The increasing interest in anaerobic MBRs (AnMBRs) relates largely to resource recovery and the circular economy. Anaerobic treatment permits energy recovery through conversion of the organic carbon (OC) to a methane biogas, rather than the considerably more energy-intensive aerobic process which converts the OC to carbon dioxide.
Clogging can take place within MBR module channels as a thick deposit which fills the channel (‘sludging’ or ‘localised dewatering’). Sometimes long rags or braids can develop in the tank itself which wrap around the membrane tank infrastructure (‘ragging’ or ‘braiding’). Chemical cleans are largely ineffective since they can only attack the foulants on the membrane surface, so leaving the clogged material filling the membrane channels largely unaltered. Cranfield University and Qatar University have completed work on this largely neglected research area.
Disinfection by MBRs. Unlike regular physical membrane filtration, virus removal by MBRs is not limited to simple size exclusion. Adsorption onto the sludge solids and the membrane cake layer (as well as the membrane itself) represent important removal mechanisms, as well as removal by predation (the feeding on the pathogens by other higher organisms).
How advanced CFD modelling accelerates and improves the design and scale-up of membrane applications
Advanced CFD is increasingly used by technology developers and end users to optimise, design and scale-up their technologies. 3D computer simulation can reduce, replace or complement real-life testing. In MBR applications, the value lies in OpEx minimisation, footprint reduction, fouling control, optimisation of performance and the reduction of real-life experimenting and testing.
A feature of the MBR market over the past decade is the surge in the number of very large (≥100 MLD, or megalitres/day) installations, particularly in China. Of the 55 known global installations of greater than 100 MLD capacity, 39 are in China. The Chinese plants account for 74% of the total capacity of this group.