Photocatalytic treatment in the presence of aqueous TiO2 suspensions was applied to an aqueous percolate containing various hydrophilic aromatic pollutants, in particular naphthalene sulfonates. A preliminary feasibility study was accomplished on standards of pure compounds, for which a degradation rate trend inversely proportional to the sulfonation degree was found, demonstrating the important role played by the substrate adsorption on semiconductor particles. The evolution of primary processes, the abatement of TOC and the release of sulfate were monitored. Further experiments performed on samples of percolates taken from an abandoned industrial site demonstrated the suitability of photocatalysis for the effective destruction and mineralization of the investigated contaminants in these complex matrices after a few hours irradiation.