Will high concentrations of substances affect the life cycle of the filter membrane?

High concentrations of substances can affect the membrane life cycle. The specific effect depends on the type of substance and the material of the filter membrane. Here are some factors to consider:

1. High concentrations of particulate matter, organic compounds or colloids will cause fouling of the filter membrane, that is, these substances accumulate on the surface of the membrane, block the pores, and reduce the overall filtration efficiency. Because complex colloids usually contain particles smaller than the pore size of the filter membrane. These particles can pass through the membrane and accumulate on the surface, causing fouling. Particles in complex colloids may have different surface charges, which can cause them to attract or repel each other, and can also cause particles to aggregate and form deposits on the membrane surface. At the same time, its chemical composition will also affect the interaction with the filter membrane, including the shear force generated during flow, and the pollution generated by adsorption, etc., which will cause the formation of fouling. As fouling progresses, the pressure required to maintain the filtration process may increase and more frequent membrane cleaning or replacement may be required.

2. The influence of chemical degradation on the life cycle of the membrane. Some filter membranes will be chemically degraded due to the high concentration of certain substances, resulting in the decomposition or chemical changes of the membrane substances, and the changes in the properties or structure of the membrane. For example, in the membrane material Some of the polymers used are attacked by high concentrations of acids, bases or oxidizing agents, resulting in degradation of mechanical strength or integrity, which can lead to premature failure of the membrane.

3. The effect of substances such as salt on the membrane, such as in the case of reverse osmosis (RO) or nanofiltration (NF) membranes, high concentrations of salt or other dissolved solids can cause fouling, that is, these substances precipitate on the membrane surface , Long-term accumulation will form fouling, forming stubborn deposits on the surface or the inner wall of the membrane pores, which will reduce the permeability, flow and other factors of the membrane, requiring more frequent cleaning or replacement.

4. The accumulation of biological fouling, some high concentrations of microorganisms or nutrients will lead to the growth of biofilm on the surface of the filter membrane. Although this type of organism is not as complicated as the above mentioned situations, it will reduce the filtration efficiency and may cause harmful side effects. product production. Biofouling also increases the pressure required to maintain the filtration process, which puts additional stress on the membrane and shortens its life cycle.

Therefore, when selecting and using filter membrane materials, it is necessary to consider application conditions and costs, appropriate selection, etc. In order to alleviate these problems mentioned above, the filter membrane system must be properly maintained and monitored, including regular cleaning and monitoring of influent water quality And consider the pretreatment plan to reduce the concentration of substances that may have a negative impact on the life cycle of the membrane, and use scientific methods to maintain the filtration membrane, etc.

Citation

1.Drioli, E., & Curcio, E. (2018). Membrane engineering for sustainable development: A review and perspective. Journal of Membrane Science, 550, 33-70.

2.Kimura, K., & Amy, G. (2018). Membrane fouling control in membrane bioreactors (MBRs) for wastewater treatment. Water Research, 133, 27-42.

3.Zhang, X., Zhao, Y., Chen, V., & Chen, G. (2018). Membrane fouling control in ultrafiltration: A review. Journal of Membrane Science, 549, 101-114.