Mechanism of cadmium binding on the cell wall of an acidophilic bacterium

► Acidiphilium symbioticum H8 can act as a good biosorbent for cadmium ions. ► 248.62 mg of cadmium was adsorbed per gram biomass at pH 6.0. ► The process can be well explained by Langmuir-Freundlich dual isotherm model. ► Anionic functional groups in the cell envelop are capable of binding the Cd ion. ► Cadmium binding occurs through electrostatic reaction and complex formation.