Membrane photoreactors submerged membranes

The ultrafiltration or microfiltration membrane used in the described submerged membrane photoreactors showed high fluxes and a good removal efficiency of organic molecules, nevertheless, they are not able to reject compounds with low molecular weight. 

Particular attention is addressed to the permeate flux and to this purpose some preliminary experiments were realized on a different configuration of membrane photoreactor with a submerged membrane module located separately from the photoreactor. Bubbled oxygen on the membrane surface has the roles to reduce the catalyst deposition, to increase the flux through the membrane and to facilitate the photocatalytic reaction. 

The submerged membrane photoreactor was more advantageous in terms of permeate flux, with values almost twice those measured with the flat-sheet membranes. Nevertheless, the UF membranes used in the submerged system were not able to reject the drug and its degradation products [94],... 

Chin S S, Lim T M, Chiang K and Fane A G (2007a), Hybrid low-pressure submerged membrane photoreactor for the removal of bisphenol A , Desalination, 202,253-261. 

The experimental plant consisted of an annular photoreactor with an immersed UV lamp connected with the permeation cell in which a pressurized flat sheet membrane or a submerged membrane module was located. 

The catalyst deposition on the membrane surface and fouling caused flux decUne during the photocatalytic process. To overcome these problems the depressurized (submerged) membrane system, in which the membrane module was located separately from the photoreactor, was studied. The achieved results showed pharmaceuticals abatement of 100% after ca. 20 min and mineralization of 44.5% after ca. 150 min in the retentate. The UF membrane used in the submerged system did not allow the rejection of GEM and of its oxidation products compared to the NF membranes of the pressurized system. 

However, the submerged membrane photoreactor offered more advantages in terms of permeate flux than those obtained operating with pressurized module. 

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