Before going any further, it should be noted that dielectric materials are not widely used in the water treatment industry. However, they are found in some specific equipment such as corona discharge electro-deionization systems. In these deionization modules, dielectric materials are used to contain the electric current in a controlled, enclosed space to allow for the exchange of ions through corona discharge.
To learn more about electrodeionization systems, we encourage you to consult these articles:
What are dielectric materials?
A dielectric material is a medium that does not carry an electric charge that can travel. Therefore, the current emitted on such a material does not move. This non-conductivity comes from the fact that the material has no free electrons that can carry electric charges.
- Note that dielectric materials can generate electrostatic charges due to a displacement of electric charges within the dielectric medium.
There are several dielectric materials, here are some of them:
- Dry air ;
- Dry wood;
- Teflon ;
- Ceramic;
- Pure water.
Indeed, pure water does not conduct electricity. This is partly due to the absence of total dissolved matter in it. If you would like to learn more about the conductivity and resistivity of water, consult these articles:
The use of dielectric materials
As discussed above, in the water treatment industry, dielectrics are used in EDI modules. However, they can also be found elsewhere. Generally speaking, they are used in capacitors. They are generally placed between conductive plates or sheets and allow the capacitors to store current.
C’est pourquoi on peut retrouver ces matériaux dans certaines autres technologies de traitement d’eau ; entre autres les ozonateurs.