水处理滤料填充床流动电位测定的可行性研究  

Study on the feasibility to measure the streaming potential of the filter media in a packed bed

作　　者：李闯[1] 常青[1] 杨斌武[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《安全与环境学报》2009年第1期41-44,共4页Journal of Safety and Environment

基　　金：国家自然科学基金资助项目(50578072)

摘　　要：根据流动电位与ζ电位的关系,设计研制了一台测定滤料表面流动电位的装置,并测定了石英砂、核桃壳、沸石滤料的流动电位。研究滤料流动电位的稳定时间及压差对稳定时间的影响,并讨论电解质溶液pH值对滤料流动电位的影响。结果表明,1)pH=7.0、压差为2 cm水柱时,石英砂、核桃壳和沸石流动电位的稳定时间分别为45min、60 min和120 min;2)压差越大,各滤料流动电位的稳定时间越短,因此在保证水流流态为层流条件下,应尽量在大压差条件下测定流动电位;3)随着电解质溶液pH值的升高,各滤料流动电位由正值向负值转变,其中石英砂滤料的等电点约在pH=5.0,核桃壳和沸石滤料约在pH=3.0。可见,研究滤料表面的流动电位对提高过滤效率以及开发改性滤料十分重要。This paper intends to report our study on measuring streaming potential of filter media and introduce an improved measuring device for it so as to provide some more accurate information and technical guide on how to construct such simple streaming devices properly. Due to the diversity of streaming potential and zeta potential values reported in the literature concerned, it has become necessary to design such a device for measuring streaming potential of filter media. Knowing the principle of the technology, it will be easy to use such a device to study many kinds of granular materials. Generally speaking, it has become a well-known technical practice to carry out such measurements in the electrolyte solution of KCl at a well-controlled temperature of 25 ℃ . The paper has also discussed the problem on how to display the streaming potential and its influential factors in addition to measuring of the streaming potentials of quartz sand, walnut shell and zeolite by using the above device. We have examined the stability time of the filter media and the influence of pressure on stability time, meanwhile researched the influence of the pH values on the streaming potential. The results show that, （1） When the pressure descents are equal to 2 cm water column （pH = 7.0）, the stability time of quartz, walnut shell and zeolite can be 45 min, 60 rain, 120 rain respectively; （2） The higher the pressure, the shorter the stability time, therefore it is necessary to measure the streaming potential under the condition of laminar flow and the higher pressure ; （3） The streaming potential tends to change from positive value to negative one as the pH value turns from lower to higher. Thus, the isoelectric points of quartz, walnut shell and zeolite can be shown as follows ： pH = 5.0 around, pH = 3.0 around, pH = 3.0 around, respectively.

关 键 词：环境工程 流动电位 Ζ电位 过滤 滤料 含油废水 

分 类 号：X703.1[环境科学与工程—环境工程]