Developing a More Fundamental Understanding of Drinking Water Biofiltration

对饮用水生物过滤有更基本的了解

• 批准号: RGPIN-2015-06369
• 负责人: Huck, Peter
• 金额: $ 2.48万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614111
• 关键词: Developing; More; Fundamental; Understanding; Drinking

In the last decade, the interest in using biological processes as part of drinking water treatment has increased substantially. This is driven by their ability to biodegrade portions of the natural organic matter (NOM) in water that can interfere with good treatment. A classical issue associated with NOM is the formation of potentially harmful disinfection byproducts. Of particular interest is rapid biofiltration, which takes place in filters normally used for particle and pathogen removal. In the absence of a disinfectant residual, the very high surface area in the filters allows for the development of biofilm that can undertake biodegradation. In the last several years, research has shown that such biofilters can also effectively reduce the concentrations of biopolymers, the high molecular weight fraction of the NOM. Biopolymers have been shown to be critical in fouling low-pressure membranes such as ultrafiltration that are increasingly being used for pathogen and particle removal in drinking water treatment. This defines a potential new application for biofiltration, i.e. as a “green” membrane pretreatment. In the last several years, a significant portion of the applicant’s research has been directed towards this. In the conduct of this research several important issues have arisen that require more fundamentally-oriented investigation. These research questions form the basis of this application and are important for the understanding and successful application of biofiltration, regardless of its treatment objective. The first issue is that conflicting information has appeared in the literature regarding the appropriate macronutrient ratio for biofilters so that nitrogen or phosphorus are not limiting. This is of important practical significance, because if, for example, phosphorus were to be supplemented, it could potentially need to be removed at the downstream wastewater treatment plants. Additionally, the role of extracellular polymeric substances (EPS) in biofiltration has not been properly addressed. Further, commonly used parameters to quantify biomass such as adenosine triphosphate (ATP) have been shown not to have a unique relationship with biofilter performance. A second research question is that in terms of biofiltration as a membrane pretreatment, the biodegradability of the biopolymer fraction appears to be different for different waters. Ozonation prior to biofiltration assists in reducing membrane fouling, but appears to negatively impact the removal of biopolymers by biofiltration.   Because biofiltration can also remove the easily biodegradable NOM that contributes to biofouling in reverse osmosis (RO) membranes used for desalination, a third need is to explore biofiltration's potential in RO applications, where it could reduce chemical usage for membrane cleaning.

在过去的十年中，使用生物学过程作为饮用水处理的一部分的兴趣大大增加了。这是由于它们在水中生物降解部分（NOM）的能力所驱动的，这可能会干扰良好的治疗方法。与NOM相关的经典问题是形成潜在有害的消毒副产品。 特别令人感兴趣的是快速生物过滤，这发生在通常用于颗粒和病原体去除的过滤器中。在没有消毒物残留物的情况下，过滤器中非常高的表面积允许开发可以进行生物降解的生物膜。在过去的几年中，研究表明，这种生物过滤器还可以有效降低生物聚合物的浓度，即NOM的高分子量分数。已经证明，生物聚合物在污染低压膜（例如超滤）中至关重要，这些膜越来越多地用于饮用水处理中的病原体和颗粒去除。这定义了潜在的生物过滤应用，即作为“绿色”膜预处理。在过去的几年中，该申请的研究中很大一部分是针对这一点的。 在这项研究的进行中，已经出现了一些重要的问题，需要更根本地注重投资。这些研究问题构成了本应用的基础，对于理解和成功应用生物过滤至关重要，无论其治疗目标如何。 第一个问题是文献中出现了有关生物过滤器的适当大量营养比率的相互冲突信息，因此氮或磷不会限制。这具有重要的实际意义，因为例如，如果要补充磷，则可能需要在下游废水处理厂中除去磷。另外，尚未正确解决细胞外聚合物（EP）在生物过滤中的作用。此外，已证明常用的参数来量化生物量（例如三磷酸腺苷（ATP））与生物滤器性能没有独特的关系。 第二个研究问题是，就膜预处理而生物过滤而言，生物聚合物分数的生物降解性对于不同的水域似乎有所不同。生物过滤之前的臭氧化有助于减少膜结垢，但似乎对通过生物过滤的生物聚合物的去除产生负面影响。   由于生物过滤还可以去除易于生物降解的NOM，从而有助于用于脱盐的反渗透（RO）膜的生物污染，因此第三种需求是探索生物过滤在RO应用中的潜力，在该膜中，它可以减少用于清洁膜清洁的化学用途。