Potentiometric Titration and Out-Of-Equilibrium pH Response of the Biotite‑Water System

Minerals in soils contribute significantly to the capacity of soils to buffer pH disturbance. In this paper, we present the pH buffering capacity of a common soil phyllosilicate mineral, biotite. We performed equilibrium potentiometric titrations and we also monitored the pH response kinetics of the mineral-water system in order to develop an out-of-equilibrium model able to capture the interactions between minerals and the surrounding aqueous fluid. During titrations, after each addition of titrant solution from pH 11 to ca. 3, the pH response patterns were monitored over time until reaching ...