生态浮床植物根系分泌物对氨氧化微生物的化感作用及复合系统对污染河道氨氮去除效应

The urban river contaminated with ammonia-nitrogen and low dissolved oxygen is a widespread problem in China. The ammonia-oxidizing microorganisms，included ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (Anammox), play an important role in removing ammonia nitrogen from wastewater. In this project, the compound system, made of ecological floating bed and bionic macrophytes, will be placed in the polluted urban river. Community structures of ammonia-oxidizing microorganisms in the biofilm attached compound system and its responses to environmental factor will be investigated using molecular ecology technology. Meanwhile, the effects of root exudates from plants cultivated on a ecological floating-bed on community structure, diversity, dominant populations, abundance, activity and phylogenetic of ammonia-oxidizing microorganisms will also be studied. In addition, under the different environmental factors, by assaying nitrifying capacity, nitration rate, and nitration potential of ammonia-oxidizing microorganisms attached in compound system and the structure of kinetic model, explore the optimum conditions of ammonia nitrogen removing from wastewater by ammonia-oxidizing microorganisms. Moreover, the coupled relation of ammonia nitrogen removal efficiency and abundance of ammonia-oxidizing microorganisms attached in compound system will be analysed together in order to better understand the ammonia nitrogen removal mechanism. Those results will be useful in using compound system to remediate the degraded urban river pollution.

我国大部分城市河道都呈现出低氧高氨氮污染状态，制约着城市的发展。氨氧化古菌（AOA）、氨氧化细菌（AOB）和厌氧氨氧化细菌（Anammox）在水体氨氮去除中起着关键作用。本项目以生态浮床和仿生植物构建复合系统，在城市重污染河道内开展原位试验，利用分子生态学技术，研究复合系统附着氨氧化微生物的生态分布及其对水体理化因子的响应规律；通过室内控制试验，研究生态浮床植物根系分泌物对氨氧化微生物的群落结构、多样性、优势种群、数量、活性及系统发育的影响；研究不同环境因子影响下复合系统附着氨氧化微生物硝化作用强度、硝化速率、硝化势等硝化作用能力，构建动力学模型，探讨复合系统对水体氨氮去除的最佳条件。结合复合系统附着氨氧化微生物数量变化与水体氨氮去除的耦合关系，阐述复合系统对氨氮去除效能，为利用复合系统修复城市污染河道提供数据支持和理论依据。

本项目以生态浮床和仿生植物构建复合系统，在污染水体开展原位试验，利用分子生态学技术，研究系统内氨氧化微生物的生态分布及其对水体理化因子的响应规律；通过室内实验，研究挺水植物腐解过程对水体质量的影响，以及对沉积物氨氧化微生物生态分布的影响；研究湿地水体和沉积物氨氧化微生物的生态分布及其对环境因子的响应规律。研发了一种绿色农药用于杀灭人纹污灯蛾幼虫，研发了微型一体化净水装置、小型一体化净水装置和生态浮船。获得主要结论如下：（1）植物根际氨氧化微生物生态分布存在差异，且与水体环境密切相关；水体环境同样影响着仿生植物氨氧化微生物生态分布；（2）植物腐解速率与植物成分密切相关；植物腐解对水体和沉积物造成显著影响，对于湿地植物应科学的管理；植物腐解过程对沉积物氨氧化微生物生态分布的影响较大；（3）各组复合系统对水体污染物的去除均有较好的效果，以菖蒲-仿生植物组合最优；氮素去除效果与氨氧化微生物生态分布不具有显著相关性；（4）湿地植物根际氨氧化微生物生态分布特征存在差异，与所处环境密切相关；（5）基于本项目支持申报的专利，均已在实际中开展应用。