Removal of dissolved organic matter in road runoff with sludge-based filters from the drinking water treatment plant

ABSTRACT Road runoff underwent treatment using a filter filled with sludge from drinking water treatment plants to assess its capacity for removing dissolved organic matter (DOM). This evaluation utilized resin fractionation, gel permeation chromatography, three-dimensional excitation–emission matrix fluorescence spectroscopy, and UV–Visible spectroscopy. The filter demonstrated enhanced efficiency in removing dissolved organic carbon, achieving removal rates between 70 and 80%. It effectively targeted macromolecular DOM components present in road runoff, with hydrophobic organic compounds showing higher removal rates than hydrophilic ones. Additionally, acidic and neutral organic substances were preferentially removed over basic organic compounds. Fluorescent substances identified in road runoff DOM included fulvic acid-like, humic acids, and protein-like substances, all of which exhibited significantly reduced intensities in fluorescence peaks after filtration. Furthermore, filtration led to a decrease in the aromatization and humification of runoff DOM due to the effective removal of aromatic compounds and macromolecular structural components.