Coupling anammox and advanced oxidation-based technologies for mature landfill leachate treatment

The aim of this study was to evaluate the suitability to couple anammox process with advanced oxidation processes (AOPs) to treat mature landfill leachate with high nitrogen and non-biodegradable organic matter concentrations (2309±96mgN-TNL^-1 and 6200±566mgCODL^-1). The combination of a partial nitiration-anammox system coupled with two AOP-based technologies (coagulation/flocculation+ozonation and photo-Fenton) was assessed in terms of nitrogen and carbon removal. Total nitrogen removal efficiency within a range of 87-89% was obtained with both configurations without the need of any external carbon source. The COD removal efficiencies attained were 91% with coagulation/flocculation+ozonation and 98% with photo-Fenton. Applying the biological treatment prior to advanced oxidation processes-based technologies reduced the quantity of needed reagents giving attaining higher removal efficiencies. From a basic economical point of view and taking into account the results of this study, the combination of partial nitritation-anammox system with photo-Fenton treatment was more favorable than with coagulation/flocculation+ozonation treatment.