Inducing Aerobic Granulation in Continuous-Flow Reactors using Shear Variability

CBET-1336544 Francis de los Reyes和Joel Ducost北卡罗来纳州立大学好氧颗粒化可能是好氧废水处理领域最令人兴奋的发展之一，有望在较小的反应器中处理流量更大、浓度更高的废水，减少生物质沉淀和分离的问题，并能够处理各种有机基质，以及同时去除氮和磷。如果能在现有的污水处理设施中发展好氧颗粒污泥，其影响将是广泛的。然而，尽管前景看好，连续流好氧颗粒污泥反应器的全面实施还没有发生。理论上，连续流动反应堆提供了更稳定的环境，需要较少的自动化，并且可以由工程师使用较小的测试系统进行设计。然而，在连续流动反应器中，非颗粒状生物固体形成好氧颗粒的机理尚不清楚。在前人研究的基础上，假设诱导好氧颗粒化的关键不是序批式模式，而是生物反应器提供可变剪切的能力。这项研究将检验这一假说，并调查好氧条件下反应器流体动力学、微生物反应和最终颗粒化之间的机制联系。将结合使用多种方法，包括微型反应器中微生物形态变化的分析，实验室规模反应器中种群和基因的分子微生物分析，以及计算流体力学和拉格朗日传感器的使用，以说明剪切变异性是好氧颗粒化的必要条件。最后，这项研究将通过建造和运行连续流中试反应器来实现规模化，以诱导好氧颗粒化。这种结合的方法将展示如何使用好氧颗粒污泥技术来改造现有的活性污泥厂，潜在地提供了好氧处理技术的重大飞跃，并影响到世界各地数以千计的污水处理厂。好氧颗粒生物质反应器的发展激起了污水处理行业的兴奋，因为它代表了一种创新、高效、紧凑、潜在更可持续的废水处理方法。好氧颗粒生物质反应器可以处理含有机物的高浓度废水。该项目可能会使市政和工业废水处理厂受益，包括那些进行养分去除的工厂。在现有的污水处理厂中开发好氧颗粒污泥代表着技术的飞跃，为国家的污水基础设施带来了经济和效率方面的好处。这项创新研究的结果还将产生可在课堂上使用的信息，并通过发现的兴奋促进学习。

CBET-1336544Francis de los Reyes and Joel DucosteNorth Carolina State UniversityAerobic granulation is perhaps one of the most exciting developments in aerobic wastewater treatment, promising the ability to treat higher flows of higher strength wastewater in smaller reactors, with fewer problems with settling and separation of biomass, and with the ability to treat a variety of organic substrates, as well as simultaneously removal of nitrogen and phosphorus. If aerobic granular sludge can be developed in existing wastewater treatment facilities, the impacts would be widespread. Yet despite the promise, full-scale implementation of continuous flow aerobic granular sludge reactors has not happened. Continuous flow reactors theoretically provide more stable environments, need less automation, and can be designed by engineers using smaller test systems. However, the formation of aerobic granules from non-granular biosolids in continuous flow reactors is not understood. Based on prior research, it is hypothesized that the key to inducing aerobic granulation is not the sequencing batch mode, but the ability of a bioreactor to provide variable shear. This research will test this hypothesis and investigate the mechanistic links between reactor hydrodynamics, microbial responses, and ultimately granulation under aerobic conditions. A combination of approaches, including analysis of microbial morphological changes in a micro-reactor, molecular microbial analysis of populations and genes in lab-scale reactors, and use of computational fluid dynamics and Lagrangian sensors, will be used to show how shear variability is a necessary condition for aerobic granulation. Finally, this research will demonstrate scale up by constructing and operating a continuous-flow pilot-scale reactor to induce aerobic granulation. This combined approach will show how aerobic granular sludge technology can be used to retrofit existing activated sludge plants, potentially providing a significant leap in aerobic treatment technology, and impacting thousands of wastewater treatment plants around the world.The development of aerobic granular biomass reactors has excited the wastewater treatment industry, as it represents an innovative, efficient, compact, and potentially more sustainable method for treating wastewater. Aerobic granular biomass reactors can treat high strength wastewaters containing organics. This project will potentially benefit municipal and industrial wastewater treatment plants including those that perform nutrient removal. Developing aerobic granules in existing wastewater treatment plants represents a leap in technology with economic and efficiency benefits for the nation's wastewater infrastructure. The results from this innovative research will also generate information that can be used in the classroom and foster learning through excitement of discovery.