Synthesis, flocculation and adsorption performance of amphoteric starch

► Amphoteric copolymer flocculant is synthesized with microwave radiation. ► Etherification occurrs on the particle surface. ► Cross-linking among the particles in amphoteric starch elongates the molecular chain. ► Flocculation characteristics mainly depend on the charge neutralization, followed by the interchain bridging. ► Adsorption capacity correlates with pH value, adsorption time and initial ion concentration.