Degradation of phenol in refinery wastewater by CuFe2O4 catalyst

The purification of wastewater from phenol and other phenolic compounds which are discharged from different industrial activities is an important environmental issue. Such compounds cause severe damage to the human body and to the environment. In this study, the degradation of phenol is investigated by using copper ferrite CuFe2O4 catalysts. CuFe 2O4 powders were prepared by two different methods: sol-gel and co-precipitation methods, and followed by thermal treatments at 500 °C and 750°C. The prepared ferrites were characterized for their morphology, crystallinity, purity, and stability using various techniques such as X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and BET surface area analysis. These techniques revealed that the sol-gel derived samples exhibited spinel ferrite phases of higher crystallinity and purity than the co-precipitation derived CuFe2O4 samples. Both methods demonstrated CuFe2O4 thermal stability up to about 750 °C as confirmed by TGA measurements. The IR spectra showed the vibrational mode around 600 cm-1 which emphasizes the presence of the ferrite phase. The SEM images indicated that the "asprepared" CuFe2O4 powders exhibited a porous sponge-like morphology which changed significantly upon calcination at 500 °C and 750 °C.;The catalytic activity of the CuFe2O4 was investigated for the degradation of phenol using high performance liquid chromatography (HPLC). The experimental results suggested that CuFe2O4 is an effective catalyst for the removal of phenol from wastewater. Several parameters were studied such as the effect of catalyst loading which showed that a greater phenol removal was achieved as the catalyst loading increased. Also increasing the H2O2 concentration enhanced the degradation of phenol. The highest phenol removal was achieved at a pH value of 2.6 while the lowest removal was at a pH value of 10. The experimental results showed that the degradation of phenol increases as the reaction temperature increases from 25 °C to 50 °C. A complete phenol removal was achieved in less than 30 min when the reaction temperature was 50 °C. The effect of radiation (UV or sunlight) was also studied. The degradation process of phenol was enhanced significantly in the presence of a radiation source. A comparison in catalytic activity between CuFe2O4 and other catalysts such as ferrites (ZnFe2O4 and MgFe 2O4) and TiO2 was conducted. Among these catalysts, CuFe2O4 showed the highest catalytic activity towards the degradation of phenol. The successful regeneration and reusability of CuFe2O4 catalyst for phenol removal were also studied.