Ferrous sulfate is a kind of inorganic compound, which is easily soluble in water. It is often used as flocculant and catalyst. It has good effect in wastewater treatment.

With the improvement of living standards in China, the eutrophication of water body is becoming more and more serious, and the increase of phosphorus in water eutrophication is one of the important factors, and also one of the important factors affecting people's drinking water safety. With the increase of environmental protection and the requirement of wastewater discharge, the technology of phosphorus removal by adding ferrous sulfate is gradually developed. Ferrous sulfate is mainly used as catalyst and iron supplement in the process of strengthening phosphorus removal, so it is widely used in sewage treatment plants without additional treatment process. Using ferrous sulfate to increase the effect of chemical phosphorus removal and biological bacteria phosphorus removal can effectively remove total phosphorus and organic matter in wastewater, and the effect is better than the general phosphorus removal process.

Ferrous sulfate also has a good flocculation effect. It can effectively remove some harmful suspended substances in wastewater while removing phosphorus. It has a good effect on preventing eutrophication of water body. It is widely used in urban sewage and industrial phosphorus removal.