Particle speciation analysis of inorganic polymer flocculants: an examination by photon correlation spectroscopy

The particle size distribution for two typical kinds of inorganic polymer flocculants is characterized comparatively by using photon correlation spectroscopy (PCS). The experimental results indicate that there exists large difference in particle speciation distribution between PFCl and PACl prepared under similar conditions. The particle size of PFCl samples range in a narrow distribution. Their mean effective hydrodynamic diameters calculated by translational diffusion coefficient are between 5 and 11 nm. For PACl samples at certain basicity, no visible particle species can be determined. At high basicity, both laboratory prepared and commercial products, show a bimodal distribution: one in 2–5 nm and the other ranges in several decades of nm with wide distribution. The latter may be colloidal aluminum hydroxide and also some aggregates of polymers.