Adsorption of benzene, aniline and benzoic acid in water by fullerene ($$\hbox {C}_{60})$$ and fullerene nanowhiskers

Most aromatic hydrocarbons and their derivatives are harmful organic molecules. Despite their low solubility, trace amounts of aromatic hydrocarbons can be present in water. If water is contaminated by aromatic hydrocarbons, it is very difficult to remove these from water. Through contaminated water, these compounds can exert deleterious effects in plants and animals, as well as on human health. Fullerenes and their derivatives typically exhibit hydrophobic characteristics, and are therefore considered as good adsorbents for the removal of aromatic hydrocarbons. Herein, the removal of benzene, aniline and benzoic acid by fullerene and fullerene nanowhiskers was evaluated. While benzene was removed satisfactorily from water, aniline and benzoic acid were not, owing to the presence of ionized functional groups. However, adjustment of the solution pH to values where the functional groups of aniline or benzoic acid do not have any charge, resulted in an increase in their adsorption. High pH values were found to have a positive effect on the removal of aniline, while low pH values were beneficial for the adsorption of benzoic acid. Fullerenes and fullerene nanowhiskers were thus found to be promising adsorbents for the removal of aromatic hydrocarbons.