| Recent researches have proved that the Al13 which is considered as the most efficient fraction of PAC will transform into Al30 when PAC is aged at a high temperature.The morphology of both the original and aged PAC samples was analyzed by Al-Ferron method. The absorbance at 370 nm versus time curve of original sample turns flat after 120 mins' reaction while the aged sample continues to increase after 120 mins' reaction. The reaction curve was nonlinearly fitted using the Origin software to study the reaction kinetics. Conclusions showed that the longer the aging time was, the less concentration and complex the fraction of Alb1 became and the fraction of Alb2 had the opposite trend. The solution was stable after 12h aging time.When both the aged sample and original sample of PAC were used to treat wastewater, the aged sample had a better turbidity removal efficiency compared to the original sample, especially to water with low temperature and low turbidity. So it draws the conclusion that aging can increase the ability of PAC to removal waste from water. This provides a new way to develop high efficient coagulant.At the same time, the best aging condition is studied according to the turbidity removal efficiency of different samples. The optimal aging condition is aged at 90℃for 12 h with stirring. The turbidity removal efficiency results show that aging time and temperature are two negative correlation conditions, if the aging temperature is increased, the aging time should be decreased at the same time. At the other hand, stirring was essential, cause stirring can promote the formation of Al monomers, then the newly formed A1 monomers-will act as a bridge for the formation of Al30.As aging can promote Al13 turns into Al30, and also improve the turbidity removal efficiency, it provides a new way to find out a better flocculent.
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