大亚湾海域2009—2018年重金属时空分布及污染评价

为了解大亚湾海域海水中重金属的污染状况，对近10年来大亚湾海域不同水质功能区海水中Cu、Pb、Zn的质量浓度的变化情况及空间分布进行了研究，并采用综合污染指数法对海水中重金属污染程度进行评价.结果表明:(1)大亚湾海域一类功能区海水中存在Cu、Pb、Zn的质量浓度超标现象，二类功能区海水中存在Pb的质量浓度超标现象，沿岸排放的工业废水可能是重金属的主要来源; (2)大亚湾海域3个功能区按海水中重金属的综合污染指数均值由高到低依次排序为:一类功能区、二类功能区、三类功能区，一类功能区海水受到重金属污染物的影响，二类、三类功能区尚未受到影响; (3)大亚湾海域海水中Cu、Pb、Zn的质量浓度呈现一定的波动，没有伴随着石化区污水排放量的增长而显著上升.

Pollution Assessment and Temporal-Spatial Distribution of Heavy Metals in Seawater of Daya Bay During 2009-2018

To study the status of heavy metal pollution in the seawater of Daya Bay, the 10-year changes of Cu, Pb and Zn concentrations and their spatial distributions in the seawater of Daya Bay were investigated, and the severity of heavy metal contamination in the seawater was evaluated with the comprehensive pollution index. The following results were obtained. First, the concentrations of Cu, Pb and Zn in Class I functional area and the concentrations of Pb in Class II functional area exceeded the national standards and the industrial waste water discharged along the coast might be the main source of heavy metals. Second, the average comprehensive pollution index of heavy metals in three functional areas in Daya Bay are ranked as Class I, Class II and Class III, indicating that the seawater in Class I area was contaminated by heavy metals while Class II and III areas haven't been affected yet. Third, during the research period, the levels of Cu, Pb and Zn in the seawater of Daya Bay fluctuated, but concentrations of these metals did not rise significantly with increasing sewage discharge from the petrochemical zone.