GOALI: Evaluating mechanisms and Developing strategies for simultaneous sludge reduction and nutrient removal in activated sludge processes

工程生物反应器如活性污泥系统处理城市污水在世界范围内得到了广泛的应用。活性污泥生物反应器中的细菌从废水中的有机碳和营养物质中获取能量。活性污泥工艺被设计成这样一种方式，即需要从这些配置中不断浪费生物质来补偿细菌的生长，这样生物质（通常称为污泥）就不会在系统中积累。这些多余的污泥需要进一步处理和处置，这可能占处理厂总运营成本的25%至65%。随着污泥处理选择的减少以及与剩余污泥进一步处理相关的成本，活性污泥处理过程的可持续性受到质疑。该GOALI项目与工业合作伙伴西门子水务公司合作，将探索在活性污泥处理系统中同时减少污泥和去除营养物质（氮和磷）的可能性。该研究将揭示在高固体滞留时间下运行的活性污泥过程中污泥减少的机制，以诱导生物质厌氧，并检查污泥最小化过程中营养去除的可持续性，并评估氮和磷去除细菌群落的生态学。研究者将使用真实的废水运行实验室规模的反应器，以检查同时减少污泥和去除营养物的可行性。研究者将使用稳定同位素探测来分析实验室规模反应器中的细菌群落，并在污泥最小化反应器中实现碳质量平衡。研究人员还将开发污泥最小化反应器中碳、氨和磷去除的细菌动力学参数，以建立设计参数，从而在西门子的帮助下全面实施所提出的创新工艺。该项目将深入了解世界上最广泛使用的废水处理工艺中污泥减量与营养物去除的可能性。通过建立污泥减量机制和开发关键过程的设计动力学参数，该项目有望在活性污泥系统的操作和设计中实现重大的范式转变。这个NSF GOALI提案是第一次尝试在引入真实废水时使用污泥禁食和盛宴来同时去除营养和减少污泥。这项研究直接解决了两个重要的重大挑战；(1)美国环境保护署关于生物固体管理和减少的研究重点；(2)减少氮污染——国家工程院确定的优先领域之一。该GOALI提案将对污水处理行业产生强烈的积极影响，而全球污水处理技术开发领导者西门子的参与将进一步确保这种影响。PI将与当地学区合作，将环境工程实验室实践纳入高中课程。这个项目将有助于一名研究生和几名本科生的专业发展，特别强调少数民族学生。

1236832GoelThe treatment of municipal wastewater using engineered bioreactors such as activated sludge system is widely used around the globe. The bacteria present in activated sludge bioreactor gain their energy from organic carbon and nutrients present in wastewater. The activated sludge processes are designed in a manner such that a continuous wastage of biomass from these configurations is needed to compensate for the growth of the bacteria so that the biomass, commonly known as sludge, does not accumulate in the system. This excess sludge requires further processing and disposal which may account for 25 to 65% of the treatment plant's total operation cost. With diminishing sludge disposal options and the cost associated with further processing of the excess sludge, the sustainability of activated sludge treatment processes is in question. This GOALI project, in collaboration with SIEMENS Water Company as an industrial partner, will explore the possibility of simultaneous sludge reduction and nutrients (nitrogen and phosphorus) removal in activated sludge treatment systems. The research will shed light on the mechanisms of sludge reduction in activated sludge processes operating at significantly high solid retention time to induce biomass anaerobiosis, and examine the sustainability of sludge minimizing processes for nutrient removal and also evaluate the ecology of nitrogen and phosphorus removing bacterial community. The investigator will run lab scale reactors using real wastewater to examine the feasibility of simultaneous sludge reduction and nutrient removal. The investigator will use stable isotope probing to profile bacterial community in the laboratory scale reactors and to achieve carbon mass balance in the sludge minimizing reactor. The investigator will also develop bacterial kinetic parameters for carbon, ammonia and phosphorus removal in sludge minimizing reactor to establish design parameters leading to full scale implementation of the proposed innovative process with the help from SIEMENS. This project will provide insights into the possibility of sludge reduction coupled with nutrient removal in world's most widely used wastewater treatment processes. By establishing the mechanisms of sludge reduction and by developing the design kinetic parameters for key processes, this project promises a significant paradigm shift in the operation and design of activated sludge systems. This NSF GOALI proposal is the first attempt to demonstrate simultaneous nutrient removal and sludge reduction using sludge fasting and feasting during introduction of real wastewater. The research directly address two important grand challenges; (1) U.S. Environmental Protection Agency's research priority about biosolids management and reduction and, (2) reducing nitrogen pollution- one of the priority areas defined by National Academy of Engineering. This GOALI proposal will have a strong positive impact on wastewater treatment industry and that impact is further ensured by the involvement of SIEMENS, a global leader in wastewater treatment technology development. The PI will work with local school district to integrate environmental engineering lab practices in high school curricula. This project will contribute to the professional development of one graduate student and several undergraduate students with particular emphasis on minority students.