Table 4.

Two-way factorial ANOVA and post hoc Tukey results of the activated sludge experiment in the lab-scale MBR. Bacterial cell density (log cells cm⁻² membrane) was selected as dependent variable and membrane type (PSF, PVDF, and PS) and treatment (adhesion, biofilm formation in Ringer's solution, and biofilm formation in lab-scale MBR) as predictor variables. The pairwise comparison was performed between the bacterial cell density (log cells cm⁻² membrane) among the different membrane types and treatment. Bacterial cell density data were log transformed before analysis.

Activated sludge experiment in lab-scale MBR	F	P
Membrane	3.030	0.073
Treatment (adhesion-Ringer-biofilm)	6.419	0.008
Membrane ∗ treatment	2.972	0.047
Post hoc Tukey test
PSF biofilm-PE biofilm		0.016
PSF biofilm-PE Ringer		0.006
PSF biofilm-PSF Ringer		0.034
PSF biofilm-PVDF Ringer		0.011