本文關(guān)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(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：針對(duì)光發(fā)酵細(xì)菌絮凝困難、細(xì)菌隨出水嚴(yán)重流失和反應(yīng)裝置運(yùn)行穩(wěn)定性差等主要問題。本論文采用光發(fā)酵細(xì)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(duì)光發(fā)酵細(xì)菌生物膜形成、細(xì)菌生長(zhǎng)和產(chǎn)氫的影響,并對(duì)生物膜形成和產(chǎn)氫關(guān)鍵參數(shù)進(jìn)行優(yōu)化調(diào)控,然后多尺度考察了光發(fā)酵細(xì)菌生物膜促進(jìn)產(chǎn)氫的機(jī)制。本論文的目的是通過形成生物膜使反應(yīng)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(shù)支持和理論依據(jù)。載體加入對(duì)產(chǎn)氫培養(yǎng)基細(xì)菌生長(zhǎng)沒有明顯影響。載體的投加使得反應(yīng)體系產(chǎn)氣過程高效產(chǎn)氣時(shí)間從2-5d拓寬到了1-10d,累積產(chǎn)氣量達(dá)到4300 m L/L,相比于對(duì)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(shí)產(chǎn)氣過程更加平穩(wěn)持續(xù)。生物膜法反應(yīng)裝置底物最終可利用到74mg/L而對(duì)照組反應(yīng)終止時(shí)底物仍剩余320mg/L,對(duì)應(yīng)底物轉(zhuǎn)化效率由24%提高到58%。針對(duì)反應(yīng)裝置關(guān)鍵參數(shù)進(jìn)行優(yōu)化調(diào)控時(shí),通過綜合考慮并比較產(chǎn)氫量、運(yùn)行時(shí)間、產(chǎn)氫速率和底物利用率等幾個(gè)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(zhǎng)度數(shù)量組合對(duì)對(duì)應(yīng)是最優(yōu)的反應(yīng)裝置條件。同時(shí)生物膜的出現(xiàn)使得反應(yīng)裝置能夠抵抗外界環(huán)境波動(dòng)并維持產(chǎn)氫能力。實(shí)驗(yàn)證實(shí)生物膜的形成可以促進(jìn)光發(fā)酵細(xì)菌對(duì)底物更充分的利用,并更高效穩(wěn)定的產(chǎn)生氫氣,對(duì)于反應(yīng)裝置整體效能有著極強(qiáng)的提高作用。最后,多尺度對(duì)生物膜促進(jìn)產(chǎn)氫機(jī)制進(jìn)行分析。發(fā)現(xiàn)生物膜的形成使得光發(fā)酵細(xì)菌固氮酶和產(chǎn)氫酶這兩種產(chǎn)氫關(guān)鍵酶活性均得到提高,直接增強(qiáng)了細(xì)菌產(chǎn)氫能力。針對(duì)光發(fā)酵細(xì)菌胞外聚合物進(jìn)行研究表明,生物膜并沒有改變細(xì)菌EPS元素的相對(duì)含量,而是使得細(xì)菌胞外聚合物(Extracellular Polymeric Substances,EPS)結(jié)構(gòu)尤其是苯環(huán)結(jié)構(gòu)和氫鍵發(fā)生改變,使得細(xì)菌表面能下降,有利于細(xì)菌與基質(zhì)的物質(zhì)和能量交換,同時(shí)細(xì)菌形成小凝聚體,導(dǎo)致細(xì)菌EPS結(jié)構(gòu)松散、濃度下降,將更多的能源和物質(zhì)轉(zhuǎn)化為氫氣。生物膜的形成能夠宏觀調(diào)控整體反應(yīng)裝置,并提供生物膜細(xì)菌和游離細(xì)菌兩種生存策略,所以細(xì)菌可以有機(jī)分配能源和物質(zhì),同時(shí)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(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：TQ116.2
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本文編號(hào)：1492373