Recent studies have investigated the interactions of SAA and HCB with SOM. Ahmed et al. combined sorption experiments with allatom MD simulations to show that HCB binds more strongly to SOM than SAA, attributed to HCB's hydrophobicity and aromaticity, which agrees with the probability calculations (Figure ) and interaction energies (Figure ). In a related density functional theory (DFT) study, Ahmed et al. demonstrated that water destabilizes SAA-SOM complexes and that SAA shows a strong affinity for ionic sites, consistent with the observations of the present study.