Study on the flocculation condition of Poly-Silicate-Aluminum-Ferric (PSiAF) coagulant prepared with coal gangue as raw material

Si, Al, Fe were leached from coal gangue to prepare Poly-silicate-aluminum-ferric (PSiAF) coagulant. The optimal dosage and the most adaptive pH value was explored when PSAF was used to treat simulated wastewater, simulated dyeing wastewater and domestic sewage respectively. The flocculation conditions of PSiAF were investigated with the removal efficiency of turbidity, COD_Cr or chrominance as the inspecting parameters. The experiment results show that, when PSiAF was usede to treat the three kinds of water sample, the optimal dosage is 1.2ml/L, and the most adaptive pH is 8 for simulation wastewater, under this condition, the turbidity removal ratio was 76.04%, the COD_Cr removal ratio was 58.33%. There is no decolorization effect for simulation dyeing wastewater, and PSiAF is not suitable for simulation dyeing wastewater. the optimal dosage is 8.0ml/L, and the most adaptive pH is 6 for domestic sewage, under this condition, the turbidity removal ratio was 67.25.04%, the COD_Cr removal ratio was 46.15%. (paper)