Preparation and Property of Nano-polyaluminum Ferric Silicate Flocculant

A new type of flocculant nano-polyaluminum ferric silicate (Nano-PAFSI) was prepared by ultrasonic waves using sodium silicate, iron trichloride and aluminium chloride. The factors influencing the removal efficiency for the wastewater, such as coagulant dosage,pH and stirring intensity were investigated and the coagulating mechanism was also analyzed. The results of the coagulation-flocculation showed that the performance of nano-polyaluminum ferric silicate was much better than that of polyaluminum ferric silicate. The removal ratio of turbidity was 97.8% , the removal ratio of chromaticity was 94.6% and the removal ratio of chemical oxygen demand(CODCr) was 55.1%.