Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5582
標題: 甲烷氧化菌在厭氧腐熟土中之動力活性探討
Kinetic activity of methanotrophs in soil mixed with anaerobic refuse from landfill
作者: 劉卜逢
關鍵字: landfill;掩埋場;methane oxidation;methanotrophic;anaerobic organic refuse;甲烷氧化;甲烷氧化菌;腐熟土
出版社: 環境工程學系
摘要: 
本研究利用, 嘉義市南區市郊,湖內里八掌溪河川行水區內,開挖分類出之腐熟土,作為掩埋場覆土或土壤改良劑。試圖提高掩埋場覆土中之甲烷氧化能力,以減少掩埋場甲烷排放,並同時減低全球溫室效應的持續惡化情形。
在實驗室的條件下,分析結果顯示,腐熟土在初期時有抑制甲烷氧化的情況,但在馴化42天後,腐熟土開始有明顯促進甲烷氧化反應的發生,並於145天後腐熟土中甲烷氧化速率更提高到1701nmolCH4/hr-g dry soil,明顯的高於覆土EW-11的甲烷氧化速率54 nmolCH4/hr-g dry soil。
實驗土壤中甲烷氧化菌數,主要受基質濃度及馴養時間所控制,利用10000-20000ppm甲烷,所馴化出的甲烷氧化菌數為105-106MPN/g soil;50%甲烷所馴化出的甲烷氧化菌數為106-107 MPN/g soil,並且20%混合土中甲烷氧化菌數,隨馴養時間的增加有增加的現象,由初期時的1.6×104 MPN/g soil提高到6.9×106MPN/g soil的現象。
甲烷氧化菌與基質甲烷間親和力,主要受到NH4+所控制,實驗中得知,NH4+與半速率常數(Km)具有正相關性(R2=0.8422),故隨著NH4+濃度的增加,將會造成半速率常數(Km)的增加,促使甲烷氧化菌與基質甲烷間的親和力下降,並降低了甲烷氧化速率。此外,實驗中可以明顯得知,硝化作用的進行可以有效的減少NH4+濃度的累積,並且促使甲烷氧化作用的進行。

The simulations of methane oxidation under multi-conditions in batch experiments and pretreated fixed-bed columns were carried out in this study. Anaerobic refuse, excavated from a stabilized landfill onto the watershed of Pa-Chiang River near Chia-Yi city, is our focus. After separation the organic matters can be utilized directly as a fertilizer in soil or as the final cover on landfill.
It is proposed that the activity of methanotrophs is the driving force of oxidative transformation of methane. So far, there is very limited reports which relate such effect with nitrification, transformation upon substrate species, microbes population, and domestication age. The objective of this study is to investigate the optimum conditions that can be controlled to achieve the highest rate of oxidation of methane.
Results of this study demonstrated that inhibition occurred on methane oxidation of samples mixed with anaerobic refuse during the initial period. However, the oxidation reached a promotion level within 42 days, and the highest rate of 1701 nmol CH4/hr-g dry soil was observed at the 145th days. For cover soil EW-11, the oxidation rate is 54 nmol CH4/hr-g dry soil.
A higher concentration of methane in culture stage can nurse more population of methantrophs. The population of methanotrophs is 105-106 under 10000-20000 ppm, compared to 106-107 MPN/g soil under 50% methane. On the other hand, the anaerobic refuse can enhance the bacterial micro-environment, such that the population of methanotrophs increased from 1.6×104 to 6.9×106 MPN/g soil in the 20% refuse-soil mixture.
Results also indicate that the increase of half-rate constant(Km)is in accordance with a linear decrease of NH4+ concentration(R2=0.8422). The evidence for a slower oxidation rate of methane due to the anaerobic refuse suggested the disadvantage of affinity involved a site competition on mono-oxygenase. Nevertheless, nitrifications in the sample can effectively reduce the amount of NH4+, then benefits methane oxidation.
URI: http://hdl.handle.net/11455/5582
Appears in Collections:環境工程學系所

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