PESTAB. The effect of molecular structure was studied on the adsorption of some selected low molecular weight aromatic pollutants from aqueous solution. Sorption was monitored by gas-liquid chromatography (GLC) with a flame ionization detector system using the direct injection of aqueous solutions. Compounds studied included phenol, aniline, benzyl alcohol, benzaldehyde, nitrobenzene, o-nitrophenol, o-cresol, m-cresol, p-cresol, 2-chlorophenol, 4-chlorophenol, o-methoxyphenol, 2-naphthol, o-toluidine, p-toluidine, o-anisidine, m-anisidine, p-anisidine, anisaldehyde, salicylaldehyde, vanillin, pyridine, 2-methylpyridine, quinaldine, pyrrole, and indole. Some of these compounds are important pesticide breakdown products. Equilibrium data for the adsorption of individual compounds correlated with both the Langmuir and Freundlich equations. There was a general tendency of increase in adsorption capacity with increase in molecular weight. The carbon capacity for the adsorption of the polycyclic compounds was higher than that for the corresponding monocyclic compounds. No general tendency of increase in adsorption with increase in solubility was noted. If the dipole moment can be used to measure the polarity of a compound, then no correlation was noted between polarity and the carbon capacity for the adsorption of the compounds studied. Adverse effect of the OH, CH2OH, and NH2 groups on adsorption may be attributed to the capability of these groups to form hydrogen bonds with the water, rendering the compound less adsorbable. The introduction of OCH2 groups generally had a favorable effect on carbon adsorption. The isomers did not follow any particular pattern in their adsorption.