Electrochemical Treatment of Landfill Leachate under Cold Climate Conditions

This study shows that electrochemical oxidation of landfill leachate (LL) is significantly affected by cold temperatures prevailing in Nordic climate areas. As hypothesized, the degradation of common wastewater parameters (TOC, COD) exhibited lower efficiency when low average temperature (13°C) was applied than compared to room temperature (25°C). At low temperature, 35 % of COD and 64 % of TOC were removed, compared to 69 % of COD and 74 % of TOC removal at high temperature. Electrochemical oxidation of ammonium (NH4) has also been observed, whereas only 1 % was removed at 13°C compared to 11 % at 25°C. In addition, the formation of three hazardous trihalomethanes (THMs) has been confirmed when a high current (7A) was applied, but THMs remained below the quantification limit of 3 ppb at low current (0.3 A). Even though kinetics decrease when cold temperatures are prevailing, electrochemical oxidation is considered still a suitable choice for the treatment of landfill leachate in areas with Nordic climate.