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），鼓励生物膜在其中形成。生物过滤可以去除可生物降解的物质，包括特定的污染物，也可以去除颗粒。这项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）的基本认识。促进其使用有助于更环保和更可持续的处理过程。多年来，理解和改进生物过滤一直是申请人研究的主要焦点，包括他最近的发现基金。包括生物过滤在内的饮用水处理面临着新的挑战。未来5年的研究重点将集中在其中的3个方面：蓝藻毒素、微塑料/纳米塑料和反渗透脱盐预处理。以下具体目标将在本授权期内解决：目标1：进一步了解生物膜群落在生物过滤器去除藻类/蓝藻毒素（特别是微囊藻毒素- lr）的能力中的作用。目标2：了解生物过滤去除微和纳米塑料的能力。为了了解和提高生物过滤的能力，为海水淡化反渗透膜提供更环保的预处理。蓝藻毒素微囊藻毒素lr是加拿大的一个监管参数。蓝藻毒素可以通过生物过滤去除，但这不是在开花期间立即，因为需要驯化。对影响生物过滤器对蓝藻华反应的因素以及对去除效果的影响进行机械理解是很重要的。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去除微塑料/纳米塑料，但了解去除机制（可能是物理而不是生物降解，因为接触时间短）至关重要。与传统的过滤工艺相比，生物膜可以提高去除率。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。第三个目标建立在申请人之前在新加坡进行的概念验证工作的基础上。这项中试规模的研究表明，生物过滤是反渗透淡化的一种更环保的预处理方法，尽管还需要进一步的研究，这种方法可能最终被广泛采用。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.