The application of the packed bed reactor theory to Pb and Zn uptake from the binary solution onto the fixed bed of natural zeolite

• Application of the packed bed reactor theory (PBRT).
• Derivation of breakthrough curves, definition of the inflection as a critical area.
• Application of the ADR model, calculation of tmin, kf and DL parameters.
• Construction of the modeled curves and comparison with experimental data.

The packed bed reactor theory was applied to define the mass transfer mechanism between the liquid and the solid phase for Pb and Zn removal from binary solutions at different flow rates. The typical breakthrough curves were converted into the derived form, from whose maximum the inflection point was successfully determined. Up to the inflection point, the mass transfer through the liquid phase is the slowest process and controls the overall rate due to available exchangeable sites in zeolite particles. The quantity of (Pb + Zn) ions increases linearly from the beginning of the experiment to the inflection point. After inflection, the mass transfer through the boundary layer of the zeolite particle becomes more significant and controls the overall process rate. The Advection–Dispersion-Reaction (ADR) model has been applied, and parameters DL, tmin and kf have been calculated for different experimental conditions. It has been found that parameter tmin corresponds to experimentally determined inflection time on the breakthrough curve. This confirms the successful application of the ADR model in definition of mass transfer mechanism in the packed bed.

The concentration profile in the column filled with a fixed zeolite bed.Figure optionsDownload as PowerPoint slide