【作者】 宋雪红；

【导师】 蒋新元；

【作者基本信息】 中南林业科技大学 ， 环境工程， 2012， 硕士

【摘要】 水生植物具有良好的水质净化效果,在富营养化水体的生物修复中应用广泛,但生长繁殖速度过快,易腐烂分解,造成水体的二次污染。若将水生植物看作一种高产的能源植物,用厌氧发酵技术加以利用,可制取清洁能源。本文将选取一些水生植物进行生化成分测定和厌氧发酵实验,探索其作为沼气发酵原料的可行性,并分析植物成分对其厌氧发酵过程的影响；对香蒲厌氧发酵过程的接种率、料液浓度等工艺条件进行优化。主要的结论如下：(1)从美人蕉和香蒲的厌氧发酵实验得出,增加接种量和原料添加量、粉碎以及选取合适的接种物都能明显提升产气效果,表现为：产气稳定性增强,产气周期延长,产气量增加。(2)木质纤维素、碳水化合物以及蛋白质是水生植物的主要有机成分,原料的可生物性较好。各水生植物在37℃的产气率分别为：香蒲513.23mL·g-1VS、香菇草539.09mL·g-1VS、再力花577.96mL·g-1VS、菖蒲508.95mL.g-1VS、美人蕉555.05mL·g-1VS、紫芋629.41mL·g-1VS、梭鱼草473.09mL·g-1VS,可以作为良好的厌氧发酵原料。(3)香蒲和紫芋的C/N分别为18.59和16.97,理论产沼气潜力分别为969.21mL·g-1VS和897.69mL·g-1VS,厌氧降解率分别为52.95%和70.11%。(4)本实验对发酵原料木质纤维素含量与厌氧生化产沼气潜力(ABP)之间的联系进行相关性分析,得出木质素与ABP之间的相关性(r=-0.259,p>0.05)很微弱,而半纤维素与ABP间有一定的相关性(r=-0.781,p<0.05),说明半纤维素的含量会对ABP产生直接影响,这与以往的研究成果认为ABP受木质素的影响不同。以半纤维素作为单独变量,建立预测ABP的模型方程,得出：半纤维素与ABP间的一元线性回归方程斜率为3.592,截距为587.104,相对偏差为6.81%。(5)在香蒲的工艺条件优化实验中得出,固体浓度6%、接种率50%的实验组产气率最高,发酵过程中pH值变化最稳定,累积产气量和产气率分别为6482mL和581.39mL·g-1VS、固体浓度8%、接种率40%的实验组累积产气量最高,累积产气量和产气率分别为9297mL和.521.17mL·g-1VS,可以作为香蒲厌氧发酵的较佳条件。更多还原

【Abstract】 The aquatic plants have good ability for the water purification, so they are widely used in the bioremediation of entropic water. However, the rapid growth and decomposition of aquatic plants could easily cause the secondary pollution of water bodies, if the aquatic plants were used as a high yielding energy plant to convert to biogas through anaerobic fermentation, which will not only stop the secondary pollution, but also produce economic value. In order to explore the feasibility of using aquatic plants for biogas through anaerobic fermentation, several aquatic plants were explored as fermentation materials for biogas production in this paper. The composition of the selected aquatic plants was determined and their effects on anaerobic fermentation were analysised, and the fermentation concentration and inoculums rate were also optimized in the fermentation process of Typha. The main conclusions are as follows:(1)The exploratory anaerobic fermentation experiments of Canna indica and Typha orientalis were carried out first. The results indicated that the measures like increasing the inoculation amount and raw materials, grinding and selecting suitable inoculums all had notable influence on the biogas production, enhancing the stability of the gas production, prolonging the gas production cycles and increasing the gas volume.(2)The major organic components of the aquatic plants are lignocellulose, carbohydrates and protein, which showed a good biodegradability. The biogas production rates of the seven aquatic plants were:Typha orientalis513.23mL·g-1VS, Hydrocotyle vulgaris539.09mL·g-1VS, Thalia dealbata577.96mL·g-1VS, Acorus calamus508.95mL·g-1VS, Canna indica555.05mL·g-1VS, Colocasia tonoimo629.41mL·g-1VS and Pontederia cordata473.09mL·g-1VS respectively, which suggested that the aquatic plants can be utilized to be resources for biogas production.(3)The C/N of Typha orientalis and Colocasia tonoimo was18.59and16.97respectively, and their theoretical biogas potential was969.21mL·g-1VS and897.69mL·g-1VS respectively, so their anaerobic degradation rate was52.95%and70.11%respectively.(4) The correlation between lignocellulose content and anaerobic biogas potential(ABP) was studied in this paper. The results showed that the correlation between lignin and ABP (R2=0.067) is very weak, while there is a certain correlation between hemicelluloses and ABP (R2=0.610, p<0.05). The conclusion believed that the hemicelluloses content directly affected the ABP. While the previous research results suggested a different opinion that the ABP was affected by lignin. We established a model equation for predicting ABP by using hemicellulose as an independent variable. The inclination, intercept and relative deviation of the linear regression line was3.592,587.104and6.81%respectively.(5) In the experiment of optimizing parameters of anaerobic fermentation for Typha, the results showed that:the pH value for the fermentation concentration of6%with inoculums rate of50%was most stable, and the biogas production rate of which was the highest, total biogas yield and biogas production rate were6482mL and581.39mL·g-1VS respectively. While the total biogas yield for the fermentation concentration of8%with inoculums rate of40%was the highest, and the total biogas yield and biogas production rate were9297mL and521.17mL·g-1VS respectively, and the above process conditions was the most suitable for the anaerobic fermentation of Typha.更多还原