Preparation Of Polysilicate Aluminum Ferric And Application In Printing And Dyeing Wastewater Treatment

The researches related to the development of metal-polysilicate complex coaulant were reviewed. The polysilicate aluminum ferric(PSAF)was prpared by using water glass, aluminium sulphate, ferric chloride as raw materials;the viscosity as controlling parameter. Coagulation property was analyzed and discussed systematically on the turbidity removal and the decorization of dyeing wastewater containing reactive red and disperse brilliant blue dyes, which could provide the basis for PSAF's industrial production and engineering application development of being used actually.Polymerized silicic acid was prepared under acidic conditions.The processes for the praparation of polymerized silicic acid were optimized,and the viscosity was used as the key indicator of polymerization degree of polymerized silicic acid. The influences of temperature,pH value, SiO2 concentration,and different acidifiers on the viscosity were systematically investigated.PSAF with high efficiency was prapared by using self-made polymerized silicic acid,and the processes of PSAF were optimized. The (Al + Fe) / Si mole ratio, Al / Fe mole ratio, the viscosity of polymerized silicic acid,aging time, dosage, pH value on turbidity removal and dye decorization were studied.The result showed that:PSAF had excellent coagulation property on the turbidity removal; for the synthetic reactive red and disperse brilliant blue dye wastewater,the use of PSAF could achieve 88.48% and 80.48% of dye removal efficiency in appropriate conditions, respectively.PSAF were evaluated with comparation of different coagulants such as aluminum sulfate, ferric chloride, polysilicate aluminum, polysilicate ferric.The PSAF was found to be more efficient on turbidity removal and dye decorization than those coagulants.