Prediction of heavy metal biosorption mechanism through studying isotherm kinetic equations

Abstract

AbstractThe kinetic constants for free and immobilized cells were determined by measuring reaction rates at different metal concentrations at the optimum reaction conditions. (Kmax and Vmax) were calculated from the slope and intercept of the straight lines. The pseudo-second-order rate constants are derived based on the sorption capacity of the solid phase, where K2 is the rate constant for the pseudo-second-order model. Determined experimentally by plotting t/q against t. The mean free vitality of adsorption (E) was figured as 2.62 kJ mol−1 and the extent of E communicated gives data on the adsorption mechanism. An E value ranging from 1 to 8 indicates physisorption and 8–16 kJ mol−1 predicts ion exchange. Thus, the evaluated value of 2.62 kJ mol−1 predicts the phenomenon of physisorption, which suggests that metal ions were favorably adsorbed by this biosorbent in a multi-layer fashion. The overall result suggested that 98.2% of U (VI) by biosorption of U in the mechanism of adsorption will include chemisorption mechanistic pathway: Langmuir, Freundlich, equations and the values of Kf 5.791 where KL 3.9 were determined from the linear plot of log qe vs. log Ce at 30 °C, indicating that metal ions were favorably adsorbed by this biosorbent in a multi-layer fashion and instrumentation of beads characterizing novel Binding sites using FTIR & SEM beside change in peaks position which assigned for its groups confirm biosorption of metal.