植物建植对垃圾填埋场生物覆盖层甲烷氧化及其微生物群落的影响

利用柱试验模拟填埋场生物覆盖层,研究了白三叶和苜蓿建植对增强覆盖层甲烷(CH4)氧化能力及保持甲烷氧化优势菌群的影响。结果表明:植物建植能明显降低基质含水率,提高氮含量,改善O2和CH4扩散,提高基质CH4氧化能力;在CH4氧化的高速期和下降期,植物建植的CH4氧化速率显著高于对照,白三叶和苜蓿处理之间无显著差异;在CH4氧化的低速期,对照与植物建植之间的CH4氧化速率无显著差异,而苜蓿处理显著高于白三叶处理。基于磷脂脂肪酸(PLFA)的微生物群落结构分析表明,植物建植有利于Ⅰ型菌在深层的分布,随着CH4氧化速率逐渐下降,柱体底部甲烷氧化细菌群落由Ⅰ型为主向Ⅱ型为主转变。

Effects of vegetation establishment on the methane oxidation and methanotrophs community in landfill biocover

In order to search for an effective way to reduce the methane emission from landfill,three columns were installed,two of which were planted with Medicago sativa and Trifolium repens,respectively to simulate the biocover of landfill,and one was taken as the control,with the effects of vegetation establishment on the methane oxidation and methanotrophs community in the landfill biocover investigated.Vegetation establishment could markedly contribute to the decline of substrate moisture,increase of substrate total nitrogen,and the promotion of the diffusion of O2 and CH4 in the landfill biocover,being beneficial to the enhancement of methane oxidation in the substrate.At the high-speed phase and declining phase of methane oxidation,the oxidation rate of methane in the columns with vegetation establishment was significantly higher than that in the control,but there was no significant difference between the columns covered with different plants.At the low-speed phase,the methane oxidation had no significant differences between the vegetated columns and the control one,but the methane oxidation rate was significantly higher in the column planted with M.sativa than with T.repens.The microbial community derived from phospholipid fatty acid analysis(PLFA) showed that vegetation establishment promoted the growth of type I methanotrophs in the bottom layer of the columns,and,with the decline of methane oxidation rate,there was a shift from type Ⅰ methanotrophs to type Ⅱ methanotrophs at the bottom layer of the columns.