武汉市湖泊表层沉积物磷形态组成特征

The Characteristics of the Composition of Various Phosphorus Forms in Lake Surface Sediments in Wuhan City.

为了解武汉地区湖泊磷形态组成特征,选取Ⅱ、Ⅲ、Ⅳ、Ⅴ和劣Ⅴ类5种水质类型湖泊进行采样,利用标准测试程序测定了武汉市40个湖泊表层沉积物样品的总磷(TP)、有机磷(Org-P)、无机磷(IP)、铁铝磷(Fe/Al-P)和钙磷(Ca-P)含量。TP和不同形态磷含量变化范围如下:w(TP)为444.0~2055.5 mg·kg-1,w(Org-P)为146.8~400.5 mg·kg-1,w(IP)为237.5~1889.3 mg·kg-1,w(Fe/Al-P)为96.1~1152.8 mg·kg-1,w(Ca-P)为108.4~812.7 mg·kg-1。TP含量以IP为主,Fe/Al-P、Ca-P、Org-P次之。在5种不同水质类型湖泊中,随水质变差,TP和不同形态磷(Org-P除外)含量总体呈升高趋势。在所有40个样品中,26个样品易释放的生物有效磷占TP含量的50%以上,这表明即使在外源磷输入减少的背景下湖泊仍存在较高的富营养化风险。空间关联的局域指标聚类图显示,在工业区的4个湖泊中TP、IP和Fe/Al-P含量存在高高型空间集聚,Ca-P和Org-P含量呈随机分布特征。

In order to reveal the characteristics of phosphorus composition within lake sediments in Wuhan City,forty surface sediment samples were collected from five types of lakes with water quality of gradesⅡ,Ⅲ,Ⅳ,Ⅴand inferiorⅤ.Concentrations of total phosphorus(TP),organic phosphorus(Org-P),inorganic phosphorus(IP),Fe/Al-bound phosphorus(Fe/Al-P),and Ca-bound phosphorus(Ca-P)in these samples were analyzed using the standard measurement and test procedure(SMT).The ranges of phosphorus concentrations were 444.0-2055.5 mg·kg-1 for TP,146.8-400.5 mg·kg-1 for Org-P,237.5-1889.3 mg·kg-1 for IP,96.1-1152.8 mg·kg-1 for Fe/Al-P and 108.4-812.7 mg·kg-1 for Ca-P,respectively.The results indicate that TP was dominated by IP,followed by Fe/Al-P,Ca-P,and Org-P.Among the five different types of lakes,contents of TP and various species of phosphorus(except Org-P)generally increased with the deterioration of water quality.In 26 samples,readily-released bioavailable phosphorus accounted for more than 50%of TP,indicating that these lakes would be faced with high risk of eutrophication,even under a scenario of decreased external phosphorus inputs.According to the local indicators of spatial association cluster map of various phosphorus species in Wuhan City,TP,IP and Fe/Al-P have high-high type of spatial agglomeration in four lakes of the industrial zone,while random distribution is observed in Ca-P and Org-P.