有机质对三峡库区水体中土壤胶体颗粒凝聚影响机制研究

发布时间：2018-04-21 18:42

本文选题：三峡库区 + 有机质　；参考：《水土保持学报》2017年04期

【摘要】：采用联合测定法和光散射技术分别研究了有机质对土壤颗粒表面电荷性质和水体中胶体颗粒凝聚过程的影响。结果表明:添加有机质能显著改变土壤表面电荷性质,使得土壤颗粒表面电荷数量降低6.8%,比表面积增加12.3%,使颗粒表面电荷密度减小,表面电位降低;进一步理论计算表明添加有机质降低了胶体颗粒间的静电排斥力,使得净引力增大,胶体颗粒更易发生凝聚。通过动态光散射分析水体中土壤胶体颗粒的凝聚特征,发现有机质去除前后的临界聚沉浓度(CCC)分别为91.6 mmol/L和139.3mmol/L,去除有机质土壤显著大于未去除有机质的土壤,相应浓度下的临界电位值计算结果均为-150mV左右,与颗粒间出现净引力的临界浓度值基本一致。有机质对水体中胶体颗粒凝聚特性的影响主要是通过改变颗粒表面性质使得颗粒间的相互作用发生变化而引起。
[Abstract]:The effects of organic matter on the surface charge properties of soil particles and the condensation process of colloid particles in water were investigated by combined determination of organic matter and light scattering. The results showed that the charge properties of soil surface could be significantly changed by adding organic matter, the surface charge quantity of soil particles was reduced by 6.8%, and the surface area was increased by 12.3%, so that the surface of the particles was electrically charged. The charge density decreases and the surface potential decreases. Further theoretical calculation shows that the addition of organic matter reduces the electrostatic repulsion between the colloid particles, making the net gravitation increasing and the colloid particles more likely to be condensed. Through the analysis of the condensation characteristics of the colloid particles in the water body by dynamic light scattering, the critical settlement concentration (CCC) of the organic matter before and after the removal of organic matter is found. For 91.6 mmol/L and 139.3mmol/L, the soil removal of organic matter is significantly greater than that of unremoved organic matter. The calculation results of the critical potential value at the corresponding concentration are about -150mV, and the critical concentration of the net gravitation is basically the same. The effect of organic matter on the agglomeration of colloid particles in water is mainly through the change of the particle table. The properties of the surface cause the interaction between particles to change.

【作者单位】：重庆文理学院环境材料与修复技术重庆市重点实验室;西南大学土壤多尺度界面过程与调控重庆市重点实验室;
【基金】：国家自然科学基金项目(41101223,41501240) 重庆市自然科学基金项目(cstc2014jcyjA80031,cstc2015jcyjA80015) 重庆市教委科技项目(KJ1501115) 重庆市大学生创新性训练计划项目(201410642005)
【分类号】：S153.6

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