Preparation and Performance of a Novel Inorganic Polymer Flocculant-Polysilicic Acid Ferrir and Zinc Sulfate Containing Boron

A new type of inorganic polymer flocculant, polysilicate boron ferric and zinc sulfate (PSBFZ), was prepared through reaction of sodium silicate, ferric sulfate, zinc sulfate and sodium tetraborate. The Optimal synthesis process and material mixture ratio were determined by Orthogonal and single-factor experiments. Experimental results demonstrated that the optimal preparation conditions were as follows: the concentration of Na2SiO3 was 0.5mol/L ; polymerization time was 120 min; activation pH value was 2.2; aging time was 48h; n(B)/n(Si), n(Fe)/n(Si), n(Zn)/n(Si) were 0.4, 1.5, 1.5, respectively. PSBFZ had a favorable stability that it will not gel within 4 months. In addition, PSBFZ , an more excellent flocculant than PAC or PFS, exhibited a better flocculation performance that 93.4% of chromaticity and 97.2% of turbidity could be removed from printing and dying wastewater.