A series of polyaluminum silicate sulfate (PASiS) with different basicities, Al/Si molar
ratios and silicic acid polymerization degrees was prepared by the copolymerization (COPOLY) and
composite polymerization (COMPOLY) techniques. The distribution of aluminum species in
PASiS, the charged characteristic of its hydrolysis products and their affecting factors were
investigated by the Al-Ferron timed complex colorimetric method and the micro-electrophoresis
method. In addition, the interaction between polysilicic acid and hydrolysis aluminum species in
PASiS was discussed. The experimental results of water treatment show that the flocculation effect
of PASiS is better than polyaluminum chloride, polyaluminum sulfate, polyaluminum sulfate-
chloride and polyacrylamide, and PASiS (COPOLY) is better than PASiS (COMPOLY). The
flocculation properties of PASiS are related to the basicity, Al/Si molar ratio and polymerization
degree. The adsorbing-bridging and entrapping-settling are the principal mechanisms of PASiS
functioning.