水体扰动对三峡库区泥沙磷吸附解吸特性的影响

Effects of Water Disturbance on Phosphorus Adsorption and Desorption Properties in Sediment from the Three Gorges Reservoir Area

选取三峡库区上游寸滩河段泥沙,研究在不同水体扰动强度下三峡库区泥沙对磷的吸附解吸特性。结果表明,泥沙对磷的吸附可分为快速和慢速两个阶段,符合准二级动力学模型,Langmuir能较好地描述三峡库区泥沙对磷的等温吸附行为。单位质量泥沙对磷的吸附量随着扰动强度增大而增大,250 r/min转速下单位质量泥沙对磷的平衡吸附量是静置(0 r/min)条件下的1.39倍。饱和吸附磷的污染泥沙对磷的解吸动力学过程也分为快、慢两个阶段,符合准二级动力学模型,在中等、较强强度的扰动下,污染泥沙对磷的解吸随着扰动强度增强而增加,但当扰动强度较小时(如100 r/min),泥沙对磷解吸量与静置时相近,说明泥沙对磷的吸附有一定的稳定性。

The sediment in the inch beach river in the upper reaches of the Three Gorges Reservoir was selected to study the adsorption and desorption characteristics of phosphorus in the Three Gorges Reservoir area under different water disturbance intensities.The results show that the adsorption process of phosphorus by sediment can be divided into two stages:fast and slow,which conforms to the quasi-second-order kinetic model.Langmuir can describe the isotherm adsorption behavior of phosphorus by sediment in the Three Gorges reservoir area.The adsorption amount of phosphorus per unit mass of sediment increases with the increase of the disturbance intensity,and the equilibrium adsorption amount of phosphorus per unit mass of sediment at a speed of 250 r/min is 1.39 times that under the condition of standing(0 r/min).The desorption kinetics of phosphorus from polluted sediment with saturated adsorption of phosphorus is also divided into two stages:fast and slow,which conforms to the quasi-second kinetic model.Under moderate and strong disturbances,the desorption of phosphorus by polluted sediments increases with the increase of disturbance intensity.But when the disturbance intensity is small(for example,100 r/min),the desorption of phosphorus by sediments is similar to that of standing still,which shows that the adsorption of phosphorus by sediment has a certain stability.