大纵湖沉积物中磷形态特征分析

Characteristics Analysis of Phosphorus Forms in Sediments of Dazong Lake

为了探究中小型富营养化湖泊的演变过程,了解沉积物中磷的形态分布规律,以江苏省里下河地区大纵湖为例,采用改进的磷分级分离法分析了大纵湖3个采样点沉积物中各组分磷的垂向分布,探讨了大纵湖沉积物的潜在释磷能力和生物可利用磷的来源。结果表明,大纵湖DZ1采样点的沉积物中TP含量最高,而DZ2和DZ3采样点的TP含量则相差不大;沉积物中碎屑钙磷(De-P)和有机磷(Or-P)对TP的贡献巨大,而可交换态磷(Ex-P)、自生钙磷(ACa-P)和De-P与生物有效磷显著相关,这部分磷具有潜在的释放风险;活性磷由Ex-P、Fe-P、Al-P三种形态组成,其中以Ex-P为主;生物有效磷的含量次序为:AAP>Olsen-P>WSP>RDP,垂直方向上,AAP、Olsen-P含量随沉积物深度增加呈下降趋势。

In order to explore the evolution of small and medium eutrophic lakes and understand the distribution of Phosphorus forms in sediments, Dazong Lake in Lixiahe Area of Jiangsu Province was taken as an example. Based on improved Phosphorus separation method, the vertical distribution of Phosphorus fractions in sediment from three different sampling points of Dazong Lake were analyzed. And then the potential release capacity of Phosphorus from the vertical sediments and their sources were discussed. The results show that DZ1 sampling point held the highest TP content in the sediments, TP content of DZ2 and DZ3 sampling points was almost the same; De P and Or P had made a huge contribution to the TP; Ex P, ACa P and De P were significantly associated with the bio available Phosphorus, which had a potential risk of the release of Phosphorus; active Phosphorus was made up of Ex P, Fe P and Al P, which was given priority to Ex P; the descended ranking sequence of the contents of four kinds of BAP was as follows： AAP, Olsen P, WSP, RDP; the contents of AAP and Olsen P in sediments decreased exponentially with increase of sediment depth.