Greensand is regenerated using which chemical?

• A. Sodium hypochlorite
• B. Potassium permanganate
• C. Calcium hydroxide
• D. Chlorine dioxide

Answer: (B)

Greensand filtration, often used in water treatment for iron and manganese removal, is regenerated using potassium permanganate. This chemical serves to restore the manganese oxide coating on the greensand media, which is essential for its function in adsorbing and removing target contaminants.

When greensand becomes exhausted after a period of use, it loses its ability to effectively filter out these metals. Potassium permanganate reacts with the media to regenerate the manganese oxide coating, enabling the greensand to perform its filtration tasks again. This regeneration process is crucial for maintaining the efficiency and longevity of greensand filters in water treatment applications.