Why Titanium Anode is an Excellent Choice For Electrochemical Water Treatment System?

Jun 07, 2022

Why Titanium Anode is an Excellent Choice for Electrochemical Water Treatment System?

Electrochemical water treatment systems utilize electricity to induce the removal of dissolved contaminants in the water. Positively charged contaminants such as calcium, magnesium, sodium, lead, and uranium are called cations. Negatively charged contaminants such as chlorides, nitrates, nitrites, sulfates, and fluorides, are called anions. The introduction of a negatively charged electrode, or cathode, into the water will cause positively charged cations to move towards it.  

The anode type is critical for electrochemical water treatment efficiency and result. Anodes used for electrochemical waste treatment include lead, lead alloy, stainless steel, magnetite, graphite, and precious metal coated titanium. Although all of these anodes have been successfully used for the different elect, electrochemical applications, each anode type has its advantages and disadvantages. For example, lead and carbon anodes dissolve during operation to form toxic materials (lead oxides from lead and carcinogenic organic compounds from carbon due to the phenolic binders) which have to be removed prior to discharge. The dissolved impurities will also contaminate the process and result in poor quality products. Stainless steel and magnetite anodes can only be used in an alkaline electrolyte and the service life for magnetite anodes is very short, even in alkaline solutions.

Comparisons are made between titanium anodes and other insoluble anodes such as lead, lead alloy, and graphite, in terms of their electrochemical performance and environmental impact.  Titanium anodes are more expensive than other anode materials. However, because of their operating stability and energy efficiency, titanium anodes have become the anode of the choice for a wide variety of electrochemical processes.

This titanium anode is prepared by applying an electrocatalytic coating (precious metals or oxides of precious metals, typically platinum or indium) on titanium substrates through either an electroplating or thermal decomposition method. The titanium substrate is available in rod, tube, mesh (expanded metal), and solid sheet and can be further fabricated to any shape and size. Thus, this versatile material can be employed in virtually all different types of electrochemical cells.