Treatment of intermediate landfill leachate using different anode materials in electrooxidation process

Abstract

This study aims to investigate the performances of widely used anode materials in the treatment of intermediate landfill leachate treatment by electrooxidation (EO) process. The raw leachate was collected from an 8-year-old landfill facility and had a chemical oxygen demand (COD) of 4660 mg/L, biological oxygen demand (BOD5) of 1370 mg/L, and total organic carbon (TOC) of 2260 mg/L. TOC and COD removal efficiencies of Boron-Doped Diamond (BDD), Pt, and four different Ti-based mixed metal oxide (MMO) anodes ((RuO2-TiO2, RuO2-IrO2, PtO2-IrO2, and IrO2-Ta2O5) were compared at the current densities of 25 mA/cm(2), 75 mA/cm(2), and 125 mA/cm(2). At the highest current density, the BDD achieved 100% TOC and COD removal efficiencies in 240 min. BDD was followed by the Pt anode, which achieved 95.53% COD and 92.74% TOC removal efficiencies. The Pt electrode also had the lowest SEC values at all current densities. Although the performances of four MMO electrodes were very close, RuO2-TiO2 achieved a slightly higher performance than the others. It was concluded that Pt anode can be a promising alternative to BDD, which was 18 times more expensive, with its comparable pollutant removal performance and low specific energy consumption.