九龙江口表层沉积物碘含量分析

A Preliminary Study on the Iodine in Surface Sediments of Jiulong River Estuary

于2021年5—6月对九龙江红树林保护区与非红树林保护区进行布点采样,测定其表层沉积物碘含量和有机碳含量。结果表明:13个采样点中,碘含量范围为3.7~24.8 mg·kg^(-1),差值最高可达7倍,平均值为12.3 mg·kg^(-1);有机碳含量范围为16~45 g·kg^(-1),平均值为30 g·kg^(-1)。不同类型样品碘含量大小依次为:长林龄林下沉积物>河道清淤沉积物>非林下沉积物>短林龄林下沉积物,其中长林龄林下沉积物碘含量范围为15.7~24.8 mg·kg^(-1),平均值为19.2 mg·kg^(-1);短林龄林下沉积物含量为5.5~6.9 mg·kg^(-1),平均值为6.2 mg·kg^(-1);二者相差3倍以上。有机碳含量最高的为长林龄林下沉积物和河道清淤沉积物,平均值均为32 g·kg^(-1);最低值为短林龄沉积物,含量为22 g·kg^(-1)。不同类型沉积物有机碳含量与碘含量基本呈正相关关系,但相关性不显著;同等有机碳含量的样品,长林龄林下沉积物碘含量显著高于其它样品。

Surface sediment samples were collected in May and June 2021,in the Jiulong Riv er mangrove reserve and non-mangrove area.The iodine and organic carbon of the samples were analyzed.The results showed that,in the 13 samples,the iodine r anged from^(3).7 to 24.8 mg·kg^(-1),the difference among them could be as h igh as 7 times,with an average of 12.3 mg·kg^(-1);the range of organic ca rbon was 16~45 g·kg^(-1) and the average value was 30 g·kg^(-1).Differ ent types of sampl es were made sequentially:long-aged mangrove sediment>river dredging sediment>non-mangrove sediment>short-aged mangrove sediment.The concentration of iodi ne in the long-aged mangrove sediment with the highest content ranged from 15.7 to 24.8 mg·kg^(-1),with an average of 19.2 mg·kg^(-1),while the co ncentration of iodine in the short-aged mangrove sediment ranged from 5.5 to 6.9 mg·kg^(-1),with an average of 6.2 mg·kg^(-1),the difference was m ore than three times between the two types of samples.The highest organic carbo n content was both 32 g·kg^(-1) in the long-aged mangrove sediment and rive r dredging sediment,while the lowest content was 22 g·kg^(-1) in the short-aged mangr ove sedimen t.Basically,there was a positive correlation between organic carbon content an d iodine content in different types of sediments,but the co-relaitonship was n ot significant.For the samples with the same organic carbon content,the iodine of long-aged mangrove sediment was significantly higher than that of other sam ples.