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Density functional theory (DFT) is applied to theoretically study the capture and storage of three different nitro polycyclic aromatic hydrocarbons, 4-Nitrophenol, 2-Nitrophenol and 9-Nitroanthracene by activated carbon, with and without the presence of water. These species are pollutants derived from vehicles and industry emissions. The modeling of adsorption is carried out at the molecular level using high level density functional theory with the B3LYP-GD(BJ)/6-31+G(d,p) level of theory. The adsorption energies of polluting gases considered isolated and in a humid environment are compared to better understanding the role of water. The calculations reveal different possible pathways involving the formation of chemicals bonds between adsorbent and adsorbate on the formation of intermolecular Van der Waals interactions. The negative adsorption energy on AC for the three species is obtained when they are treated individually and in mixture with H2O. The basis-set superposition error, estimated using the counterpoise correction, varies the adsorption energies by 2 to 13%. Dispersion effects were also taken into account. The adsorption energy ranges from -10 kJ/mol to -414 kJ/mol suggesting a diversity of pathways. The resulting analysis suggests three prefered pathways for catupre. The main pathway is physical interaction due to ¿-¿ stacking. Other means are capture due to the formation of hydrogen bonds resulting from water adsorbed on the surface, and the simultaneous adsorption of pollutant and water where water can act as a link that promotes adsorption. The thermodynamic properties give a clue to the most eco-friendly approaches for molecular adsorption.