Advanced Biological Platform for Generation of High-Purity Methane and Other Products: A Circular Economy Approach

传统的有机废物管理主要依赖于填埋、焚烧和堆肥，所有这些都与重大的环境影响有关，包括温室气体排放、空气污染和土壤和水污染。这些技术不是以有效的资源回收为基础，也不是与循环经济办法相一致。然而，有机废物的厌氧消化(AD)等生物过程提供了潜力；必须进行重大研究，以解决各种技术挑战，包括废物成分和装载率可变、能量产量低、过程不稳定以及对沼气有效定价的了解有限。此外，在寒冷气候下实施厌氧消化是一个应该填补的知识空白。我们的目标是通过建立在我们对厌氧消化-微藻培养生物精炼的多年研究中产生的知识来应对上述挑战，并开发一种新的原位生物甲基化工艺，用于从混合有机垃圾(例如，食物垃圾和垃圾污泥)中生产高纯度甲烷，同时回收营养物质和其他生物产品。在古生菌平台催化的原位生物甲基化过程中，二氧化碳的生物转化为甲烷是通过补充氢气来驱动的。已确定的主要挑战是由于氢的分压增加而引起的代谢限制，以及由于氢的低气液传质而引起的物理化学限制。对本实验室研制的新型厌氧折流板反应器(ABR)的结构进行了改进。我们假设，安装一个均匀流量分配的管道网络，向富含甲烷菌的最后一个隔室补充氢气，并结合膜来减少冲刷，将产生更高的生物降解率、工艺稳定性、甲烷纯度，并增强对废物异质性和负荷波动的稳健性。通过从沼气中回收营养物质，将有可能实现有机废物的闭环评估方法。我们将单独评估沼泽上的微藻培养以及光生物电化学系统的营养恢复。我们假设，创新的系统设计、驯化和发展藻类-细菌联合体将消除克服沼泽成分对藻类生长的抑制作用所需的显著稀释。我们建议的方法将针对有机废物管理部门的关键挑战，包括混合废物的异质性、流量波动、相对较低的能量产量和宝贵养分的损失。实施与养分回收方法相结合的新型先进古菌-细菌平台的整体阵列提供了将有机废物管理系统转变为符合循环经济概念的可持续创收平台的巨大潜力。

Conventional organic waste management mainly relies on landfilling, incineration, and composting, all of which are associated with significant environmental impacts including, greenhouse emission, air pollution and soil and water contamination. These technologies are not based on efficient resource recovery or aligned with the circular economy approach. Biological processes such as anaerobic digestion (AD) of organic waste offers potential, however; significant research must be directed towards addressing the technical challenges including variable waste composition and loading rate, low energy yield, process instability, and limited knowledge on the efficient valorization of digestate. Additionally, the implementation of anaerobic digestion in cold climates represents a knowledge gap that should be filled. We aim to address the above challenges by building upon the knowledge generated from our multi-year research into anaerobic digestion-microalgae cultivation biorefinery and develop a novel in-situ biomethanation process for production of high-purity methane from mixed organic waste (e.g., food waste and waste sludge), while recovering nutrients and other bioproducts. In the process of in-situ biomethanation, catalyzed by archaea platform, the bioconversion of carbon dioxide to methane is driven by hydrogen gas supplementation. The major challenges identified is metabolic limitation due to the inhibitory effects of increased partial pressure of hydrogen, and physico-chemical limitation arising from low gas-liquid mass transfer of hydrogen. The configuration of novel Anaerobic Baffled Reactor (ABR), developed in our lab will be modified. We hypothesize that installing a network of pipes for even flow distribution, hydrogen supplementation to the last compartment, which is rich in methanogens and incorporating membrane to reduce wash-out will result in higher biodegradation rate, process stability, methane purity and enhanced robustness with respect to waste heterogeneity and load fluctuation. A closed-loop organic waste valorization approach will be possible by recovering nutrients from digestate. Microalgae cultivation on digestate as well as photobioelectrochemical system will be individually evaluated for nutrient recovery.  We hypothesize that innovative system design, acclimatization and developing algae-bacteria consortium will eliminate significant dilution required to overcome the inhibitory effect of digestate constituents on algal growth. Our proposed approach will target the key challenges in the organic waste management sector including the mixed waste heterogeneity, flowrate fluctuation, relative low energy yield and loss of valuable nutrients. Implementing a holistic array of novel advanced archaea-bacteria platform integrated with nutrient recovery approaches offers significant potential to transform organic waste management systems into a sustainable, revenue generating platform, aligned with the concept of circular economy.