Massachusetts Wastewater Practice Exam

The optimum pH for a coagulant used to treat an industrial waste must be determined:

1. From an economic study

2. With a pH meter

3. Experimentally

4. By acid titration

The correct answer is: Experimentally

Determining the optimum pH for a coagulant used in treating industrial waste is primarily carried out experimentally. This approach allows for the assessment of how different pH levels affect the performance of the coagulant in real-time conditions. The effectiveness of coagulation can vary significantly with pH, as it influences the charge of the particles in suspension and the solubility of the coagulants themselves. By conducting experiments, operators can identify the specific pH range that maximizes the removal of contaminants, leading to more efficient wastewater treatment. Other methods like economic studies or acid titration might provide insights in different contexts, but they do not directly lead to establishing the conditions under which coagulation is most effective for a specific waste stream. Using a pH meter is also vital in the process of measuring and monitoring pH levels but does not by itself determine the optimum pH without experimental validation.