Abstract
The coagulation characteristics of four kinds of suspension, such as Chlorella sp., Dictyosphaerium sp., Microcystis viridis and Kaoline, was discussed by the results of Jar test and photograph of Scanning Electron Microscope (SEM) and Energy Dispersive System (EDS). Although the turbidity of Dictyosphaerium sp. is the highest of the four kinds of suspension at the optimum Alum dosage, its zeta potential is -35mV and the smallest of the four kinds of suspension. From the photograph of SEM and the analysis of EDS, although Aluminium hydroxide insuffciently absorped on the surface of Chlorellasp., it stronglly absorped on that of Dictyosphaerium sp., Although the floc of Microcystis viridis and Kaoline was easy to be formed by sweep flocculation, the floc of Chlorella sp. and Dictyosphaerium sp. was easy to be formed by adsorption of Aluminium hydroxide on the algae surface. Therefore, the coagulant dosage of Dictyosphaerium sp. and Chlorella sp. becomes larger than that of Kaoline.
