مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

In this study, colloidal silica model was aggregated by ferric chloride in presence of increased phosphate concentrations. Coagulation flocculation was realized by using a mixing reactor of lL. Destabilization mechanisms were studied by coupling the jar-test experiments with Atomic Absorption Spectroscopy analysis, Zeta Potential, transmission Electron Microscope and Laser Diffraction. Increased concentration of phosphate in the colloidal suspensions was found to be followed by an increase of the optimal coagulant concentration (OCC) and an increase in settled volume. Results ofAAS revealed that OCC is reached after a complete removal of phosphate from supernatant. Hence, hydrolyzed Iron III species are complexed preferably with phosphate ligands. Size distribution of aggregates indicated that phosphate in suspensions enhances the formation of aggregates with greater size. Beyond a critical concentration of phosphate, aggregate size decreases in parallel with the settled volume