Thesis (Ph.D.)--Chulalongkorn University, 2007

The aims of this research are to characterize the hydrodynamics in the hydrocyclones and find out the optimum operating conditions for the hybrid process. The objective of this hybrid process is to separate the solid particle from the turbid raw water. The hydrodynamics characterization study is carried out in the hydrocyclones to investigate the velocity profiles and velocity gradients. In this study, a new, simple and effective method is developed to study the hydrodynamics for the further research. The obtained experimental results are used as the background knowledge to design and explain the found phenomena in the hybrid process. This hybrid process is the integration of the conventional coagulant, flocculation and separation process in a reactor which is an innovation for the water treatment. Many operating conditions are tested in the hydrocyclone to find out the optimum condition such as the hydrocyclone geometry, air fraction, and coagulant concentration.