垃圾填埋场甲烷氧化菌及甲烷通量的研究

采用静态箱法、滚管计数法和气相色谱法,对6个不同封场时间填埋区的甲烷通量、覆土层甲烷氧化菌数量和甲烷氧化速率的变化趋势进行了测定,并分析了它们与封场时间、植被覆盖率等因素之间的相关性。结果发现6个填埋区甲烷通量的变化范围在-0.34～5.31 mg/(m2.h)之间;覆土层甲烷氧化菌的数量范围为3.10×107～20.77×107 cfu/g干土,甲烷氧化速率在1.65×10-8～4.34×10-8mol/(h.g)之间。覆土层甲烷氧化菌的数量与甲烷氧化速率呈正相关,但前者并不是后者的决定性因素;甲烷通量高时可刺激甲烷氧化菌数量及氧化速率的提高,且三者均与封场时间呈显著负相关,与植被覆盖率呈负相关;当含水率大于15%时,随着覆土层含水率的增加,甲烷氧化速率呈下降趋势;覆土pH、有机质和铵态氮与甲烷氧化速率等无明显相关性。提高覆土层的甲烷氧化速率可有效减少垃圾填埋场的甲烷排放。

Study on methanotrophs and methane fluxes in municipal solid waste landfills

The methane fluxes,populations of methanotrophs in landfills cover soil and methane oxidation rates were investigated in different municipal solid waste landfills using enclosed chamber,hungate roll tube method and gas chromatography.The results showed that the methane fluxes ranged from-0.34 to 5.31 mg/(m2·h),populations of methanotrophs ranged from 3.10×107 to 20.77×107 cfu/g dried soil,and the methane oxidation rates ranged from 1.65×10-8 to 4.34×10-8 mol/(h·g) in landfill cover soils.The populations of methanotrophs are positively correlated with the methane oxidation rates,but they are not the determinative factor to the oxidation rates.The more methane fluxes,the higher methanotroph populations and methane oxidation rates,and they are all negatively correlated with the closure time and plants coverage of the landfills.A negative correlation is found between high moisture content of cover soil and methane oxidation rates.No significant correlations are found among pH,organic matter,ammonium nutrition and methane oxidation rates.Raising methane oxidation rates can not only reduce methane emissions from landfills but also oxidize methane in the atmosphere.