洪泽湖不同湖区表层沉积物对磷的吸附特征

研究了洪泽湖9 个湖区表层沉积物对磷的吸附行为和沉积物对磷的吸附/解吸平衡质量浓度, 并分析了沉积物理化性质与磷吸附特征参数的关系。结果表明, 在低磷浓度条件下(0~1 mg/L), 沉积物对磷的最大吸附量为50.67~85.17 mg/kg, 沉积物在磷酸盐初始质量浓度较低时都存在负吸附(释放)现象。各湖区沉积物的吸附/解吸平衡磷浓度(EPC0) 范围为0.06~0.11mg/L, 均小于其上覆水中磷的含量, 沉积物对其上覆水中的磷表现为吸附作用。沉积物最大磷吸附量(Q_max)、本底吸附态磷量(NAP) 和总最大吸附磷量(TQ_max) 与沉积物中活性铁和活性铝的含量显著正相关, 与沉积物中总磷、无机磷、有机磷和有机质的含量相关性不显著。吸附/解吸平衡浓度(EPC₀) 与沉积物各理化参数之间没有表现出显著相关性。

Characteristics of Phosphorus Sorption on Surface Sediments of Hongze Lake

Sorption behavior and adsorption-desorption equilibrium mass concentration of phosphorus on surface sediments samples taken from Hongze Lake at nine sites were determined in laboratory, the correlation between chemical-physical properties of sediments and their phosphorus sorption characteristics were analyzed. Under low mass concentration conditions, the maximum phosphorus sorption capacities were 50.67-85.17 mg/kg, and there was a negative sorption process during phosphate sorption on surface sediments. The zero equilibrium P concentration (EPC0) of the sediments ranged from 0.06 to 0.11 mg/L, less than the level for the overlying water, showing a positive phosphate adsorption on surface sediments. The maximum phosphate adsorption, NAP and the total maximum phosphate adsorption were positively correlated with active iron and active aluminous contents in the sediments, but had poor correlation with total P, organic P, inorganic P and organic matter in the sediments. The zero equilibrium P concentration (EPC0) had poor correlation with chemical-physical parameters of surface sediments.