Which term means the ability of water to buffer acids?

• A. Anoxic
• B. Base
• C. Alkalinity
• D. Aliquot

Answer: (C)

Alkalinity is the water’s capacity to neutralize acids. It comes from dissolved carbonate, bicarbonate, and hydroxide ions that react with added hydrogen ions, helping to keep the pH from dropping quickly. This buffering ability is important in wastewater because it helps maintain stable pH during processes that produce acids, supporting biological activity and treatment efficiency. Alkalinity is typically reported as milligrams per liter as calcium carbonate (mg/L as CaCO3), reflecting how much acid the water can neutralize.

Anoxic means lacking oxygen, which isn’t about buffering capacity. A base is a chemical term for substances that accept protons or donate hydroxide, but it doesn’t describe the overall buffering capacity of the water. An aliquot is just a measured sub-sample taken for analysis.