What is the primary process used to remove dissolved iron and manganese from water?

The primary process used to remove dissolved iron and manganese from water is oxidation. In this context, oxidation involves the chemical conversion of dissolved ferrous iron (Fe²⁺) and manganous manganese (Mn²⁺) into their insoluble forms, ferric iron (Fe³⁺) and manganic manganese (MnO₂), respectively. Once oxidized, these elements can precipitate out of the water, forming solid particles that can then be removed through subsequent filtration.

The oxidation process is crucial because dissolved iron and manganese can cause a range of problems, such as staining and taste issues in drinking water. By effectively converting these soluble contaminants into solid forms, water treatment systems can ensure that the water meets safety and aesthetic standards.

While filtration can remove the precipitated solids after oxidation, it is not the primary process that transforms dissolved iron and manganese into a removable form. Decantation typically refers to separating liquids based on density and is not specific to iron and manganese removal. Mechanical scrubbing involves physically cleaning surfaces and is not applicable to treating dissolved metals in water. Thus, oxidation stands out as the essential initial step in the removal of these specific contaminants from water.