Kinetic analysis of arsenic and iron oxidation by Acidianus brierleyi for biogenic scorodite formation

The contamination of arsenic from natural processes and anthropogenic activities represents a global concern; therefore, the study of arsenic transformation is an important research topic. This work proposes a simple phenomenological kinetic model that describes the removal of arsenic by means of the crystallisation of scorodite using an extremophile archaeon (Acidianus brierleyi), considering the chemical reaction network to propose the corresponding mass balances. To determine the satisfactory predictive capacitive of the kinetic model structure and the usefulness of the parametric identification, two additional experimental campaigns of the formation of bioscorodite performed in shaking flasks with initial As(III) concentrations of (mM): 4.3–13 and Fe(II) concentrations of (mM): 6–18 were tested. Furthermore, a parametric sensitivity analysis was performed to determine points of special importance related to analytical techniques, to improve the precision of the results that can be used for further in silico studies. Statistical results suggest that the proposed model showed an acceptable fit for all tested conditions.