Hollow fibre (hollow fiber) configurations comprise one of the three main configurations for membrane bioreactor technology. Hollow fibre (HF) membranes are normally vertically oriented with the aerators integrated either with the module or frame.
The element is most commonly referred to as a ‘module’. The fibres are usually provided with some slack, to allow them to move laterally in the flow of air bubbles, which also air lift the sludge through the fibre bundle.
Water flows from outside to inside the individual fibres and is collected from the fibre ends potted either at one or both ends and fed into a collection chamber or manifold. For some products, the fibres are reinforced with a braided core to which the membrane is bonded.
Hollow fibre membranes are used almost exclusively for immersed MBRs, both for industrial and municipal applications, where they are often favoured for larger installations on the basis of their lower membrane aeration energy demand.