泥沙在紊动状态下的垂向分布及其对氨氮吸附影响

Vertical Distribution of Sediment in Turbulent State and Its Influence on Ammonia Nitrogen Adsorption

泥沙是自然水体中污染物的主要载体,在吸附作用下,泥沙成为污染物的“汇”。泥沙的沉降、悬扬对于污染物的迁移和输运有着重要的影响。以三峡库区表层泥沙为研究对象,在自研的沉降柱中进行了不同紊动条件下的泥沙的垂向分布研究,对准一级动力学、准二级动力学、Elovich模型对吸附过程的拟合效果进行了对比。结果表明:水体中的悬浮泥沙受多种因素影响,不同紊动强度、泥沙投加量以及不同深度下泥沙的分布有所差异;泥沙对氨氮的吸附受泥沙垂向分布的影响,紊动强度及含沙量的改变会使得泥沙对氨氮的吸附过程及总吸附量发生改变;准一级动力学、准二级动力学、Elovich模型都能够对紊动状态下泥沙吸附氨氮过程进行拟合,但不同模型对吸附变化的判断及趋势的预估有所不同。

Sediment is one of the main carrier of pollutants in water,it acts as a sink of pollutants under the action of adsorption.The migration and transportation of pollutants are largely affected by the sedimentation and overhang of sediment.The sedimentation was designed and built to study the vertical distribution of the surface sediment in the Three Gorges Reservoir area under different turbulent conditions.Furthermore,the fitting effects of quasi-first-order kinetics,quasi-second-order kinetics and Elovich models on the adsorption process were compared.The result shows that the suspended sediment in water may be affected by many factors,and the distribution of sediment varies with different turbulence intensity,sediment dosage and different depth.With the vertical distribution of the sediment changes,the adsorption behavior of ammonia nitrogen changes.Similarly,the adsorption process and total adsorption capacity of ammonia nitrogen is affected by turbulence intensity and sand content.The process of adsorption in turbulent state can be fitted by the three models,but the judgments on the adsorption process and prediction of the adsorption trend are different.judgment of adsorption change and prediction trend of different models are different.