本文選題：生物制氫　切入點(diǎn)：混合菌群　出處：《太原理工大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：氫能作為理想的能源載體,具有清潔無(wú)污染、燃燒熱值大、可儲(chǔ)可輸、來(lái)源廣泛等優(yōu)點(diǎn)。在眾多生物制氫技術(shù)中,光合細(xì)菌光發(fā)酵制氫因低能耗、高效率,底物降解速率快,以及能將廢水處理和能源生產(chǎn)有效地耦合起來(lái),而備受關(guān)注。本文從湖底淤泥中采用生長(zhǎng)培養(yǎng)基富集篩選得到混合菌群,命名為NG07。結(jié)合16S rDNA高通量測(cè)序?qū)ζ溥M(jìn)行鑒定分析,確定混合菌群NG07的優(yōu)勢(shì)菌種主要為紅假單胞菌Rhodopseudomonas oryzae和類(lèi)球紅細(xì)菌Rhodobacter sphaeroides。以篩選的混合菌群NG07為研究對(duì)象,主要研究了培養(yǎng)過(guò)程中底物和環(huán)境因素對(duì)混合菌群的生長(zhǎng)及產(chǎn)氫特性的影響。實(shí)驗(yàn)研究成果表明:(1)混合菌群NG07可利用多種糖類(lèi)有機(jī)化合物產(chǎn)氫,其中葡萄糖為碳源時(shí),產(chǎn)氫總量最大。隨著葡萄糖濃度的增加,NG07的產(chǎn)氫總量逐漸增大,當(dāng)葡萄糖濃度為100 mM時(shí),產(chǎn)氫總量為4238.8±74 mL/L。但葡萄糖濃度對(duì)混合菌群的產(chǎn)氫速率、底物轉(zhuǎn)化率、葡萄糖降解率的影響不同,當(dāng)?shù)孜餄舛葹?0 mM,NG07的最大產(chǎn)氫速率、底物轉(zhuǎn)化率、和葡萄糖降解率都達(dá)到最大,分別為105.28±7.6 mL/h/L,底物轉(zhuǎn)化率15.37%,和葡萄糖降解率99.40%。(2)在10 mM尿素的條件下,混合菌群NG07的產(chǎn)氫總量和最大產(chǎn)氫速率達(dá)到最大,分別為2872.2±38.31 mL/L和105.28±7.6 mL/h/L。(3)混合菌群NG07產(chǎn)氫的最佳Fe~(2+)濃度為5 mg/L。在5 mg/L的條件下,NG07的產(chǎn)氫總量和最大產(chǎn)氫速率達(dá)到最大,分別為3102.5±95.7 mL/L和114.9±9.1 mL/h/L,與對(duì)照相比分別增加了1.94倍和2.54倍。(4)攪拌能夠提高光合細(xì)菌產(chǎn)氫的產(chǎn)氫速率和縮短反應(yīng)停留時(shí)間,但對(duì)混合菌群的產(chǎn)氫總量影響比較小。在攪拌的條件下,其最大產(chǎn)氫速率為136.0±5.6mL/L/h,與對(duì)照組相比提高了29%。(5)NG07的最佳產(chǎn)氫溫度是35℃。但溫度為40℃時(shí)NG07仍具有良好的產(chǎn)氫性能,產(chǎn)氫總量為2638.5±52.7mL/L;而在45℃的條件下,NG07仍具有產(chǎn)氫活性,產(chǎn)氫總量為1050.0±28.7 mL/L,說(shuō)明NG07具有很強(qiáng)的耐熱性。(6)不同光照條件對(duì)混合菌群NG07的產(chǎn)氫總量和最大產(chǎn)氫速率的影響不同:產(chǎn)氫總量依次是12 h暗/12 h光循環(huán)連續(xù)光照≥連續(xù)黑暗12 h光/12 h暗循環(huán)條件;最大產(chǎn)氫速率依次是12 h暗/12 h光循環(huán)連續(xù)光照連續(xù)黑暗≥12 h光/12 h暗循環(huán)條件。(7)以聚乙烯醇作為固定化包埋材料時(shí),混合菌群NG07的產(chǎn)氫活性明顯優(yōu)于瓊脂和海藻酸鈉。(8)Box-Behnken Design是以單因素試驗(yàn)為基礎(chǔ),以最大產(chǎn)氫速率為評(píng)價(jià)指標(biāo),對(duì)光合產(chǎn)氫工藝條件進(jìn)行優(yōu)化。得出最優(yōu)條件為:Fe~(2+)濃度4.39 mg/L,溫度33.36℃,葡萄糖濃度78.32 mM。在該條件下獲得了199.3±6.5 mL/L/h的產(chǎn)氫速率,與最初條件相比提高了25.2%。由此可知,通過(guò)多因素實(shí)驗(yàn)優(yōu)化得出的最佳產(chǎn)氫條件,不同于單因素實(shí)驗(yàn)的最佳條件,這就表明影響混合菌群產(chǎn)氫的各個(gè)因素之間存在交互作用。
[Abstract]:Hydrogen energy, as an ideal energy carrier, has the advantages of clean and pollution-free, high combustion calorific value, storage and transportation, wide source and so on. In many biological hydrogen production technologies, photofermenting hydrogen production by photosynthetic bacteria is characterized by low energy consumption, high efficiency, fast substrate degradation rate, and so on. In this paper, the mixed microflora was obtained by using growth medium enrichment and screening from the sludge of lake bottom, named NG07. combined with 16s rDNA high-throughput sequencing, it was identified and analyzed. The dominant species of mixed NG07 were Rhodopseudomonas oryzae and Rhodobacter sphaeroids. The effects of substrate and environmental factors on the growth and hydrogen production characteristics of mixed bacteria were studied in this paper. The experimental results showed that NG07 could produce hydrogen from various carbohydrate organic compounds, especially when glucose was a carbon source. With the increase of glucose concentration, the total hydrogen production of NG07 gradually increased. When glucose concentration was 100 mm, the total hydrogen production was 4238.8 鹵74 mL / L. However, the hydrogen production rate and substrate conversion of mixed bacteria were increased by glucose concentration. The maximum hydrogen production rate, substrate conversion rate, and glucose degradation rate were all the highest when the substrate concentration was 70 mm / L NG07, which was 105.28 鹵7.6 mL / h / L, respectively, and the substrate conversion rate was 15.37%, and the glucose degradation rate was 99.40.0.72) under the condition of 10 mm urea, respectively, when the substrate concentration was 70 mm / L NG07, the maximum hydrogen production rate, the substrate conversion rate and the glucose degradation rate were 105.28 鹵7.6 mL / h / L, respectively. The total hydrogen production and the maximum hydrogen production rate of mixed NG07 were 2872.2 鹵38.31 mL/L and 105.28 鹵7.6 mL / L 路L 路L ~ (-3) respectively. The best Fe~(2 concentration of mixed NG07 was 5 mg / L 路L ~ (-1) 路L ~ (-1). The maximum hydrogen production and maximum hydrogen production rate were obtained at 5 mg/L. The hydrogen production rate and residence time of photosynthetic bacteria were increased by 1.94 times and 2.54 times, respectively (3102.5 鹵95.7 mL/L and 114.9 鹵9.1 mL / h / L, respectively, compared with the control). However, the effect of stirring on the total hydrogen production of mixed bacteria was relatively small. The maximum hydrogen production rate was 136.0 鹵5.6 mL / L / h, and the optimum hydrogen production temperature was 35 鈩，

本文編號(hào)：1573981