Estimation of river discharge loadings of PAHs in a suburban river in Hiroshima Prefecture, Japan

Abstract

The PAHs loadings on river discharge was estimated based on consecutive measurements during rainfall and non-rainfall periods at a river in a suburban area in Hiroshima Prefecture, Japan. The PAH concentrations ranged from 12 to 58 ng L^-1 for dissolved PAHs, and from 8 to 105 ng L^-1 for particulate PAHs on rainy periods. In non-rainy periods, they ranged from 10 to 58 ng L^-1 for dissolved PAHs, and from 4 to 418 ng L^-1 for particulate PAHs. PAH concentrations on non-rainy periods were stable for diurnal and seasonal terms. The dissolved PAH concentration was negatively correlated with EC and the particulate PAH concentration was negatively correlated with SS concentration. The yearly loading amount of PAHs was calculated with the data of river flow rate and PAH concentration, and the calculated yearly PAHs specific loading in the River on rainy days was 37 μg m^-2 year^-1 and the loading in non-rainy days was 29 μg mm^-2 year^-1. The total loading was 66 ?g m^-2 year^-1. From these estimations and our previous studies, the atmospheric loadings and river discharge were compared. From the comparison, the order of the loading from river basin area was comparable to this from atmospheric loadings.