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

Chih-Feng Chen; Yun-Ru Ju; Yu-Ci Su; Yee Cheng Lim; Chih-Ming Kao; Chiu-Wen Chen; Cheng-Di Dong

doi:10.1016/j.marpolbul.2020.111029

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

Mar Pollut Bull. 2020 May:154:111029. doi: 10.1016/j.marpolbul.2020.111029. Epub 2020 Mar 31.

Authors

Chih-Feng Chen¹, Yun-Ru Ju², Yu-Ci Su¹, Yee Cheng Lim¹, Chih-Ming Kao³, Chiu-Wen Chen⁴, Cheng-Di Dong⁵

Affiliations

¹ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan.
² Department of Safety, Health and Environmental Engineering, National United University, Miaoli 36063, Taiwan.
³ Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
⁴ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan. Electronic address: cwchen@nkust.edu.tw.
⁵ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan. Electronic address: cddong@nkust.edu.tw.

PMID: 32319888
DOI: 10.1016/j.marpolbul.2020.111029

Abstract

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 < 0.01), and their slopes were 0.427 and 0.316, respectively. The fugacity fraction was used to evaluate the exchange of PAHs in water-SPM-sediment systems. Results showed that in SPM, 2-4-ring PAHs tend to be released into water, whereas 5-6-ring PAHs in water tend to be adsorbed onto SPM. The exchange of PAHs between water and sediment occurs in the direction of adsorption onto sediment from water. The assessment of the mean risk quotient, total toxicity equivalence, and mean effect range-median quotient of PAHs showed that the PAHs in the water and SPM of Salt River may have moderate to high ecological risk. In sediment, PAHs in the lower reaches and estuary may pose moderate to high ecological risk, whereas PAHs in the middle and upper reaches show low to moderate ecological risk.

Keywords: PAHs; Partition; Risk assessment; River; Sediments; Transfer and fate.

MeSH terms

China
Environmental Monitoring
Geologic Sediments
Polycyclic Aromatic Hydrocarbons*
Rivers
Taiwan
Water
Water Pollutants, Chemical*

Substances

Polycyclic Aromatic Hydrocarbons
Water Pollutants, Chemical
Water