2.2. Sample collection and preparation
Influent, effluent (membrane permeate) and mixed liquor
were regularly taken from the outlets of feed pump, permeate
pump and main anaerobic reactor, respectively, for analysis.
The supernatant of mixed liquor (SML) was obtained using the
centrifugationefiltration procedure with centrifugation at
9000 rpm for 10 min followed by filtration through a 0.45-mm
filter. The SML sample was also used to determine SMP
compositions. EPS was extracted using heating method at
80 C for 10 min in a water bath, then prepared by the same
centrifugationefiltration procedure.