anaerobic baffled reactor (ABR) is a modified form of
UASB. The advantage of the ABR over UASB lies in
the separation of acidogenesis and methanogenesis along
the reactor process, allowing the reactor to behave as a
multi-phase system without the associated control problems.
The separation also reduces operating cost.[12] The
design of ABR with a low height:diameter ratio also make
the ABR system easily buried underground to provide thermal
insulation and a lower space requirement compared
to UASB reactors. Researches on ABR-septic tanks in
the aspects of reactor hydrodynamics, treatment performance,
biomass characteristics and retention capabilities
were largely undertaken in 1980s and 1990s,[13] and have
since been further documented reported from time to time
in the last decade.Witthauer and Stucley [14] used an ABRseptic
tank to treat greywater at a low temperature of 16◦C
to achieve an 84% removal of chemical oxygen demand
(COD) from wastewater. Anh et al. [4] reported using an
ABR-septic tank to treat blackwater fromdomestic toilets in
Vietnam. The COD, biological oxygen demand (BOD) and
SS removal efficiency was averaged at 74.85%, 71.47% and
71.14%, respectively. Pillay et al. [15] coupled ABR and
membrane for waterborne sanitation. The research focused
on the fouling characteristics of the membrane and operating
requirements of the overall system. It was found that
the compartmentalized design of the ABR was favourable
for anaerobic membrane operation.