Among them, flocculation is a high efficiency and simple execution chemical method, to select of a suitable flocculant is the key factor for a better flocculation efficiency . cationic polyacrylamides (CPAMs), a water-soluble linear polyelectrolyte with high molecular weight and positive charge density, is widely employed as chemical conditioners in sludge flocculation pretreatment before mechanical dewatering due to the advantages of low costs, satisfactory efficiency, and easy operation
ding fr ee r adical copol ymer iza tion method , cationic modif ica-tion of PAM methods and cationic grafting polymerization methods11,12. The modif ica tion methods could obtain r ela tively high molecular weight of cationic polyacrylamide polymer, but which had poor stability, short duration and high price13.