The properties of polymeric ferric sulfate

Polyferric Sulfate (PFS), with the chemical formula [Fe (2OH) (nSO4) 3-0.5n] m, is dark brownish red in color. It is more viscous and less corrosive than other inorganic flocculants. The preparation of PFS mainly includes air (oxygen) catalytic oxidation method, nitric acid oxidation method, hydrogen peroxide oxidation method, etc. The essence is to control n (SO24-) : n (Fe3+) <3:2 to obtain PFS with different basicity degrees. PFS is prone to hydrolysis reactions in water, generating particles such as [Fe (OH) n] m + and [Fe (H2O)] m +. These particles exist in water in the form of chain polymers and carry a large amount of positive charges. They can effectively disrupt the stability of colloidal suspensions, adsorb negatively charged pollutant particles in water, and then rapidly settle. During the sedimentation process, multiple chain-like high-molecular polymers interweave with each other, forming a structure similar to a network. This captures more pollutant particles during the sedimentation process, thereby reducing the concentration of pollutant particles in the water and achieving the purpose of water purification. Therefore, PFS is a type of highly efficient flocculant. In recent years, PFS has gradually gained favor in the market and demonstrated excellent flocculation and pollution reduction performance in related research and applications. However, single-component PFS is difficult to meet the requirements in the treatment of complex wastewater. Therefore, by adding new compounds that can react with various cations and anions in the PFS system to form precipitates or polymers, and under appropriate reaction conditions, a new type of composite flocculant is formed through full reaction. This flocculant has significant advantages in a certain water purification field. These composite flocculants have significant application prospects in the treatment of domestic sewage, papermaking wastewater, printing and dyeing wastewater, slaughterhouse wastewater, oily wastewater and other fields.