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Go to Editorial ManagerThe use of nanomaterials in asphalt binders has become a very promising approach to improve the performance of pavements under growing traffic and environmental load. This research focuses on the influence of zinc oxide (ZnO) nanoparticles on physical and rheological properties of asphalt binder. ZnO was added in dosages of 1%, 3%, 5% and 7% by binder weight in a high shear mixing process. The modified and control binders were tested for their physical properties (penetration, softening point, ductility, flash point and viscosity), Dynamic Shear Rheometer (DSR) tests for rutting and fatigue performance and Bending Beam Rheometer (BBR) testing for low temperature behaviour. The results showed that the addition of ZnO nanoparticles reduced penetration and increased softening point, flash point and viscosity, which indicated the improvement of stiffness and thermal stability. Ductility was not affected, which confirmed that flexibility was maintained. Rheological analysis revealed that rutting resistance was significantly improved and a 76.7% reduction in the fatigue factor was observed in intermediate temperatures, whereas BBR results revealed acceptable low-temperature performance. The Performance Grade (PG) of the binder was improved up to two grades in higher contents of ZnO without exceeding limits for workability or thermal cracking. These results show that ZnO nanoparticle is an efficient asphalt modifier that enhances thermal, mechanical and rheological properties and thus can be used in high performance pavements applications with a wide range of temperature.
Removal of reactive red dye (Cibacron Red FN-R) from simulated wastewater has been investigated as a function of solar advanced oxidation process. The photocatalytic activity using ZnO as a photocatalyst has been estimated. Different parameters affected the removal efficiency, including pH of the solution; initial dye concentration and H2O2 concentration were evaluated to find out the optimum value of these parameters. The results proved that, the optimal pH value was 8 and the most efficient H2O2 concentration was 100mg/L. Reduction of organic content for effluent solution was also monitored by measuring chemical oxygen demand (COD) to assess the degradation process. This treatment method was able to strongly reduce the organic content of reactive red dye-238 to 90% while the colour removal was 99%. It can be concluded, from these experiments, that the using of ZnO as a photocatalysis was exhibited as economical and efficient treatment method to remove reactive red dye-238 from aqueous solution by reducing its colour and COD value. Results were properly fitted to LH model.