本文關鍵詞： 光發(fā)酵制氫 生物膜 胞外聚合物　出處：《哈爾濱工業(yè)大學》2016年碩士論文　論文類型：學位論文

【摘要】：針對光發(fā)酵細菌絮凝困難、細菌隨出水嚴重流失和反應裝置運行穩(wěn)定性差等主要問題。本論文采用光發(fā)酵細菌性形成穩(wěn)定的生物膜解決這一問題。首先研究載體的投入對光發(fā)酵細菌生物膜形成、細菌生長和產(chǎn)氫的影響,并對生物膜形成和產(chǎn)氫關鍵參數(shù)進行優(yōu)化調控,然后多尺度考察了光發(fā)酵細菌生物膜促進產(chǎn)氫的機制。本論文的目的是通過形成生物膜使反應裝置能夠高效穩(wěn)定產(chǎn)氫,為后續(xù)工業(yè)化生產(chǎn)提供技術支持和理論依據(jù)。載體加入對產(chǎn)氫培養(yǎng)基細菌生長沒有明顯影響。載體的投加使得反應體系產(chǎn)氣過程高效產(chǎn)氣時間從2-5d拓寬到了1-10d,累積產(chǎn)氣量達到4300 m L/L,相比于對照組2120 m L/L提升約100%,氫氣濃度由60%提高約到70%,產(chǎn)氫量由1060 mLH2/L提升到2580 m LH2/L,產(chǎn)氫量提高約180%,同時產(chǎn)氣過程更加平穩(wěn)持續(xù)。生物膜法反應裝置底物最終可利用到74mg/L而對照組反應終止時底物仍剩余320mg/L,對應底物轉化效率由24%提高到58%。針對反應裝置關鍵參數(shù)進行優(yōu)化調控時,通過綜合考慮并比較產(chǎn)氫量、運行時間、產(chǎn)氫速率和底物利用率等幾個方面,證明4 g/L碳源濃度、0.5 g/L L-半胱氨酸濃度、10cm*1的載體長度數(shù)量組合對對應是最優(yōu)的反應裝置條件。同時生物膜的出現(xiàn)使得反應裝置能夠抵抗外界環(huán)境波動并維持產(chǎn)氫能力。實驗證實生物膜的形成可以促進光發(fā)酵細菌對底物更充分的利用,并更高效穩(wěn)定的產(chǎn)生氫氣,對于反應裝置整體效能有著極強的提高作用。最后,多尺度對生物膜促進產(chǎn)氫機制進行分析。發(fā)現(xiàn)生物膜的形成使得光發(fā)酵細菌固氮酶和產(chǎn)氫酶這兩種產(chǎn)氫關鍵酶活性均得到提高,直接增強了細菌產(chǎn)氫能力。針對光發(fā)酵細菌胞外聚合物進行研究表明,生物膜并沒有改變細菌EPS元素的相對含量,而是使得細菌胞外聚合物(Extracellular Polymeric Substances,EPS)結構尤其是苯環(huán)結構和氫鍵發(fā)生改變,使得細菌表面能下降,有利于細菌與基質的物質和能量交換,同時細菌形成小凝聚體,導致細菌EPS結構松散、濃度下降,將更多的能源和物質轉化為氫氣。生物膜的形成能夠宏觀調控整體反應裝置,并提供生物膜細菌和游離細菌兩種生存策略,所以細菌可以有機分配能源和物質,同時滿足自身生存和產(chǎn)氫的需求
[Abstract]:It is difficult to flocculate photofermenting bacteria. The main problems such as the serious loss of bacteria with the effluent and the poor stability of the reactor were solved in this paper. In this paper, the biofilm was solved by the formation of stable biofilm. Firstly, the input of the carrier to the biofilm of the photofermenting bacteria was studied. Form. The effects of bacteria growth and hydrogen production on biofilm formation and key parameters of hydrogen production were optimized. Then the mechanism of biofilm promoting hydrogen production by photofermenting bacteria was investigated in multi-scale. The aim of this thesis is to make the reactor to produce hydrogen efficiently and stably by forming biofilm. The addition of carrier has no obvious effect on the growth of bacteria in hydrogen production medium. The addition of carrier makes the efficient gas production time of reaction system widen from 2 to 5 days. 1-10 days. The cumulative gas production reached 4300mL / L, which was about 100mm higher than that of the control group (2120mL / L), and the hydrogen concentration increased from 60% to 70%. Hydrogen production increased from 1060 mLH2/L to 2580 mLH2/L, and hydrogen production increased by about 180%. At the same time, the gas production process was more stable and sustained. The substrate of the biofilm reactor could be used to 74 mg / L at the end of the reaction, but the substrate was still 320 mg / L when the reaction of the control group was terminated. The conversion efficiency of substrate was increased from 24% to 58. When the key parameters of the reactor were optimized, the hydrogen production and operation time were considered and compared. The hydrogen production rate and substrate utilization rate proved that the concentration of 4 g / L carbon source was 0.5 g / L L-cysteine concentration. At the same time, the biofilm can resist the fluctuation of the environment and maintain the hydrogen production ability. The shape of the biofilm has been confirmed by experiments. It can promote the utilization of the substrate by the bacteria of photofermentation. And more efficient and stable production of hydrogen, for the overall efficiency of the reactor has a strong improvement. Finally. The mechanism of biofilm promoting hydrogen production was analyzed in multi-scale. It was found that the formation of biofilm increased the activity of two key hydrogen-producing enzymes, nitrogenase and hydrogen-producing enzyme. Direct enhancement of bacteria hydrogen production capacity. The study of photofermentation bacteria extracellular polymer showed that the biofilm did not change the relative content of bacterial EPS elements. The structure of extracellular Polymeric substances-EPSs, especially the structure of benzene ring and hydrogen bond, were changed. The surface energy of bacteria is decreased, which is beneficial to the exchange of substance and energy between bacteria and matrix. Meanwhile, bacteria form condensates, which leads to the looseness of EPS structure and the decrease of concentration. The formation of biofilm can macro-control the overall reaction device and provide biofilm bacteria and free bacteria two survival strategies so bacteria can allocate energy and substances organically. At the same time to meet their own survival and hydrogen production needs
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TQ116.2
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本文編號：1492373