Adsorption kinetics and isotherm of vanadium with melamine.

Melamine, possessing three free amino groups and three aromatic nitrogen atoms in its molecule, has great potential as an adsorbent for metal ions. We investigated three impact factors of the adsorption process: the initial pH of the vanadium solution, contact time and reaction temperature. The adsorption kinetics could be accurately described by the pseudo-second-order kinetic model. Langmuir and Freundlich models fitted well with the experimental equilibrium data, and the maximal adsorption capacity was found to be 1,428.57 mg vanadium/g melamine, and the Freundlich model showed the adsorption is privilege type.