof in water softening, sterilization and algae removal Technical Field The invention belongs to the technical field of water softening and sterilization, and particularly relates to an ion selective adsorption electrode, a micro-electric field adsorption system and application thereof in water softening, sterilization and algae removal. Background The hardness of water is a water quality problem commonly existing in various countries in the world, and the development of water softening technology is a fundamental measure for solving the hazard of hard water. At present, the traditional method for softening hard water mainly comprises chemical precipitation, membrane separation, ion exchange and other technologies. Wherein, the chemical precipitation method can affect the water quality, and generate a large amount of wastes which can pollute the environment, and the treatment is incomplete and the potential safety hazard is easily caused; the water softened by the cation exchange resin contains a large amount of sodium salt, is destructive to part of environment after being discharged, and has the industrial application problem of easy water shutoff due to high swelling rate, while the membrane separation technology has certain requirements on water inlet pressure, has high construction cost and running cost, has the risk of scaling and blocking, and is generally rarely specially used for hard water softening treatment in practical engineering. Compared with the prior art, the novel water treatment technology utilizes the micro-electric field adsorption technology (MEFB) to enrich and concentrate dissolved salts and other charged substances in water on the surface of the electrode so as to realize water purification and desalination. At present, the technology is mainly used for sea water desalination, but the research on application to fresh water softening is less. The carbon-based electrode material of the micro-electric field adsorption technology can utilize the electric double layer effect thereof to adsorb ions in water in a broad spectrum. However, the conventional activated carbon electrode has the defects of low adsorption capacity and no ion selectivity, so that the conventional activated carbon electrode is difficult to be practically applied to the softening of hard water in a complex system. For daily drinking water, sodium and potassium are essential macroelements for maintaining human health. Thus, it is desirable that the drinking water contains a certain amount of Na + and K +. In addition, when hard water of a multi-ion system is softened, non-target ions such as Na + and K + compete for adsorption sites with target ions Ca 2+ and Mg 2+ due to the homoionic effect, so that the adsorption capacity of a common carbon-based electrode material for the hard ions is low, and the softening effect on the hard water is not ideal. In recent years, chinese patent CN106395814B discloses a capacitive deionization activated carbon electrode block for desalting water or removing hardness ions, and the electrode has good conductivity, high mechanical strength and adsorption capacity reaching 3.39mg/g. However, the electrode prepared by the method has no selectivity on ion adsorption and has lower adsorption capacity on hardness ions. For surface water, not only is the problem of high hardness, but also serious potential safety hazards of microorganisms exist, and common microorganisms such as bacteria and algae in the water body often coexist with metal ions, which can cause great economic cost for human safety in utilizing the surface fresh water. However, the micro-electric field adsorption technology is recently reported in the aspect of microorganism inhibition, and the application of the micro-electric field adsorption technology to selectively remove hardness ions and realize synchronous microorganism inhibition has not been reported yet. Importantly, the micro-electric field adsorption technology is applied to killing microorganisms, on one hand, for purifying drinking water, and on the other hand, for avoiding the adhesion and propagation of microorganisms on the surface of the active material, so that the adsorption performance of the electrode material is reduced. Therefore, an electrode material capable of selectively and efficiently removing hardness ions and synchronously inhibiting and killing microorganisms and a preparation method thereof are developed, and a micro-electric field deionization system assembled by the electrode is provided, so that the electrode material has a wide application prospect. Disclosure of Invention In order to solve the defects of the prior art, the primary aim of the invention is to provide an ion selective adsorption electrode and a microorganism inhibition electrode, which are composed of a carbon-based composite electrode modified by polycarboxylic acid ion exchang