【摘要】：海洋區(qū)域蘊(yùn)藏了豐富的天然氣水合物資源,是地球上巨大的碳儲(chǔ)庫(kù)之一。當(dāng)海洋環(huán)境發(fā)生變化時(shí),部分水合物會(huì)分解釋放出大量天然氣,其向上運(yùn)移過(guò)程中會(huì)發(fā)生厭氧或好氧氧化反應(yīng),從而減少由海洋向大氣的碳排放量,起到消耗截流的作用。本文選取含烷烴好氧氧化菌的海底沉積物進(jìn)行了水合物分解氣的微生物好氧降解模擬實(shí)驗(yàn),實(shí)驗(yàn)中用混合氣(C_1+C_2+C_3)來(lái)模擬多組分水合物分解氣。實(shí)驗(yàn)結(jié)果顯示,在微生物作用下烴類(lèi)混合氣發(fā)生好氧氧化降解反應(yīng)至消耗殆盡,反應(yīng)優(yōu)先順序?yàn)镃_1C_2C_3,降解速率C_1C_2C_3。且隨著烴類(lèi)組分含量的減少,其碳?xì)渫凰亟M成發(fā)生了微生物降解分餾效應(yīng),并呈現(xiàn)出不同程度的富集趨勢(shì)。C_1、C_2和C_3的碳同位素富集變化量分別為71.05‰、12.03‰和4.61‰,碳同位素分餾系數(shù)(εC)的平均值分別為-11.219‰、-2.951‰和-1.539‰;氫同位素富集變化量分別為368.64‰、156.00‰和111.97‰,氫同位素分餾系數(shù)(εH)的平均值分別為-56.092‰、-99.696‰和-73.303‰。可見(jiàn),三者的碳位素富集程度C_1C_2C_3,而氫同位素富集程度C_2C_3C_1。此外,水合物分解氣在微生物降解過(guò)程中氣體成分組成及碳?xì)渫凰靥卣靼l(fā)生了改變,對(duì)判別氣體成因起到一定的干擾作用,因此,利用分解溢出氣體樣品進(jìn)行氣體溯源時(shí)需要適當(dāng)考慮這一影響因素。
[Abstract]:The marine area contains abundant natural gas hydrate resources and is one of the huge carbon reservoirs on the earth. When the marine environment changes, some hydrates will decompose and release a large amount of natural gas, and anaerobic or aerobic oxidation will occur during their upward migration, which will reduce the carbon emissions from the ocean to the atmosphere and play the role of consumption and closure. In this paper, the microbial aerobic degradation simulation experiment of hydrate decomposition gas was carried out in seabed sediments containing alkane aerobic bacteria. In the experiment, the multicomponent hydrate decomposition gas was simulated by C _ 1C _ S _ 2C _ 3 (C _ 1C _ S _ 2C _ 3). The experimental results show that the aerobic oxidation degradation reaction of hydrocarbon mixture under the action of microorganism is exhausted, the priority of the reaction is C1C _ 2C _ 3 and C _ 1C _ 2C _ 3, and the degradation rate is C _ 1C _ 2C _ 2C _ 3. With the decrease of hydrocarbon composition, microbial degradation fractionation effect occurred in the hydrocarbon isotopic composition, and the enrichment trend of C _ 1C _ 2 and C _ 3 was 71.05 鈥，

本文編號(hào)：2311178