On the other hand, anionic pentavalent arsenicals show a high stabilization via polarization effects, with a relative EPOL contribution of 43% (Fig. ). According to their speciation, aMMA V and aDMA V are found with a negative charge at the removal pH due to their acid-base equilibria (Eq. 3-5); the negative charge of adsorbates induces strong polarization in the phosphorene oxide nanoadsorbents, leading to the on-fragment relaxation of each species to the presence of their nuclei and electrons. The on-fragment relaxation comes in the form of electron density rearrangements that create favorably aligned induced multipole moments, favoring the energy lowering. Consequently, the anionic charge of pentavalent species ensures higher adsorption energies and lower mobility compared to the uptake of neutral pollutants. Note that part of the polarization stabilization also comes from the covalent O-P bonding, but charge transfer effects are almost balanced with electrostatics effects in these complexes (combined ECT+EELEC contribution of 53-54%). Finally, dispersion forces show a negligible contribution to the stability of anionic/neutral pentavalent methylarsenicals (EDISP, up to 7%).