Synthesis, characterisation and application in coagulation experiments of polyferric sulphate

Abstract

The process of coagulation is a core environmental protection technology, which is mainly used in the wastewater treatment facilities. Research is now focused on the development of new inorganic coagulants. A characteristic example is PFS (polyferric sulphate), a relatively new pre-polymerised inorganic coagulant with high cationic charge. It consists of medium and high molecular weight polymeric chains and it can be described with the chemical formula [Fe2(OH)n(SO4)(6-n)/2]m. In this paper, the role of some parameters including temperature, types of chemical reagents etc in the preparation stages of PFS were investigated. Furthermore, the prepared PFS was characterized based on typical properties such as the percentage of the polymerised iron present in the compound etc. Furthermore, dynamics of coagulation process were examined by means of the Photometric Dispersion Analyzer (PDA). Finally, the coagulation performance of PFS in reducing the turbidity of synthetic kaolinite suspensions was studied.