Olive Mill Wastewater (OMW) Treatment Using Photocatalyst Media

Abstract

A new nanophotocatalysts series of M2Zr2O7 (M = Mn, Cu, and Fe) and doped Fe2Zr2O7 systems were prepared via sol-gel using the pechini method, characterized, and tested in photocatalytic degradation of olive mill wastewater (OMW). The photocatalytic degradation of the prepared materials was evaluated by measuring total phenolic compounds (TPCs) using the Folin-Ciocalteu method for variable pH under a commercial LED lamp (45 W). The removal of TPCs was measured at different contact times ranging from 2 h to 6 days. X-ray diffraction (XRD) and transmission electron microscope (TEM) analysis approved the nano size of (5–17 nm) and quasi-spherical morphology of the prepared materials. ICP-OES analysis confirmed the XRD analysis and approved the structure of the prepared materials. Aggregation of the nanomaterials was observed using TEM imaging. Brunauer-Emmett-Teller (BET) analysis measured a 67 m2/g surface area for Fe2Zr2O7. Doping Fe with Mn increased the surface area to 173 m2/g and increased to 187 m2/g with a further increase of the Mn dopant. Increasing the Mn dopant concentration increased both surface area and photocatalytic degradation. The highest degradation of TPCs was observed for Mn2Zr2O7 around 70% at pH 10 and exposure time up to one day.