Citation:
Ewan J. McAdam, Mark Pawlett, Simon J. Judd, Fate and impact of organics in an
immersed membrane bioreactor applied to brine denitrification and ion exchange
regeneration, Water Research, Volume 44, Issue 1, January 2010, Pages 69-76
Abstract:
The application of membrane bioreactors (MBRs) to brine denitrification for ion
exchange regeneration has been studied. The developed culture was capable of
complete brine denitrification at 50 gNaCl.l−1. Denitrification reduced to c.60%
and c.70% when salinity was respectively increased to 75 and 100 g.l−1, presumed
to be due to reduced growth rate and the low imposed solids retention time (10
days). Polysaccharide secretion was not induced by stressed cells following salt
shocking, implying that cell lysis did not occur. Fouling propensity, monitored
by critical flux, was steady at 12–15 l.m−2.h−1 during salinity shocking and
after brine recirculation, indicating that the system was stable following
perturbation. Low molecular weight polysaccharide physically adsorbed onto the
nitrate selective anion exchange resin during regeneration reducing exchange
capacity by c.6.5% when operating up to complete exhaustion. However, based on a
breakthrough threshold of 10 mgNO3−-N.l−1 the exchange capacity was comparative
to that determined when using freshly produced brine for regeneration. It was
concluded that a denitrification MBR was an appropriate technology for IEX spent
brine recov
