Poly ferric sulfate have well effect in effluent treatment as inorganic polymer coagulant.So,It is widely used for drinking water, industrial water, various industrial waste water, municipal sewage, sludge dehydration etc.

The details usage:Poly ferric sulfate not only can treat the common heavy metal ions, but also has a very good removal effect on COD, BOD and water color, and the removal rate of BOD can reach over 93%
link:https://www.senloschemical.com/water-treatment-chemicals/polyferric-sulfate.html