As a highly efficient separation element, hollow fiber ultrafiltration membranes involve numerous technical and management details during operation. Ignoring these requirements can easily lead to performance degradation or even irreversible damage. To ensure system stability and maximize membrane lifespan, clear precautions must be followed in each stage of selection, installation, operation, and maintenance.
First, the quality of the feed water must be strictly controlled. Suspended solids, grease, high concentrations of organic matter, and strong oxidants can accelerate membrane fouling or cause chemical erosion. Reliable pretreatment should be installed upstream, such as bar screens, sand filters, activated carbon adsorption, or security filters, to control turbidity, oil content, and residual chlorine within the membrane's allowable range. In particular, instantaneous shock loads and abnormal pH values must be avoided from entering the membrane system to prevent structural damage.
Second, operating parameters should be set appropriately. Transmembrane pressure differential, crossflow velocity, and recovery rate must be matched to the membrane specifications and application scenario. Excessive pressure differential can easily cause membrane compaction and fiber breakage, while excessively low flow rates exacerbate concentration polarization and fouling. The start-up and shutdown process should involve slow pressure increases or decreases to avoid sudden pressure changes that could damage the fiber structure. Frequent start-ups and shutdowns, as well as prolonged low-pressure operation, should be avoided to maintain membrane pore stability and flux balance.
Chemical cleaning must be performed with caution. Appropriate cleaning agents should be selected based on the type of contaminant; indiscriminate mixing or use at excessive concentrations is strictly prohibited to prevent corrosion of the membrane material. Before cleaning, all residual liquid in the system must be thoroughly drained. After cleaning, the system should be thoroughly rinsed with pure or deionized water to prevent residual chemicals from affecting subsequent separation performance or causing secondary pollution.
Installation and storage are also crucial. Membrane modules should be handled with care to prevent impact and compression to avoid fiber breakage. For long-term outages, cleaning, disinfection, and moist storage should be performed according to specifications to prevent dehydration, embrittlement, or microbial growth. Operators should receive professional training, be familiar with instrument monitoring and emergency response methods, and be able to promptly identify abnormal pressure differences, flow rate drops, and other signs of malfunction.
In summary, following these precautions can ensure the separation efficiency of hollow fiber ultrafiltration membranes while maximizing their service life, providing continuous and reliable support for water treatment and related industrial processes.
