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研究报告

Characteristics of the methane oxidation-denitrification coupling in the aged refuse

基金项目：国家自然科学基金(No.410013230);广东高校优秀青年创新人才培育项目(No.LYM09030);暨南大学创新与培育基金项目(No.21612435)

摘要：设计全因素实验研究了填埋龄10～12年的矿化垃圾中的甲烷氧化反硝化耦合特性.结果表明,每g矿化垃圾中甲烷氧化菌、反硝化细菌可达10⁹个数量级,适合作为甲烷氧化-反硝化耦合反应介质.CH₄、O₂和NO₃^--N浓度对CH₄去除有明显影响(p<0.01),其大小顺序为CH₄>O₂>NO₃^--N,且3种因素具有显著的交互作用(p<0.01).NO₃^--N对甲烷氧化的抑制或者促进作用主要与环境中的O₂浓度和C/O比有关.相对较低的CH₄初始浓度和较低的C/O、C/N比有利于甲烷氧化和反硝化作用耦合,而且反应产物中N₂O含量较低.当CH₄、O₂浓度分别为10%,20%时,甲烷去除率能达到97.7%,产生的N₂含量为11.5%以上,且N₂O的产生量低于0.2%.

Abstract：The work investigated the characteristics of methane oxidation-denitrification coupling in the refuse landfilled for 10～12 years by full-factor experiments. The results showed that the number of methanotrophs and denitrifiers reached to 10⁹ CFU·g^-1 and 10⁹ MPN·g^-1, respectively. Therefore, the aged refuse could provide a good condition for methane oxidation-denitrification coupling. The concentrations of CH₄, O₂ and NO₃^--N had significant influences on the oxidation of CH₄ (p<0.01), and followed the orders of CH₄>O₂>NO₃^--N. Furthermore, the concentrations of CH₄, O₂ and NO₃^--N indicated significant interactions (p<0.01). This study also suggested that the inhibited or promoted effects of NO₃^--N on the oxidation of methane mainly depended on the concentrations of O₂ and the ratio of C/O in the environment. The methane oxidation coupled to denitrification was more favorable in lower concentrations of initial CH₄ and the ratios of C/O and C/N, which resulted in less N₂O. When the concentration of CH₄ was 10% and the concentration of O₂ was 20%, the oxidation efficiency of CH₄ could reach to 97.7%, the production of N₂ was more than 11.5% and N₂O was less than 0.2%.