ABSTRACT
The kinetic and isotherm data can be fitted by either linear curve fitting or nonlinear curve fitting. The kinetic and isotherm model can be estimated by the coefficient-of-determination values, chi-square values, and closeness of experimental and theoretical data. The concentration also alters the kinetics of the adsorption process. The rate of adsorption of uranyl ion on nano-magnesium hydroxide increased with an increase in the concentration. Similarly, an increase in the concentration of manganese led to a decline in the pseudo-second-order rate constant. The decrease in the adsorption rate constant with an increase in the concentration is attributed to increased occupation of the active sites on the surface of the adsorbent by adsorbates. An adsorption isotherm is a quantitative method to characterize adsorbate equilibrium between the aqueous and solid phases at a constant ambient temperature. Each isotherm model has its own assumption. The Langmuir isotherm is based on the assumption that only one site is available for each adsorbate.
