摘要
絮凝体广泛存在于自然界水体中,而在河口海岸动水环境下的黏性细颗粒泥沙的絮凝变化过程是一个重要且有待完善的研究课题。利用长江口北槽现场悬沙样本开展了系统的室内絮凝实验。采用粒径分布与有效粒径两种分析方法,研究了在水流紊动、盐度和悬沙浓度等不同絮凝因子条件作用下对长江口北槽泥沙絮凝体粒径变化的影响。实验结果表明:紊动剪切率对絮凝体粒径作用为先促进后减小,临界值出现在23. 09 s^(-1),此时最大有效粒径为50. 26μm;而悬沙浓度会抑制絮凝体生长;同时长江口北槽悬沙的絮凝饱和盐度要大于高岭土,约为14. 4 ppt。
Flocs are widely found in natural waters, and the flocculation process of viscous fine-grained sediments in the dynamic water environment of the estuary is a significant topic and yet to be studied. Systematic laboratory flocculation experiments were carried out by using suspended sediment samples from the North Channel of the Yangtze Estuary. The effects of different flocculation factors such as turbulent shear rates, salinity and suspended sediment concentration on the particle size change of sediment flocs were analyzed by means of particle size distribution and effective particle size. The experimental results indicate that the floc size under turbulent shear rates is firstly promoted and then reduced, and the critical value appears at 23.09 s ^-1 . The maximum effective particle size is 50.26 μm, and the suspended sediment concentration inhibits the growth of flocs. At the same time, the flocculation saturation salinity of the sediment in the north channel of the Yangtze River estuary is greater than that of kaolin, which is about 14.4 ppt.
作者
海希
邵宇阳
张健玮
HAI Xi;SHAO Yu-yang;ZHANG Jian-wei(College of Harbour, Coastal and Offshore Engineering, Hohai University ,Nanjing 210098,China;Changjiang Water Resources Commission of The Ministry of Water Resources , Shanghai 200136,China)
出处
《科学技术与工程》
北大核心
2019年第11期262-266,共5页
Science Technology and Engineering
基金
国家重点研发计划(2017YFC0405402)
国家自然科学基金重点项目(51339005)
国家自然科学基金青年项目(51409081)
江苏省研究生科研与实践创新计划项目
中央高校基本科研业务费(学生项目)(2018B640X14)资助
关键词
絮凝
紊动剪切率
盐度
悬沙浓度
粒径分布
有效粒径
flocculation
turbulent shear rates
salinity
suspended sediment concentrations
particle size distribution
effective particle size
