Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

How can excess fluoride in water be removed effectively?

1. Ion exchange

2. Activated alumina

3. Carbon filtration

4. Reverse osmosis

The correct answer is: Activated alumina

Activated alumina is an effective method for removing excess fluoride from water due to its specific properties that enable it to adsorb fluoride ions. Activated alumina is a porous and highly adsorbent material made from aluminum oxide, which has a high surface area that attracts and holds fluoride ions from the water. This method relies on the principle of adsorption, where fluoride ions adhere to the surface of the activated alumina, ultimately reducing the concentration of fluoride in the water. While other options have their merits in water treatment, they are less effective for fluoride removal. For example, ion exchange can be used for various contaminants, but it is not primarily designed to target fluoride specifically and may require additional steps for effective removal. Carbon filtration effectively removes organic compounds and chlorine but is less efficient at removing fluoride ions. Reverse osmosis can also effectively reduce fluoride levels in water, but it is generally considered a more complex and expensive system compared to activated alumina. Thus, activated alumina stands out as a straightforward and efficient option for specifically addressing fluoride contamination in drinking water.