However, in recent years the development of
a hybrid biofilm MBR (BF-MBR) combining a moving-bed-biofilm
reactor (MBBR), instead of activated sludge as the bioreactor unit,
and a submerged membrane reactor has been developed and
assessed for wastewater treatment (Leiknes et al., 2006; Leiknes
and Ødegaard, 2007; Ivanovic and Leiknes, 2008; Sun et al., 2010).