Photocatalytic decontamination petrochemical wastewater via ZnO/TiO2/GO nanocomposite: Operational conditions and electrical energy consumption

Title : Photocatalytic decontamination petrochemical wastewater via ZnO/TiO2/GO nanocomposite: Operational conditions and electrical energy consumption

Abstract:

ZnO/TiO₂ anchored on a reduced graphene oxide (rGO) ternary nanocomposite heterojunction was synthesized via the multi-step method including hydrothermal, solvothermal and sol–gel methods. XRD, Raman, FESEM, EDX, Dot Mapping EDS, BET, FTIR, UV-VIS, TGA, and EIS techniques were utilized for characterizing as-synthesized catalysts. The XRD and Raman data proved the formation of anatase phase TiO₂ and wurtzite phase ZnO in the prepared samples. Further, the UV-Vis spectrum confirmed that the band gap value of ZnO/TiO₂ diminished on introduction of graphene oxide. Photocatalytic performance of the fabricated catalysts was investigated by decontamination of polychlorinated biphenyl (PCBs), perfluorinated compounds (PFCs), brominated compounds (BFR), dioxins and furans  in petrochemical wastewaters. The effect of different operational factors such as pH, catalyst dosage, phenol concentration, and light illumination was investigated to find the optimum decontamination conditions. According to the results, complete degradation of polychlorinated biphenyl (PCBs), perfluorinated compounds (PFCs), brominated compounds (BFR), dioxins and furans  were achieved at pH = 4, catalyst dosage of 0.6 g L⁻¹, light intensity of 150 W, and  initial pollutant concentration of 400 ppm at 40 min under visible light illumination. With the addition of graphene oxide to the composite, a significant increase was detected in the photocatalytic performance due to the higher available surface area and lower electron/hole recombination rate. In addition, the scavenging experiments revealed that the ·OH is responsible for the degradation of  all pollutants during the reaction. The degradation mechanism, economic performance, mineralization, and recyclability were also investigated. Kinetic studies confirmed that photocatalytic degradation process followed the pseudo-first-order kinetic model. A case of real wastewater treatment was used to examine the performance of the catalyst for real case studies.

Biography:

Dr. Rukiye Öztekin is currently working as a Researcher at Dokuz Eylül University, Department of Environmental Engineering, İzmir/Turkey. She completed her undergraduate education at Ondokuz Mayıs University, Department of Environmental Engineering, Samsun/Turkey. [B.S. (Eng)]. She studied her master education at Dokuz Eylül University, The Graduate School of Natural and Applied Sciences, Department of Environmental Engineering, İzmir/Turkey. (MSc.). She completed her doctorate education at Dokuz Eylül University, The Graduate School of Natural and Applied Sciences, Department of Environmental Engineering, İzmir/Turkey. (Ph.D.). She completed her post-doctorate education at The Scientific and Technological Research Council of Turkey (TUBITAK) the Department of Support for Scientists (BİDEB) 2218-Domestic Postdoctoral Research Scholarship Program with a scholarship postdoctoral researcher, (Post-Dr.) at Natural (World) Sciences Program. She has many international publications