Electrochemical Treatment of Biotreated Landfill Leachate Using a Porous Carbon Nanotube-Containing Cathode: Performance, Toxicity Reduction, and Biodegradability Enhancement

The electrochemical treatment of biotreated landfill leachate was carried out using a Ti/SnO2-Sb2O5-IrO2 anode and a porous carbon nanotube-containing cathode. The ideal pollutant removal has been achieved by the electrochemical treatment evaluated by the decay of total organic carbon (TOC), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total nitrogen (TN). The influences of cathodic potential and external addition of Fe2+ on TOC decay evidenced that both electro-Fenton oxidation and anodic oxidation were accounted for pollutant degradation. Cl- can play an important role in the removal of NH3-N and TN. The determination of dehydrogenase activity and BOD5/COD showed that the leachate toxicity became weaker and the biodegradability was enhanced after the electrochemical treatment. These results suggest that the electrochemical process may present a promising alternative for the advanced treatment of biotreated landfill leachate.