Preparation and Performance of Polysilicate Aluminum Ferric-Chitosan

A new-type composite flocculant, Polysilicate Aluminum Ferric-Chitosan (PSAF-CTS), was prepared using polysilicate aluminum ferric (PSAF) and Chitosan(CTS). The performance of PSAF-CTS was analyzed by testing turbidity and chrominance of papermaking wastewater, as well as removal efficiency of Cu²⁺, Ni²⁺, Zn²⁺, Cd²⁺, Cr⁶⁺ of heavy-metal wastewater. The orthogonal experiments showed that the optimal preparation conditions were pH 1.6, material ratio 1:1, reaction temperature 70°C, and reaction time 24 h. For papermaking wastewater, the test of turbidity and chrominance indicated that the highest removal efficiencies were 99.5% and 92.3%, respectively, For different heavy-metal ions, the best removal efficiency of Cr⁶⁺ and Ni²⁺ were 100% and 82.2%, respectively.