富含微藻的颗粒污泥中胶凝型胞外多糖特性研究

At present, the increasingly serious pollution of water environment and the energy crisis force us to recycle the water, energy and nutrients from the wastewater. The high activity and excellent settling performance of "microalgae-rich granular sludge" make it feasible to convert sewage to microalgae biomass and achieve resource recovery. "Gel-forming exopolysaccharides" is vital in maintaining the structural stability of granules, but lacks of in-depth study. Through the construction of microalgal-bacterial symbiotic system, this project investigates the mass content of microalgae biomass in the granule during the steady operation of the process. The characteristics of the granule and pollutants removal are studied. The fine structure of gel-forming exopolysaccharides is acquired by using MALDI-TOF-MS, NMR, FTIR, AFM etc. Combined the fine structure with EPS matrix features, the characteristics of granular sludge, community structure, gene expression, etc., we can disclose the origin, synthesis mechanism and variation law of the gel-forming exopolysaccharides. The mechanism of steady operation of the microalgae-rich granular sludge is elucidated from the angle of gel-forming exopolysaccharides. The results of this research will provide significant information and technical support for the application of microalgal-bacterial mutualism in wastewater reuse.

当前，日益严重的水环境污染与能源危机迫使我们必须对污水中的水、能量和营养物进行回收。由于“富含微藻的颗粒污泥”活性高、沉淀性能好，能够有效将污水向微藻生物质转化，从而实现资源回收。“胶凝型胞外多糖”在维持颗粒结构稳定性方面极其重要，然而缺乏深入的研究。本项目通过构建藻菌共生系统，探索不同策略形成的富含微藻的颗粒污泥稳定运行条件和微藻生物质在颗粒中含量变化，并考察颗粒性质和污染物去除效能，采用MALDI-TOF-MS、NMR、FTIR、AFM等表征胶凝型胞外多糖以获得其精细结构，并结合EPS基质特征、颗粒污泥特性、群落结构、基因表达等，深入理解胶凝型胞外多糖的来源、合成机制及变化规律。从胶凝型胞外多糖的角度阐明富含微藻的颗粒污泥稳态机制。本项目研究可为藻菌共生颗粒应用于废水资源化提供理论基础和技术支持。