Membrane bioreactor (MBR) has been proved to be an efficient technology capable of treating various industrial effluents. However, the evaluation of its performances in the case of olive mill wastewater (OMW) over a conventional activated sludge (CAS) have not been determined yet. The present study aims at comparing OMW treatment in two laboratory scale pilots: an external ceramic MBR and CAS starting with an acclimation step in both reactors by raising OMW concentration progressively. After the acclimation step, the reactors received OMW at 2 gCOD/L with respect of an organic loading rate of 0.2 and 0.3 kgCOD/kgMLVSS/d for MBR and CAS respectively. Biomass acclimation occurred successfully in either systems; however, the MBR tolerated more OMW toxicity than CAS as the MBR always maintained an effluent with a better quality. At stable state, a higher reduction of 95% COD was obtained with MBR compared to CAS (86%); but, both succeeded in polyphenols removal (80%). Moreover, a higher MLSS elimination from the MBR treated water (97%) was measured against 88% for CAS. Therefore, CAS was suitable for OMW treatment and MBR could be proposed as an alternative to CAS when a better quality of treated water is required.
OMW treatment by Membrane bioreactor MBR and activated sludge AS were compared.
Biomass acclimation and polyphenols degradation occurred successfully in both systems.
At 0.2 and 0.3 kgCOD/kgMLVSS/d, MBR showed higher efficiency 95% than CAS (86%).
MBR showed better performances (95%) than CAS (86%) for OMW COD treatment.
Considering Moroccan situation the CAS could be more adapted for OMW treatment.