Comparative study of metal adsorption interaction properties of benzene di-, tri-, and tetra- carboxylate metal organic frameworks

E. Dixon Dikio, N. Ayawei, D. Wankasi
Niger Delta University,
Nigeria

Keywords: MOF, lead ion, benzene carboxylic acids, copper

Summary:

Novel metal organic frameworks of copper with benzene-1,4-dicarboxylic acid, benzene-1,3,5-tricarboxylic acid and benzene-1,2,4,5-tetracarboxylic acid were synthesized, characterized and their adsorption interactions towards lead ion in aqueous solution studied. Batch experiments were employed at various contact time, pHs, concentrations and temperatures. The removal of lead ions was enhanced at pH 2 from 2.85mg/g to 27.25mg/g within the equilibrium time (30 min). The kinetic study showed that lead ion adsorption capacity of these metal organic frameworks of followed the pseudo second order, although the fractal pseudo second order also described the reaction sufficiently. A maximum capacity of 58.mg/g was obtained from the experimental data. The Freundlich and Langmuir isotherms are presented in this comparative study. The thermodynamic parameter analysis of the adsorption of lead ion on these MOFs indicated the process was spontaneous and exothermic.