泥沙在紊动状态下的垂向分布及其对氨氮吸附影响

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。本文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。结果显示：（1）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；（2）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；（3）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。

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

Sediment is one of the main carrier of pollutants in water, it acts as a sink of pollutants under adsorption. The sedimentation and overhang of sediment have an important influence on the migration and transportation of pollutants. Herein, the vertical distribution of the surface sediment in the Three Gorges Reservoir area under different turbulence conditions was studied in a self-developed subsidence column. Furthermore, the fitting effects of quasi-first-order kinetics, quasi-second-order kinetics and Elovich models were compared. The results show that: (1) The suspended sediment in water body will be affected by many factors, and the distribution of sediment varies with different turbulence intensity, sediment dosage and different depth.(2) The adsorption of ammonia nitrogen by sediment is affected by the vertical distribution of sediment. The change of turbulence intensity and sediment concentration will make the adsorption process and total adsorption amount of ammonia nitrogen change. (3) The process of ammonia-nitrogen adsorption by sediment in turbulent state can be fitted by quasi-first-order kinetic model, quasi-second-order kinetic model and Elovich model, but the judgment of adsorption change and prediction trend of different models are different.