辽河支流条子河表层水体中多环芳烃的污染特征

摘要

The pollution characteristics of polycyclic aromatic hydrocarbons ( PAHs) in the surface water from Tiaozi River were investigated, a tributary of Liaohe River. Water samples were collected from 10 representative sites in summer, autumn and winter, respectively. The concentrations of 16 priority PAHs were investigated, and their distribution, sources and ecological risk were also evaluated. Results indicated the total mass concentrations of PAHs (∑PAHs) were 319. 8 to 3 715. 9 ng/L, with an average of 1 746. 0 ng/L. PAHs in the surface water were dominated by 2 rings to 3 rings ( 53. 1% to 81. 0%) , 5 to 6 ring PAHs were undetected out. The average of ∑PAHs decreased in the order of winter (2 035. 0 ng/L) > autumn (1 272. 5 ng/L) > summer (967. 9 ng/L).∑PAHs in the water sample collected near Siping city ( Huihekou) showed the highest measurement concentrations (3 715. 9 ng/L) and the highest average concentrations (3 194. 8 ng/L). The PAH source identification indicated that they were mainly from the combined combustion of petroleum, grass, wood and coal. The Benzo[ a] pyrene e-quivalent in the surface water of Tiaozi River ranged from 5. 1 to 36. 1 ng/L, which was higher than the National Surface Water Quality Standards. The PAHs post a bit high ecological risk to aquatic organisms.%为了解辽河源头区典型支流———条子河四平段表层水体中多环芳烃( PAHs )的污染特征,分别于丰水期、平水期和枯水期采集条子河10个代表性断面的上覆水水样,测定了样品中16种优控PAHs的质量浓度、分析了其时空分布和来源,并对其生态风险进行了评价。结果表明：条子河表层水体中总PAHs的质量浓度(∑PAHs)范围为319．8~3715．9 ng/L,平均值为1476．0 ng/L,PAHs的组成以2~3环为主,占∑PAHs总量的53．1%~81．0%,5~6环的PAHs均未检测出。不同水期间,∑PAHs均值的大小顺序为：枯水期(2035．0 ng/L)>平水期(1272．5 ng/L)>丰水期(967．9 ng/L)。空间分布上,∑PAHs的检测最高值(3715．9 ng/L)和平均浓度最大值(3194．8 ng/L)均出现在位于四平市城区出境断面(汇合口)处。 PAHs主要来源是石油、草木、煤炭的混合燃烧。条子河表层水体中苯并[ a]芘的当量为5．1~36．1 ng/L,高于国家地表水环境质量标准值,条子河表层水体中PAHs存在一定的生态风险。