ABSTRACT
The aim of the present study is to firstly study the effect of the extraction solvents (ethanol, acetonitrile, distilled water), pH, temperature, and the extraction method (maceration, sonication, maceration in two steps) on the flavonoid and phenolic contents of olive leaves. Furthermore, qualitative and quantitative analyzes of phenolic compounds by (HPLC) were performed. Results showed that the extract macerated in two steps by ethanol followed by distilled water of dried leaves showed high contents of phenolic compounds and flavonoids compared to the extracts obtained by the other studied techniques and solvents. On the other hand, the macerated extracts were studied for their antibacterial activity against five pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Listeria monocytogenes). The results showed a strong antibacterial activity of the same macerated extract in two steps for dried leaves, which could be attributed to its richness in bioactive compounds such as oleuropein.
ABSTRACT
OBJECTIVES: To assess the combination of electrocoagulation and anaerobic co-digestion of olive mill wastewaters (OMWW) with other substrates, such as chicken manure, in a continuous stirred tank reactor for biogas production. RESULTS: Anaerobic digestion of OMWW treated by electrocoagulation allowed higher production of biogas, up to 0.74 l biogas g-1 COD introduced compared to untreated or diluted olive mill wastewaters (OMWW) (0.37 and 0.6 l biogas g-1 COD) respectively. Pretreated OMWW co-digested with chicken manure at different volumic ratios OMWW/manure in a continuous stirred tank reactor under mesophilic conditions revealed that OMWW/manure (7:3 v/v) was optimal for biogas production and process stability. CONCLUSION: Anaerobic digestion could achieve promising results in depollution and valorization of OMWW under a continuous stirred tank reactor.
