Alkalinity is defined as which of the following?

Alkalinity is defined as which of the following?

• A. The color of water
• B. The temperature of water
• C. The amount of dissolved oxygen
• D. Buffering capacity (meq/L or mg/L as CaCO3)

Answer: (D)

Alkalinity is the buffering capacity of water—the ability to resist changes in pH when acids are added. This buffering comes mainly from dissolved carbonate species (bicarbonate and carbonate) and hydroxide ions, which neutralize added hydrogen ions and are expressed as milliequivalents per liter or milligrams per liter as CaCO3. It is not related to the color, temperature, or dissolved oxygen of water. Measuring alkalinity in CaCO3 equivalents provides a standard way to quantify how much acid the water can neutralize before the pH drops, helping to stabilize treatment processes.

Alkalinity is the buffering capacity of water—the ability to resist changes in pH when acids are added. This buffering comes mainly from dissolved carbonate species (bicarbonate and carbonate) and hydroxide ions, which neutralize added hydrogen ions and are expressed as milliequivalents per liter or milligrams per liter as CaCO3. It is not related to the color, temperature, or dissolved oxygen of water. Measuring alkalinity in CaCO3 equivalents provides a standard way to quantify how much acid the water can neutralize before the pH drops, helping to stabilize treatment processes.