Floc character : measurement and role in optimum dosing

This paper describes how optimum coagulation conditions can be identified for both coloured waters and turbid suspensions in terms of floc properties: notable size, effective density and strength. There was a general correspondence between the optimal coagulation conditions identified in the jar test with optimal characteristics of the floc. Particular attention is paid to the techniques for discerning the floc-size density distribution and the methodology for determining floc strength. Strength measurements depend on the accurate measurement of the rate of energy dissipation, a feature which is described for oscillatory mixers used in this study.