南四湖及主要入湖河流河口区表层沉积物磷的形态与分布特征研究

利用化学连续提取法对南四湖湖区及主要入湖河流河口区的表层沉积物样品中的磷的化学形态进行了提取.分析结果表明:南阳湖、独山湖和位于湖西的入湖河流沉积物中总磷含量较高,变化范围为571.67～1113.55mg·kg-1;不同形态磷的含量差异较大,排序为:钙磷(Ca-P)>有机磷(OP)>弱吸附态磷(Ads-P)>铁磷(Fe-P)>铝磷(Al-P);TP与Ca-P、Ads-P、OP之间存在正相关关系,相关系数r分别为0.85(p<0.01)、0.85(p<0.01)和0.63(p<0.01);Ads-P与Ca-P、Ads-P与OP之间也存在正相关关系,r分别为0.74(p<0.01)和0.60(p<0.05);Fe-P与Ca-P之间存在负相关关系(r=-0.62,p<0.05);BAP只与OP之间显著正相关(r=0.82,p<0.01),由OP可以粗略地估算出沉积物中潜在的可释放磷,即有效的内源磷负荷;南四湖沉积物中有机磷的含量很大程度上取决于有机质含量的多少.

Phosphorus fractions and distribution characteristics in sediments of Nansi Lake, China, and its main inflow rivers

Phosphorus fractions were studied in the surface sediments of Nansi Lake and its main inflow rivers using the sequential extraction procedure. The phosphorus contents in the sediments of Nanyang Lake, Dushan Lake and the inflow rivers located in the west lake were higher and the total phosphorus (TP) content in the sediments ranged from 571.67 mg·kg-1 to 1113.55 mg·kg-1. The concentrations of various contents differed greatly, and the order was Ca-P>OP>Ads-P>Fe-P>Al-P. Significant positive correlations existed between TP and Ca-P, between Ads-P and OP, between Ads-P and Ca-P, and between Ads-P and OP. Negative correlations existed between Fe-P and Ca-P. The correlation between BAP and OP was also significant, and the effective internal phosphorus loads could be calculated roughly by OP. The contents of OP depended largely on the contents of the organic matter in the sediments.