Leachate pre-treatment strategies before recirculation in landfill bioreactors

• Published in: Water Science & Technology Vol. 52; no. 1-2; pp. 289 - 297
• Main Authors: Vigneron, V, Bouchez, T, Bureau, C, Mailly, N, Mazeas, L, Duquennoi, C, Audic, J M, Hébé, L, Bernet, N
• Format: Journal Article Conference Proceeding
• Language: English
• Published: England IWA Publishing 01.01.2005
• Subjects: Acid production; Ammonium; Ammonium compounds; Anaerobic digestion; Anaerobic treatment; Bacteria, Anaerobic - metabolism; Biodegradability; Biodegradation; Biodegradation, Environmental; Bioreactors; Bioreactors - microbiology; Carbon Dioxide - metabolism; Denitrification; Earth Sciences; Hydrogen sulfide; Hydrogen Sulfide - metabolism; Hydrology; Landfill; Landfill management; Landfills; Leachates; Methane - metabolism; Municipal solid waste; Municipal waste management; Nitrate reduction; Nitrates; Nitrates - pharmacology; Nitrogen - metabolism; Nitrogen fixation; Nitrous oxide; Nitrous Oxide - metabolism; Organic carbon; Pretreatment; Quaternary Ammonium Compounds - metabolism; Reactors; Reduction; Refuse Disposal - methods; Reproducibility; Sciences of the Universe; Solid waste management; Solid wastes; Waste disposal sites; Waste management industry; Waste treatment; Water Movements; DISSIMILATORY NITRATE REDUCTION TO AMMONIUM; LANDFILL BIOREACTOR MANAGEMENT; DENITRIFICATION; LEACHATE RECIRCULATION; NITROGEN FIXATION
• ISBN: 1843395509; 9781843395508
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2005.0530

Nitrified leachate recirculation represents a promising strategy for a more sustainable landfill management. Our objective was to determine the reactions involved in nitrate reduction in municipal solid waste batch biodegradation tests. Anaerobic digestion of waste in the three control reactors showed a good reproducibility. In two test reactors, nitrate was added at various moments of the waste degradation process. We observed that: (1) H2S concentration controlled the nitrate reduction pathway: above a certain threshold of H2S, dissimilatory nitrate reduction to ammonium (DNRA) replaced denitrification. (2) N2O/N2 ratio varied with the organic carbon concentration: the lower the easily biodegradable carbon concentration, the higher the N2O/N2 ratio. (3) N2 was consumed after denitrification. The possibility of a nitrogen fixation reaction in the presence of NH4 is discussed. Nitrified leachate recirculation during acidogenesis should be avoided because of higher H2S production which could induce DNRA.