Impact of diffuse layer processes on contaminant forward and back diffusion in heterogeneous sandy-clayey domains

Surface complexation reactions in sandy porous media: Effects of incomplete mixing and mass-transfer limitations in flow-through systems

“…Reactive transport in porous media is determined by the complex interplay between physical mass transfer processes (e.g., advection, diffusion and hydrodynamic dispersion) and biogeochemical reactions (Kitanidis, 1994;Dentzet al, 2011;Valocchi et al, 2019;Rolle and Le Borgne, 2019). In particular, mixing exerts a fundamental control on both homogenous reactions, involving aqueous solutes (Rolle et al, 2009;Haberer et al, 2011;Hochstetler et al, 2013;Rolle et al, 2013a), and heterogeneous reactions, taking place at the solid-solution interface (Berner, 1978;Casey., 1987;Murphy et al, 1989;Valocchi, 1985;De Simoni et al, 2005;Li et al, 2008;Molins et al, 2012;Salehikhoo et al, 2013;Muniruzzaman and Rolle, 2021), over a large range of spatial and temporal scales.…”

Oxidative Dissolution of Arsenic-Bearing Sulfide Minerals in Groundwater: Impact of Hydrochemical and Hydrodynamic Conditions on Arsenic Release and Surface Evolution

“…For instance, the impact of additional minerals (e.g., carbonates and pyrite) that can control the pore water pH and, thus, the oxidative dissolution of As-bearing minerals. These additional minerals can also affect the hydrochemistry by the release of dissolved species, such as high sulfate concentrations that are often observed in many natural and engineered subsurface systems. , Finally, the developed process-based model, validated with the experimental observations in the different flow-through experiments, could be extended to multidimensional systems with complex patterns of physical and/or geochemical heterogeneity. − This will represent a valuable tool to explore arsenic release and reactive mineral dissolution and transformation in different subsurface systems.…”

Impact of Variable Water Chemistry on PFOS-Goethite Interactions: Experimental Evidence and Surface Complexation Modeling

“…These findings hold particular significance when investigating the environmental fate of PFOS in sediments and aquifers rich in iron mineral surfaces. 34 Furthermore, the molecularlevel insights of this study help elucidating the key mechanisms regulating PFOS removal in natural environments characterized by strong ionic strength gradients and pH fluctuations, such as physically and chemically heterogeneous formations, 70 river estuaries and coastal aquifers affected by seawater intrusion, 71,72 contaminated sites where concentrated solutions of reactants are typically injected for in situ degradation of organic compounds, 73 as well as at mining facilities and sites 74 where fluorinated surfactants may be utilized for ore extraction purposes. 75 This study successfully advanced a combination of adsorption experiments, spectroscopic analyses, and surface complexation modeling to elucidate the binding mechanisms of PFOS to goethite.…”