Which chemical compound primarily contributes to scale formation within pipes?

• A. Calcium carbonate
• B. Magnesium sulfate
• C. Sodium bicarbonate
• D. Iron oxide

Answer: (A)

Calcium carbonate is a primary contributor to scale formation within pipes due to its solubility characteristics and prevalence in water supplies. When water contains bicarbonate ions, it can form a soluble compound with calcium ions. However, under certain conditions, such as increased temperature or pressure, this soluble form can precipitate out as calcium carbonate. This precipitation leads to deposits that build up on the inside of pipes, valves, and equipment, causing blockages and reducing system efficiency.

The formation of scale from calcium carbonate can be exacerbated in hard water areas, where higher concentrations of calcium and carbonate ions are present. Since many water treatment systems encounter calcium carbonate, understanding its role in scale formation is crucial for managing and maintaining water distribution systems effectively.