Distribution, sources, and behavior of PAHs in estuarine water systems exemplified by Salt River, Taiwan

Water, suspended particulate matter (SPM), and sediment samples were collected from Salt River in Taiwan and analyzed the concentrations of 16 types of polycyclic aromatic hydrocarbons (PAHs). The analysis results were used to examine the distribution, source, partition behavior, and potential ecological risks of PAHs in the estuarine water systems. The mean concentration of total PAHs in water, SPM, and sediment samples was 0.485–10.2 μg/L, 26.7–169 mg/kg dw, and 0.343–29.4 mg/kg dw, respectively. The highest concentration was found at the river mouth and decreased toward the river and sea with the tide. The distribution of the diagnostic ratios of PAHs showed that the combustion of coal and petroleum products are the main sources of PAHs in Salt River. The in site organic carbon normalized partition coefficients for SPM-water (K'oc(SPMW)) and sediment-water (K'oc(SedW)) were 2.8–4.5 and 4.6–6.0 (log units), respectively, increasing with the number of rings in PAHs. The values log K'oc(SedW) and log K'oc(SPM-W) showed a significant linear correlation with their octanol-water partition coefficients (p