In situ nitrogen management in landfill bioreactors using combined sharon and anammox processes

Abstract

Landfill bioreactors (LFBR) are gaining significant attention as sustainable alternative for conventional landfilling. Nitrogen management is an important issue in landfill bioreactors. The present study is to establish the combined SHARON (single reactor system for high activity ammonia removal over nitrite) and ANAMMOX (anaerobic ammonium oxidation) processes in landfill bioreactors for in situ nitrogen management. Laboratory scale landfill bioreactors (43 L volume capacity) as SHARON-ANAMMOX LFBR were loaded with mined municipal solid waste operated for 147 days at a nitrogen loading rate of 1.2 kg N/m³/d. The results showed a nitrogen removal efficiency of 84% with maximum partialnitritation efficiency of 56% and specific ANAMMOX activity of 0.7 mg Amm-N/mg MLVSS/d was achieved in the LFBR. Nitrogen transformations, biomass development and, hydrazine and hydroxylamine formation authenticated the aerobic ammonium oxidising bacteria (AOB) and anaerobic ammonium oxidising bacteria (AnAOB/ANAMMOX) activities responsible for combined SHARON-ANAMMOX processes in LFBR. 99% of the biogas in LFBR as N₂ the end product confirmed the combined SHARON-ANAMMOX processes. The study successfully demonstrated the combined SHARON-ANAMMOX processes for in situ nitrogen management in landfill bioreactors with shorter start-up time and stable operation.