Titanium electrodes for water disinfection
At present, in terms of the types of water disinfection, there are chlorine, sodium hypochlorite, bleaching powder, chlorine dioxide, trichloroisocyanuric acid, hydrogen peroxide, ozone and other agents and methods, in addition to iodine water, high-value oxidized water, ultraviolet disinfection and other means .
Among all disinfectants, although chlorine gas is the most economical, due to the potential safety hazards of chlorine gas in transportation, storage, and use, and the problem of difficult to accurately control the dosage and measurement;
Compared with other disinfectants, sodium hypochlorite solution is very advantageous. It is clear and transparent, soluble in water, and completely solves the technical difficulties that gas disinfectants such as chlorine, chlorine dioxide and ozone are insoluble in water and difficult to accurately add. Ozone and other chemicals often have potential safety hazards such as running, leaking, leaking, and poisoning, and no side-reactants that are harmful to health and damage the environment are produced during disinfection, and there are no many sediments caused by the use of bleaching powder. Because of these characteristics, sodium hypochlorite has been widely used in the disinfection and epidemic prevention and disinfecting of various water bodies including tap water, reclaimed water, industrial circulating water, swimming pool water, and hospital sewage. However, because the sodium hypochlorite solution is not easy to store for a long time, and the transportation is inconvenient, sodium hypochlorite is mostly prepared and used on-site by electrolyzing salt water.
Application of Titanium Anode
The invention of titanium anodes and their use in sodium hypochlorite generators is undoubtedly an important breakthrough in the use of on-site production of sodium hypochlorite technology for drinking water treatment and disinfection of private and public swimming pools. Comparing the on-site production of sodium hypochlorite with titanium anodes and the use of chlorine gas or pouring in large quantities of sodium hypochlorite is not only safe but also environmentally friendly. Using titanium anodes to produce sodium hypochlorite avoids the use of corrosive and dangerous chemicals such as hydrochloric acid.
The reaction principle of electrode preparation of sodium hypochlorite is to electrolyze sodium chloride dissolved in water. During electrolysis, sodium hypochlorite is formed. The most suitable salt concentration is 3-5 g/L. To improve salt utilization, diaphragms can be used, which are commonly used in large equipment and swimming pools.
The overall response is expressed as follows:
NaCl + H2O → NaClO + H2↑
Electrode reaction:
Anode: 2Cl- - 2e → Cl2
Cathode: 2H+ + 2e → H2
Solution reaction: 2NaOH + Cl2 → NaCl + NaClO + H2O
Products and services: For the sodium hypochlorite generator, Yiantan has developed special anode products that are very suitable for use, in order to achieve the effect of improving the use efficiency of salt and prolonging the service life of anodes. The main products are as follows:
1. Ruthenium metal oxide coated titanium anode;
2. Iridium platinum oxide coated titanium anode.
Titanium anode for domestic water, food utensil disinfection and swimming pool water disinfection
In recent years, the production of miniature sodium hypochlorite disinfectant generators has been increasing. The smallest generator electrolytic cell volume is only 0.5L, the effective chlorine content is 1.2g/L, and the size of the coated titanium electrode is 3cm in diameter. The generator is very popular due to its lightness and portability.
Hypochlorous acid is a small neutral molecule that can diffuse to the surface of negatively charged bacteria and penetrate into the interior of the bacteria through its cell wall for oxidation, thereby killing bacteria. The natural pond water contains 1.1×105/L of Escherichia coli, and the total number of bacteria is 2×104/mL. After adding sodium hypochlorite for disinfection for 5 minutes, the number of Escherichia coli is 100/L, and the total number of bacteria is only 100/mL. The disinfected pond water has been tested by the health department and meets the drinking water standard. The small sodium hypochlorite generator is suitable for sterilization and disinfection of unclean drinking water, such as river water, well water, and sugar water. It is especially useful for field operations, field troops, and areas where a water supply system is also purchased.
Sodium hypochlorite can quickly kill various pathogenic bacteria and viruses, such as Escherichia coli, Staphylococcus aureus, hepatitis B virus, Bacillus subtilis black variant spores, etc. Disinfecting and sterilizing household daily necessities and home environment with disinfectant can effectively prevent infectious diseases such as hepatitis, typhoid fever, cholera and dysentery.
Sodium hypochlorite can be used for disinfection of tableware and tea sets, and the effect is better than high temperature disinfection;
It can be used for disinfection, cleaning and deodorization of kitchen utensils, bathtubs and sanitary ware;
Can be used for disinfection of articles and clothes used by patients;
It can be used to sterilize feeding bottles and toys for infants and young children;
Can be used for surface disinfection of fruits, fish and vegetables;
It can be used for disinfection and sterilization of swimming pool water.
