Effects of intermittent and continuous aeration on accelerative stabilization and microbial population dynamics in landfill bioreactors

• Published in: Journal of bioscience and bioengineering Vol. 108; no. 4; pp. 336 - 343
• Main Authors: Sang, Nguyen Nhu, Soda, Satoshi, Inoue, Daisuke, Sei, Kazunari, Ike, Michihiko
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2009; Elsevier
• Subjects: Accelerative stabilization; Aerobiosis; Archaea; ARN RIBOSOMAL; ARN RIBOSOMIAL; BACTERIA; BACTERIA METANOGENA; Bacteria, Anaerobic - genetics; Bacteria, Anaerobic - isolation & purification; Bacteria, Anaerobic - metabolism; BACTERIE METHANOGENE; Biological and medical sciences; BIOREACTEUR; BIOREACTORS; BIORREACTORES; Biotechnology; Carbon - analysis; Carbon Dioxide - analysis; CLOSTRIDIO; CLOSTRIDIUM; Clostridium - genetics; Clostridium - metabolism; DECHARGE; DESCARGA; DINAMICA DE POBLACIONES; DNA, Bacterial - genetics; DNA, Bacterial - isolation & purification; DNA, Ribosomal - genetics; DNA, Ribosomal - isolation & purification; DYNAMIQUE DES POPULATIONS; Energy Metabolism; Fundamental and applied biological sciences. Psychology; Gases - analysis; Intermittent aeration; Landfill bioreactors; LANDFILLS; METHANOGENS; Methanosarcina - genetics; Methanosarcina - metabolism; Methanosarcinales; Methods. Procedures. Technologies; Organic Chemicals - analysis; Polymorphism, Restriction Fragment Length; POPULATION DYNAMICS; Refuse Disposal - methods; RFLP; RIBOSOMAL RNA; Various methods and equipments; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - analysis; Intermittent aeration; Bacteria; Accelerative stabilization; Landfill bioreactors; Methanogens; Waste dumping; Stabilization; Aeration; Continuous process; Bioreactor; Methanogenic bacteria; Population dynamics; Microorganism
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/j.jbiosc.2009.04.019

Performance and microbial population dynamics in landfill bioreactors were investigated in laboratory experiments. Three reactors were operated without aeration (control reactor, CR), with cyclic 6-h aeration and 6-h non-aeration (intermittently aerated reactor, IAR), and with continuous aeration (continuously aerated reactor, CAR). Each reactor was loaded with high-organic solid waste. The performance of IAR was highest among the reactors up to day 90. The respective solid weight, organic matter content, and waste volume on day 90 in the CR, IAR, and CAR were 50.9, 39.1, and 47.5%; 46.5, 29.3 and 35.0%; and 69, 38, and 53% of the initial values. Organic carbon and nitrogen compounds in leachate in the IAR and the CAR showed significant decreases in comparison to those in the CR. The most probable number (MPN) values of fungal 18S rDNA in the CAR and the IAR were higher than those in the CR. Terminal restriction fragment length polymorphism analysis showed that unique and diverse eubacterial and archaeal communities were formed in the IAR. The intermittent aeration strategy was favorable for initiation of solubilization of organic matter by the aerobic fungal populations and the reduction of the acid formation phase. Then the anaerobic H 2-producing bacteria Clostridium became dominant in the IAR. Sulfate-reducing bacteria, which cannot use acetate/sulfate but which instead use various organics/sulfate as the electron donor/acceptor were also dominant in the IAR. Consequently, Methanosarcinales, which are acetate-utilizing methanogens, became the dominant archaea in the IAR, where high methane production was observed.