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: 0348594
• 负责人: Andrew Schuler
• 金额: $ 40万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0348594&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.

0348594 SchulerA全面的五年计划提出了一个创新的研究项目和补充教育计划。这项研究的动机是增加环境和人类健康保护和成本节约的巨大利益，这可能是由于生物废水处理系统中固体沉降过程的改进，以及观察到影响沉降的基本但潜在的关键因素（密度）几乎没有研究。 有效的生物固体沉降对于提供澄清的流出物和浓缩的固体流以用于系统再循环和废弃至关重要。 驱动所有沉降过程的重力是浮力密度（液体和固体密度之间的差异）的函数。 据推测，虽然生物质浮力密度可以有很大的变化，新的，有效的策略可以开发，以提高固体分离的基础上密度优化。 这是基于以下观察结果：（1）高密度微生物储存产物（MSP）浓度在处理系统中变化，（2）MSP积累影响细菌密度，以及（3）先前的报告表明，选择MSP积累生物体的系统独立于细丝控制改善沉降。 此外，MSP、密度和沉降如在初步实验中预期的那样相关。 絮凝物的大小和长丝含量等因素明显影响沉降速率，目前的假设表明，生物质密度可能是一个额外的，基本的，以前被忽视的因素，应该考虑在分析和控制生物质沉降。 本提案的管理目标是生成并验证将工艺参数、密度和沉降联系起来的模型。 这将需要确定操作参数和MSP积累（和影响密度的其它因素）之间、这些因素和密度之间以及密度和沉降性之间的关系。 这项工作的更广泛影响包括：通过提高工艺性能，加强对环境和人类健康的保护，节约成本;更好地了解MSP，MSP在自然和工程系统中普遍存在，但并不总是得到很好的理解;更好地了解生物除磷工艺和好氧MSP积累;增加科学领域代表性不足群体的人数;改进高中课程;培养本科生和研究生先进的实验室和建模技能。