Leachate post treatment, using Ag-TiO2 nanoparticles immobilized on rotating vanes

Abstract

The current study investigated the capability of Ag-TiO2 nanoparticles in photocatalytic landfill leachate post-treatment. Silver doped Titanium dioxide nanoparticles were coated on rotating vanes and used in an immobilized photoreactor for the first time. The system's efficiency in COD, color, turbidity, and TOC removal, was monitored, and the effect of different parameters including pH, coating surface area, and concentration of immobilized nanoparticles was investigated. Based on the results, the maximum COD, color, turbidity, and TOC removal rates were 62%, 66%, 53%, and 55%, respectively, after 4 h of irradiation under optimal conditions. Experimental data on COD removal were also compared with the first and second-order kinetic models and it was concluded that the degradation process is more compatible with the second-order model. Finally, vanes' durability was tested, and according to the results, each set of vanes was capable of being used for at least six consecutive cycles with a negligible decrease in the treatment efficiency. In comparison with pure TiO2, the synthesized Ag-TiO2 nanoparticles showed higher removal rates in equivalent time intervals, and the whole system proved to be a promising post-treatment approach.