pH值对玄武湖沉积物中磷的释放及形态分布的影响

Influence of pH Value on the Release and the Chemical Fractions of Phosphorus in Sediments of Xuanwu Lake

为了探讨pH值对沉积物中磷释放行为的影响,采用淡水沉积物中磷形态标准测试程序(SMT)研究了玄武湖沉积物中磷形态分布情况,并通过室内模拟实验研究了不同pH值条件下沉积物中不同形态磷的释放行为。结果表明,在玄武湖沉积物的总磷(TP)中,NaOH-P赋存比例最高(370.42～414.65mg·kg-1),其次是HCl-P(359.41～378.64mg·kg-1),有机磷(OP)含量最低(237.23～276.86mg·kg-1)。酸性条件下,促进HCl-P的释放,NaOH-P的百分含率显著升高,而OP和HCl-P的百分含率则均明显下降;碱性条件下,促进NaOH-P的释放,HCl-P的百分含率升高,OP和NaOH-P的百分含率则均出现了下降现象。研究表明,pH值对沉积物中磷的释放以及磷形态在磷释放过程中的重新分布均具有重要影响。

To investigate the influence of pH value on the release behavior of phosphorus from sediments, the chemical fractions of phosphorus in sediments of Xuanwu Lake were investigated by using the SMT extraction procedure. The release behavior of phosphorus from sediments under different pH values was also investigated in lab. The results showed that the most abundant portion of total phosphorus in these sediments was NaOH-P （370.42-414.65 mg·kg^-1）, then followed by HCl-P （359.41-378.64 mg·kg^-1） and organic phosphorus （OP, 237.23- 276.86 mg·kg^-1）. The HCl-P was released under acid conditions, while the percentage of NaOH-P in total phosphorus in sediments was increased significantly, but OP and HCl-P decreased. Besides, the NaOH-P was prone to be released under alkaline conditions, while the percentage of HCl-P in total phosphorus in sediments was increased, and OP and NaOH-P decreased. It could be concluded that the pH value would influence significantly on the release behavior of phosphorus in sediments and the distributions of chemical fractions of phosphorus in sediments.