Treatment of Olive Mill Effluent by Adsorption and Photooxidation to Nano-ZnO and Nano-ZnO-Magnetite

Abstract

Olive oil mill wastewater contains high concentration of organic matter, acidic pH values, suspended solids and high content of phenols and polyphenols which are toxic substances. In this study, Nano-ZnO-Magnetite composite was produced to treat the olive mill industry wastewaters by adsorption photodegradation processes.  Nano-ZnO and Nano-ZnO-Magnetite concentrations varied between 0.5 - 3 g/L. The effects of contact time and pH on adsorption and photooxidation were investigated. The photocatalytic reactions were performed under UV irradiation. For maximum COD and phenol yield (78% and74%) the optimum retention time and Nano-ZnO concentration were found as 180 min and 3 g/L,respectively at pH 10. For maximum TS yield (47%) the optimum retention time and Nano-ZnO-Magnetite concentration were found as 180 min and 3 g/L at pH 4.