From this batch experiment, the key factors that affected the
removal efficiencies of toxic organic micro-pollutants were
described as follows:
(1) Hydrophobicity: This was determined by the ‘log Kow’ of
those toxic organic micro-pollutants and with low log Kow
were degraded well with biodegradation such as BPA and
DCP
(2) Molecular weight: From our experiment, those compounds
with low molecular weight were degraded well and better
than those compounds with high molecular weight. For
example, DEHP and BBzP which have high molecular weight
and were degraded in lower rate with biodegradation compared
to other compounds.
(3) Chemical structure e.g. branch structure or aromatic ring: From
the experiment, it was shown that DEHP and BBzP with long
branch chain and many aromatic rings were deranged later
when compared to other compounds. Tadkaew et al.
(2011) reported that functional group in chemical structure
was one of the factors that affected the degradation rate. In
our study, function group of all compounds contained electron
donating group (EDG) which were considered to be easily
degraded in the MBR system. The EDG group were
including primary amine group, hydroxyl group, ether
group, carbonyl group and alkyl group.