Collaborative Research: Enhancing Bioenergy Recovery from Wastewater in an Integrated Microbial-Algal Photobioelectrochemical System

城市污水处理过程消耗大量能源。然而，如果有机废物可以转化为能量，那么进入废物处理过程的有机材料就有可能提供正能量的废水处理。微生物燃料电池是一种包含特殊细菌菌株的装置，它们消耗废水中的有机物作为燃料来发电并帮助清洁水。尽管微生物燃料电池在可持续和节能的废水处理方面显示出前景，但其性能较低。提高其性能的一种非常规方法是将微生物燃料电池装置集成到一个利用阳光生长藻类的培养室中。该项目将研究海藻-微生物联合燃料电池的协同作用，以提高电力产量，通过消除外部曝气需求来降低运营成本，并从废水中去除无机和有机物质。与此项目相关的教育活动利用微生物燃料电池的演示来激发本科生、K12学生和教师以及公众对环境工程和废水处理主题的兴趣。该研究的总体目标是研究集成到藻类生物反应器中的微生物燃料电池作为能源积极废水处理的新平台的潜在协同作用。在这个组合系统中，藻类产生微生物燃料电池电极驱动好氧微生物电化学过程所需的氧气，而这个过程产生藻类所需的二氧化碳。这种就地氧气源具有加强发电和消除曝气需求的潜力。藻类还可以去除无机氮和磷，帮助进一步处理废水。这项研究有四个目标。第一个目标是基于对藻类-微生物燃料电池中无机和有机营养形式转化的基本理解，构建一个营养预算模型。第二个目标是研究不同的藻类物种如何影响微生物燃料电池电极内细菌的稳定性和藻类生物量生产力。为此，宏基因组分析将用于识别与不同分类群相关的代谢功能，这些功能对过程性能至关重要。第三个目标是量化使用混合营养藻类对藻类-微生物燃料电池中有机物质的处理。第四个目标是使用不同的配置（包括可伸缩的系统）进行系统开发和优化。通过这些目标，本研究旨在获得对营养吸收和发电过程中关键藻类-细菌相互作用的基本理解，并将揭示通过物理，化学和代谢过程转化碳，氮和磷的途径。

Municipal wastewater treatment processes consume significant amounts of energy. However, the organic materials fed into the waste treatment process offer the potential for energy-positive waste water treatment if this waste organic material can be converted into energy. A microbial fuel cell is a device that contains special strains of bacteria which consume organic matter in waste water as a fuel to generate electricity and help clean up the water. Although microbial fuel cells have shown promise for sustainable and energy- positive waste water treatment, their performance is low. An unconventional way to improve their performance is to integrate the microbial fuel cell device into a cultivation chamber which grows algae from sunlight. The project will investigate the synergistic aspects the combined algal-microbial fuel cell for its potential to boost electricity production, reduce operating costs by eliminating the external aeration requirement, and remove inorganic as well as organic materials from waste water. The educational activities associated with this project make use of microbial fuel cell demonstrations to stimulate interest in environmental engineering and waste water treatment topics with undergraduate students, K12 students and teachers, and the public.The overall goal of the research is to study the potentially synergistic interactions of a microbial fuel cell integrated into an algal bioreactor as a new platform for energy-positive waste water treatment. In this combined system, the algae generate oxygen which is needed by the microbial fuel cell electrode to drive aerobic micro-bioelectrochemical processes, whereas this same process generates carbon dioxide needed by the algae. This in situ source of oxygen has the potential to intensify electricity generation and eliminate the aeration requirement. The algae can also remove inorganic nitrogen and phosphorus to help further treat the waste water. The research has four objectives. The first objective is to construct a nutrient budget model based on fundamental understanding of the transformation of inorganic and organic nutrient forms within the algal-microbial fuel cell. The second objective is to examine how different algal species affect the stability of bacteria within the microbial fuel cell electrode and the algal biomass productivity. Towards this end, metagenome analysis will be used to identify metabolic functions related to different taxa which are critical to process performance. The third objective is to quantify treatment of organic materials within the algal-microbial fuel cell using mixotrophic algae. The fourth objective is to conduct system development and optimization with different configurations, including scalable systems. Through these objectives, this research seeks to gain a fundamental understanding of critical algae-bacteria interactions during nutrient uptake and electricity generation, and will also reveal the pathways of carbon, nitrogen, and phosphorous transformation via physical, chemical, and metabolic processes.