Abstract
The quality of roof runoff water from an inclined tiled roof was investigated during two rain events. The runoff characteristics of polycyclic aromatic hydrocarbons (PAHs) with two to five rings were elucidated. The following results were obtained: (1) The runoff of roof sediments depended on their state and rain conditions. (2) The concentration of particulate PAHs increased with an increase in SS concentration, whereas the concentration of soluble PAHs decreased with time, which is due probably to a gradual decrease in both PAH concentration in the rain and the amount of PAHs remaining in the roof sediments over time. (3) When the molecular weight of PAH was higher, the ratio of soluble PAH to total PAH became smaller because of the lower water solubility. (4) PAH partition to particulate phase was 10 to 1000 times greater compared to the experimental equilibrium equation. (5) The major components of the particulate PAHs were four- to five-ring PAHs, while those of soluble PAHs were two- to three-ring PAHs.
