Distributions, compositions, and ecological risk assessment of polycyclic aromatic hydrocarbons and phthalic acid esters in surface sediment of Songhua river, China

Abstract

The distribution, composition, and ecological risk of 16 types of polycyclic aromatic hydrocarbons (PAHs) and 6 types of phthalic acid esters (PAEs) in the surface sediment of Songhua river, northeast China, were investigated. The total weight of the PAHs (∑16PAHs) varied from 226.70 to 7086.62 ng/g dry weight (dw), whereas that of the PAEs (∑6PAEs) ranged from 819.44 to 24,035.39 ng/g dw. The dominant PAHs were four-membered ring PAHs, which varied from 18.65% to 78.10% of the total PAHs. The most abundant PAEs was di-2-ethylhexyl phthalate ester (DEHP), which accounted for 65.02–99.07% of the total PAEs, followed by di-n-butyl phthalate ranging from 1.50 to 55.43%. Pyrolytic origin was the dominant PAH source. Approximately 12.70% target PAHs in the Songhua river sediment exhibited moderate ecological risk with 23.49–1404.09 ng/g carcinogenic toxicity equivalent. DEHP in 80.95% of the sediment samples exceeded the effects range low, indicating its potential harmfulness to the aquatic environment.