An emerging application of chitosan and chitosan/spirulina films for Pb2+ adsorption: New physicochemical insights via experimental and theoretical studies

•The adsorption mechanism of Pb2+ ion using chitosan and chitosan/spirulina was elucidated.•Pb2+ data were quantified at 25 –55 °C and pH 6 to analyze this adsorption mechanism.•A monolayer physical model was applied on lead adsorption data.•The model parameters were studied at different temperatures.