Florida Drinking Water Operator "B" Practice Test

What is often used to improve water quality when iron levels are high?

1. Flocculation

2. Chlorination

3. Reverse osmosis

4. Aeration

The correct answer is: Aeration

Aeration is commonly used to improve water quality when iron levels are high because it introduces oxygen into the water, which facilitates the oxidation of dissolved iron. When iron oxidizes, it converts from a soluble ferrous state (Fe²⁺) to an insoluble ferric state (Fe³⁺). The ferric iron can then precipitate out of the water, often forming rust-colored sediments that can be easily removed through filtration or sedimentation processes. This method is particularly beneficial because it effectively reduces both the concentration of dissolved iron in the water and associated unpleasant taste or staining issues without the addition of chemicals. While other methods, such as flocculation, chlorination, and reverse osmosis, are employed for different purposes or contaminants, aeration specifically targets the oxidation of iron and is a straightforward, cost-effective treatment option.