Choosing the UF Membrane Filtration Mode Based on the Turbidity of Feed Water

When the feed water contains few suspended solids and has a low turbidity, for example, clean surface water, well water and tap water, or stringent pretreatment facilities are provided before the UF system and can provide high quality raw water, the UF system can choose the dead-end filtration mode.

When the feed water flows into the membrane element, all feed water passes through the membrane surface and flows out from the membrane element filtrate side as permeate. In the dead-end filtration mode, as the filtration time increases, the retained particles are collected on the membrane surface forming a filtration cake and leading to filtration resistance going up. The permeate efficiency of the UF membrane decreases under constant operation pressure. As a result, dead-end filtration only performs intermittently and needs to clean the filtration cake on the membrane surface or replace the membrane periodically.