三峡库区悬浮态泥沙对磷酸盐的吸附特性研究

河流中的悬浮态泥沙对污染物质在河流中的输移转化过程具有十分重要的作用,就三峡库区悬浮态泥沙对磷酸盐的吸附特性展开研究,通过室内平衡吸附实验和吸附动力学实验对三峡库区悬浮态泥沙的泥沙粒径、初始泥沙浓度等关键要素对磷酸盐吸附特性的影响及其变化规律进行了探讨,主要结论如下:(1)研究了三种泥沙粒径在不同泥沙浓度时的吸附特性,认为泥沙对磷酸盐的吸附量随着泥沙浓度和粒径的增加呈递减趋势。(2)通过Langm iur吸附等温式的拟合,求取了相关的动力学参数,认为三峡库区悬浮态泥沙对磷酸盐的吸附是Langm iur型第五类吸附,在清样浓度和吸附量较高时出现吸附最大值,并随着清样浓度的继续增加而减少;(3)泥沙对磷酸盐的吸附量随着磷酸盐初始浓度增加而增加,达到吸附平衡的时间约为2~4 h。

Study on Adsorption of Suspended Sediments to Phosphate in the Three Gorges Reservoir Area

Suspended sediments play an important role in the transformation process of pollutants in rivers.The adsorption characteristic of suspended sediments in Three Gorges Reservoir Area to phosphate was studied in this paper.Based on the indoor adsorption balancing experiment and kinetic modeling experiment,the main factors for adsorption process of sediments(particle size of sediment,initial concentration etc.) were discussed.The major results of the experiment were as follows:(1) Three kinds of suspended sediments with different particle sizes were used for the study of adsorption characteristic with different sediment concentration.The amount of phosphate adsorption increased with the increase of the sediment concentration and sediment particle size.(2) With the help of Langmuir isotherm theory,the related parameters in kinetic model were estimated,the experiment results indicated that the adsorption isotherm of phosphate in Three Gorges Reservoir Area fitted with the fifth type of Langmuir adsorption isotherm,the maximum amount of phosphate adsorption would emerge when the phosphate concentration was relatively high,but it would move down when the phosphate concentration increased afterwards.(3) Phosphate adsorption increased with the increase of initial phosphate concentration,the average time for adsorption balance was 2-4 hours.