河流泥沙磷迁移过程的数学模型研究  

Mathematical model of phosphorus transport with river sediment

作　　者：黄磊[1] 方红卫[1] 王靖宇[1] 何国建[1] 

机构地区：[1]清华大学水利水电工程系水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水利学报》2014年第4期394-402,共9页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点基金项目(51139003)

摘　　要：水体中磷的迁移转化过程,对于河流生态环境有着至关重要的影响。传统的水质模型缺乏对磷迁移转化过程机理和规律的深入探讨与分析。本文建立河流中水动力-泥沙-磷迁移过程的分相模型,在水流运动与泥沙输移模拟的基础上,从基本的化学反应出发,研究磷在河流中的迁移过程。首先,考虑天然河流中磷的来源及其不同形态,基于泥沙颗粒表面电荷非均匀分布的认识,利用修正后的表面络合模型研究悬移质泥沙对磷的吸附;其次,分析有氧与无氧条件下泥沙颗粒中铁/铝(氢)氧化物的不同形态,以描述磷在活性底泥层中的赋存形式;然后,重点关注河床冲淤变形,分析磷在河床表面的沉积与再释放。最后,本文设计磷水槽试验,分析泥沙颗粒运动对磷迁移的影响,并对模型进行验证。结果表明,泥沙运动对磷迁移有显著影响,磷浓度沿程分布与含沙量间存在较好的线性关系,尤其是溶解相磷;本文建立的模型可以合理地反映磷随着泥沙颗粒的迁移过程。Phosphorus transport in natural water plays a crucial role in ecological environment. Traditional models of water quality mostly simplify such processes into some empirical parameters, without a comprehen-sive understanding of the intrinsic mechanisms. In this paper, a model of hydrodynamic-sediment-phospho-rus transport has been established, in which the chemical and sediment dynamics are integrated to study the phosphorus transport with river sediment. The phosphorus adsorption by sediment is considered using the modified surface complexation modeling based on the heterogenous surface charge distribution of natural sediment. In addition, the aerobic layer and anaerobic layer are distinguished to study the distribution of phosphorus between dissolved phase and particulate phase in the active sediment layer. Furthermore, the riv-erbed deformation is introduced to analyze the deposition and release of phosphorus at the bed surface. A flume experiment is designed to study the effects of sediment on phosphorus transport and validate the mod-el. The results show that the phosphorus concentration is linearly correlated with sediment concentration, and the proposed model can reasonably reflect the phosphorus transport with sediment.

关 键 词：河流泥沙 磷迁移 水槽试验 

分 类 号：P333.4[天文地球—水文科学] TV131.2[水利工程—水文学及水资源]