Novel Oscillatory Flocculation System for Colloids Removal from Water

According to a novel “grouping” methodology, applying sinusoidal oscillatory linear mixing enhances the aggregation of colloid particles in water. To verify this concept, an oscillatory mixing system was constructed. The methodology was tested on simulative synthetic surface water containing fine kaolin clay, with alum as a coagulant. The system was examined under various operational and configurational conditions. Process efficiency was assessed by turbidity removal. The hydrodynamic properties of the created oscillatory waves, flow patterns, and obtained vortices were evaluated. At the optimal conditions, the oscillatory system created the theoretically predicted “moon shape” sedimentation pattern, removing turbidity at a higher rate than conventional coagulation. Both the configurational and operational conditions had considerable effects on aggregate size thus changing the turbidity removal rate. The methodology appeared to be efficient, as significant sedimentation had already occurred during the oscillatory mixing. Hence, the method has a high potential to contribute to the coagulation–flocculation process.