Properties and Coagulation Behaviour of Polyferric Silicate Sulphate by Different Preparation

Abstract

Polyferric silicate sulphate (PFSS) can be used in wastewater treatment as modified inorganic polymeric coagulant. Polyferric silicate sulphate is prepared through following steps: (1) alkalization of the mixture consisting of ferric sulphate and polysilicate (PFSSa) and (2) oxidation of the mixture consisting of ferrous sulphate and polysilicate (PFSSo). The typical properties (e.g., pH, z-potential and morphology) of PFSSa and PFSSo were characterized. The coagulation performances of the two PFSS samples were studied by using synthetic wastewater and paper wastewater. PFSSa exhibits excellent coagulation performance in comparison with PFSSo and polymeric ferric sulphate for turbidity removal. PFSSo have better ratio COD removal than PFSSa for paper wastewater treatment. It is evident that methods of production play a significant role in the structure and property of polyferric silicate sulphate coagulants.