摘要
对15年来王港潮滩重金属Pb、Zn、Cu积累规律和污染状况进行了研究,第一次测到了王港地区^210Pb的本底值为1.16dpm/g,校正了前人对王港地区沉积速率的研究。研究表明,王港潮滩现代平均沉积速率为4.13cm/a;王港潮滩重金属垂直方向的含量变化具有趋同性;Cu、Zn的归一化值在15年内相对Pb的归一化值稳定,其中Cu的波动范围在0.4-2之间,Zn在1.5-2.6之间狭小的范围内波动;Pb归一化以后在4个柱状样中,都表现出随时间的变化发生了较大的波动,可能受人类活动影响较大。采用瑞典科学家Hakanson潜在生态危害指数法对王港潮滩重金属的潜在生态危害进行了评价分析,并与单因子指数评价比较,对王港污染状况进行综合性的评价。结果显示,Pb为该区域的主要污染因子。王港近岸海域表层沉积物中Cu、Pb、Zn的潜在生态危害指数均小于95,总体王港潮滩重金属污染状况属于潜在轻微生态危害。
The vertical distribution law of heavy metals of Pb, Cu and Zn from Wanggang tidal flat and status of its pollution were studied. The background value of Wanggang ^210Pb is measured, which is 1. 116dpm/g. It was suggested by the study that the modern average rate of sedimentation in Wanggang tidal flat is 4.13cm/a. It was found that the vertical changes of heavy metal content of Wanggang tidal flat have the same homoplasy, that it reduces from surface layer to bottom step by step, in accordance with granularity. This argued more obviously the conclusion summarized previously that heavy metals and granule sediment have good relativity. The common rule that the content of heavy metals was in the order of high tide〉middle tide〉low tide has straight correlation with the process of water dynamics. It was deduced by the relativity of heavy metals that the Fe, Cu,Pb,Zn and Li have better relativity. Thereinto the relation of Fe, Ni and Cr was very marked, exceeding 0. 900. It was obvious that the vertical changes of heavy metals were relatively stable and possibility came from rock. Pb, Cu and Al have minus-correlations with Fe,indicating that Pb and Cu of Wanggang tidal flat were impacted by anthropogenic activities to a greater degree. The Cu and Zn normalization value in 15 years is stable in contrast to that of Pb. The undulating scope of Cu is between 0.4 and 2 and Zn is between 1.5 and 2.6. But Pb has a greater scope. Using Hokanson＇s latency ecological risk index method, it was deduced that the latency ecological risk index of Pb, Cu and Zn was less than 95, an indication of light harmfulness. But it had pollution of Pb and Cu by all means in this area. Pb was the main pollution factor in the estimated area. The application of pesticide and fertilizer was the main reason of heavy metal pollution. It is suggested that the heavy metals in Wanggang tidal flat come from pollution of land-based farming activities.
出处
《地理研究》
CSCD
北大核心
2007年第4期809-820,共12页
Geographical Research
基金
国家自然基金资助项目(40371048)
关键词
王港
潮滩
重金属
污染
Wanggang
tidalflat
heavy metal
pollution
