雷州半岛高桥红树林沉积物中砷的分布

The Distribution of Arsenic Concentration in the Mangrove Sediments in Gaoqiao, Leizhou Peninsula

采用五态连续提取法(SEP)对雷州半岛高桥红树林群落内外不同深度的沉积物砷含量进行测定。结果表明,高桥红树林湿地0～60cm深处沉积物中除Al-结合态砷和Ca-结合态砷含量低,难以检出外,交换态砷、残渣态砷、Fe-结合态砷皆可检出,沉积物砷积累以残渣态砷和Fe-结合态砷为主,总砷测定含量为7.34±0.39～10.32±0.48 mg/kg,其中以20～40cm深处沉积物总砷测含量最多;不同深度沉积物砷含量中林内与林区外裸滩呈现不同的分布规律,林外裸滩-林缘-林内的表土总砷含量的分布呈波浪式分布,以林缘为最高,总砷达9.97±1.29 mg/kg,林内显著大于林外裸滩(p值<0.05)。

The As contents in sediments collected from inside mangrove and outside mangrove area in Gaoqiao,Leizhou Peninsula,were analyzed with SEP method.The result showed that the total arsenic contents in every sampled sediments were less then 11 mg/kg,the main fractions of As in the 0-60cm deep sediments were in residual As and Fe-As forms,the fractions of Al-As and Ca-As were little and hardly could be detected.The exchangeable state As,Fe-As and residual state As did not obviously increase or reduced with the increase of sediments deepness outside and inside the area of the West Village mangrove community,except for the exchangeable state As other forms of As contents in Bruguiera gymnorrhiza sediments of the area’s Hongzhai tourist area were showed decreasing tendency with increasing sediment depth,and the As contents at surface sediments displayed a wave type distribution line from outside edge to inside edge of the area.The seawater wave was the main potential powerful factor to cause the mangrove arsenic concentration in the area.