ABSTRACT
The flocculation performance of PFS can be improved by introducing different inorganic ions. Polyferric phosphate sulfate (PFPS), polyferric silicate sulfate (PFSiS), and polyferric aluminum phosphate sulfate (PFAPS) with similar content of total iron element [TFe] were prepared in this work. Their properties and particle size distribution were measured, and their flocculation performance on real oily wastewater and coal-gas washing wastewater were compared with that of commercial polyferric sulfate (PFS). The results show that the particle size distributions of three inorganic ion modified PFSs are different, due to the different polymerization mechanisms. These modified PFSs all have certain advantages over PFS. PFAPS has the strongest electric neutralization ability, and the effect of COD removal is the best in the treatment of two kinds of wastewater; PFSiS has the strongest adsorption and bridging capacity, and the effect of removing turbidity is the best in the treatment of two kinds of wastewater.
