Abdel BOUGHRIET, Nicole POUMAYE, Oscar ALLAHDIN, Michel WARTEL; Kinetic and diffusional aspects of heavy metals adsorption onto zeolitized brick; Advanced Materials and Technologies Environmental Sciences; 2019:3(4): 281-297
A kinetic study of the removal of Cd2+, Co2+, Fe2+, Mn2+, Ni2+, Pb2+ and Zn2+ cations from single component solution by zeolitized brick was undertaken at 298 K under batch conditions. Kinetic data were well explained by a pseudo-second-order rate model. Correlation analysis showed that the metal affinity sequence of the activated brick followed the metal affinity order predicted by ionic potential, first hydrolysis constant, free energy of metal dehydration and Jones-Dole viscosity coefficient. Weber-Morris model had allowed to proving the involvement of two main steps (external and internal diffusion). This assumption was confirmed owing to the application of double-exponential model to our system. Crank’s and Reichenberg’s equations permitted us to calculate film diffusion and pore/surface diffusion coefficients. A new simplified method for estimating film mass transfer and surface diffusion coefficient was also used in this work and sustained predicted data by the other applied methods. To evidence competition between metallic cations for reactive brick sites and metal selectivity, kinetic studies were performed in binary and tertiary-metal systems. Lead(II) was the heavy-metal cation most strongly adsorbed, whereas nickel(II) was the least adsorbed, in a competitive situation highlighted by metal properties.