盐度和腐殖酸共同作用下的长江口泥沙絮凝过程研究  

Flocculation process of fine-grained sediments by the combining effect of salinity and humus in the Changjiang Estuary in China

作　　者：刘启贞[1] 李九发[2] 徐灿华 戴志军[2] 李道季[2] 

机构地区：[1]上海市环境监测中心,上海200030 [2]华东师范大学河口海岸学国家重点实验室,上海200062 [3]上海市城市排水有限公司,上海200070

出　　处：《海洋学报》2008年第3期140-147,共8页

基　　金：国家自然科学基金资助项目(50579021);“973”国家重点基础研究发展规划资助项目(2002CB412405)

摘　　要：长江河口有机质含量丰富,盐度变化较大,因此研究长江河口以细颗粒泥沙为主的多因子共同作用下的絮凝有助于了解最大浑浊带的形成机制。通过实验研究盐度和腐殖酸共同作用对长江口细颗粒泥沙浊度变化影响的过程,从浊度相对变化率、絮团粒径和电位变化三方面综合分析了其絮凝机理,并且对絮凝体进行了红外和电镜分析,探讨了絮凝体的微观结构。结果表明:(1)随着盐度增大细颗粒泥沙浊度相对变化率逐渐增大,粒径增大,而电位绝对值变小;(2)随着腐殖酸浓度增大细颗粒泥沙浊度相对变化率先略有升高后迅速降低,粒径增大,电位绝对值增大;(3)微观结构的分析表明腐殖酸是以腐殖酸盐的形式包覆在泥沙表面,同时也验证了河口中C-P-OM(C代表黏土,P代表阳离子,OM代表有机化合物)的泥沙絮凝模式。For the great amount of organic compounds and the variation of salinity in the Changjiang Estuary, the study on the flocculation process of fine-grained sediments by the combining effect of salinity and humus on the high-turbid system is of critical significance in the understanding of the mechanism of the formation of maximum turbidity zone. The effects of salinity and humus on the fine-grained sediments are analyzed through the synthetic study of the aspects of flocculation/coagulation power, diameter and electric potential. And the microcosmic configuration of the flocs is analyzed by using the scan electron microscope and Fourier transform infrared spectrometry. The results show that： （1） with the increase of salinity, floculation/coagulation power and diameter become greater and the electric potential becomes smaller, and with increase of the concentration of humus, flocculation becomes smaller, but the diamerer and the electric potential become greater; （2） the microcosmic configuration of the flocculation shows that humus packs on the fine sediments in the form of salt, and the flocculation model of clay-positive ion-orgamic compound can successfully demonstrate the mechanism of the formation of the fine-grained sediments in the high-turbid area of Changjiang Estuary.

关 键 词：长江河口 有机质 盐度 细颗粒泥沙 絮凝 

分 类 号：TV148.1[水利工程—水力学及河流动力学] P734.232[天文地球—海洋化学]