| Abstrakt: |
The present work discusses the removal of diazinon pesticide on the surface of magnetic graphene oxide composite via two different complementary methods specifically adsorption and Photo-Fenton degradation. Nanomagnetite (NG), graphene oxide (GO), and nanomagnetite/graphene oxide composite (NGO) were prepared as three solid materials. Developing TGA, nitrogen adsorption/desorption analysis, XRD, DRS, FTIR, pHpzc, and TEM, the morphological and physicochemical characteristics of the solid samples were examined. Characterization techniques proved that GO showed a higher specific surface area (505.5 m2/g) while NGO is characterized by a lower energy band gap (2.69 eV) and relatively high surface area (380.2 m2/g) in comparison with NG (2.90 eV and 103.5 m2/g). Both of GO and NGO are distinguished by the presence of different surface chemical functional groups. The main experimental application conditions were considered such as the effect of sample dose, pH, time, initial diazinon concentration, UV light power, and temperature. The results of the experiments showed that NGO adsorption capacity reached 149.54 mg/g at 25 °C orrelation coefficient values served as evidence that all generated solid samples follow nonlinear pseudo-second-order, Elovich, and Langmuir isotherm models. Using 1.5 g/L of catalyst mass and an initial diazinon concentration of 20 mg/L, the greatest percentage of diazinon Photo-Fenton degradation at 35 °C by NGO composite (99%) was reached after 50 min. Diazinon Photo-Fenton degradation is nonspontaneous, endothermic, fitting well the PFO kinetic model, Arrhenius models, and Eyring-Polanyi models. [ABSTRACT FROM AUTHOR] |
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