The role of fouling mechanisms in a membrane bioreactor.
The present study has aimed to quantify the role of pore blocking and cake layer in a laboratory scale hollow fibre membrane module in submerged configuration, The membrane reactor (MBR) was fed with raw wastewater, only screened with a 2-mm sieve, collected from the Palermo WWTP. The MBR was characterised by an operating volume of 190 L and equipped with an aeration system located on the bottom of the reactor. The MBR operated for 65 days. The permeate was extracted by imposing a constant flux through the membrane (21 Lh(-1) m(-2)). The results confirm the importance of pore blocking control during start-up. In particular, it provides a rapid irreversible fouling that takes place at the beginning of the filtration process, before the deposition mechanism. Therefore, low suspended solids concentration in the initial phase causes a fast irreversible fouling. This circumstance creates the need for more frequent chemical cleaning after start-up without inoculum. Finally, the results underline that the cake has a mainly reversible feature.
Di Bella
G
G
Dipartimento di Ingegneria Idraulica ed Applicazioni Ambientali dell'Universita di Palermo, Viale delle Scienze 90146, Palermo, Italy. dibella@idra.unipa.it
Durante
F
F
Torregrossa
M
M
Viviani
G
G
Mercurio
P
P
Cicala
A
A
D018533:Biomass; D019149:Bioreactors; D005374:Filtration; D008567:Membranes, Artificial; D016062:Porosity; D014865:Waste Disposal, Fluid / Q000379:methods*
D008567:Membranes, Artificial