【摘要】 研究了黄河干流内蒙古段6个地理位置的沉积物对磷的吸附行为,并分析了沉积物组成及其理化性质与磷吸附特征的关系.结果表明,沉积物对磷的最大吸附量为43.64～85.46 mg/kg,吸附能力较弱.各沉积物的吸附/解吸平衡磷浓度(EPC0)范围在0.000 3～0.019 8 mg/L,与可解吸的内源磷含量正相关,与地理位置没有表现出相关性.本研究条件下,在石嘴山、乌拉特前旗、清水河断面,沉积物对磷表现为"源";在乌海、临河、包头断面表现为"汇",但释放量和吸附量不大.内蒙古段黄河沉积物对磷吸附的Langmuir吸附常数(k)与阳离子交换量(CEC)、有机质含量、粘土含量均呈正相关,与平均粒径呈负相关.活性态Fe含量与最大吸附量显著正相关,是沉积物对磷的主要持留因素.更多还原

【Abstract】 Sorption behavior of phosphorus on sediment samples taken from Inner Mongolia reach of the Yellow River in 6 different geographical sites was determined in laboratory,and the correlation between chemical-physical properties of the sediments and their phosphorus sorption characteristics was analyzed.The maximum sorption capacities were 43.64-85.46 （mg/kg）.The zero equilibrium P concentration（EPC₀） of the sediments ranged from（0.0003） to（0.0198）（mg/L）,which was positively correlated to the contents of native adsorbed P（NAP）.The sediments played a dual role of sink and source of P at different geographical sites.Sediments from Shizuishan,Wulateqianqi and Qingshuihe along the Yellow River were sources of phosphorus,while sediments from Wuhai,Linhe and Baotou cross sections were sinks of phosphorus,at the typical P concentrations of the river water.However,both the sorption and desorption capacities were low at the conditions tested here.The Langmuir sorption constant（k） was positively correlated to the cation exchange capacity（CEC）,organic matter and clay mineral content,but negatively correlated to the particle size of the sediments.The maximum sorption capacity of phosphorus was remarkably correlated to the active Fe content.Active Fe played a key role in holding phosphorus on the sediments.更多还原