基于沼液培养小球藻（Chlorella vulgaris）提纯沼气技术研究

【作者】 李博；

【导师】 郑正；

【作者基本信息】 复旦大学 ， 环境工程， 2012， 硕士

【摘要】 我国年产生约40多亿吨畜禽粪便和秸秆等农村固废,这些固体废弃物的数量大、种类多、性质复杂。而广大农村由于缺乏集中处理和利用的能力,大量的可再生利用资源,如秸秆等常在田间焚烧或随处堆放,既浪费了能源又污染了农村环境。对农村固体废弃物进行发酵产出沼气是一种很适合在我国发展的绿色能源途径,其具有操作技术简单、建造费用低和使用基础广泛的优点。但是现存小规模农用式沼气发酵有两个严重的问题。第一是沼气品质低下,沼气中可燃烧的有效成分CH4的含量偏低,而CO2浓度偏高；第二就是产生沼气的厌氧发酵过程除产生沼气外还会产生难以处理的高浓度污染物——沼液,对其不当的处理会对环境造成极为严重的污染。小球藻细胞除了在自养条件下利用光能和二氧化碳进行正常的自养生长外,还可以在异养培养条件下利用有机碳源进行生长和繁殖,与CO2的固定和沼液的处理过程相耦合。本论文探索把利用微藻固定CO2与污水处理结合起来：利用营养丰富的沼液培养小球藻,固定沼气中的二氧化碳,达到一定量时小球藻藻收获后可以作为发酵原料返回到发酵产沼体系中。构成一个几乎零污染的“资源化循环”之环。本论文将在系统地研究沼气品味提升机理的基础上探讨各种反应条件的优化,寻求在提升沼气品味的同时实现沼液、沼渣和微藻的资源化利用的方法。得出了最佳培养条件：沼液浓度50%、初始pH值6.0、接种小球藻干重为0.20mg/mL、光质为红光、光照强度为60001x。在此条件下,沼液中的COD、TN、TP和BOD5的去除率分别达到了88.5%、91.2%、95.3%和87.6%,沼气中甲烷含量由原先的40%提升到60.2%。本研究成果将有助于大幅度提高厌氧发酵所产生的沼气品味,从而使得农村固废可以通过厌氧发酵而得以资源化利用。更多还原

【Abstract】 Every year, China produces about40million tons of animal manure, straw, and other rural solid waste. In the rural areas, due to the lack of ability to focus and the large number of renewable resources available, many of these resources such as straw are often piled up and burn in the fields.This process is a waste of energy, and pollutes the rural environment.Rural solid waste fermentation produces biogas that is very suitable for the development of green sources of energy in China. The technology and operation required are simple, and the construction costs are low. Existing small-scale agricultural biogas fermentation has two serious problems.The first is the low quality methane. Low CH4content of the active ingredients that can burn biogas, and the high CO2concentration.The second is the difficulty to produce biogas anaerobic fermentation process in presence of high concentrations of pollutants slurry:on these conditions, improper handling will cause very serious pollution.Chlorella vulgaris cells in addition to the use of organic carbon source for growth and reproduction, health long, but also in heterotrophic culture conditions, normal use of solar energy and carbon dioxide under autotrophic conditions and slurry process with CO2coupled. This thesis is to explore the CO2fixation by microalgae and sewage treatment:the use of nutrient-rich biogas slurry culture chlorella, fixed methane in carbon dioxide, chlorella harvest a certain amount can be used as a fermentation raw materials return to the fermentation marsh system. Constitute an almost zero pollution "resource cycle" ring. This research focused on the feasibility of purifying biogas slurry and upgrading biogas simultaneously. The biogas slurry and CO2in biogas was utilized as the culture medium and carbon source of Chlorella vulgaris, respectively.The optimum operating conditions were biogas slurry concentration of50%, initial pH6.0, initial algal dry weight0.20mg/mL, and light wavelength red. Then, the removal efficiency of COD, TN, TP and BOD5was achieved at88.5%,91.2%,95.3%, and87.6%, respectively. Particularly, the content of CH4in biogas was upgraded from40%to60.2%. These results indicated that the method of biogas slurry purifying and biogas upgrading by Chlorella vulgaris studied in this research was able to solve the problem of environment pollution caused by high load pollutants biogas slurry, as well as low quality of biogas.更多还原