Ferrous sulfate is widely used in flocculating and purifying waste water in pulp printing and dyeing industries, as well as removing phosphate from urban and industrial sewage to prevent eutrophication of water. Ferrous sulfate can be used as reducing agent mainly to reduce chromate in cement. It can be used as a iron supplement of plant to prevent and control plant physiological diseases due to iron deficiency Ferrous sulfate can be used to treat iron deficiency anemia. It can also be used to add iron to food. But long-term excessive use may cause side effects such as abdominal pain and nausea.