典型城市浅水湖泊沉积物中磷与铁的形态分布及相关关系

应用改进的SEDEX法和BCR法对3个典型城市浅水湖泊(玄武湖、大明湖和莫愁湖)表层沉积物中的磷和铁的形态进行了测定与分析，并探讨了二者之间的相关关系.结果表明，玄武湖、大明湖和莫愁湖沉积物中Al-P含量都较低(<1%)，Fe-P质量分数分别为17.10%～27.88%、16.68%～27.06%和0.06%～0.17%，分布顺序与湖泊富营养化程度相符.Ex-P和ACa-P、De-P含量的分布顺序均为大明湖＞莫愁湖＞玄武湖，其中钙磷的质量分数为32.51%～75.39%，是湖泊沉积物磷的主要赋存形态；3个城市湖泊沉积物中的铁元素主要以残渣态(F4)存在，占总量的69.17%～99.88%.其中，玄武湖沉积物中的F1和F2态的含量较高，占总量的6.46%～17.35%，可能与玄武湖频繁的蓝藻暴发有密切关系；TP与铁的F1、F2和F3态相关系数分别达到-0.95、-0.94、-0.81，呈极显著负相关(p＜0.01).Ex-P、Al-P、Or-P与F1、F2态相关显著，与它们性质活泼，易受环境条件影响有关.ACa-P、De-P是生物难利用磷，但二者却与F1、F2和F3态存在显著负相关关系，其反应机制还有待深入研究.

Distribution and Correlation of P and Fe Fractions in Sediments of Typical Urban Shallow Lakes

The fractions of phosphorus(P) and Fe in the surface sediments of three typical urban shallow lakes(Xuanwu Lake,Daming Lake and Mouchou Lake) were determined using improved methods of SEDEX and BCR,respectively,and the relationship between P and Fe in sediments was also analyzed.P analyses showed that the relative lower content of Al-P was found in sediments of three urban lakes,while the percentage of Fe-P was in the range of 17.10%-27.88%,16.68%-27.06% and 0.06%-0.17%,respectively,in Xuanwu Lake,Daming La...