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sur le développement des zones arides et semi-arides

Titre : Treatment of Olive Mill Wastewater Via the Fenton Reaction

Auteur : Alsaad, Enas Ahmad Breithe

Université de soutenance : Yarmouk University

Grade : Master of Science (MS) Chemistry 2018

Résumé
Olive Oil Mill Wastewater (OMWW) represents a serious environmental issue in the Mediterranean countries in general and in Jordan in particular. In this work, we investigated the heterogeneously catalyzed Fenton-like treatment of OMWW over Cu(II) ferrite (CuFe2O4) catalyst. This catalyst was prepared by means of the sol-gel auto-combustion method followed by thermal treatment at 550°C under flowing oxygen. XRD investigation shows that the dominant phase is the tetragonal spinel CuFe2O4 phase in addition to small amounts of Į-Fe2O3 and monoclinic CuO. The COD of original OMWW was however rather large (71 g/L) requiring thus large amounts of H2O2 (at least 500 mL of 24% H2O2 per 1 L OMWW) to achieve complete mineralization. For this reason, pretreatment of original OMWW with natural bentonite was introduced to decrease its COD before attempting the Fenton degradation. Pretreatment with natural bentonite (40 g/ 1 L OMWW) was found to decrease the COD value by 13% and the total phenolic by 25%. Moreover, the OMWW solution volume was reduced by 20%. Combining the two results shows that almost 30% of the organics has been removed by the bentonite pretreatment. Concerning the effect of amount of H2O2 added in the Fenton-like degradation of bentonite pretreated OMWW, higher amounts of H2O2 werefound to lead to a higher degradation. However, doubling the amount of added H2O2 degradation, suggesting that the ineffective decomposition route of H2O2 is enhanced at higher H2O2 concentrations, leading to a decrease in degradation efficiencies. It was also found that the higher the pH of reaction solution, the higher is the degradation efficiency. This behavior was attributed to the suppression of the undesired route of H2O2 decomposition at high pH values, but also to the enhanced adsorption of organics in solution on the catalyst surface due to the formation of anionic species at high pH values. Best performance was observed at pH 10 and 11. A slight enhancement in the degradation efficiency could be also achieved upon irradiation with visible light via two 20-Watt compact fluorescent lamps.

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