To Chlorinate or Not to Chlorinate

氯化或不氯化

• 批准号: EP/W037270/1
• 负责人: Joby Boxall
• 金额: $ 148.45万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW037270%2F1
• 关键词: Chlorinate

The majority of countries around the world maintain a disinfectant residual to control planktonic microbial contamination and/or regrowth within Drinking Water Distribution Systems (DWDS). Conversely, some European countries prohibit this practice because the residuals react to create disinfection by-products, which are regulated toxins with carcinogenic effects. Critically, the impact of disinfectant residuals on biofilms is unknown, including their role in creating a preferential environment for pathogens. Biofilms grow on all surfaces; they are a matrix of microbial cells embedded in extracellular polymeric substances. With biofilms massively dominating the organic content of DWDS, there is a need for a definitive investigation of the processes and impacts underlying DWDS disinfection and biofilm interactions such that all the risks and benefits of disinfection residual strategies can be understood and balanced. This balance is essential for the continued supply of safe drinking water, but with minimal use of energy and chemicals.The central provocative proposition is that disinfectant residuals promote a resistant biofilm that serves as a beneficial habitat for pathogens, allowing pathogens to proliferate and be sporadically mobilised into the water column where they then pose a risk to public health. This project will, for the first time, study and model the impact of disinfectant residual strategies on biofilms including pathogen sheltering, proliferation, and mobilisation to fill this important gap in DWDS knowledge.The potential sources of pathogens in our DWDS are increasing due to the ageing nature of this infrastructure, for example, via ingress at leaks during depressurisation events. Volumes of ingress and hence direct exposure risks are small but could seed pathogens into biofilm, with potential for proliferation and subsequent release. An integrated, iterative continuum of physical experiments and modelling is essential to deliver the ambition of the proposed research. We will make use of the latest developments in microbiology, internationally unique pilot scale experimental facilities, population biology and microbial risk assessment modelling to understand the interactions between the disinfection residuals, biofilms, pathogens and hydraulics of drinking water distribution systems. This research will combine globally renowned expertise in mathematical modelling, drinking water engineering, quantitative microbial risk assessment, and molecular microbial ecology to deliver this ambitious and transformative project.If the central proposition is proven, then current practice in the UK and the majority of the developed world could be increasing health risks through the use of disinfectant residuals. The evidence generated from this research will be central to comprehensive risk assessment. A likely outcome is that by testing the hypothesis, we will prove under what conditions the selective pressures on biofilms are unacceptable, and in so doing understand and enable optimisation of disinfection residuals types and concentrations for different treated water characteristics. Although focused on the impacts of disinfectant residuals and pathogens, the research will also generate wider knowledge of biofilm behaviour, interactions and impacts between biofilms and water quality within drinking water distribution systems in general and relevant to other domains.The impact of this research will be to deliver a step change in protecting public health whilst minimising chemical and energy use through well informed trade-offs between acute drinking water pathogen (currently unknown) and chronic disinfectant by-product (known and increasing) exposure. The ultimate beneficiaries will be the public, society and economy due to the intrinsic link between water quality and public health.

世界上大多数国家都保持消毒剂残留，以控制饮用水分配系统（DWDS）内的有害微生物污染和/或再生。相反，一些欧洲国家禁止这种做法，因为残留物会产生消毒副产品，这些副产品是具有致癌作用的受管制毒素。关键是，消毒剂残留物对生物膜的影响尚不清楚，包括它们在为病原体创造有利环境方面的作用。生物膜生长在所有表面上;它们是包埋在细胞外聚合物中的微生物细胞基质。由于生物膜在DWDS的有机物含量中占主导地位，因此需要对DWDS消毒和生物膜相互作用的过程和影响进行明确的调查，以便了解和平衡消毒残留策略的所有风险和益处。这种平衡对于持续供应安全饮用水至关重要，但需要最大限度地减少能源和化学品的使用。最具争议性的论点是，消毒剂残留物促进了一种抗性生物膜，成为病原体的有利栖息地，使病原体能够增殖并零星地进入水体，然后对公共卫生构成风险。该项目将首次研究和模拟消毒剂残留策略对生物膜的影响，包括病原体的遮蔽、增殖和动员，以填补DWDS知识中的这一重要空白。由于该基础设施的老化性质，DWDS中病原体的潜在来源正在增加，例如，在减压事件期间通过泄漏进入。侵入的风险和因此直接暴露的风险很小，但可能将病原体种入生物膜，具有增殖和随后释放的潜力。物理实验和建模的综合、迭代连续体对于实现拟议研究的目标至关重要。我们将利用微生物学的最新发展，国际上独特的中试规模实验设施，种群生物学和微生物风险评估模型，以了解消毒残留物，生物膜，病原体和饮用水分配系统水力学之间的相互作用。这项研究将结合联合收割机在数学建模、饮用水工程、定量微生物风险评估和分子微生物生态学方面的全球知名专业知识，以实现这一雄心勃勃的变革性项目。如果中心命题得到证实，那么英国和大多数发达国家目前的做法可能会通过使用消毒剂残留物增加健康风险。这项研究产生的证据将是全面风险评估的核心。一个可能的结果是，通过测试假设，我们将证明在什么条件下生物膜上的选择性压力是不可接受的，并在这样做的理解和实现消毒残留物的类型和浓度的优化不同的处理水的特性。虽然重点是消毒剂残留物和病原体的影响，但这项研究也将产生更广泛的生物膜行为知识，生物膜和水质之间的相互作用和影响，在饮用水分配系统的一般和相关的其他领域。这项研究的影响将提供一个步骤的变化，在保护公众健康，同时尽量减少化学品和能源的使用，通过充分知情的贸易-急性饮用水病原体（目前未知）和慢性消毒剂副产品（已知和增加）接触之间的差距。由于水质与公众健康之间的内在联系，最终受益者将是公众、社会和经济。

项目成果

Emerging investigator series: Optimisation of Drinking Water Biofilm Cell Detachment and Sample Homogenisation Methods for Rapid Quantification via Flow Cytometry

新兴研究者系列：优化饮用水生物膜细胞分离和样品均质方法，通过流式细胞仪进行快速定量

• DOI: 10.1039/d3ew00553d
• 发表时间: 2024
• 期刊: Water Research & Technology
• 作者: Pick F

Forecasting bacteriological presence in treated drinking water using machine learning

• DOI: 10.3389/frwa.2023.1199632
• 发表时间: 2023-06
• 作者: Grigorios Kyritsakas;J. Boxall;V. Speight