Photocatalytic degradation of humic acids and landfill leachate using a solid industrial by-product containing TiO2 and Fe

Abstract

Landfill leachates contain a large number of recalcitrant compounds that make it unsuitable for conventional waste water treatment. This work has studied the effectiveness of a treatment method for the degradation of landfill leachates, based on a photocatalytic advanced oxidation process. The process consists of a photocatalytic treatment under UV radiation at a maximum emission wavelength of 365 nm using a solid by-product obtained from the titanium dioxide production industry, which contains TiO2 and Fe(III) as a catalyst. The product which has been used in these kinds of applications for the first time has also been compared with commercial TiO2. A multifactorial design was used to analyze the influence of significant factors that affect degradation yield such as the type of catalyst, type of oxidizable compound, catalyst loading, reaction time and pH. In addition to a landfill leachate, we have studied the abatement of some specific organic compounds, such as p-cresol and humic acids that are regularly present in landfill leachates and are considered refractory compounds. The results demonstrated that the application of this by-product resulted in a higher level of pollutant degradation as compared to commercial TiO2.