Improvement in anaerobic degradation of olive mill effluent (OME) by pre-treatment using H2O2, UV-H2O2 and Fenton's process

The pre-treatment using single H2O2, UV-H2O2 and Fenton's process as a pre-treatment option for olive mill effluent (OME), which is known to contain a significant amount of inhibitory compounds (e.g., phenolics and tannins) was carried out in order to enhance anaerobic degradation of OME. Biochemical Methane Potential (BMP) assay was employed in order to monitor and comparatively evaluate any increase in biogas production as an indicator of improvement in anaerobic biological degradation before and after pre-treatment. The results suggested that pre-treatment using Fenton's process resulted in an almost 3.5-fold enhancement in the biodegradability of OME, which was much lower if it was digested alone (without pre-treatment). Pre-treatment in the form of UV-H2O2 also significantly increased the biogas production (1.75-fold higher gas production than raw OME sample); on the other hand, the use of H2O2 alone negatively affected the biogas production. It was demonstrated that the anaerobic biodegradability of OME could be significantly enhanced by pre-treatment using Fenton's process and therefore anaerobic degradation after a suitable pre-treatment could be proposed for the safe disposal of OME.