Drinking Water Biofiltration: Addressing 21st Century Challenges

生物过滤已成为饮用水处理的重要工艺。该工艺使用颗粒介质过滤器（通常是沙子，无烟煤或颗粒活性炭），其中生物膜被鼓励发展。生物过滤可以去除可生物降解的物质，包括特定的污染物，以及去除颗粒。该研究计划的长期目标是增加对饮用水处理中生物过滤（生物过滤）的基本理解。促进其使用有助于更环保和更可持续的处理过程。了解和改进生物过滤一直是申请人多年来研究的主要重点，包括他最近的发现补助金。包括生物过滤在内的饮用水处理面临着新的挑战。拟议的研究将在未来五年集中在其中三个方面：蓝藻毒素，微塑料/纳米塑料和反渗透脱盐的预处理。在此资助期内，我们将致力于实现以下具体目标：目标1：进一步了解生物膜群落在生物过滤器去除蓝藻毒素能力中的作用目标2：了解生物过滤去除微塑料和纳米塑料的能力了解和提高生物过滤的能力，为海水淡化中使用的反渗透膜提供更环保的预处理。在加拿大，藻毒素微囊藻毒素-LR是一个规定参数。蓝藻毒素可以通过生物过滤去除，但在水华期间这不是立即的，因为需要驯化。重要的是要发展一个机械的理解的因素，影响生物过滤器的蓝藻水华的反应，并实现清除的影响。饮用水是人类接触微塑料/纳米塑料的潜在途径。虽然生物过滤有助于微塑料/纳米塑料的去除，但了解去除机制（由于接触时间短，可能是物理而不是生物降解）至关重要。与常规过滤工艺相比，生物膜可以增强去除。这项研究具有独特的方面，因为它侧重于生物过滤器的物理颗粒去除，而不是其作为“生物反应器”的功能。第三个目标是以申请人以前在新加坡进行的概念验证工作为基础。中试规模的研究表明，生物过滤是一种更环保的反渗透脱盐预处理的潜力，但需要进一步的研究，使这种方法最终可能被广泛采用。这项研究将提供有助于在加拿大提供安全饮用水的理解。进行研究的学生将获得宝贵的知识和经验，这将有助于他们在饮用水行业获得良好的职位。

Biofiltration has become an important process in drinking water treatment. The process uses a granular media filter (usually sand, anthracite or granular activated carbon) in which a biofilm is encouraged to develop. Biofiltration can remove biodegradable substances, including specific contaminants, as well as remove particles. The long-term goal of this research program is to increase the fundamental understanding of biological filtration (biofiltration) in drinking water treatment. Facilitating its use contributes to greener and more sustainable treatment processes. Understanding and improving biofiltration has been a major focus of the applicant's research for a number of years, including his most recent Discovery Grant. Drinking water treatment, including biofiltration, faces new challenges. The proposed research will focus on three of them for the next five years: cyanotoxins, microplastics/nanoplastics, and pretreatment for reverse osmosis desalination. The following specific objectives will be addressed in this granting period: Objective 1: To further develop our understanding of the role of the biofilm community in a biofilter's ability to remove cyanotoxins (specifically microcystin-LR) during an algal/cyanotoxin bloom) Objective 2: To understand the ability of biofiltration to remove micro- and nanoplastics Objective 3: To understand and improve the ability of biofiltration to provide greener pretreatment for reverse osmosis membranes used in desalination The cyanotoxin microcystin-LR is a regulated parameter in Canada. Cyanotoxins can be removed by biofiltration, however this is not immediate during a bloom, because acclimation is required. It is important to develop a mechanistic understanding of the factors that impact a biofilter's response to a cyanobacterial bloom, and the impact on the removals achieved. Drinking water is a potential route of human exposure to microplastics/nanoplastics. Although biofiltration can contribute to microplastics/nanoplastics removal, it is crucial to understand the mechanisms of removal (likely physical rather than biodegradation, because of the short contact time). The biofilm may enhance removals, compared to conventional filtration processes. This research has unique aspects because it focuses on a biofilter's physical particle removal, rather than its function as a "bioreactor". The third objective builds on previous proof-of-concept work conducted by the applicant in Singapore. That pilot scale research demonstrated the potential of biofiltration to be a greener pretreatment for reverse osmosis desalination, however much further investigation is required so that this approach might ultimately be broadly adopted. This research will provide understanding that will contribute to the provision of safe drinking water in Canada. The students conducting the research will gain valuable knowledge and experience that will help them to obtain good positions in the drinking water sector.