Harnessing microbially mediated redox processes for sustainable water treatment

作为气候变化缓解战略的一部分，国际社会面临着减少温室气体排放的巨大压力，开发低碳足迹、可持续技术对于人类适应不断变化的气候至关重要。鉴于联合国的可持续发展目标6(SDG6)旨在到2030年实现所有人都能获得安全和负担得起的饮用水，对低成本和可持续的全球废水处理系统的需求迅速变得更加迫切。该项目将使用跨学科的方法，利用富含铁的沉积矿物与土著微生物群落的自然相互作用，通过一种新的高级氧化工艺(AOP)处理废水，并以非常低的成本去除目标有机污染物。尽管这些耦合的生物地球化学过程可以在实验室中孤立地发生，但目前尚不清楚这个潜在的动态系统是否能够自我再生，从而在几个氧化还原(氧化还原)循环和现实环境条件下对水污染物进行有效处理。该项目旨在消除这些知识差距，办法是：(A)监测中尺度处理和再生的几个周期的处理性能，只使用水流和柱饱和度来刺激还原环境和氧化；b)调查再生期间推动铁还原的自然存在的微生物群落，它们在几个处理周期中的演变，以及这如何影响处理效率；c)研究是否以及如何可以使用网络生态学工具和地球化学参数来评估这个可持续废水处理系统的性能。为了为这个废水处理系统提供概念证明，将进行实验室中隔实验，使用富铁粘土矿物和氧化还原活性沉积物(包括原位土著微生物)的不同组合来处理选定的有机污染物。水的流量和氧饱和度将随着时间的推移进行调整，以刺激在自然环境中发生的连续氧化还原循环。收集关于污染物降解、矿物学和微生物群落变化的时间序列数据集，将有助于评估系统的现场微生物如何影响处理过程的性能，并受到处理过程的影响。综合应用地球化学、工程学、微生物学和生态学的方法来理解中观实验中的相互作用和支撑过程，将是进一步发展这一新的水处理技术规模的关键。

With the international community under considerable pressure to reduce greenhouse gas emissions as part of climate change mitigation strategies, the development of low carbon footprint, sustainable technologies is critical to humanity's adaptation to our changing climate. Given the UN's Sustainable Development Goal 6 (SDG6), which aims to achieve universal access to safe and affordable drinking water for all by 2030, the need for low cost and sustainable global wastewater treatment systems, has rapidly become more urgent. This project will use an interdisciplinary approach, exploiting the natural interaction of iron-rich sedimentary minerals with indigenous microbial communities, to treat wastewater via a novel advanced oxidation process (AOP) and remove target organic pollutants, at very low cost. Although these coupled biogeochemical processes can occur in isolation in the laboratory, it is not yet clear whether this potentially dynamic system is able to self-regenerate and therefore perform effective treatment of water pollutants over several oxidation-reduction (redox) cycles and under realistic environmental conditions. This project aims to address these knowledge gaps, by: a) monitoring the treatment performance over several cycles of treatment and regeneration at mesocosm scale, using only water flow and column saturation for stimulating reducing environments and oxidation; b) investigating the naturally present microbial communities that drive iron reduction during regeneration periods, their evolution over several treatment cycles, and how this affects treatment efficiency; c) examining whether and how network ecology tools and geochemical parameters can be used to evaluate the performance of this sustainable wastewater treatment system. To provide the proof of concept for this wastewater treatment system, laboratory mesocosm experiments will be undertaken using different combinations of iron-rich clay minerals and redox-active sediments (including in-situ indigenous microbiology) to treat selected organic pollutants. Water flow and oxygen saturation will be adjusted over time to stimulate successive redox cycles that would occur in the natural environment. Collection of time-series data sets on contaminant degradation, changes in mineralogy and microbial communities will allow for assessing how the in-situ microbiology of the system affects the performance of, and is affected by, the treatment process. Applying a combination of geochemical, engineering, microbiological and ecological methods to understand the interactions and underpinning processes in the mesocosm experiments will be crucial for further developing this novel water treatment technology at scale.