肖洋+韩柯尧+成浩科+李青霞

基金项目:国家自然科学基金资助项目（51179055;51239003）

作者简介:肖洋（1974），男，贵州铜仁人，教授，博士，主要从事水力学及河流动力学研究。Email：sediment_lab@hhu.edu.cnDOI：10.13476/j.cnki.nsbdqk.

摘要：为探究泥沙分级后表面特性的变化规律，采集了鄱阳湖入江水道和长江南京段江心洲尾的泥沙，依据粒径分组对泥沙颗粒的级配和表面特性（比表面积、孔体积及孔径）进行了实验分析，结果表明，鄱阳湖入江水道和长江南京段泥沙颗粒均以黏粒、粉粒和细砂粒为主，比表面积范围为32~2512 m2/g，属于中孔材料；泥沙颗粒的比表面积随中值粒径的增大而减小，两者呈良好的幂指数关系，即在黏粒和细粉粒范围内，比表面积随中值粒径的减少而迅速减小；与分级沙样相比，混合沙样中值粒径与比表面积的关系与分级沙样趋势相近，量值略大于分级沙样；泥沙颗粒的相对比表面积和轴比较大，当粒径大于15 μm时，相对比表面积和轴比随泥沙粒径增大而缓慢增加，而当粒径小于15 μm时，随泥沙粒径增大相对比表面积和轴比急剧上升。

关键词：泥沙颗粒；表面特性；比表面积；鄱阳湖；长江

中图分类号：TV143文献标志码：A文章编号：16721683（2014）04004704

Surface Properties of Sediments in the Waterway of Poyang Lake to Yangtze

River and the Nanjing Reach of Yangtze River

XIAO Yanga，b，c,HAN Keyaob,CHENG Haokeb,LI Qingxiab

(Hohai university a State key laboratory of hydrologywater resources and hydraulic engineering;

b.College of water conservancy and hydropower engineering,Nanjing 210098,China;c.National engineering

research center of water resources efficient utilization and engineering safety,Nanjing 210098,China)

Abstract:The surface characteristics of sediments are important to understand the environmental impact of sediments.In order to investigate the effects of grain size and grading of different origins on surface properties of sediments,sediment samples were collected from the PoyangYangtze Waterway and Yangtze River in Nanjing,respectively.The sediments were divided into four particlesize fractions:030μm,3062μm,6290 μm,and 90125μm,and then the surface properties (specific surface area,pore volume,and pore diameter) were investigated.The results showed that (1) the sediments in the Poyang Lake and Yangtze River are mainly clay,silt,and fine sand,and the specific surface area is from 3.2 to 25.12 m2/g,indicating that the sediments are mesoporous materials;(2) the specific surface area is in a power exponent relationship with grain size,and it decreases with the increasing of grain size for silt and clay;(3) the relationship between the median grain size of mixing sediments and specific surface area is similar to that of grading sediments,with a slightly higher magnitude;and (4) the values of axial ratio and relative surface area increase along with the increasing of median diameter,and the increasing rates of axial ratio and relative surface area are much higher when the median grain size is in the range of 0~15 μm.

Key words:sediment;surface characteristics;specific surface area;Poyang Lake;Yangtze River

泥沙对污染物的物理吸附主要发生在泥沙颗粒表面，其平衡吸附量和吸附动力学过程与泥沙的表面特性直接相关，故研究泥沙颗粒的表面特性及其随粒径的变化规律是理解泥沙与污染物相互作用机理的基础。

在传统的泥沙研究中，描述泥沙颗粒几何特性的参数主要有：粒径、形状、圆度等［1］。……