Engineering low-cost, low-energy decentralized anaerobic wastewater treatment processes by guided evolution of microbial communities

据估计，今天有多达24亿人生活在没有得到改善的卫生设施的地方，农村地区有70%的人生活在没有卫生设施的地方。以全球北方地区为代表的能源和水密集型集中废水处理系统的普遍模式，使目前的技术不仅不适合解决农村穷人经历的卫生危机，而且越来越被认为是不可持续的，即使在能源和水资源丰富的经济体也是如此。因此，迫切需要开发低成本、低能耗的分散式废水处理系统。厌氧消化(AD)是一种生物处理过程，能够通过从废流中去除有机物来稳定废物。此外，随着厌氧微生物将有机物转化为甲烷气体，AD具有获得净能量的潜力，甲烷气体是一种易于储存的可再生能源。然而，AD工艺在处理可变废流方面的反复无常是出了名的，以至于即使在集中化在一定程度上为废水基础设施提供冗余的全球北部，AD也很少应用于未经处理的污水的处理。分子生物学的最新进展现在使人们能够对WWT系统中发现的复杂微生物群落有新的见解。许多已发表的研究指出种子群落在消化池定植中的重要性，从而与生物过程的效率和稳定性有关。然而，到目前为止，还没有合理的方法来优化AD技术种子污泥中的微生物群落组成。该项目旨在将UOG开发的新型机器人平台‘WASTEBOT’的应用与环境‘组学’方法结合起来，以进化和表征用作AD种子污泥的最佳微生物群落。优化的种子群落提供稳健和可预测的处理的有效性将在新型家用沼气池中进行现场测试，这些沼气池与泰国亚洲理工学院合作，服务于全球南部的农村社区，并通过与苏格兰水务的合作，在全球北部服务。如果成功，优化程序可能会提高一系列低成本、低能源消化器类型的信心，从而为卫生危机提供亟需的解决方案。

It is estimated that today as many as 2.4 billion people live without access to improved sanitation with rural areas home to 7 out of 10 people living without access. The prevailing paradigm of energy and water intensive centralised wastewater treatment (WWT) systems typified in the Global North renders current technologies not only unsuitable for address of the sanitation crisis experienced by the rural poor, but is increasingly recognised as unsustainable even in energy and water rich economies. As such, there is an urgent need to develop low-cost, low-energy decentralized wastewater treatment systems. Anaerobic digestion (AD) is a biological treatment process enabling stabilisation of wastes by removal of organics from the waste stream. Further,AD has the potential to operate with a net energy gain as anaerobic microbes convert organics to methane gas, a readily storable form of renewable energy. However AD processes are notoriously fickle in the treatment of variable waste streams, so much so, that even in the Global North where centralisation provides a degree of redundancy in the wastewater infrastructure, AD is rarely if ever applied to the treatment of raw sewage. Recent advances in molecular biology are now enabling new insights to the complex microbial communities found in WWT systems. Many published studies point to the importance of the seed community in relation digester colonisation, and hence to the efficiency and stability of biological processes. Yet to date, no rational methodology exists to optimise microbial community composition in the the seed sludge for AD technologies. This project aims to couple application of 'WASTEBOT', a novel robotics platform developed at UoG, with an environmental 'omics approach to evolve and characterize optimal microbial communities for use as seed sludge in AD. The efficacy of the optimized seed communities to deliver robust and predictable treatment will be tested in-situ in novel household-scale digesters serving rural communities in boththe global south in collaboration with Asian Institute of Technology in Thailand, and, in the global north via collaboration with Scottish Water. If successful, the optimization procedure has potential to improve confidence across a range of low-cost, low-energy digester types and thus deliver much needed solutions to the sanitation crisis.