The principles of gas-phase biofilter systems, modeling, and operations are quite different from liquid-phase biofilter systems. Because of "biofilter" terminology used in both gas and liquid-phase systems, researchers often mistakenly use gas-phase models in liquid-phase applications for the analysis of data and determining kinetic parameters. For example, recent studies show a well-known gas-phase biofilter model, known as Ottengraf-Van Den Oever zero-order diffusion-limited model, is applied for analysis of experimental data from an aqueous biofilter system which is used for the removal of toxic divalent copper [Cu(II)] and chromium (VI). The objective of this research is to present the limitations and principles of gas-phase biofilter models and to highlight the incorrect use of gas-phase biofilter models in liquid-phase systems that can lead to erroneous results. The outcome of this work will facilitate scientists and engineers in distinguishing two different systems and selecting a more suitable biofilter model for the analysis of experimental data in determining kinetic parameters.
Keywords: Cr (VI); Cu (II); Ottengraf–Van Den Oever diffusion-limited model; aqueous systems; biofilter model; chromium; copper; gas-phase biofilter; kinetic parameters; liquid-phase biofilter; toxic metals.