| 近50年来深圳湾红树林湿地Hg、Cu累积及其生态危害评价 |
| 摘要点击 2896 全文点击 2025 投稿时间：2012-02-17 修订日期：2012-07-02 |
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| 中文关键词 红树林 沉积物 重金属积累 生态危害 深圳湾 |
| 英文关键词 mangrove sediments heavy metal accumulation ecological risk Shenzhen Bay |
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| 中文摘要 |
| 海湾地区沉积物在输运和沉积过程中记录了人类活动的信息. 对深圳湾红树林湿地柱状沉积物进行测年分析结果表明,该地区沉积物沉积速率为1.38 cm·a-1. 沉积物容重、pH、电导率和总有机碳(TOC)在整个剖面的变化范围分别为0.36~0.71 g·cm-3、6~7、2.93×103~4.97×103 μS·cm-1和1.5%~3.8%. 随着沉积物剖面深度的增加,沉积物容重和电导率逐渐升高,TOC逐渐降低,pH变化不明显. 沉积物中Hg和Cu含量在整个剖面的变化范围分别为92~196 ng·g-1和29~83 μg·g-1,两者在14 cm以上表现为逐渐升高的趋势,再往下又逐渐降低. 沉积物Hg和Cu的生态危害系数随沉积物剖面深度的增加,均呈现先增加后降低的变化趋势,在14 cm深度处达到最大,分别为39.10和13.85. Hakanson潜在生态风险评价表明,Hg和Cu的生态危害系数均属于低潜在生态危害. 1960~1985年间,香港经济的快速发展,以及1985~2000年间深圳经济的快速崛起对深圳湾红树林湿地沉积物的Hg和Cu污染积累及生态危害有显著贡献. 2000年后,一系列环保措施的实施降低了红树林湿地沉积物的Hg和Cu含量,改善了红树林的环境生态状况. 深圳湾重金属含量及潜在生态危害较好地反映了深圳湾周边地区及流域内的人类活动对深圳红树林湿地沉积物重金属污染的影响过程和程度. |
| 英文摘要 |
| The processes of sediment transport and deposition can record some relative anthropogenic information in gulf region. Chronological analysis of the sediment core collected from mangrove wetland in Shenzhen Bay showed that the sedimentation rate was about 1.38 cm·a-1. Soil buck density, pH, electrical conductivity (EC) and total organic carbon (TOC) changed in range of 0.36-0.71 g·cm-3, 6-7, 2.93×103-4.97×103 μS·cm-1, and 1.5%-3.8%, respectively. With the increase of soil depth, the soil buck density and EC increased gradually. However, the TOC decreased, with no significant change of pH. Contents of Hg and Cu in the whole depth of core ranged between 92-196 ng·g-1 and 29-83 μg·g-1, respectively. And both of them in sediment increased firstly and then decreased with the increasing soil depth. At 14 cm depth, contents of Hg and Cu reached up to the highest levels. Correspondingly, the ecological risk of Hg and Cu changed similarly with the contents of Hg and Cu. At 14 cm depth, the ecological risk indexes of Hg and Cu were at the highest levels of 39.10 and 13.85, respectively. The potential ecological risks of both Hg and Cu in sediments were mild. The rapid economical development of Hong Kong in 1960-1985 and Shenzhen in 1985-2000 contributed much to the Hg and Cu accumulation in mangrove wetland of Shenzhen Bay, China. Since the year of 2000, the reduction in contents of Hg and Cu has been expected as a consequence of the adoption of contamination control policies, improving the environment for growth of mangrove. In conclusion, the variations of core sediment heavy metal contents and its ecological risk assessment along the vertical profile reveal the interaction processes and extent of anthropogenic influences from the areas around the Shenzhen Bay and the catchments. |
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