Polyferric sulfate is a common water purification agent in industrial wastewater treatment, which not only has good effect in wastewater treatment, but also has excellent effect in sludge dewatering. But sometimes due to improper operation, the sludge floats up in sludge dewatering.

When PFS is used to treat sludge, the suspended particles in the water after flocculation will form alum and precipitate, so what is the reason for sludge floating? In the process of using PFS, the excessive use and too little addition of PFS will affect the flocculation effect of PFS and cause sludge floating. When using PFS, if some coagulant aids such as polyacrylamide are added, the effect will be better. However, if the polyacrylamide is used incorrectly, the sludge will not agglomerate well and float up under the action of water flow. In addition, with the increase of water volume and insufficient sedimentation time, some sludge will float on the water again. Carbon dioxide, methane and other gases are produced at the bottom of the tank, which will also make the lighter sludge float up with the gas.

As an important iron salt, polyferric sulfate needs to master the corresponding use method in order to achieve the ideal use effect.