Oladoja N.A., Ololade I.A., Olatujoye V.O., Akinnifesi T.A.
Department of Chemistry, Adekunle Ajasin University, Akungba Akoko, Nigeria
Oladoja, N.A., Department of Chemistry, Adekunle Ajasin University, Akungba Akoko, Nigeria; Ololade, I.A., Department of Chemistry, Adekunle Ajasin University, Akungba Akoko, Nigeria; Olatujoye, V.O., Department of Chemistry, Adekunle Ajasin University, Akungba Akoko, Nigeria; Akinnifesi, T.A., Department of Chemistry, Adekunle Ajasin University, Akungba Akoko, Nigeria
The shell of a gastropod (Achatina Achatina) was used as a precursor for the synthesis of nano calcium oxide (NC) via the sol-gel technique. The NC was characterized and the performance evaluation in chromium (Cr) (VI) abstraction was assessed in a fixed bed. The operating characteristics of the NC-Cr (VI) system were analysed with the mass transfer model and the mass transfer zone parameters were found to fluctuate with changes in the initial Cr (VI) concentration. The evaluation of the equilibrium data, generated from the fixed bed studies, showed that the sorption of Cr (VI) occurred via monolayer adsorption mechanism, and the monolayer sorption capacity was 833.33 mg/g. Different kinetic models (i.e., Adams-Bohart, Thomas,Wolborska, and Yoon-Nelson models) were applied to experimental data to predict the breakthrough curves and to determine the parameters of the column useful for process design. The kinetic analysis showed that the Yoon and Nelson model had the best fitting of the experimental data. The data obtained for Cr (VI) removal, when the NC bed height was optimized, were well described by bed depth service time model. © Springer Science+Business Media B.V. 2011.
Bed depth service time model; Bed height; Break through curve; Equilibrium data; Experimental data; Fixed bed; Gastropod shell; Hexavalent chromium; Kinetic analysis; Kinetic models; Mass transfer models; Monolayer adsorption mechanism; Operating characteristics; Performance evaluation; Sol-gel technique; Sorption capacities; Transfer zones; Abstracting; Chromium; Lime; Mass transfer; Sol-gels; Sorption; Chromium compounds; calcium oxide; chromium; metal nanoparticle; adsorption; bioreactor; breakthrough curve; chromium; gastropod; mass transfer; nanotechnology; performance assessment; reaction kinetics; shell; adsorption kinetics; animal shell; article; bed depth; bed height; chemical analysis; controlled study; environmental parameters; evaluation; fixed bed reactor; gastropod; heavy metal removal; mass transfer; mass transfer zone; monolayer culture; nonhuman; process design; process model; process optimization; receiver operating characteristic; water supply; Achatina achatina; Gastropoda