Which chemical is commonly used to boost pH when aiding coagulation?

Prepare for the American Water Works Water Treatment Plant Operator Test. Study with multiple choice questions, each with hints and explanations. Get ready to excel!

Raising pH to the right level helps coagulation work effectively, since coagulants like alum perform best in a near-neutral pH range. Using a strong base to boost pH provides a rapid, controllable adjustment, so operators can dial in the exact pH needed for optimal floc formation. Sodium hydroxide is concentrated and easy to feed with precise dosing, making it a reliable choice for quickly increasing pH without introducing additional ions that might complicate the coagulation chemistry. In contrast, acids would lower pH, and other bases like lime or sodium carbonate either add extra hardness/alkalinity (lime) or bring in carbonate buffering (sodium carbonate), which isn’t always desirable when fine-tuning pH for coagulation.