pH值对微粒释放影响的微观机理研究  

Study on Microcosmic Mechanism of Particle Release Influenced by pH Value

作　　者：韩志勇[1] 冯欣[1] 郑泉[1] 黎叩晨[1] 

机构地区：[1]兰州理工大学石油化工学院,甘肃兰州730050

出　　处：《水文》2010年第5期7-11,共5页Journal of China Hydrology

基　　金：国家自然基金资助项目(40572142)

摘　　要：以典型水敏感性细砂为研究对象,通过水平室内砂柱试验,对不同pH值(pH=6,7,9)影响微粒释放过程的微观机理进行了探讨。研究结果表明:相同盐浓度条件下,pH值对微粒释放过程具有明显影响,酸性条件对微粒释放过程具有很强的抑制作用,致使砂柱存在二次释放现象,而碱性条件对微粒释放具有明显的增强作用,致使释放量大大增加,释放时间大大增长。微观力学分析可知,上述现象的原因是:不同pH值影响微粒物质与骨架颗粒zeta电位的变化,导致范氏引力与双电层斥力变化幅度发生差异,使得两者合力的大小和方向发生变化,在酸性条件下为引力占主导,碱性条件下为斥力占主导。With the study object of silver sand and level laboratory sand column experiments,the microcosmic mechanism for the particle release influenced by different pH values（pH=6,7,9） was discussed.The results indicate that different pH values have ob-vious influence effects on the particle release processes with the condition of same salt concentration.The acid atmosphere will re-strain the particle release strongly and result in a phenomenon of particle re-release.However,the trend of the particle release under alkaline conditions is strengthened obviously with behave of more release quantity and longer release time than the acid one.The reason for the above phenomenon can be gotten by analyzing microcosmic mechanics,and it is the change of the zeta poten-tial of the particles and sand grains under different pH value,which will result in the increase or decrease extents of the Van der Waals attraction and double electric layer repulsion changing discordantly,and it induces both the quantity and the direction of the resultant forces transforming,and the attraction and repulsion is dominant at acid and alkaline atmospheres respectively.

关 键 词：微粒释放 PH值 水敏感性 微观机理 

分 类 号：X523[环境科学与工程—环境工程]