What primary test is used to indicate proper sedimentation?

• A. pH test
• B. Conductivity test
• C. Turbidity test
• D. Chlorine residual test

Answer: (C)

The turbidity test is the primary method used to indicate proper sedimentation in water treatment processes. Sedimentation involves allowing suspended particles in water to settle under the influence of gravity, which is essential for producing clean, potable water. Turbidity measures the cloudiness or haziness of water caused by large numbers of individual particles that are generally invisible to the naked eye. A high turbidity level typically indicates that there are a significant number of suspended solids, which means that sedimentation may not be achieving its intended effect.

As the sedimentation process is effective, the turbidity of the water should decrease, demonstrating that solid particles have settled out. Thus, monitoring turbidity provides a direct indication of the effectiveness of sedimentation. If turbidity levels remain high, it can signal that sedimentation is inadequate, prompting further investigation or adjustments in the treatment process.

Other tests, such as pH, conductivity, and chlorine residual tests, serve different functions within water treatment. They do not provide specific insights into sedimentation efficiency, making them less relevant in this context.