Tennessee Wastewater Operator Practice Exam

Which type of filtration is not included in membrane filtration types?

1. Microfiltration

2. Ultrafiltration

3. Granular filtration

4. Reverse osmosis

The correct answer is: Granular filtration

Membrane filtration involves processes that use semi-permeable membranes to separate particles from fluids based on size and other properties. Microfiltration, ultrafiltration, and reverse osmosis are all techniques that rely on membranes to filter smaller particles from fluids, with each process targeting specific sizes and types of contaminants. Granular filtration, on the other hand, utilizes a bed of granules or particles such as sand or gravel to physically capture solids from liquid, without the use of membranes. This process is different because it relies on the physical space between the granules for filtration, rather than a membrane's selective permeability to different sizes of particles. Therefore, granular filtration is distinct from the other methods listed as it does not involve any type of membrane technology, leading to its classification as the correct answer in this context.