亜熱帯・熱帯地域の廃棄物埋立地における微生物生態系の調査

Abstract

To understand the behavior of waste degradation in landfills and landfill stabilization in tropical and subtropical climate zones, eubacterial community analysis using waste landfill leachate was conducted. Waste landfills in Thailand, Vietnam and Japan were investigated of the bacterial communities. The waste landfills in Hua Hin (Thailand) and Go Cat (Vietnam) had high concentrations of organics in the leachate and organics in these high amounts of gas generated, indicating the active degradation of organic waste, as well as the disposal of large amounts of landfills. The landfills in the Japanese subtropical zone were suggested to be under going a comparatively stable degradation because of the long — term use of the landfill and the preliminary mineralization of landfill materials. All the bacterial communities isolated from observed in the landfills showed the existence of bacteria phylogenically related to Firmicutes and Bacteroidetes, indicating a highly reducing condition of the waste layer in the landfills. On the other hand, bacteria related to CFB (Cytophaga-Flexibacter-Bacteroidetes) group and ε-Proteobacteria were specifically detected from the Hua Hin landfill and Go Cat landfill but not from the Japanese landfills. The presence of these bacterial groups indicates the regional specificity of waste degradation in landfills under active degradation. Some common bacterial groups such as γ-Proteobacteria in the Hua Hin landfill and Japanese subtropical landfills were also found, suggesting certain similarities between these landfills.