Sorption of Pb2+ on mercapto functionalized sepiolite

► The ΔH0 and ΔS0 of the reaction were 33.637 kJ mol−1 and 202.697 J mol−1 K−1. ► Freundlich isotherm and second order kinetics could fit sorption processes well. ► The sorption mechanisms were chemical adsorption and physical adsorption. ► The samples were characterized by XRD, FT-IR, 29Si and 13C CP/MAS NMR and XPS.