CAREER: Microbial Storage Products and Density: Overlooked Fundamentals and Promising Opportunities in Biological Solids Separation

职业：微生物储存产品和密度：生物固体分离中被忽视的基础知识和有前途的机会

• 批准号: 0843777
• 负责人: Andrew Schuler
• 金额: $ 23.5万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0843777&HistoricalAwards=false
• 关键词: CAREER; Microbial; Storage; Products; Density

0348594SchulerA comprehensive five-year plan is proposed for an innovative research project and a complementary educational program. The research is motivated by the large benefits in increased environmental and human health protection and cost savings, which may result from improvements to solids settling processes in biological wastewater treatment systems, and the observation that a fundamental yet potentially critical factor (density) affecting settling has been scarcely studied. Efficient biosolids settling is vital the provision of a clarified effluent and a concentrated solids stream for system recycling and wasting. The gravitational force that drives all settling processes is a function of buoyant density (the difference between liquid and solid densities). It is hypothesized that although biomass buoyant density can vary substantially, and that new, effective strategies can be developed to improve solids separation based on density optimization. This is based on observations that (1) high-density microbial storage product (MSP) concentrations vary in treatment systems, (2) MSP accumulation affects bacterial density, and (3) previous reports indicate systems selecting for MSP-accumulating organisms improve settling independently of filament control. Furthermore, MSPs, density, and settling were correlated as expected in preliminary experiments. Factors such as floc size and filament content clearly affect settling rates, and the current hypothesis suggests that biomass density may be an additional, fundamental, and previously neglected factor that should be considered in the analysis and control of biomass settling. A governing objective of this proposal is to produce and validate a model linking process parameters, density, and settling. This will require determination of the relationships between operational parameters and MSP accumulation (and other factors affecting density), between these factors and density, and between density and settleability. The broader impacts of this work include increased protection of environmental and human health and costs saving through increased process performance; development of a better understanding MSPs, which are ubiquitous in natural and engineered systems but not always well-understood; improved understanding of biological phosphorus removal processes and aerobic MSP accumulation; increased representation of underrepresented groups in the sciences; improved high school curricula; and development of advanced laboratory and modeling skills in undergraduate and graduate students.

schulera综合五年计划提出了一个创新的研究项目和一个补充的教育计划。这项研究的动机是由于生物废水处理系统中固体沉降过程的改进，在增加环境和人类健康保护以及节省成本方面有很大的好处，并且几乎没有研究影响沉降的一个基本但潜在的关键因素（密度）。有效的生物固体沉降是至关重要的，为系统回收和浪费提供澄清废水和浓缩固体流。驱动所有沉降过程的重力是浮力密度（液体和固体密度之差）的函数。假设虽然生物质浮力密度可以有很大的变化，但可以开发新的、有效的策略来改善基于密度优化的固体分离。这是基于以下观察：(1)高密度微生物储存产物（MSP）浓度在处理系统中不同，(2)MSP积累影响细菌密度，以及(3)先前的报告表明，选择MSP积累生物的系统可以独立于灯丝控制改善沉降。此外，MSPs、密度和沉降的相关性与初步试验结果一致。絮团大小和细丝含量等因素明显影响沉降速率，目前的假设表明，生物量密度可能是一个额外的、基本的、以前被忽视的因素，应该在生物量沉降的分析和控制中加以考虑。本建议的一个控制目标是产生并验证一个连接工艺参数、密度和沉淀的模型。这将需要确定操作参数与MSP积累（以及影响密度的其他因素）之间的关系，这些因素与密度之间的关系，以及密度与沉降性之间的关系。这项工作的更广泛影响包括加强对环境和人类健康的保护，以及通过提高工艺性能节省成本；更好地理解msp，它们在自然和工程系统中无处不在，但并不总是被很好地理解；提高了对生物除磷过程和好氧MSP积累的认识；增加科学领域代表性不足群体的代表性；改进高中课程；以及培养本科生和研究生先进的实验室和建模技能。