Florida Drinking Water Operator "B" Practice Test

What is the increasing tendency for precipitation of sparingly soluble salts and deposition of particulate on the membrane surface called?

1. Membrane fouling

2. Concentration polarization

3. Osmotic pressure

4. Flocculation

The correct answer is: Concentration polarization

The increasing tendency for precipitation of sparingly soluble salts and deposition of particulate on the membrane surface is best described as concentration polarization. This phenomenon occurs when solutes accumulate at the membrane surface, leading to a higher concentration of particles and salts than in the bulk solution. As this concentration gradient develops, it can diminish the performance of the membrane system, impacting the efficiency of filtration processes. In membrane operations, when water is drawn through the membrane, the solutes can become more concentrated on the feed side of the membrane, which not only leads to scaling and fouling but can also hinder the flow of water across the membrane. Understanding concentration polarization is critical for water operators as it influences how membranes are maintained and how effective water treatment processes are managed. While the other terms mentioned relate to membrane operations, they do not describe the specific dynamic of increased solute concentration at the membrane surface that leads to operational challenges like scaling or fouling. Therefore, recognizing concentration polarization is essential for developing strategies to mitigate its effects and ensure efficient water treatment.