2007 Volume 13 Issue 2 Pages 97-104
The fate of hydrophobic pollutants in rivers depends on the partition of pollutants between river water and sediments. Understanding the partition of pollutants in a sediment-water system is important for the environmental quality management of a water environment. The concentration of polycyclic aromatic hydrocarbons (PAHs) in water and sediment was monitored at downstream locations of the two main rivers of Kanazawa City, the Asano and Sai Rivers. Sediments were classified into three different particle size fractions. The estimated sediment-water partition coefficient, Kd was found to be correlated with the organic carbon contents of the sediment. The organic carbon normalized partition coefficient Koc was calculated as Kd/foc, where foc is the content of sedimentary organic carbon values. No apparent relation was found between the Koc and sediment particle size. The Koc and Kow values of PAHs except for Benzo[k]fluoranthene were fitted to the linear free energy relationship logKoc = alogKow + b. Value of a = 0.562 and b = 3.55 for the Asano River and a = 0.814 and b = 2.19 for the Sai River were obtained. These results suggest that the organic carbon content, not the particle size, controls the sediment-water partition coefficient.
