AWWA ACE95051

Very little research has been performed involving the hydrodynamic aspects of mixing in the coagulation-flocculation process. Some researchers in environmental engineering have shown in isolated studies that both rapid and slow mixing stages are important to the coagulation-flocculation process in water treatment. Mixing in the coagulation-flocculation process can be varied in two different ways; first, by changing the mixing equipment and second, by changing the mixing pattern in time and intensity. Thus the prime objective of this study was to investigate and determine the effect of different mixing devices and patterns on the kinetics of flocculating kaolin clay suspension at both warm and cold water temperatures using ferric nitrate coagulant under a number of physico-chemical conditions. The authors describe a series of experiments and provide a detailed discussion of the procedures and results of different mixing variables being tested with different combinations of physico-chemical variables such as rapid mixing intensity, rapid mixing pattern, coagulant injection pattern, dosing solution concentration, and slow mixing intensity and pattern.