Titanium Anodes for Wastewater Treatment

In the process of treating domestic sewage, industrial water, and factory wastewater, titanium anodes not only play a role in transmitting current but also have a catalytic effect on the oxidative degradation of organic matter. Since this process causes no pollution, it is called green water treatment. With the development of industry, the discharge of organic wastewater is increasing day by day. Especially the high – concentration wastewater discharged from industries such as chemistry, food, pesticides, and medicine has high chroma and high toxicity, containing a large number of bio – refractory components, which seriously pollutes rivers, lakes, and seas. The new electrolytic water treatment technology does not require the addition of chemical agents, has small – sized equipment, occupies little space, and does not produce secondary pollution. It has been used to treat wastewater contaminated with organics such as hydrocarbons, alcohols, aldehydes, ethers, and phenols. The removal of COD mainly relies on the oxidation reaction on the anode surface. Organic matter in sewage is directly oxidized and degraded on the anode surface, and through electrochemical conversion, it is directly or indirectly converted into CO₂ and water. The anode potential must be higher than the decomposition potential of organic matter, so there are two competitive reactions on the anode: organic matter oxidation and oxygen evolution.

Product Shapes

The shapes of titanium anodes include mesh, plate, tube, rod, etc.

Advantages of Titanium Anodes

1. The size of the anode is stable. The electrode spacing does not change during the electrolysis process, which can ensure that the electrolysis operation is carried out under a stable cell voltage.
2. The working voltage is low, the power consumption is small, and the energy consumption can be reduced by about 20%.
3. Titanium anodes have a long working life. In the chlorine production industry by the diaphragm method, the coated titanium anode is resistant to the corrosion of chlorine and alkali.
4. It can overcome the dissolution problems of graphite anodes and lead anodes, avoid the pollution of the electrolyte and cathode products, and improve the product quality.
5. The current density can be increased. For example, in the production of chlor – alkali by the diaphragm method, the current density of graphite electrodes is 8 A/dm², while that of titanium anodes can be doubled to 17 A/dm². In this way, with the same electrolysis workshop and electrolytic cells, the output can be doubled.
6. It has strong corrosion resistance and can work in many electrolytic media with strong corrosion and special requirements.
7. It can avoid the short – circuit problem caused by the deformation of lead anodes, thereby improving the current efficiency.
8. The titanium substrate can be reused.

Applications in Wastewater Treatment

Electrolytic Oxidation

1. During the electrolytic oxidation process, titanium anodes can promote the oxidative decomposition of organic matter by generating oxygen and other oxidizing substances to decompose harmful substances in water.
2. This process is widely used in the removal of refractory organic matter, especially in industrial wastewater treatment.

Electro – catalytic Oxidation (EC)

1. As an electro – catalyst, the titanium anode can accelerate the oxidation reaction, especially playing an important role in the removal of toxic and harmful substances in water (such as heavy metal ions, oils, benzenes, etc.).
2. This technology is widely used in the wastewater treatment of industries such as petrochemical, pharmaceutical, and food processing.

Disinfection and Sterilization

Titanium anodes can generate chlorine (Cl₂) through electrolysis, which has a strong disinfection and sterilization effect. Chlorine can effectively kill germs and bacteria in water, so titanium anodes are also commonly used in sewage disinfection treatment.

Electrodialysis

In the electrodialysis process, titanium anodes participate in the ion – exchange process in water as electrodes, which helps to remove salts and pollutants in water and improve water quality.

Manufacture of Titanium Anodes

1.Titanium Substrate

1. Titanium anodes usually use pure titanium or titanium alloys (such as titanium – aluminum alloy, titanium – molybdenum alloy, etc.) as the substrate. These materials have strong mechanical strength and good corrosion resistance.

2.Coating Materials

1. The surface of titanium anodes is generally coated with precious metal coatings, such as iridium, platinum, ruthenium, tantalum, etc. These coatings can improve the catalytic activity and electrical conductivity of the anode, enhancing its corrosion resistance and service life.
2. Currently, iridium – titanium anodes (Ir/Ti) and ruthenium – titanium anodes (Ru/Ti) are common coating materials, which can significantly improve the electrochemical performance of the anode.

3.Surface Treatment

The surface treatment of titanium anodes is very important. Usually, nitriding treatment, oxidation treatment, or coating treatment is carried out to improve its electrical conductivity and corrosion resistance.

Advantages of Titanium Anodes in Wastewater Treatment

1.Long – term Durability

The durability of titanium anodes far exceeds that of other traditional materials, especially suitable for long – term and high – intensity electrolytic reaction processes.

2.Low Maintenance Cost

1. Due to its long – term stability and corrosion resistance, the maintenance and replacement frequency of titanium anodes is low, thus reducing the maintenance cost in long – term operation.

3.Improved Treatment Effect

Titanium anodes can effectively improve the efficiency of the electrolytic reaction, accelerate the degradation rate of pollutants, reduce the treatment time, and lower the energy consumption.

4.Strong Environmental Friendliness

Titanium anode materials are environmentally friendly themselves, will not cause secondary pollution to the environment, and can effectively improve the removal rate of pollutants in wastewater treatment, meeting the requirements of green environmental protection.

Conclusion

Titanium anodes for wastewater treatment play an important role in modern environmental protection technologies. With their excellent corrosion resistance, electrical conductivity, and long – term stability, titanium anodes are widely used in the field of electrochemical wastewater treatment, especially in electrolytic oxidation, catalytic oxidation, disinfection, and sterilization. With the continuous development of wastewater treatment technology, titanium anodes will occupy a more important position in future wastewater treatment systems.