New approaches to microbial ecology in biological phosphorus removal systems

废水处理可以缓解水资源短缺和污染，并在生物经济中发挥关键作用。使用生物废水处理工艺可以提供有效的处理，通常可以提高效率，并作为增值化合物的来源，如磷和聚羟基烷酸酯，这些化合物可以从这些系统中的微生物群落中回收。特别是磷可以是一种污染物，导致富营养化，也是一种宝贵的资源，预计在未来100年内可提取的磷资源将会短缺。据估计，从废水中回收这种营养物能够满足全球22%的磷需求。增强型生物除磷（EBPR）通常被认为是废水除磷最具吸引力的工艺之一，它不需要添加化学沉淀剂，并且与磷回收技术具有明显的协同作用磷的吸收主要是由一组被称为聚磷生物（PAOs）的细菌完成的。然而，由于操作和环境条件的变化、不同生物之间的竞争、噬菌体的捕食和感染，现有混合微生物群落的种群动态往往会影响有效的除磷。此外，由于废水中碳源浓度低，该过程通常需要添加碳原料，如醋酸盐，这有助于整体过程成本和碳足迹。因此，为了确保该技术的弹性和有效性，需要进一步研究工艺操作和不同微生物胁迫对PAOs微生物生态和表型的影响，特别是“在野外”，即在真实的全尺寸混合酒中。该项目将侧重于开发和使用创新方法来研究生物废水处理系统中存在的混合群落的微生物生态学和功能。具体来说，它将探讨应用于EBPR系统的三个关键方面：1 - PAO丰度对EBPR性能的重要性。这将通过人工生物增强真正的混合液样品，在EBPR中富集关键生物，绘制不同PAO生物与性能的比例，与威塞克斯水务公司合作进行样品采购；开发EBPR系统中噬菌体种群识别和培养技术。这些技术将用于开发一种新的噬菌体治疗方法，以敲除EBPR中混合微生物培养的特定群体，从而研究它们的功能；3 -与Anglian Water合作，研究在EBPR中使用甘油作为碳补充的可行来源，其对系统微生物生态的影响及其效率。甘油是生物柴油工业的副产品，含碳量为40%，作为原料价值低，需要适当处理和排放。因此，甘油将是废水处理中使用的其他原料的有吸引力的替代品。最终，尽管该项目的重点是EBPR系统，但所开发的大多数方法都可以应用于其他生物系统。Cordell， D, Rosemarin， A., Schroeder， J. J. & Smit， A. L.迈向全球磷安全，磷回收和再利用方案的系统框架。2.《化学学报》（英文版），2011。欧门，A.等。强化生物除磷研究进展：从微观到宏观。[j] .中国科学：自然科学版，2007。

Wastewater treatment can attenuate water scarcity, pollution and play a key role in the Bioeconomy. Using biological wastewater treatment processes can deliver effective treatment, often promoting higher efficiencies and acting as a source of value-added compounds, such as phosphorous and polyhydroxyalkanoates, that can be recovered from the microbial communities in these systems. In particular phosphorus can be both a pollutant, contributing towards eutrophication, and a valuable resource with a shortage of extractable phosphorus resources predicted within the next 100 years. Recovery of this nutrient from wastewater is estimated to be able to meet 22% of global phosphorus demand. 1 Enhanced Biological Phosphorus Removal (EBPR) is often considered one of the most attractive processes for phosphorus removal from wastewater, one that does not require the addition of chemical precipitants, and with clear synergies with phosphorus recovery technologies.2 The uptake of phosphorus is performed mainly by a group of bacteria named polyphosphate-accumulating organisms (PAOs). However, effective phosphorus removal is often compromised by the population dynamics of the existing mixed microbial communities following variability in operational and environmental conditions, competition between different organisms, predation and infection by bacteriophages. Also, due to low concentration of carbon source in the wastewater, the process often requires the addition of carbon feedstocks such as acetate, which contribute to the overall process cost and carbon footprint. Hence, to ensure the resilience and effectiveness of this technology, further research is needed on the impact of process operation and different microbial stresses on the microbial ecology and phenotype of PAOs, especially 'in the wild', i.e. in real full-scale mixed liquors.This project will focus on developing and using innovative approaches for the study of the microbial ecology and function of the mixed communities present in biological wastewater treatment systems. Specifically, it will explore three key aspects applied to EBPR systems:1 - Importance of PAO abundance on EBPR performance. This will be explored by artificially bio-augmenting real mixed-liquor samples with enrichment of key organisms in EBPR, mapping the ratio of different PAO organisms in relation to performance, in collaboration with Wessex Water for sample procurement; 2 - Development of techniques to identify the phage populations in EBPR systems and cultivate them. These techniques will be used to develop a new phage therapy methodology to knock-out specific populations of the mixed microbial cultures in EBPR and hence investigate their function; 3 - In collaboration with Anglian Water, investigate the use of glycerol as a viable source of supplementary of carbon in EBPR, its effect on the microbial ecology of the system and its efficiency. Glycerol is a by-product of the biodiesel industry with 40% carbon, low value as feedstock and that needs to be properly treated and discharged. Hence, glycerol would be an attractive alternative to other feedstocks used in wastewater treatment. Ultimately, even though the project is focused on the system of EBPR, most of the approaches developed can be then applied to other biological systems.1. Cordell, D., Rosemarin, A., Schroeder, J. J. & Smit, A. L. Towards global phosphorus security, A systems framework for phosphorus recovery and reuse options. Chemosphere 84, 747-758 (2011).2. Oehmen, A. et al. Advances in enhanced biological phosphorus removal, From micro to macro scale. 41, 2271-2300 (2007).