Evaluation of different full scale landfill leachate treatment systems

Sanitary landfills are one of the most used disposal methods for municipal solid waste (MSW) disposal. Due to its high strength, these wastewaters need a combination of several treatment steps, which combine biological with physical-chemical processes. The main goal of this study was to assess the removal efficiency for specific treatment steps in three different full scale treatment facilities in Portugal. Results indicate a good BOD5 removal (75; 93; 96%) on all facilities but low TOC removal (2; 58; 64%) indicating that recalcitrant organic matter remains after treatment. Total dissolved nitrogen was poorly removed (0; 0.2 and 47%) possibly due to limited nitrate removal, even in the facility with an anoxic tank. This suggests biodegradable carbon limitations and salinity toxicity. The major cations, anions and heavy metals are only partially removed with advanced filtration. The heavy metal concentrations and the high conductivity (22-67 dS m-1) indicate the need for further treatment steps. Copyright © 2017 Inderscience Enterprises Ltd.