The Research On Preparation And Application Of A Silicon-Based Coagulant

Through analyzing the development situation domestically and abroad of flocculants, we have prepared the inorganic polymer flocculant-poly silicate zinc sulfate containing boron (PSZB), on the basis of preparing the polysilicic acid, which performance is good and no secondary pollution.First, we studied the preparation of poly acid through single factor experiments, Results showed that:activation pH 4.5, concentration of sodium silicate 0.3-0.6 mol/L, experiment action temperature 20-30℃. By orthogonal test to determine the best preparation process:(1) the molar concentration of sodium silicate 0.3 mol/L; (2) activation time 90min; (3) Zn/SiO2 molar ratio of 2.0; (4) B/SiO2 molar ratio of 0.3.The study of flocculant performance showed that the flocculant has good stability and its performance was also good after 60 d. it had less dosage, a wide range of pH and temperature. In wastewater treatment, the flocculant body was close-grained and settlemen is fast.IR analysis showed that PSZB was not the simple blends with several substances in polymerization process, its structure had changed. Silicate, poly-silk acid, zinc hydroxyl and boric acid composition existed interaction; SEM analysis showed that the morphology of PSZB flocculant was aquatic thin strips, totally different poly-silk acid, which was spherical or elliptic, it had a special web-like structure, high spicific surface characteristic; size with larger molecular size test showed that the flocculant flocculation performance was better, it can fully exert absorbing and bridging function; flocculants had a positive potential, so it can fully exert neutralizing action to the colloids in the water. Results showed that flocculation properties was good.