PAHs in the Northern South China Sea: Horizontal transport and downward export on the continental shelf
PAHs in the Northern South China Sea: Horizontal transport and downward export on the continental shelf
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南海北部多环芳烃：大陆架上的水平迁移和向下输出
DOI：
10.1016/j.marchem.2018.03.004
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发表时间：
2018-05-20
期刊：
影响因子：
3
通讯作者：
Liang, Junhua
中科院分区：
文献类型：
--
作者：
Cai, Minggang;Duan, Mengshan;Liang, Junhua
为研究半挥发性污染物在大陆架或边缘海的水平迁移和颗粒输出，采集了南海北方表层和深层水样品，分析了多环芳烃（PAHs）的含量。结果表明，海水中的σ（15）PAH总浓度范围为1.6 ~ 14 ngL（-1），平均值为5.5ngL（-1），近岸海域的下降趋势表明，陆源物质在陆架上的迁移作用较强，主要来源于燃烧活动。在垂直方向上，颗粒相中的多环芳烃呈现出表面富集、深度亏损的特征，在生物量最大处浓度最大（2.9ngL（-1）），而溶解态多环芳烃浓度在同一深度处最小（1.5ngL（-1））。根据U-238/Th-234平衡计算，南海北方颗粒物中PAHs的输出通量在24 ~ 195 ngm（-2）d（-1）之间，可以用来定量计算其在上层水体中的向下通量。南海北方海域存在着高效的海洋生物泵，驱动多环芳烃向下输出到深海。
To investigate horizontal transport and particulate export of semivolatile pollutants on the continental shelf or marginal sea, surface and depth water samples were collected across the northern South China Sea (SCS) and analyzed for polycyclic aromatic hydrocarbons (PAHs). The total concentrations of Sigma(15)PAH in seawater were in the range of 1.6-14ngL(-1) (mean 5.5ngL(-1)), and the offshore decreasing trend of PAHs revealed intense terrigenous transport on the continental shelf, which was originated from combustion activity. Vertically, PAHs in the particulate phase followed surface-enrichment and depth-depletion pattern with a concentration maximum (2.9ngL(-1)) at the biomass maximum, while the dissolved PAH concentrations showed a minimum (1.5ngL(-1)) at the same depth. Particulate export fluxes of PAHs were between 24 and 195ngm(-2)d(-1) in the northern SCS based on U-238/Th-234 equilibria, which is suggested appropriate to quantify their downward flux in the upper water column. Efficient oceanic biological pump drives PAHs downward export to the deep ocean in the northern SCS.