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

据估计，目前有多达24亿人无法获得经改善的卫生设施，其中70%的人生活在农村地区。以全球北方为代表的能源和水密集型集中式废水处理（WWT）系统的主流模式，使得当前的技术不仅不适合解决农村贫困人口所经历的卫生危机，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，通过去除废物流中的有机物来稳定废物。此外，当厌氧微生物将有机物转化为甲烷气体（一种易于储存的可再生能源）时，AD有可能以净能量增益运行。然而，在处理多变的废物流方面，AD工艺是出了名的反复无常，以至于即使在全球北方，集中化在废水基础设施中提供了一定程度的冗余，AD也很少被应用于处理原始污水。分子生物学的最新进展使人们对污水处理系统中复杂的微生物群落有了新的认识。许多已发表的研究指出了种子群落在消化器定植方面的重要性，因此对生物过程的效率和稳定性至关重要。然而到目前为止，还没有合理的方法来优化AD技术的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”与环境组学方法相结合，以进化和表征AD中用作种子污泥的最佳微生物群落。优化的种子群落在提供稳健和可预测的处理方面的功效将在新型家庭规模的沼气池中进行现场测试，这些沼气池将与泰国的亚洲理工学院合作，服务于全球南部的农村社区，并与苏格兰水务公司合作，服务于全球北部的农村社区。如果成功，优化程序有可能提高对一系列低成本、低能耗消化器类型的信心，从而为卫生危机提供急需的解决方案。

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.