Green Sand Filtration: Effective Iron Removal for Water Treatment

Public safety depends on clean water supplies. A variety of chemicals and methods can be used to treat water with a high metal content. When removing iron from water supplies, one widely used method of purifying water of iron content is greensand filtration.

Identification

• Greensand refers to a type of sediment used in water filtration. This sediment contains glauconite, a mineral that reduces iron to small granules through oxidation. When reduced in size, the iron can be filtered out.

Preparation

• Before greensand filtration can be implemented, oxidation must occur. Depending on the filtration project, this may be accomplished with an air pump full of oxygen or with chlorine.

How It Works

• Once iron is oxidized by pre-treatment chemicals, it is run through the greensand sediment. This sediment filters out the granules of oxidized iron. For groundwater or rivers, an area of greensand sediment is laid and the water is pre-treated before it reaches the greensand.