Author: Site Editor Publish Time: 2022-09-06 Origin: Site
Compared to hollow fibre membranes, mbr flat membranes are more advantageous because they have better resistance to pollution and generally do not break, and the cleaning cycle is longer than that of hollow fibre membranes, and most importantly, the cost is lower.
mbr flat membranes have better resistance to contamination.
1. compared to hollow fibre membranes, mbr flat sheet membrane bioreactors can operate at higher activated sludge concentrations while the original flux remains constant (i.e. water production is less affected) and the requirements for pre-treatment are not as high.
2. In practice, even if the pre-treatment facilities have grids and lint removers, there will still be some hair in the aeration tank, which is inevitable. When the hollow fibre membrane bioreactor is in operation, the membrane filaments are always in a jittering state under aeration, so these hairs can easily make the membrane filaments tangle together, and when the sludge concentration reaches a certain level, there will be mud heaps, so that more and more membrane filaments will be tangled together, which greatly reduces the effective membrane area of the hollow fibre and makes the membrane flux drop a lot, and this The problem is also difficult to solve and can only be replaced in general.
3. The applicable activated sludge concentration (MLSS) of the mbr flat membrane ranges from 6000-10000mg/L, which is very much higher than that of the hollow fibre membrane. The structure of the mbr flat membrane module is an assembly of multiple membrane elements arranged in such a way that the gap between the membranes can be controlled, which is conducive to the online cleaning of the membrane surface by gas-liquid mixing and anti-pollution performance.
1. In real life use, the phenomenon of broken filaments in hollow fibre membrane components is unavoidable, and there are two reasons for this problem: one is uneven wall thickness due to defects in the membrane filament process, which generally occurs less frequently and can be further avoided by means such as purchasing high quality products. The second is root fracture caused by fatigue of the membrane filament material.
2. Hollow fibre filaments need to be sealed with epoxy resin at both ends where the component is connected, and due to the capillary phenomenon of the fibre filaments themselves, a small section will certainly be sucked up at the root. Due to aeration, the hollow fibres will always be in a large vibration amplitude in the working condition, which will cause material fatigue at the roots in the long run, and the epoxy resin itself is a brittle material, and the broken filaments caused by this material fatigue are often of a large scale once they occur. This can be fatal to the membrane bioreactor, not only in terms of effluent quality, but also in terms of the entire module.
3. Unlike this, the mbr flat membrane has a non-woven fabric as the internal flow guide layer and a 3mm to 5mm ABS plate as the support layer, so the strength is much higher than that of the hollow fibre.
1. the cost of hollow fibre membranes is 1/2 to 1/3 of that of mbr flat membranes, but hollow membranes are prone to clogging, broken filaments and generally only have a service life of 1-3 years, while mbr flat membranes can have a life of 5-10 years, which is about 3-5 times that of hollow membranes.
2. Hollow fibre membranes need to be cleaned frequently, once every 1-2 months, and have to be removed from the pool for cleaning (offline cleaning), which results in a larger maintenance workload and more staff; whereas mbr flat membranes can be cleaned online (no need to remove them) and only need to be cleaned once every 6-12 months, which is easy to operate and can be operated by only one person.