Nonlinear kinetics isotherms and thermodynamic approach in the carcinogenic ions elimination by Mn2.7Al0.3O4 sorbent

Alundum was framed into hausmannite to acquire bimetallic nano Mn _2.7 Al _0.3 O ₄ sorbent to explore the synergistic effect on the adsorption of carcinogenic ions. PXRD, FESEM-EDX, FTIR, and BET were used for the characterization of Mn _2.7 Al _0.3 O ₄ . The diffractogram pattern disclosed that the tetragonal structure corresponds to JCPDS No 24–0734 with the platelet shape found in FESEM images. The BET studies of adsorbent exhibited Type-IV isotherm with H ₃ loop having a mesoporous structure of 1.968 m ² g ^− 1 surface area and 35.8 nm average pore diameter. The uptake mechanism of the carcinogenic ions on the Mn _2.7 Al _0.3 O ₄ nano adsorbent surface pronounced that adsorption followed pseudo-second-order kinetics. The adsorption capacity for Cd(II) ions was 174.6 mgg ^− 1 and 75.39 mgg ^− 1 for Pb(II) ions adsorption from the Langmuir and the Sips models, which were envisaged by R ² , RSS, ARE, and Chi ² of the statistical functions, also nearer to experimental results. The thermodynamic investigations announced that Cd (II) and Pb (II) ion adsorption is a spontaneous and exothermic process with a free energy change of -29.05 kJmol ^− 1 and − 25.8 kJmol ^− 1 , respectively. High adsorption capacity and easy recovery of adsorbent implicated to use for removal of carcinogenic ions in any aqueous stream.