Anaerobic Co-digestion Mill Wastewater—Activated Sludge Effect of Aerobic Pretreatment on the Performance of OMW Anaerobic Digestion

Abstract

Aerobic treatment of olive mill wastewater (OMW) is a promising technique for biogas recovery using anaerobic digestion, in the case of OMW it is possible to reduce polyphenols and TCOD concentration which undesirable by microorganism metabolism. OMW was subjected to the aeration process over different periods to detect the removal efficiency of polyphenols and TCOD. During this study, anaerobic co-digestion of OMW without pretreatment and activated sludge (AS) was inhibited due to the presence of a high inhibitors concentration. While anaerobic co-digestion of aerated OMW–AS were achieved TCOD removal 56.34%, 70.32%, 52.81% and polyphenols removal 42.69%, 60.45%, 63.51% when the OMW aerated for 2, 4 and 6 days respectively. The highest biogas production 0.473 Nm3/kg VS was achieved by OMW aerated for 4 days in conjunction with 68.39% CH4, 55.85% VS removal, 10.91 g/l of TCOD and 4.23 g CaCO3/l.