Which component of water treatment helps prevent scale in boilers?

Softening agents play a critical role in water treatment to prevent scale formation in boilers. The primary mechanism by which they function is by reducing the hardness of water, which is mainly caused by the presence of calcium and magnesium ions. When hard water is heated in boilers, these minerals can precipitate and form scale on the boiler surfaces, thereby leading to reduced efficiency, overheating, and potential damage.

Softening agents, such as sodium carbonate or ion-exchange resins, replace calcium and magnesium ions with sodium ions, which do not form scale. By using softening agents, the water's hardness is effectively reduced, minimizing the risk of scale buildup. This not only enhances the operational efficiency of the boiler but also extends its lifespan by preventing damaging deposits.

While other choices relate to water treatment in various contexts, they do not serve the specific function of scale prevention in boilers. Chlorine is primarily used for disinfection, acids can be used to remove existing scale but do not prevent it from forming, and surfactants are focused on reducing surface tension and facilitating cleaning rather than addressing hardness-related issues directly. Therefore, softening agents are the correct solution for preventing scale in boilers.