A method for characterizing the pore size of microporous membranes

Abstract

The invention relates to a method for characterizing the pore size of a microporous membrane. The method includes the following steps: (1) Artificially modulating spherical SiO with a normal particle size distribution 2 Microspheres are configured into 10wt% suspension; (2) microporous membrane filters this suspension to simulate the raw water experiment; (3) adopts a laser particle size analyzer to test the particle distribution in the filtrate before and after filtration; (4) Filtered SiO 2 The particle size distribution data is fitted and converted; (5) Finally, the filtrate is dried, and the powder mass change before and after filtration is used as an auxiliary characterization. The present invention is different from the conventional bubble point method, mercury intrusion method and electron microscope photo method, and has the advantages of being closer to the actual use performance evaluation, low cost of consumables, good for the environment and testers, simple and fast test speed, and scientific image of the experimental results. It is very suitable for large-scale and multi-type membrane testing, and is conducive to the promotion of membrane products.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a method for characterizing the pore size of a microporous membrane. Background technique [0002] With the industrialization of our country, population urbanization and the rapid improvement of people's living standards, water consumption continues to increase, and the accompanying sewage discharge is also increasing day by day. Once the water resource crisis occurs, it may seriously restrict the sustainable development of our country's society and economy. Actively carrying out various types of sewage treatment and water recycling is one of the technical and economic countermeasures to solve the water resource crisis. Due to the different sources of pollution in the process of sewage treatment, the treatment methods vary widely. Among them, the application of membrane separation technology in water treatment has attracted extensive attention due to its high efficiency and stabi...

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Problems solved by technology

The disadvantage is that the bubble point pressure corresponds to the maximum pore size of the membrane, and errors will occur if the membrane is not completely wetted by the liquid during the actual measurement

Another indirect measurement method is the mercury injection method. This method is to inject mercury into the dry film and measure the volume of mercury under different pressures. The relationship between pressure and pore size satisfies the Laplace equation. The disadvantage of this method is that the equipment The cost is relatively high, and the measured pressure is also relatively high, and due to the high pressure required for the test, it will cause the deformation of the sample and make the result untrue, and the use of liquid mercury in the experiment is relatively not safe and environmentally friendly.

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