Synthesis of starch-based flocculant by multi-component grafting copolymerization and its application in oily wastewater treatment

The grafting copolymerization of methacryloxyethyl trimethyl ammonium chloride (DMC), acrylamide (AM) and polyaluminum chloride (PAC) on starch was initiated by KMnO4, HIO4 and H2SO4 composite system. The modification of starch was combined its best attributes with those of inorganic and organic polymers and therefore enhanced the flocculation effect when it was used as flocculants by increasing the charge neutralization, adsorption bridging and aggregation ability. The main influence factors on oil removal ratio were investigated through orthogonal experimental design, and the optimal preparation conditions were obtained. The grafted copolymer was characterized through a series of physicochemical techniques (i.e., SEC-MALS, C-13 MAS NMR, Al-27 NMR, FTIR, SEM, and TGA and XRD), which indicated the PAC, PAM and PDMC were successfully grafted on the starch.