基于有机废水梯级利用的菌藻一体式产能体系构建及产油微藻自絮凝机制解析

Microalgae biodiesel is renewable and environmental friendly biomass energy, and it is in line with the strategic needs of clean, low-carbon and green development in the national plan for 13th Five-Year. In this research topic, the key problems in the production of microalgae lipids, such as the low biomass concentration of biological reactor, the ambiguity of microalgae self-flocculation mechanism and the shortage of raw materials are discussed. Microalgae species with high growth rate, high lipid content and good flocculation performance are screened. Key factors that can significantly promote the flocculation performance of microalgae are investigated, and the interaction law among the factors is analyzed. Furthermore, the self-flocculation mechanism of lipid-producing microalgae is shown to enhance the flocculation performance of microalgae and to increase the biomass concentration in the reactor. On this basis, a new type of integrated dark fermentation bacteria and self-flocculation microalgae reactor is constructed. This breaks through the differences of metabolic rate and niche in the culture of bacteria and microalgae, and makes the separation of bacteria and microalgae in space, while metabolites can be transported. In addition, the coupling and matching mechanism for integrated system is established in continuous culture with organic wastewater as the substrate. The utilization and transformation of carbon, nitrogen and phosphorus in wastewater are illustrated. This improves the cascade utilization efficiency and energy production performance from organic wastewater. This study provides theoretical basis and technical basis for the application of microalgae biodiesel technology.

微藻生物柴油是一种新型生物质能源，具有环保、可再生的特点，符合国家十三五规划中“清洁低碳，绿色发展”的战略需求。本课题针对产油微藻生产中反应器生物持有量低、微藻自絮凝机制不明确、培养原料不足等关键问题，选育生长速度快、油脂含量高、自絮凝性能好的产油藻种，筛选能显著促进微藻絮凝的关键自絮凝因子，解析关键自絮凝因子之间的交互作用规律，揭示微藻的自絮凝机制，以增强产油微藻的絮凝性能，提高反应器内的生物持有量。在此基础上构建新型的暗发酵细菌自絮凝微藻一体式产能反应器，突破传统菌藻培养中代谢速率和生态位上的差异，使菌藻在空间上相对分离，而代谢产物自由联通，建立有机废水连续流一体式产能系统的耦合和匹配机制，阐明废水中碳、氮、磷的利用和转化规律，提高有机废水的梯级利用效率及产能能力，为推动微藻生物柴油技术的应用提供理论依据和技术基础。

微藻生物柴油是一种有前景的石化柴油替代品，对于解决能源短缺和全球变暖具有重要意义。针对微藻油脂生产中反应器生物持有量低、微藻的絮凝机制不明确等瓶颈问题，本项目通过对富油藻种的快速选育，获得了生长速度快、油脂含量高的微藻新藻株。筛选能显著促进微藻絮凝的关键絮凝因子，发现并解析金属离子对微藻絮凝和产油的作用规律，揭示微藻的絮凝机制，以提高产油微藻的絮凝性能，进而提高微藻培养反应器内的生物持有量和油脂产量。构建了新型的暗发酵细菌微藻一体式产能反应器，优化获得了一体式产能反应器的主控运行参数，反应器的能源转化效率提高了20.2%，建立一体式产能系统的耦合和匹配机制。阐明了半连续运行系统废水中碳、氮、磷的利用和转化规律，系统的COD、TN和TP去除率分别达91.1%、89.1%和85.7%。此外，对暗发酵制氢和一体式产能体系的微生物群落结构进行了分析。本项目能够实现废水中有机物的梯级转化与深度产能，为提高废水的能源回收效率、减少环境污染做出积极贡献，具有良好的社会影响和应用价值。