G.B. Adebayo, H.I. Adegoke, L. Rashidi., J. Wasiu, B.O. Orimolade
University of Ilorin,
Summary:The carbon nanotubes-titanium dioxide nanocomposites prepared from coconut shell (CNTA/TiO2) and graphite (CNTg/TiO2) have been prepared through sol gel method. The nanocomposites were characterized and the batch adsorption experiment was conducted by examining the effects of the initial metal ion concentrations, pH, contact time, temperature and adsorbent dosage on Cr (VI) adsorption. The maximum adsorption of for Cr (VI) occurred at pH 8 and pH 10 of (CNTA/TiO2) and graphite (CNTg/TiO2) respectively. The adsorption kinetics was best described by the pseudo second order kinetics model. The equilibrium data best fitted the Langmuir model. The order of fitness was Langmuir>Freundlich>Temkins. The thermodynamic studies show the negative standard Gibb’s free energy change (ΔGo) values which confirmed the spontaneity of the adsorption process. With high capacity of adsorption revealed from the present research for Cr (VI) removal, the carbon nanotubes-TiO2 nanocomposites demonstrated to be effective.