松花江吉林市段江水与沉积物中多环芳烃的分布、来源和生态风险

摘要

在丰水期、枯水期和平水期分别采集松花江吉林市段的江水和沉积物样品,先用气相色谱-质谱联用仪(GC-MS)测定其中16种多环芳烃(PAHs)的含量,再通过比值法对各水期江水和沉积物中的PAHs进行来源识别,并分别利用商值法和风险效应值法评价江水和沉积物的生态风险.结果表明：松花江吉林市段丰水期、枯水期和平水期江水中PAHs 的质量浓度分别为0.917~3.974μg/L,0.980~3.293μg/L和0.771~4.127μg/L；丰水期和平水期沉积物中PAHs的质量比分别为1035.5~1732.0 ng/g和1188.5~1632.0 ng/g；不同水期江水中的PAHs质量浓度变化较大,沉积物中的PAHs质量比变化较小；PAHs 为石油源和燃烧源混合输入所致；江水中PAHs的生态风险较小,表层沉积物中的PAHs具有一定的生态风险.%Water samples and surface sediment samples from Jilin City section of Songhua River were collected in wet period,dry period and level period and 1 6 individual concentrations of polycyclic aromatic hydrocarbons (PAHs)were analyzed by gas chromatograph-mass spectrometry(GC-MS). The total mass concentrations of PAHs in the water samples in the wet period,dry period and the level period were 0.917—3.974μg/L,0.980—3.293μg/L and 0.771—4.127μg/L respectively.The total mass concentrations of PAHs in the surface sediment samples in the wet period and the level period were 1 035.5—1 732.0 ng/g and 1 188.5—1 632.0 ng/g respectively.The mass concentrations of PAHs in the water samples changed relatively large in different water periods but the concentrations of PAHs in the surface sediment samples were relatively stable.PAHs in the water and surface sediment in each water period originated both from the petroleum sources and the combustion sources according to the analysis by ratio method.The preliminary assessment with quotient method showed that the ecological risk of PAHs in water was low.The ecological risk assessment with effects range method showed that the surface sediments of this reach had certain ecological risk.