What is the performance degradation mechanism of ro membrane in long-term operation?
Release Time : 2025-02-17
The primary reason for the degradation of RO membrane performance is membrane fouling. During long-term operation, various pollutants such as organic matter, inorganic salts, and microorganisms will accumulate on the membrane surface. These pollutants will block the membrane pores, reduce the rate at which water molecules pass through the membrane, and lead to a decrease in filtration efficiency. Membrane fouling not only affects the water output, but may also reduce the desalination rate and make the water quality of the produced water worse.
Membrane aging is also an important factor leading to the degradation of RO membrane performance. Over time, the membrane material will gradually age due to long-term exposure to water, high pressure, and chemicals. Its physical and chemical structure may change, such as shrinkage or expansion of membrane pores, and degradation of membrane materials, which will reduce the water permeability and selectivity of the membrane.
Chemical degradation also has an adverse effect on the performance of RO membrane. Chemicals such as disinfectants and pH regulators used in reverse osmosis systems may have an adverse effect on membrane materials, resulting in degradation of membrane material performance. For example, free chlorine will deteriorate the performance of aromatic polyamide membranes, while cellulose acetate membranes may hydrolyze under acidic or alkaline conditions.
Mechanical damage is also one of the reasons for the degradation of RO membrane performance. The impact of water flow, improper installation or squeezing during transportation may cause physical damage to the membrane, affecting its structural integrity and filtration performance. Mechanical damage may cause membrane pore rupture or scratches on the membrane surface, thereby reducing the membrane's water permeability and desalination rate.
Compaction effect is also a factor in membrane performance degradation. Under long-term high-pressure operation, the membrane may cause a decrease in water permeability due to compaction effect. This compaction effect may cause the membrane pore structure to change due to long-term pressure, reducing the permeable area.
Changes in operating conditions may also accelerate the performance degradation of ro membranes. Unsuitable operating conditions, such as excessively high temperatures, too low pH values or too high operating pressures, may have an adverse effect on membrane materials and accelerate their aging and chemical degradation.
The performance degradation mechanism of ro membranes in long-term operation involves multiple factors such as membrane fouling, membrane aging, chemical degradation, mechanical damage, compaction effect and operating conditions. In order to extend the service life of ro membranes and maintain their stable performance, effective pretreatment, regular cleaning and maintenance, and optimization of operating conditions are required.