Molecular Dynamics Simulation Prediction of the Partitioning Constants (, , ) of 82 Legacy and Emerging Organic Contaminants at the Water-Air Interface.

The tendency of organic contaminants (OCs) to partition between different phases is a key set of properties that underlie their human and ecological health impacts and the success of remediation efforts. A significant challenge associated with these efforts is the need for accurate partitioning data for an ever-expanding list of OCs and breakdown products. All-atom molecular dynamics (MD) simulations have the potential to help generate these data, but existing studies have applied these techniques only to a limited variety of OCs.

Molecular dynamics simulation of the adsorption of per- and polyfluoroalkyl substances (PFASs) on smectite clay.

Molecular dynamics (MD) simulations are used to predict the partitioning of per- and polyfluoroalkyl substances (PFASs) to smectite clay, a high surface area adsorbent ubiquitous in temperate soils. Simulated systems model a stack of flexible smectite lamellae in contact with a bulk aqueous reservoir containing PFAS molecules. Perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) are simulated at various aqueous chemistry conditions to examine the effect of PFAS size, salinity, and coordinating cation type (K, Na, and Ca) on adsorption.