New technologies for wastewater resource recovery by anoxigenic photoheterotrophic biological processes

缺氧光异养生物过程废水资源化新技术

• 批准号: RGPIN-2016-06498
• 负责人: Frigon, Dominic
• 金额: $ 2.4万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684884
• 关键词: New; technologies; wastewater; resource; recovery

Tightening regulations on biosolids disposal and growing energy utilization increase the operational costs of wastewater treatment plants, and reduce the sustainability of municipal infrastructures. In response, the wastewater industry is converting from only treating wastewater for environmental protection to additionally recovering resources wasted with the water. In terms of energy content, recoverable organics and nutrients (nitrogen, phosphorus) account for ~15% of the per capita electricity consumption; accordingly, recovery will improve sustainability and reduce CO2 footprint. However, recovery using current aerobic biological processes is limited. Thus, the current program will contribute to the development of new anaerobic biological processes enabling recovery. The results will improve infrastructure efficiencies and reduce burden to tax payers.******Anaerobic processes pose challenges for Canada because many wastewater facilities operate below 12C for periods of up to 6 months. Indeed, anaerobic microbes typically have lower maximum growth rates than aerobic ones, resulting in lower process stability and capacity to meet discharge regulations at low temperatures. Additionally, municipal wastewater is relatively dilute for nutrient recovery, and biological concentration is necessary prior to physico-chemical extractions. We propose to use purple non-sulfur bacteria (PNSB) to address these challenges. Their ability to simultaneously obtain energy from light and carbon from organics provides them with higher biomass yields and faster growth rates than other anaerobes. Consequently, high biomass yields make them suitable for concentration of nutrients in biomass, and high growth rates reduce their sensitivity to colder operation temperatures. Finally, because they are the only photosynthetic organisms utilizing infrared light (>800 nm), engineers would possess powerful selection tools to control microbial communities in mixed open cultures.*******Published studies mainly focused on pure culture PNSB wastewater processes and operation at 20-35C. These conditions are inapplicable to full-scale Canadian municipal wastewater facilities; thus, significant knowledge gaps persist in developing PNSB processes. Additionally, reactor conditions need to be tightly controlled such that metabolism maximizes biomass yields instead of competing H2 and polyhydroxyalkanoate syntheses. This proposal will investigate operation conditions of non-sterile PNSB photobioreactors that are relevant to Canada for enabling implementation of wastewater resource recovery. Furthermore, control strategies for PNSB metabolism and microbial community composition will be developed by using genome-scale metabolic modeling and high-throughput metagenomic molecular tools. The program will train 2 PhD, 4 MEng and 10 undergraduate students.***

生物固体处理法规的收紧和能源利用率的提高增加了废水处理厂的运营成本，并降低了市政基础设施的可持续性。为此，废水行业正在从仅处理废水以实现环境保护转变为另外回收与水一起浪费的资源。就能源含量而言，可回收有机物和养分（氮、磷）约占人均用电量的15%；因此，恢复将提高可持续性并减少二氧化碳足迹。然而，使用当前有氧生物过程的恢复是有限的。因此，当前的计划将有助于开发新的厌氧生物过程，从而实现恢复。结果将提高基础设施效率并减轻纳税人的负担。******厌氧工艺给加拿大带来了挑战，因为许多废水处理设施在低于 12°C 的温度下运行长达 6 个月。事实上，厌氧微生物的最大生长速率通常低于需氧微生物，导致工艺稳定性较低，并且在低温下满足排放法规的能力较低。此外，城市废水对于营养物回收来说相对稀释，并且在物理化学提取之前需要进行生物浓缩。我们建议使用紫色非硫细菌（PNSB）来应对这些挑战。它们同时从光中获取能量和从有机物中获取碳的能力使它们比其他厌氧生物具有更高的生物量产量和更快的生长速度。因此，高生物质产量使它们适合生物质中营养物质的浓缩，并且高生长速率降低了它们对较冷操作温度的敏感性。最后，由于它们是唯一利用红外光 (>800 nm) 的光合生物，工程师将拥有强大的选择工具来控制混合开放培养物中的微生物群落。********已发表的研究主要集中于纯培养 PNSB 废水处理并在 20-35C 下运行。这些条件不适用于全面的加拿大市政污水处理设施；因此，在开发 PNSB 流程方面仍然存在重大知识差距。此外，需要严格控制反应器条件，以便新陈代谢最大化生物质产量，而不是竞争性的氢气和聚羟基脂肪酸酯合成。该提案将调查与加拿大相关的非无菌 PNSB 光生物反应器的运行条件，以实现废水资源回收。此外，将通过使用基因组规模的代谢模型和高通量宏基因组分子工具来开发 PNSB 代谢和微生物群落组成的控制策略。该项目将培养2名博士生、4名硕士生和10名本科生。***