Photocatalytic Degradation of Some Phenolic Compounds Present in Olive Mill Wastewater

Abstract

The olive oil industry in Palestine is an important and widely spread one and accomplished with the release of large amounts of olive-mills wastewater. This wastewater represents a significant environmental problem due to its high phenolic content. In this work, the photocatalytic degradation of the some phenolic compounds (gallic acid, oleuropein and resorcinol) present in olive-mills wastewater using the synthesized nanoparticles of mixed SnO₂-MgO catalyst and solar irradiation was performed. The nanoparticles of mixed SnO₂-MgO catalyst with different ratios were prepared by sol gel method using a modified procedure. The obtained particles were characterized by SEM and XRD. The particle size was determined as 4.32 ± 0.42 nm which is much smaller than those previously prepared by standard procedures. The degradation percentage of phenolic compounds was measured by UV spectrophotometry. The effect of time, catalyst amount and phenolic compound concentration on degradation efficiency was studied. The maximum degradation was achieved using SnO₂-MgO (4:1) catalyst, 2.5 mg catalyst per 5 mL solution, within the time of 60-120 min and ranged from 51 to 90 % for different concentrations of phenolic compounds.