Photocatalytic Treatment of Landfill Leachate Using W-Doped TiO2 Nanoparticles

Leachate is a highly toxic wastewater produced in landfills that causes many environmental problems. One imperative action related to leachate management is the implementation of a leachate collection system and leachate treatment. Because leachate contains a wide range of contaminants, an interesting method that may be used in the future for the treatment of leachate is a photocatalytic treatment process using doped TiO2 nanoparticles. In this study, the performance of tungsten-doped TiO2 (W-doped TiO2) nanoparticles in the photocatalytic treatment of landfill leachate under the fluorescent light irradiation was examined. For this purpose, four influential parameters on the photocatalytic process using doped TiO2 nanoparticles (ie., dopant content, calcination temperature, pH, and contact time of leachate with nanoparticles) were first experimentally investigated. Next, a quadratic regression equation using response surface methodology was used to predict the concentration of the leachate chemical oxygen demand (COD) in the aforementioned process. To ensure the validity of the model, eight basic assumptions of regression equations were investigated and attempted to be met. Using the model, the effect of each parameter on the photocatalytic treatment process was observed, and leachate COD concentration may be predicted with R-2 = 0.92. Finally, optimal conditions were determined using the model to achieve maximum COD removal efficiency. The confirmatory experiment results show that 46% COD removal efficiency is achievable at optimal conditions (i.e., pH of 6.63, tungsten content of 2.64% by weight, calcination temperature of 472 degrees C, and contact time of 34 h). (C) 2017 American Society of Civil Engineers.