Performance of Ultrasonic Membrane Anaerobic System (UMAS) in Membrane Fouling Control

The primary objective of this study was to evaluate the effects of the organic loading rate (OLR) on the performance of an ultrasonic-assisted membrane anaerobic system (UAMAS) treating Palm Oil Mill Effluent (POME), \nbased on the following indicators: (i) methane gas contents, (ii) chemical oxygen demand (COD) removal efficiency, and (iii) effluent variability (phenol, suspended solids, volatile fatty acids, and pH stability).Six steady states were attained as a \npart of a kinetic study that considered concentration ranges of 15,830 to 21,600 mg/l for mixed liquor suspended solids (MLSS) and 9,450 to 18,200 mg/l for mixed liquor volatile suspended solids (MLVSS). Kinetic equations from Monod, Contois and Chen & Hashimoto were employed to describe the kinetics of POME treatment at organic loading rates ranging from 0.5 to 15 kg COD/m3/d. The removal efficiency of COD was from 93 to 98.7 % with a hydraulic retention time (HRT) of 4 days. The growth yield coefficient, Y, was found to be 0.59 g VSS/g COD, the specific microorganism decay rate was 0.26 d-1, and the methane gas yield production rate was between 0.264 l/g COD/d and 0.47 l/g COD/d.