舟山近海水体和沉积物中多环芳烃分布特征

Distribution of Polycyclic Aromatic Hydrocarbons in Water and Sediment from Zhoushan Coastal Area,China

2012年,每两个月采集1次浙江省舟山近海水样及表层沉积物样品,检测16种多环芳烃（PAHs）含量.结果表明,舟山近海水体和沉积物中PAHs均存在显著的时空差异性,水体ΣPAHs浓度范围为382.3-816.9 ng·L^-1,平均值为552.5ng·L^-1;沉积物ΣPAHs含量范围为1017.9-3047.1 ng·g ^-1,平均值为2022.4 ng·g ^-1.空间分布上,水体ΣPAHs最大值和最小值分别出现在小洋山和燕窝山海域,而沉积物中分别出现在小洋山和朱家尖南沙海域.时间变化上,水体ΣPAHs最大值和最小值出现在10月和6月,而沉积物中分别出现在8月和6月.PAHs污染来源主要是油类排放和木柴、煤燃烧的共同叠加作用.结合PAHs的生物阈值,利用超标系数法评价舟山近海PAHs的生态风险,结果表明,ΣPAHs存在较低几率的潜在风险,但苊单体存在较高几率的潜在风险,二氢苊和芴可能存在生态风险.对水-沉积物界面PAHs的富集研究表明,舟山近海沉积物中富集了大量PAHs,富集系数（Kd值）岱山岛大于舟山本岛,并与沉积物的PAHs含量分布一致.

The spatial and temporal distribution of 16 polycyclic aromatic hydrocarbons（ PAHs） has been investigated in water and sediments of Zhoushan coastal area every two months in 2012. The concentrations of total PAHs ranged from 382. 3 to 816. 9 ng·L^- 1,with the mean value of 552. 5 ng·L^- 1in water; whereas it ranged from 1 017. 9 to 3 047. 1 ng·g^- 1,with the mean value of 2022.4ng·g^- 1in sediment. Spatial distribution showed that Yangshan and Yanwoshan offshore area had the maximum and minimum of total PAHs contents in water,while the maximum and minimum occurred at Yangshan and Zhujiajian Nansha offshore area in sediment.Temporal distribution revealed that total PAHs contents in water reached the maximum and minimum values in October and June,however in sediments these values were found in August and June,respectively. The PAHs pollution was affected by oil emission,charcoal and coal combustion. Using the biological threshold and exceeded coefficient method to assess the ecological risk of PAHs in Zhoushan coastal area,the result showed that Σ PAHs had a lower probability of potential risk,while there was a higher probability of potential risk for acenaphthylene monomer,and there might be ecological risk for acenaphthene and fluorene. Distribution of PAHs between sediment and water showed that Zhoushan coastal sediment enriched a lot of PAHs,meanwhile the enrichment coefficient（ Kd value） of sediment in Daishan island was larger than that in Zhoushan main island.