In order to investigate the characteristics of pure Nano-Al, Nano-Al was separated and purified from a series of poly-aluminum chloride (PAC) solutions which had the same Al percentage but different total Al concentrations, by using column chromatography, ethanol-acetone resolving and SO/Ba displacement. The Al species yield was characterized by Al-ferron timed complexation spectrophotometry and Al-NMR (nuclear magnetic resonance). The coagulation efficiency of Nano-Al, PAC and AlCl in synthetic water was also investigated by Jar tests. The dynamic process and aggregation state of kaolin suspensions coagulating with Nano-Al, PAC and AlCl were similarly investigated using a photometric dispersion analyzer 2000 (PDA2000). The experimental results indicated that the ethanol-acetone resolving method was simple and could separate the PAC solution at different concentrations, while column chromatography could separate PAC solutions at low concentrations. The SO/Ba displacement method could separate PAC solutions at high concentrations. However, extra inorganic cation and anion could be added in the solution during separation. The coagulation efficiency and dynamic experimental results showed that Nano-Al with high positive-charged species was effective in removing turbidity and color. The dynamic process results showed that Nano-Al also had the best recovery capability after shearing compared with PAC and AlCl because the Nano-Al conformation is more effective in charge neutralization.