Effect of graphene-tio2 on the photodegradation of olive mill effluent

Abstract

In this study, Graphene-TiO2 was used to treat the pollutants from the olive mill industry wastewaters by photo-degradation. The large-scale production of functionalized graphene at low cost should result in good adsorbents for water purification due to the two-dimensional layer structure, large surface area, pore volume and presence of inorganic functional groups in the surface. The photo-removals of COD, total solid and total phenol in olive mill effluent wastewater with Graphene-TiO2 were investigated under photocatalytic oxidation. The effects of increasing Graphene-TiO2 concentrations (0.5 g/L, 1 g/L 3 g/L, 5 g/L and 10 g/L), photooxidation times (15, 30, 60 and 90 min) and pH (4, 7 and 10) were evaluated on the treatment of OMW pollutants. The photocatalytic reactions were performed under UV irradiation. The maximum pollutant removal efficiencies for COD, total phenol and TS obtained under 300 W UV light were 88%, 92% and 95% throughout photocatalysis at the optimum Graphene-TiO2 concentration (3 g/L). The maximum recovery capacity of Graphene-TiO2 was found between 90 and 95% after sequential six cycles.