Flock Growth Kinetics for Flocculation in an Agitated Tank

Abstract

Flock growth kinetics was investigated in baffled tank agitated by a Rushton turbine at mixing intensity 40 W/m³ and kaolin concentration 0.44 g/l. The tests were carried out with a model wastewater (a suspension of tap water and kaolin). The model wastewater was flocculated with organic Sokoflok 56 A flocculant (solution 0.1 % wt.). The flock size and flock shape were investigated by image analysis. A simple semiempirical generalized correlation for flock growth kinetics was proposed, and was used for data treatment. The flock shape was characterized by fractal dimension D_f2. Using the statistical hypothesis test, the fractal dimension was found to be independent of flocculation time, and the value D_f2 = 1.442 ± 0.125 was determined as the average value for the given conditions.