好氧颗粒污泥生物强化体系的快速构建及同步脱氮机制

Compared to conventional activated sludge, aerobic granules (AGs) has some advantages, such as good settleability, diverse bacterial community, high tolerance to toxicity and great tolerance to shock loading, et al. However, for the highly toxic and refractory industrial wastewater, the cultivation of AGs is rather difficulty. This project aims at the bioaugmentation in the refractory compounds, with pyridine chosen as a model. In order to accelerate the cultivation of AGs capable of degrading pyridine, pyridine degraders with self-aggregation capacity was used as the inocula for inducing the rapid formation of microbial aggregates. The mechanism of the accelerated granulation by using microbial aggregates as the skeleton structure will be revealed. Through the control of parameters, such as dissolved oxygen, pyridine loading, pH and ammonium loading, et al., partial nitrification and simultaneous denitrification will be achieved in the AG system for pyridine degradation. Dominant bacterial community in AG system was analyzed through the analysis of gene clone library and PCR-DGGE, with biology evidence for pyridine degradation and simultaneous nitrogen removal revealed. Based on the FISH-CLSM and microelectrode analysis, spatial distribution and synergistic effect of microbial community in AGs, such as pyridine degrader, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria and denitrifying bacteria, will be investigated, with the mechanisms of enhanced pyridine degradation and simultaneous nitrogen removal in AGs revealed. The performance of aerobic granule-based bioaugmentation system for the treatment of raw industrial wastewater containing pyridine will be evaluated, providing the technical reference for the practical application of AG technology.

相比传统活性污泥，好氧颗粒污泥(AG)具有沉降性好、种群丰富、对有毒物质耐受性强、抗冲击负荷等优势。然而对于高毒性难降解工业废水而言，AG的培养具有较大难度。本项目面向难降解物质(以吡啶为例)的生物强化治理，拟采用具有自絮凝特性的吡啶降解菌为接种物，诱导生物聚集体的快速形成，以实现吡啶降解AG的快速培养，揭示生物聚集体作为骨架结构促进污泥快速颗粒化的机理；通过溶解氧、吡啶负荷、pH、氨氮负荷等参数的调控，实现吡啶降解AG体系的短程硝化反硝化；通过基因克隆文库结合PCR-DGGE分析，确定AG体系的优势菌群，确立吡啶降解与同步脱氮的生物学依据；根据FISH-CLSM结合微电极分析结果，探究AG结构中吡啶降解菌、氨氧化菌、亚硝酸盐氧化菌、反硝化菌等微生物群落的空间分布及协同作用，揭示AG体系吡啶强化降解同步脱氮机制；考察AG生物强化体系处理含吡啶的实际废水的效能，为AG技术的实际应用提供参考。

本研究采用自絮凝功能微生物作为接种物，成功培养了具有吡啶降解和同步脱氮功能的好氧颗粒污泥，有效缩短了好氧颗粒污泥系统的启动周期；在好氧颗粒污泥系统中，吡啶降解释放出的氨氮进一步被硝化细菌硝化为亚硝酸根离子；在好氧颗粒污泥结构内部的缺氧区，亚硝酸根离子可作为反硝化的电子受体发生反硝化脱氮反应，进而促进吡啶等难降解污染物的降解，进一步明确了吡啶降解和同步脱氮的机制；高通量测序结果证实了吡啶降解菌属、亚硝化相关菌属、反硝化相关菌属和自絮凝相关菌属的存在，明确接种微生物的作用以及菌群结构的动态变化，从而揭示了好氧颗粒污泥生物聚集体形成的生物学机制；验证了生物强化好氧颗粒污泥技术应用于含高浓度吡啶的实际工业废水的可行性，提出了复杂水质条件下好氧颗粒污泥生物强化系统的调控策略。好氧颗粒污泥培养周期≤1个月；出水吡啶浓度≤1mg/L；吡啶降解最大容积速率≥2000mg/L/h；好氧颗粒污泥沉降速率≥40m/h。本研究累计发表SCI收录论文15篇（其中JCR一区论文10篇）；授权国家发明专利3件，申报国家发明专利4件；主持人获批江苏省杰出青年基金、江苏省“333工程”、江苏省“六大人才高峰”等人才项目；培养博士研究生3名，硕士研究生5名。