MODELLING OF RUNOFF BEHAVIOUR OF PARTICLE-BOUND POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) FROM ROADS AND ROOFS

Sampling of runoff water taken at an urban storm sewer system in a residential area of Japan and chemical analysis of fine and coarse PAHs particles (smaller and larger than 45 microns) to validate a runoff model in which roads and roofs were considered separately. The model could not explain the PAH profiles of runoff particles and the profiles of 12 PAH compounds were almost constant and more similar to those of road dust than roof dust. An improved model is developed which explains the runoff behaviour by considering 2 types of road dusts with different mobility. The model is not valid during and after heavy rainfalls (more than 10 mm/h).