白洋淀沉积物理化特性及营养盐分布特征

On the physico-chemical characteristic features and the nutrient distribution in the sediments of Lake Baiyangdian

为明确白洋淀沉积物的理化特性和氮磷营养盐的分布及赋存形态,以便理解营养盐在淀内生态环境中的行为,选取表层沉积物,测定了其物理化学参数及氮磷营养盐的分布。结果表明,白洋淀沉积物组成以黏土为主,属偏碱性钙质土,其阳离子交换量和有机质质量比分别为96.55~306.93 cmol/kg、1.42~21.06 g/kg,总氮和总磷的质量比分别为1 608.04~2 350.68 mg/kg、257.48~563.34 mg/kg。氮主要以有机氮形态存在,磷主要以钙磷形态存在。沉积物中总氮与总磷无显著相关性,表明二者没有同源性,但总磷与有机质有一定相关性。

The aim of this paper is to investigate the particular physi- co-chemistry characteristics and the situation of the nutrient distribu- tions of the sediments of the Lake Baiyangdian, a very large and im- portant shallow lake in Hebei, North China. This work is of great im- portance to promote deeper understanding of the ecological environ- ment specialties of the nutrients in the lake. The physical-chemical characteristics for example, the soil particle diameter, the cation ex- change capacity （CEC）, pH value, the oxidation-reduction potential （Eh） and the organic matters （OM） in 9 surface sediments in the lake were determined. At the same time, the distributions of nutrient salts of nitrogen, phosphorus and their fractional compositions were mesured. The determination results show that the sediments in tile studied area are composed mainly of clay minerals. Since the sedi- ments of the lake have been found neutral with the calcareous soil be- ing affected by the weak alkaline, the concentrations of CEC and OM have been found in a range between 96.55 - 306.93 cmol/kg and 11.42-21.06 g/kg respectively. Moreover, the total nitrogen and the total phosphorus in the sediments account for 1 608.04 -2 350.68 mg/kg, 257.48 -563.34 mg/kg in their concentrations. Whereas the organic nitrogen serves as the main fraction of nitrogen, the calci- um boned phosphorus can be found as the major fraction of phospho- rus. Thus, these results of our analysis can be found beneficial for defining the bio-available phosphorus in the sediment. What is more, the correlation analysis fails to discover any remarkable positive cor- relative factors between TP and TN in the samples under study. Rather, the said results we have gained prove that the sediments orig- inate from the two different nutrients of the Lake. Nevertheless, we have found that there indeed exists a remarkable positive correlation between TP of sediments and OM, which can serve as evidence that it should never ignore the effects of the organic matters on the phospho- rus release. Therefore, the endogenous loadings and the species of nitrogen and phosphorus in the surface sediments can actually provide a firm basis for further research necessity over the nutrient release from the water-sediment interface.