An effect of surface runoff on polycyclic aromatic hydrocarbons in watersheds of ulsan, south korea

Abstract

Polycyclic aromatic hydrocarbons (PAHs) in surface runoff during rain, and in surface water before and after the rain were collected at rural, urban, and industrial areas of Ulsan, South Korea in 2016 to understand an effect of surface runoff on PAHs in the watersheds. The results showed that total PAHs in the surface water and runoff reached the highest concentration at the industrial area in summer (before rain: 361 ng/L) and early spring (after rain: 75.5 ng/L, runoff: 1,107 ng/L). The dissolved PAHs (2–4 rings) were more dominant than the particulate PAHs (5–6 rings) for the before rain samples. After the rain, the particulate contributions increased, indicating an effect of surface runoff on the aqueous PAHs. Results from the partition coefficient revealed that in regard to the runoff and water samples collected after rain, PAHs at the industrial site and in the late spring and summer were less mobility, and more adsorb onto suspended particles.