Yin Su, Wu Yuehan, Xu Wei, Li Yangyang, Shen Zhenyao, Feng Chenghong
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China.
Chemosphere. 2016 Jul;155:564-572. doi: 10.1016/j.chemosphere.2016.04.095. Epub 2016 May 4.
To determine whether the discharge control of heavy metals in the Yangtze River basin can significantly change the pollution level in the estuary, this study analyzed the sources (upper river, the estuarine region, and the adjacent sea) of ten heavy metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn) in dissolved and particulate phases in the surface water of the estuary during wet, normal, and dry seasons. Metal sources inferred from section fluxes agree with those in statistical analysis methods. Heavy metal pollution in the surface water of Yangtze Estuary primarily depends on the sediment suspension and the wastewater discharge from estuary cities. Upper river only constitutes the main source of dissolved heavy metals during the wet season, while the estuarine region and the adjacent sea (especially the former) dominate the dissolved metal pollution in the normal and dry seasons. Particulate metals are mainly derived from sediment suspension in the estuary and the adjacent sea, and the contribution of the upper river can be neglected. Compared with the hydrologic seasons, flood-ebb tides exert a more obvious effect on the water flow directions in the estuary. Sediment suspension, not the upper river, significantly affects the suspended particulate matter concentration in the estuary.
为了确定长江流域重金属排放控制是否能显著改变河口的污染水平，本研究分析了河口表层水在丰水期、平水期和枯水期溶解相和颗粒相中十种重金属（砷、镉、钴、铬、铜、汞、镍、铅、锑和锌）的来源（上游河流、河口区域和邻近海域）。通过断面通量推断的金属来源与统计分析方法得出的结果一致。长江河口表层水的重金属污染主要取决于沉积物悬浮和河口城市的废水排放。上游河流仅在丰水期构成溶解态重金属的主要来源，而河口区域和邻近海域（尤其是前者）在平水期和枯水期主导溶解态金属污染。颗粒态金属主要来源于河口和邻近海域的沉积物悬浮，上游河流的贡献可忽略不计。与水文季节相比，涨落潮对河口水流方向的影响更为明显。沉积物悬浮而非上游河流显著影响河口悬浮颗粒物浓度。
