What is a common application of ion exchange in wastewater treatment?

• A. Disinfection
• B. Recover metallic ions
• C. Remove organic pollutants
• D. Enhance pH levels

Answer: (B)

Ion exchange is a widely used process in wastewater treatment, particularly for the recovery of metallic ions. This process involves exchanging ions in a solution with ions bound to a solid, typically resin beads. When wastewater containing metallic ions—such as heavy metals—comes into contact with the resin, the resin will pick up the metallic ions and release a corresponding amount of other ions (often sodium or hydrogen ions) into the solution.

This mechanism is effective for removing specific contaminants from the water, allowing for both the treatment of wastewater and the recovery of valuable materials. The recovered metals can be further processed and reused, contributing to sustainability efforts within the industry.

In contrast, the other choices focus on different treatment methods or applications that are not directly related to ion exchange. Disinfection typically involves chemical or physical processes to eliminate pathogens, while the removal of organic pollutants usually employs biological processes or advanced oxidation methods. Enhancing pH levels can involve various neutralization methods but does not specifically utilize ion exchange.