Performance and membrane fouling in a pilot scale SBR process coupled with membrane

Abstract

The performance of the pilot-scale submerged membrane coupled with sequencing batch reactor (SM-SBR) for upgrading effluent quality was investigated in this study. The reactor was operated with 3-hour cycle with alternating anoxic and aerobic conditions to treat organics, nitrogen and phosphate. Despite various influent characteristics, COD removal was always higher than 95%. Sufficient nitrification was obtained within a few weeks after start-up and during the stable period, complete nitrification occurred despite short aeration time. Total nitrogen (TN) removal efficiency was reached up to 85%. Membrane flux was critical for TN removal so that the decrease of flux by membrane fouling led to increase of HRT, and it caused the endogenous respiration of microorganisms such as nitrifying bacteria. The stirred cell test revealed the significant role of the soluble fraction in membrane permeability and dissolved solids played a major role in the short-term fouling mechanism. The cake resistance by the soluble COD fraction of supernatant or soluble microbial products (SMP) was investigated as a major part of total resistance.