GLOBAL FERRONIL range of manganese di-oxide is a proven way to remove iron and manganese contamination from water. Ground water sources usually have high iron and manganese content in soluble -ous (II) form. Ferronil is an effective way to convert soluble salts of iron and manganese to insoluble -ic (III) form which can be subsequently removed by conventional filters. Manganese di-oxide oxidizes iron and manganese salts to insoluble precipitate. pH of water should be corrected to around 9 for ferrous salts and 10.5 for manganous salts. Air is injected into water to enhance the kinetics of oxidation. Residence time depends on iron and manganese load of inlet water. Manganese di-oxide is economical to use compared to greensand, offers comparable removal efficiency, but does not require handling of hazardous media for regeneration.