阳离子浓度对泥沙沉速影响实验研究  

Experimental study on effect of positively charged ion in river on the velocity of sediment particles

作　　者：王家生[1] 陈立[1] 刘林[1] 邓晓丽[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《水科学进展》2005年第2期169-173,共5页Advances in Water Science

基　　金：国家重点基础研究发展计划(973)资助项目(2003CB415205);国家自然科学基金资助项目(50479036);湖北省创新群体基金项目(2003ABA195);博士点基金项目~~

摘　　要：应用了静态沉降实验方法中的移液管法,初步研究了水中常见阳离子对河流中细颗粒泥沙沉速的影响,这些阳离子包括Na+、Ca2+、Mg2+和Al3+等。实验结果表明,阳离子浓度对泥沙沉速的影响可以分为两个阶段:①随着阳离子浓度的增加泥沙沉速也增大;②当离子浓度大于某值时,离子浓度对泥沙沉速的影响不大。在同样离子浓度条件下,离子价态高者影响较大。同时分析了长江和黄河干流中下游河段的水化学特性;分析结果表明,在一般的河水水质的情况下,有必要考虑水中阳离子(主要是Ca2+、Mg2+)对细颗粒泥沙沉速的影响。The cations in natural river would influence the velocity of sediments especially the fine sediment. The main reason of settling velocity affected by cations is the flocculation of fine grain sediments. On the basis of the experimentation of sediments settling in water with different ions concentration, the relationship between settling velocity and the positive ions concentration is given. The positive ions include Na, Ca, Mg2+ and Al3+ etc. The way used in the experimentation is called the pipette-way. The results of the experimentation show that the press can be divided into two phases: (1) The settling velocity will increase when the concentration of positively charged ion increase; (2) If the concentration of positively charged ions are excess of some critical, the settling velocity would not be change, or changed a little as the concentration increase. When different positively charged ions have the same concentration, the ion with higher valency has more influence on sediments settlement. Analyzing the characteristic of hydrochemistry in accordance with the data from the Yangtze River and the Yellow River, we can know that it is necessary to consider the effect on sediment settling velocity by the concentration of cations on condition of the ion concentration in the nature river.

关 键 词：阳离子 离子浓度 沉降试验 泥沙絮凝 泥沙沉速 

分 类 号：TV142[水利工程—水力学及河流动力学]