Abstract
The power plant desulfurization wastewater is studied in a city of North China. The optimal conditions for preparing polymeric polysilicate aluminium ferric sulphate (PSAFS) was explored by L9(34) Results of Orthogonal Experiment, and the effect of dosage, pH value, the settling time and sedimentation time on PSAFS for disposal was investigated as well. It was shown that the performance of PSAFS was the best, while the concentration of SiO2 was 2.5%, the value of pH was 5.5, and the molar ratio of Al/Fe/Si was 1:1:1, aging time about 4 h. Under the conditions of PSAFS dosage 6.7 g/l and wastewater pH 10, settling time of 20 min, the suspended solids, COD, sulfide, fluoride and Cl- in the desulfurization wastewater had a good removal effect. Comparing with the polyaluminium chloride (PAC) for the treatment of the desulfurization waste water, PSAFS has the advantages such as less dosage, the higher efficiency, shorter settling time and co- treatment many pollutants.
