Manganese dioxide nanoparticles decorated with chitosan for effective removal of lead and lanthanum ions from water by microwave sorption technique

[Display omitted] •Preparation of MnO2-F-Chitosan nanocomposite via formaldehyde cross-linkage.•Removal of lead and Lanthanum ions from water.•The surface area of MnO2-F-Chitosan nanocomposite using the BET method 49.17 m2. g−1.•Maximum capacity of Pb(II) is 1350 µmol g−1 and La (III) as 1100 µmol g−1.•Removal of lead and Lanthanum ions from real water and wastewater samples was between 95.6–96.4% and 91.2–92.3%, respectively. In this work, a novel sorbent has assembled and explored to remove lead and lanthanum ions from water using formaldehyde as a cross-linkage between manganese dioxide chitosan for the formation of MnO2-F-Chitosan nanocomposite. Microwave adsorption technique used because of its high efficiency and rapidness. MnO2-F-Chitosan nanocomposite has a particle size 19–25 nm, and surface area using BET is 49.17 m2.g−1. The microwave sorption technique was established by monitoring the maximum capacity of Pb(II) as 1350 µmol g−1 at pH 6.0 and La (III) as 1100 µmol g−1 at pH 7. The microwave sorption was studied using the four isotherm models Langmuir, Freundlich, Temkin, and D-R models, respectively. The most suitable adsorption model is the Temkin adsorption isotherm model via uniform distribution of binding energies. Adsorption of lead and lanthanum ions is spontaneous, endothermic and ordered reactions. The lead and lanthanum ions removal from real water/wastewater samples was 95.6–96.4% and 91.2–92.3%.