北部湾潮间带沉积物总Hg含量分布特征研究

Distribution Characteristics of Total Mercury Content in Top-Sediments of Intertidal Zone of the Beibu Gulf in Guangxi

采用MILESTONE DMA-80固液相自动测汞仪对广西北部湾潮间带13个站位表层沉积物中汞含量进行检测,并采用单因子指数法和潜在生态风险评价法对研究区域沉积物Hg污染水平和潜在生态风险进行判定。研究表明,研究区域各站位潮间带表层沉积物汞含量介于24.60~125.87 ng/g之间,平均值为60.58 ng/g,就不同站位所属海区而言,平均汞浓度质量分数由高到低表现为:钦州海区>北海海区>防城港海区,广西北部湾潮间带沉积物中汞污染风险系数低,个别站位接近中等风险程度临界值。广西北部湾滨海潮间带各站位中表层沉积物汞元素潜在生态风险较小,各站位沉积物中汞浓度均低于国家海洋沉积物Ⅰ类质量标准。

Mercury contained in top sediments at 13 sampling points over the intertidal zone stretching along the Beibu Gulf in Guangxi was investigated and the sediment samples collected was detected with the MILESTONE DMA-80 solid and liquid phase of direct mercury analyzer. Furthermore,mercury pollution level in sediments was determined to assess the potential ecological risks by use of the single factor index method. The investigation showed that total Hg in the sediments samples of all those points were widely ranged（24.60-125.87 ng/g） with the average value being 60.58 ng/g. As far as the differences of mercury content between the different study zone-related sea areas,the average mercury content in the descending order was：the Qinzhou sea area the Beihai sea area the Fangchenggang sea area;general speaking,mercury pollution risk coefficient in the intertidal sediments of the Beibu Gulf was low,albeit some of the places being close to the critical value of medium risk degree. In conclusion,the potential ecological risk of mercury in top sediments of the intertidal zone along the Beibu Gulf was relatively low,total Hg concentration being below the limiting value of the related national standard.