抄録
The water quality of roof runoff was investigated. The runoff characteristics of mutagenicity and polycyclic aromatic hydrocarbons (PAHs) with two to five rings were elucidated. The following results were obtained: (1) The runoff of roof deposits depended on their state and rain conditions. (2) The changes in concentration of particulate PAHs corresponded with those of suspended solids, whereas the concentrations of the soluble PAHs decreased with time because of the decrease in the rainwater concentration and the amount of detentions. (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) The partition to particulate phase was observed to be ten- to a thousand-times larger than that in the equilibrium state. (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. (6) The PAHs concentrations and mutagenicities showed a tendency to change similarly in most cases. This suggested that one of the main causes for mutagenicities was a combined effect of PAHs and their derivatives.
