太湖流域水源地多环芳烃分布、溯源与生态风险评估

Distribution,pollution sources,and ecological risk assessment of PAHs in water source area of Taihu Basin

利用GC-MS对太湖流域水源地多环芳烃(PAHs)的浓度水平进行监测分析。结果表明,3月水相、悬浮颗粒物和沉积物中PAHs的质量浓度分别为63.5~393.9 ng/L、167~4 358.2 ng/g和940.8~7 398.3 ng/g,分别远高于6月的21.1~64.6 ng/L、125.6~282.3 ng/g和337.3~1 318 ng/g。不同月份单体PAH浓度水平差异较大,可能受控于污染物来源、径流稀释和水动力条件的差异性。特征比值判源结果表明,6月水相和悬浮颗粒物中PAHs主要来源于石油类泄漏和燃烧过程,而沉积物中PAHs在3月和6月均体现为混合源。生态风险评估结果表明,水相、悬浮颗粒物和沉积物中PAHs的生态风险较小,但个别样点单体PAH的含量高于基于生物影响试验的风险评价低值ER-L和ISQV-L,说明存在一定的健康风险,需引起重视。

The concentration of PAHs in the water source area of the Taihu Basin was monitored and analyzed using GC-MS. The results show that the concentrations of PAHs in the water phase, suspended particular matter, and sediments in March were 63. 5 to 393. 9 ng/L,167 to 4 358. 2 ng/g,and 940. 8 to 7398. 3 ng/g,respectively, being higher than the values in June,which were 21. 1 to 64. 6 ng/L,125. 6 to 282. 3 ng/g, and 337. 3 to 1318 ng/g,respectively. The concentration of monomer PAH varied significantly in different months, and could be controlled by the diversities of the pollution sources, flow dilution, and hydrodynamic conditions. The characteristics ratio suggested that the PAHs in the water phase and suspended particular matter mainly came from the oil leaks and burning in June,while the PAHs in sediments in March and June had the mixing source. The ecological risk assessment shows that the ecological risks of PAHs in the water phase, suspended particular matter, and sediments were relatively small, while the concentration of monomer PAH at some sampling sites was higher than ER-L and SQV-L（low value of risk assessment） based on iological impact test, indicating certain health risks.