太湖入湖河道沉积物中生物利用磷和营养水平分析

为了解太湖入湖河道的营养状况,研究了太湖西部河流沉积物生物利用磷的组成与分布。研究结果显示,北部沉积物中营养元素较高,南部较低;沉积物中生物利用磷的含量次序为藻类可利用磷(AAP)>NaHCO3提取磷(OLP)>水溶性磷(WSP)>易解吸磷(RDP),其中AAP是重要的生物利用磷,AAP的比例越高,富营养化程度越高。AAP与营养元素的相关性在不同区域河道有所不同,北部河道与总氮(TN)、总磷(TP)相关性较好,中部和南部河道与沉积物有机质总量(TOM)相关性较好。沉积物的生物利用磷受不同污染源影响较大。对比河道沉积物与湖泊沉积物的特征,发现湖泊沉积物中生物利用磷(BAP)/总磷(TP)、藻类可利用磷(AAP)/总磷(TP)都高于河道沉积物,表明湖泊沉积物中的磷更容易被植物吸收。

Bioavailable phosphorus in sediments in the rivers to the west of the Taihu lake and their trophic level, East China

The fractions and distribution of bioavailable phosphorus in river sediments were studied in order to identify the trophic level of inflow rivers to the west of Taihu Lake.The nutritive elements in sediments show higher contents in the northern rivers and lower in the southern rivers.The contents of bioavailable phosphorus decrease in following order:algal available phosphorus(AAP)>Olsen-P(OLP)>water soluble phosphorus(WSP)>readily desorbed phosphorus(RDP).The trophic level increases with the proportion of AAP to total phosphorus.The correlations between AAP and nutritional components show different characteristics for sediments from different regions.AAP is well associated with TN and TP in the northern rivers and with TOM in the middle and southern rivers.The bioavailable phosphorus is evidently influenced by pollution sources,and its high content is corresponding to the severe algal bloom.In comparison with river sediments,the lake sediments have higher values of BAP/TP and AAP/TP,which suggests that phosphorus in lake sediments is readily Absorbed by hydrophyte.