MBR membranes are increasingly widely used in sewage treatment and play an indispensable role in water treatment. Many customers have various problems during the use process, which reduces the lifespan of the MBR membrane. What substances in the sewage that can damage the membrane? I hope this article will give you more information.
What are the features of the MBR membrane?
(1) The hydrophilic property of the membrane is good.
(2) Large water flux.
(3) MBR membrane has high anti-fouling properties.
(4) The recovery of membrane flux is strong.
(5) The tensile strength of the MBR fiber is extremely strong, and there will be no wire breakage even under severe conditions.
(6) Long service life and low operating cost. Generally, the service life of treating domestic wastewater is at least 3-5 years.
What affects the lifespan of the MBR membrane?
1) Large, sharp, hard, and particulate matter will cause mechanical damage (scratch) to the membrane surface. It also includes fibers or hair strands wrapped around membrane filaments, so the pretreatment requires that the maximum particle size of the particles is less than 2mm.
2) Concentration polarization issues on the operation and extracellular contaminants (ESP) produced in microbial growth. This can restore flux by adjusting operating conditions (such as adjusting membrane installation spacing and aeration rate) and chemical cleaning.
3) The MBR fibers have no inner support material. The sludge concentration is high, a large area of sludge is deposited on the surface of the membrane, or the aeration at the bottom is too large during operation, causing the fiber to break.
4) It is also important to be affected by temperature. The water permeability of the membrane module varies with the water temperature, and the recommended operating temperature of the MBR membrane is 5-45℃.
5) The manufacture of mbr fiber is made by dissolving PVDF in a strong polar solvent. Some industrial wastewater also exists in strong polar solvents, dissolving PVDF membrane fibers and causing irreversible damage. Finally, the PVDF membrane has reached its service life and is caused by its aging.
6) Usually at moderate and appropriate concentrations. It is not corroded by acids, alkalis, strong oxidants, and halogens and is also stable to organic solvents such as aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, and aldehydes. It can be dissolved or formed into a colloidal solution only in strong polar solvents. Acetone is its swelling agent, and its porosity and water flux are significantly reduced after soaking in acetone.
7) Microorganisms, inorganic salt scaling, oil, organic matter, and colloids will cause membrane fouling. When it cannot be removed by chemical cleaning, it causes irreversible degradation of membrane performance, such as colloidal silicon and mineral oil.
Conclusion
Since it is impossible to foresee all substances that may cause damage to the membrane, it is important to make an analysis of specific water quality and take proper pretreatment. Therefore, the staff should pay attention to the above problems in daily use and maintenance. And should regularly clean the MBR membrane to ensure the regular operation of the system and effectively ensure the service life of the MBR membrane. There is still a big gap between different brands of MBR membranes. The service life and performance are also different.
The above is the introduction of the design and the working principle of the MBR membrane. If you have any other related questions, don’t hesitate to contact SPERTA.
Shanghai SPERTA Environmental Technology Co., Ltd. has specialized in producing water treatment products for many years. The company has its own MBR membrane technology, a complete technical team, and pre-sales and after-sales service. If you have any needs, please feel free to contact us.
