Efficient decontamination of heavy metals from aqueous solution using pullulan/polydopamine hydrogels

• A novel pullulan/polydopamine (Pu/PDA) biosorbent was designed for removal of Cu2+. • The maximum sorption capacity of Pu/PDA was 100.9 mg/g. • Electrostatic interactions and hydrogen bonds facilitated the Cu2+ removal. • The adsorption matched well with the Freundlich isotherm model.