Mechanistic understanding of simultaneous energy and phosphorous recovery in a single anaerobic reactor: Path to resource-recovery based wastewater treatment

水和废水的收集和处理是能源密集型和昂贵的过程。鉴于加拿大污水处理系统的恶化状态和水基础设施的普遍老化，迫切需要向更可持续的资源回收为基础的废水管理过渡。Liu的研究小组开发了厌氧消化（AD）工艺，在AD反应器内同时回收能量和磷(P)，该工艺获得了SPRING专利。这是通过改良的上流式厌氧污泥毯（UASB）反应器实现的，该反应器在中温和亲热条件下运行，处理源转移的棕水和黑水。这两种水的甲烷产量和有机负荷率都很高，远远超过了之前报道的产量。在无化学添加的厌氧颗粒污泥中以沉淀形式回收磷的效果最为显著。需要进一步的研究来确定关键工程设计和操作参数在功能微生物群落发展中的作用，并探索工艺限制和优化方案。拟议的DG计划的长期目标是在加拿大和国外的污水管理中利用AD创新，将可持续的资源回收为基础的废水处理结合起来。该计划的短期目标是探索关键生态和代谢功能与工程参数之间的联系，并制定具有成本效益的AD能量和P回收设计和运营策略，从而实现更可持续的废水管理。拟开展的研究将实现两个目标：A)通过探索影响废水能量和磷回收的关键工程因素，研究在选定的工程操作条件和相关的局部化学条件下微生物群的相互作用，阐明与SPRING过程相关的机制；B)根据目标A中确定的关键工程参数，通过将微生物过程与工程设计联系起来，重新设计SPRING过程，以优化废水能源和磷的回收，并根据加拿大的条件评估新的AD操作策略和设计。拟议的计划将为基于资源回收的生物废水处理提供科学基础，指导可以逐步取代传统能源密集型做法的解决方案，服务于新的有前途的本地和国际市场，并解决由于排放要求日益严格而不断上升的资本和运营成本。它将支持开发商和加拿大市政当局/公用事业公司考虑的开拓性活动，使社区能够通过基于资源回收的处理技术，实现水服务中的水、能源和残留物的净零排放，这种处理技术不通过泄漏或排水口排放废水，而是回收适合重复使用的水，改善接收水质并降低温室气体（GHG）排放。

Water and wastewater collection and treatment are energy intensive and costly processes. Given the deteriorated state of Canadian wastewater treatment systems and aging water infrastructure generally, a transition towards more sustainable resource-recovery based wastewater management is urgently needed. Liu's research group developed anaerobic digestion (AD) processes for simultaneous energy and phosphorus (P) recovery within AD reactors, a process patented as SPRING. This was achieved using a modified upflow anaerobic sludge blanket (UASB) reactor, operated under mesophilic and thermophilic conditions, treating both source-diverted brown and blackwater. High methane production and organic loading rates were achieved for both water types far exceeding previously reported yields. Most significant was P recovery in the form of precipitates in the anaerobic granular sludge without chemical addition. Further studies are needed to identify the roles of key engineering design and operation parameters in the development of functional microbial communities and explore process limitations and optimisation options. The long-term goal of the proposed DG program is to integrate sustainable resource-recovery based wastewater treatment using AD innovations in sewage management in Canada and abroad. The short-term objective of the proposed program is to explore the link between key ecology and metabolic functions and engineering parameters, and to develop cost-effective design and operation strategies for AD energy and P recovery, leading to more sustainable wastewater management. The proposed research will address two aims: A) Elucidate the mechanisms associated with the SPRING process by exploring key engineering factors influencing wastewater energy and P recovery and studying interactions of the microbiota under selected engineering operation conditions and associated localised chemical conditions for P recovery; and B) Redesign the SPRING process by linking microbial processes to engineering design to optimise wastewater energy and P recovery based on key engineering parameters identified in Aim A and to assess new AD operation strategies and designs for Canadian conditions. The proposed program will provide the scientific foundation for resource-recovery based biological wastewater treatments, guide solutions that can gradually displace the conventional energy-intensive practices, serve new promising local and international markets and address escalating capital and operating costs due to the ever-increasing stringency in discharge requirements. It will support pioneering activities considered by developers and Canadian municipalities/utilities, so that communities can aspire to net zero water, energy and residuals in water services, through resource-recovery based treatment technologies that do not discharge wastewater via leakage or outfalls but recover fit-for-reuse water, improving receiving water quality and lowering greenhouse gas (GHG) emissions.