How is cathodic protection achieved?

Cathodic protection is a technique used to prevent corrosion of metal surfaces, particularly underground storage tanks (USTs). The correct answer involves the use of sacrificial anodes, which are materials that are more reactive than the metal of the tank. When sacrificial anodes are installed, they corrode preferentially, thereby protecting the tank from corrosion. This process makes the anodes the "sacrificial" components that take on the corrosive elements, preserving the integrity of the tank itself.

In the context of USTs, the use of sacrificial anodes can significantly prolong the lifespan of the tank and reduce the risk of leaks or failures due to corrosion. This method is particularly effective for tanks made of steel or other metals that are susceptible to deterioration from moisture and chemicals found in the soil or groundwater.

Other methods mentioned, such as insulating the tank or regular painting, may help protect against certain types of corrosion or damage, but they do not specifically provide cathodic protection. Insulating the tank can reduce moisture contact but does not address the electrochemical processes that lead to corrosion. Painting the tank can act as a barrier against physical damage and some corrosion, yet it does not implement a dedicated means of reducing the electrochemical reactions that cause