Basic Wastewater Operator Practice Exam

Which method is used to measure the concentration of suspended solids in wastewater?

1. Settling test

2. Filtration test

3. Colorimetric test

4. Electronic conductivity test

The correct answer is: Settling test

The method used to measure the concentration of suspended solids in wastewater is the settling test. This test typically involves placing a sample of wastewater in a graduated cylinder or similar container and allowing it to stand undisturbed for a set period of time. Over this period, the suspended solids will settle to the bottom of the container under the influence of gravity. By measuring the volume of the settled solids relative to the total volume of the sample, operators can determine the concentration of suspended solids in the wastewater. This method is particularly effective for quantifying solids as it directly observes the behavior of these particles in a controlled environment. It provides a clear visual representation and helps in evaluating the efficiency of sedimentation processes in treatment facilities. Other methods, while useful in different tests, do not specifically measure suspended solids in the same manner. For instance, the filtration test may be used to separate solids from liquids, but it does not measure how much solid is already suspended in the liquid prior to filtering.