Utilization of nano-cryptomelane for the removal of cobalt, cesium and lead ions from multicomponent system: Kinetic and equilibrium studies.

•Nano-cryptomelane was prepared by oxidation method.•Nano-cryptomelane was characterized by HRTEM, FT-IR, TGA&DTA and BET.•The diameter distribution of nano-cryptomelane was found to be 4–6 nm.•Sorption of Co2+, Cs+ and Pb2+ from multicomponent system was studied.•Sorption capacity is 4.46, 3.33 and 3.05 mmol/g for Pb2+, Cs+ and Co2+, respectively.