What to do if the microporous filtration membrane cannot filter the target substance

When using a filter membrane for directional substance filtration, the membrane material with a suitable pore size will be selected according to the size of the filter particles, but if the microporous filter membrane cannot filter the target substance, how to deal with it, here are a few suggestions, which can be obtained from the following steps Troubleshoot and seek possible solutions.

1. Check the aperture. Target substances and particles can be accurately measured to ensure that the pore size of the membrane is suitable for the target substance. If the pore size is too large, smaller particles may pass through the membrane. If necessary, select a membrane with a smaller pore size under the condition of ensuring the filtering effect. The gap between filter membrane pores and particles can vary depending on the size of the particles and the pore size of the membrane.

A typical characteristic of filtration membranes is the pore size, usually expressed in micrometers (µm) or nanometers (nm). For example, membranes with a pore size of 0.2 µm are commonly used to filter bacteria from liquids. The particle size that can pass through a filter membrane is determined by the pore size of the membrane and the size and shape of the particle. If a particle is larger than the pore size of the membrane, it will be captured and removed from the liquid or gas being filtered.

Another important purpose of measuring the structure of particles mentioned earlier is to note that not all particles are the same size and shape, and some particles may be able to pass through the filter membrane even if the size is larger than the pore size of the membrane.

2. Verify the chemical compatibility of membrane materials, different membrane materials have different chemical compatibility and performance. Chemical compatibility refers to the ability of the membrane to interact with the target substance without causing any adverse effects, for example, degradation or chemical reactions that may result in formation, etc. Of course, these confirmations should be done before use, to ensure that the membrane The material is suitable for the target substance and solvent, and if necessary, a more suitable membrane made of a different material can be exchanged.

3. Integrity inspection of the membrane, checking the membrane for any signs of damage or defects that may affect filtration performance. If the membrane is damaged, replace it with a new one.

4. Evaluate whether the conditions of filtration are suitable, because pressure, temperature and flow rate will affect the performance of the filtration process. Especially in combination with the above inspection, in the case of too high pressure, temperature, and flow rate, it will have a bad effect on the membrane itself and the filtration effect. Check these parameters and adjust them if necessary to improve filtration efficiency.

5. Appropriate optimized pretreatment will improve the quality of all filtration. If the target substance exists in a complex mixture, please consider using prefiltration or other pretreatment methods to remove larger particles and contaminants that may interfere with the filtration process.

6. The method of applying multi-step filtration is a good choice. This method can separate other factors that affect the filtration target substance as much as possible, and complete precise processing, because for some complex mixtures, only a single filtration step is not enough. Different filtration methods or membranes with different pore sizes will be more effective in achieving the desired results.

7. Changes in filtration methods. If microporous filtration is still ineffective, alternative filtration technologies such as ultrafiltration, nanofiltration or reverse osmosis can be considered. Modern membrane technology has already matured and can be filtered according to the target substance and required filtration performance. , to perform a more suitable filtering method.

The above is a summary of the failure to filter the target substance. It is important to note that the filtration process and requirements must be fully analyzed before any adjustments are made to avoid potential other anomalies.

Citations

1.Kim, J.-H.,& Lee, S. (2003). Chemical compatibility of polymeric materials used inmicrofiltration membranes. Journal of Membrane Science, 215(1-2), 173-186. doi:10.1016/S0376-7388(02)00524-0

2.Park, H. B.,& Kammermeyer, K. (1995). Chemical compatibility of polymeric membranes formicrofiltration. Journal of Membrane Science, 105(2), 175-193. doi:10.1016/0376-7388(95)00064-2

3.Ko, Y. G.,Lee, J. H., & Kim, W. S. (2004). Chemical compatibility of polymericmaterials used in microfiltration membranes. Journal of Industrial andEngineering Chemistry, 10(1), 67-76. doi: 10.1016/S1226-086X(04)00014-6