The study of the effect of magnetic nanocomposite functionalized with carboxymethyl-β-cyclodextrin for sonophotocatalytic degradation of polychlorinated biphenyls from transformer oil

In this study, efficiency of sonophotocatalytic process by CMCD-Fe3O4@TiO2 in order to remove of PCB compounds from transformer oil were investigated by applying the response surface methodology (RSM) in the central composite design (CCD). Then, the effect of important parameters such as catalyst dosage, time, temperature and oil to ethanol ratio were investigated to optimize the maximum PCBs removal. The concentration and types of PCBs congeners in the contaminated oil were determined using a gas chromatography equipped with electron capture detector (ECD) and mass spectrometer (MS). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to examine the physical and chemical properties of synthesized photocatalyst. Based on the statistical results, the removal efficiency of PCBs was achieved 98 % in the optimum conditions of catalyst dose of 7.74 mg/mL, temperature of 25 °C, exposure time of 15 min and ratio of oil to ethanol 1: 5. Among the parameters studied, temperature and ethanol (p <0.0001) had the greatest effect on PCBs removal rate. The experimental results suggests that the use of CM-β-CD-Fe3O4@TiO2 in the presence of ultrasound waves possess a high efficiency in the removal of PCB compounds and can also be used an ideal and promising method on an industrial scale for purification of PCB compounds from contaminated transformer oil.