Experiment and theory showed that SAA obeys a site-specific sorption on soil surfaces.

SAA-SOM-interaction increases by increasing polarity of SOM sorption site.

H-bonds, dispersion, and π-π-interactions were observed for SAA-SOM-interaction.

Dipole moment and atomic charges of SOM sorption sites control SAA-SOM-interaction.

The Freundlich unit capacities were estimated from the calculated binding energies.

The current SOM model is flexible to describe interactions of SOM with other pollutants.