【作者】 李扬；

【导师】 李茹莹； 杜连柱；

【作者基本信息】 天津大学 ， 环境工程（专业学位）， 2014， 硕士

【摘要】 能源危机和环境污染问题迫使人类寻求清洁可再生替代能源。氢气作为一种清洁、高热值的新能源受到了广泛关注。在众多的制氢方法中,生物制氢作为一种经济环保的方法成为近年来的研究热点之一。光发酵产氢是一种利用异养光合细菌产氢的生物制氢方法,已有研究多集中在纯种光合细菌在悬浮生长状态下以单一碳源作为基质进行光发酵产氢。近年来有研究提出在光发酵产氢系统中加入载体,利用附着生长光合细菌产氢以提高产氢速率,但多以纯种光合细菌研究为主。本研究采用混合培养的光合细菌,以乙酸和丁酸的混合物作为基质,探究附着生长的混合菌种光合细菌的产氢性能,以及其对不利环境因素的耐受性。本研究探究了可促进光合细菌产氢的载体材料,确定活性炭纤维作为光合细菌附着生长的载体。以10m M乙酸和丁酸的混合物作为基质,在光照强度为6000lux,温度为30℃条件下,研究载体投加量对光发酵产氢的影响。结果表明,在载体投加比例为0.4g/L时,氢气体积产率最高,为1904.2m L/L,比悬浮生长光合细菌产氢量提高了24.3%。在载体投加比例为0.8g/L和1.2g/L时,产氢量受到抑制。在最佳载体投加比例0.4g/L条件下,本研究还进行了附着生长光合细菌对p H值和氨氮等不利因素的耐受性探究。试验结果显示,附着生长光合细菌产氢的最佳p H值为6.0,氢气体积产率为1155.9m L/L,比p H值7.0时的氢气体积产率高21.6%,比悬浮生长光合细菌在最佳p H值7.0时的氢气体积产率高135.8%,附着生长光合细菌的酸性耐受性大幅提高。在氨氮浓度耐受性试验中发现,附着生长光合细菌产氢的最佳氨氮浓度为1.0m M,与悬浮生长光合细菌相比,光合细菌在附着生长条件下对氨氮高浓度的耐受性没有得到提高,但是在氨氮浓度0~1.0m M范围内产氢性能增强,且附着生长光合细菌对乙酸的去除率得到了提高。分子生物学分析结果显示,光发酵产氢污泥中主要起产氢作用的优势微生物为Rhodobacter blasticus。附着生长和悬浮生长光合细菌菌群结构差异性较大,而附着生长光合细菌微生物体系结构在产氢反应过程中更为稳定。更多还原

【Abstract】 The problems of energy shortage and environmental pollution stimulated humans to search clean and renewable energy. Hydrogen is brought out as such a high calory and cleaning energy to replace the fossil. A couple of hydrogen production methods were put forward, whatever, the style of bio-hydrogen production was paid more attention to because it was produced with less cost and pollution. Phototrophic fermentation is a kind of bio-hydrogen production method which product hydrogen by heterotrophic photosynthetic bacteria with the light energy. So far, these researches are majorly about the hydrogen production of the pure suspended photosynthetic bacteria with the single carbon resource. Although a few studies have given an idea of carrier addition to increase the hydrogen producing velocity by immobilized photosynthetic bacteria, most of these were conducted with pure photosynthetic bacteria. This study aimed to develop the hydrogen production of photo fermentation and the endurance of bacteria at unfavorable factor by immobilized photosynthetic bacteria consortium with the mixed carbon source of acetate and butyrate.Firstly, this study seeks to get a proper carrier to stimulate the hydrogen production, and the activated carbon fiber is tested to be effective for immobilizing the photosynthetic bacteria. The test was carried out at the concentration of 10 m M acetate and butyrate respectively, the light intensity of 6000 lux, and the temperature of 30 ℃. The highest hydrogen production of 1904.21 m L/L was got at a ratio of 0.4g/L activated carbon fiber for immobilized photosynthetic bacteria, which is increased by 24.33% for the suspended photosynthetic bacteria. However, the hydrogen production was inhibited when the dosage increased to 0.8g/L and 1.2g/L.Then, at the same condition, this study took a test for the endurance of p H and [NH4+-N] with a dosage of 0.4g/L activated carbon fibers. It concluded that the best p H for the immobilized photosynthetic bacteria hydrogen production is 6.0, which get a cumulative hydrogen production of 1155.9m L/L. This result is developed by 21.6% than p H7.0 hydrogen production by immobilized photosynthetic bacteria. What’s more, is still get an increasing of 135.8% compared with suspended photosynthetic bacteria at p H7.0. The immobilized photosynthetic bacteria seemed to be more endurable to the acid condition. On another side, the perfect [NH4+-N] for immobilized photosynthetic bacteria hydrogen production is 1m M. This result seemed did not give a good proof of endurance at high ammonia concentration for immobilized photosynthetic bacteria hydrogen production. Otherwise, the attached-growth bacteria performed better at ammonia concentration of 0~1m M, and acetate removal was also increased.A molecular biochemistry analysis is brought out in this study. The result showed that the photosynthetic bacteria named Rhodobacter blasticus played an important role in hydrogen producing process. It also found that the immobilized bacteria population was much different from the suspended one. What’s more, the immobilized photosynthetic bacteria system keeps more stable in the hydrogen production process.更多还原