International Journal of Environmental Science and Technology, cilt.21, sa.5, ss.4751-4772, 2024 (SCI-Expanded)
Landfill leachate is a mixture of highly concentrated organic and inorganic pollutants and needs to be treated properly due to their toxicity and serious adverse effects on the environment. Recently, advanced oxidation processes have been successfully applied for leachate treatment. In this study, the removal of chemical oxygen demand (COD), total organic carbon (TOC) and absorbable organic halogens (AOX) in waste leachate stabilized by the electro-Fenton (EF) process, which is one of the advanced oxidation processes, was investigated. For this purpose, a jacketed reactor in which the electrochemical process takes place was designed and iron electrodes were used for maintenance and cost efficiency in this process. Within the scope of the study, the efficiency of the important process parameters, such as pH, current density, catalyst amount, oxidant dose and electrolysis time, was determined and their values were optimized. Optimum values were found to be as pH 3, current density 150 A/m2, hydrogen peroxide amount 500 mg/L and electrolysis time 10 min. The best removal efficiencies were obtained as 71.7% COD, 97.4% AOX and 90.87% TOC under optimum conditions. In addition, within the scope of this study, the collapsibility and operating costs of the sludge having formed as a result of the EF process were also examined. It has been observed that especially the sludge formed as a result of the EF process has good settling properties. When the results were evaluated, it was confirmed that the EF process can be used efficiently to break down leachate organics in terms of wastewater quality and discharge limits.