小型浅水湖泊沉积物磷的赋存形态及其相关性分析

Fractions and correlation analysis of phosphorus in sediments of a small shallow lake

以孔目湖沉积物为研究对象,应用七步连续提取法测定其中的不同形态磷,探讨了该湖泊沉积物中各赋存形态磷的分布特征,并对其进行了相关性分析。结果表明:该湖泊遭受的磷内源负荷比较大,磷污染严重;沉积物中TP含量在2338.63-2954.98mg·kg^(-1),平均为2671.37mg·kg^(-1);沉积物中各形态磷含量从高到低依次为:Fe-P>De-P>Ca-P>OP>Al-P>Oc-P>Ex-P,分别占TP的53.9%、28.7%、8.8%、6.2%、1.2%、0.9%、0.3%;生物有效磷含量为1583.59 mg·kg^(-1),占TP的59.28%;沉积物中TP与Fe-P极显著相关,Oc-P与Ca-P和OP与Ca-P均相关,而TP与Ex-P、Al-P、Ca-P和OP相关性较差,说明沉积物中TP含量主要来自于Fe-P。这一研究结果为揭示小型湖泊富营养化发生机制提供了数据及理论支撑。

Taking the sediment in Kongmu Lake as the research object,the seven-step continuous extraction method was used to determine the different forms of phosphorus in the sediment.The distributions of all phosphorus forms were investigated,and their correlations were analyzed.The results showed that the internal phosphorus loading accounted for a considerable proportion in this lake,resulting in a serious phosphorus pollution.The contents of total phosphorus(TP)in the sediments ranged from 2338.63 to 2954.98 mg·kg^-1 with an average of 2671.37 mg·kg^-1.The order of different form phosphorus contents in the sediments was Fe-P>De-P>Ca-P>OP>Al-P>Oc-P>Ex-P.Their proportions were 53.9%,28.7%,8.8%,6.2%,1.2%,0.9% and 0.3% of TP,respectively.The content of bio-available phosphorus was 1583.59 mg·kg^-1,which accounted for 59.28%of TP.There was an extremely significant correlation between TP and Fe-P.Also,both Oc-P and OP demonstrated a correlation with CaP.In addition,a weak correlation could be inferred between the TP and Ex-P,Al-P,CaP and OP.These results indicate that the TP content in sediments is mainly from Fe-P.This study provides data and theoretical support for revealing the mechanism of lake-eutrophication in this city.