Passive Filtration for Pathogen Removal in Urban Stormwater

(2010 – current)
Yali Li

Notoriously variable and high concentrations of pathogens in urban stormwater runoff can impact negatively on the quality of receiving waters, increasing human health risks to recreational users of these systems. Moreover, if urban stormwater harvesting is to become an alternative water resource, proper treatment of pathogens is a necessity. One solution is to find cost-effective ways of removing pathogens within WSUD systems. The aim of this PhD is to develop safe, robust, affordable new filter media and to integrate the media with WSUD systems for effective removal of pathogens.

'Raw' GAC (top) and GAC coated with TiO2 (bottom)

For this purpose, a series of tasks are identified in this project:

  1. It will investigate the feasibility of surface-modifying a range of raw filter media commonly used in filtration systems (e.g. GAC, zeolite, coal and sand) with various antimicrobial reagents in order to enhance their pathogen removal capacity.
  2. Once the modifying method is optimized, columns will be built based on these new materials, and their ability to remove pathogen indicators will be monitored.
  3. Furthermore, the optimal configurations of materials (raw media, particle size and antimicrobial agents) will be tested in controlled laboratory conditions that mimic operational conditions of stormwater treatment systems to optimize and refine the filter media as well as the filtration process. The impact of factors such as flow rate, filter media depth and intermittent drought events on pathogen indicators removal will be explored.
  4. Next, this project will investigate whether the newly developed filter media could be effectively incorporated into existing WSUD systems and will explore how to further optimize the integration.
  5. With sufficient time, the material will also be tested in field conditions.

Supervisors:
Dr David McCarthy and Prof Ana Deletic

Publications (link)

Links:
Non-Vegetated Filtration Systems/BiofiltersWSUD Technologies
Project P1 (Sustainable Technologies)Cities as Water Supply Catchments Program