Bioaugmentation as a strategy to reduce the uncertainty of biological nutrient removal in granular sludge systems

这项研究计划将解决与废水处理相关的一个主要问题：如何减少生物去除营养物质的不确定性。这项研究的方法将结合数学建模和生物过程工程创新战略的实验测试。营养物(氮和磷)的去除在废水处理的总成本中起着主要作用。生物养分去除(BNR)是最经济、最环保的最先进技术。然而，BNR的设计和运营仍存在一定程度的不确定性。微生物菌群的选择和分离、生物降解和营养去除是目前面临的主要问题。聚磷菌(PAO)的选育是实现磷的可持续去除和回收的有效策略。此外，颗粒污泥技术的最新发展和应用为改善固液分离和缩小工厂规模提供了一条很有前途的途径，特别是在寒冷气候地区。根据具体情况，这两种解决方案并不总是适合实际技术。颗粒污泥的形成涉及到颗粒的形成和稳定性，而PAO的选择严格依赖于与糖原积累细菌的竞争。由于废水的高流量，控制废水的一些重要参数(如组成、pH和温度)用于过程控制的成本太高。因此，在植物生态系统中寻找替代策略来推动选择是很重要的。我和我的团队提出了一种创新的方法，基于在受控侧流反应器中选择所需的微生物群落，作为主流反应器的连续接种(生物强化)。这将促进污水处理厂的生物去除营养物质的设计和运行，并将为环境生物处理工程的新方面提供一个新的见解。研究结果将对BNR以外的环境技术具有潜在的影响和应用前景。

This research program will address a major problem related to wastewater treatment: how to reduce the uncertainty of biological nutrient removal. The approach to the research will combine mathematical modelling and experimental testing of an innovative strategy for bioprocess engineering. The removal of nutrients (nitrogen and phosphorus) plays a major role in the overall cost of wastewater treatment. Biological nutrient removal (BNR) is the most economically and environmentally sustainable state-of-the-art technology. However, a degree of uncertainty is still related to BNR design and operation. The selection and the separation from the liquid of the microbial consortia operating biodegradation and nutrient removal are the main problems to be faced. The selection of phosphorus accumulating bacteria (PAO) is a very effective strategy for a sustainable removal and recovery of phosphorus. Moreover, the recent development and application of granular sludge technologies represents a promising approach to improve solid-liquid separation and to reduce the size of the plants especially in cold climate regions. Both solutions are not always suitable, depending on the context, with actual technologies. Granular sludge formation presents some critical aspects related to granules formation and stability and the selection of PAO strictly depend on the competition with glycogen accumulating bacteria. Due to the high flow rates of wastewater, it is too expensive to control some important parameters of wastewater (such as the composition, pH and temperature) for process control. Thus, it is important to find alternative strategies to drive the selection in the plant ecosystem. My team and I propose an innovative approach, based on the selection of the desired microbial community in a controlled side stream reactor, to be used as continuous inoculum for mainstream reactors (bioaugmentation). This will facilitate the design and operation of wastewater treatment plants for biological nutrient removal and will offer an insight in to new aspects of environmental bioprocess engineering. The results of the research will have a potential impact and future application in environmental technologies other than BNR.