Team:Exeter/Applied Design


<centre> Applied Design</centre>

Our Motivations

The pollution of heavy metal ions in the South West, as a result of the areas historic and prolific mining industry, is a significant problem due to leaching of the metal ions. Such leaching has serious consequential impacts on the surrounding ecology and on human health. Motivated to find a solution our team at Exeter have spent the summer working on developing a cost effective and sustainable solution that will have a reduced effect on the environment compared to the existing technologies in use. This page is an introduction to how we have designed, engineered and experimentally tested a novel filtration system for the bio-remediation of water contaminated with heavy metal ions.

Figure 1: Wheal Maid Lagoon

"Areas affected by contaminated mine water are often damaged for many decades, if not centuries. Because the treatment of polluted mine water is usually expensive, active treatment is usually used in heavily populated areas, at working mines, or where governmental money was made available for treatment purposes." (Wolkersdorfer, C. 2008)

Our Filtration System

Many of the existing treatment methods currently employed to deal with the contamination are expensive and often produce tonnes of hazardous waste each year. The Pili+ filtration system has been developed to provide a cheaper more environmentally conscious alternative to these methods based on the use of our re-purposed adhesion mechanism of E. coli. Additionally, the filtration system is modular meaning that each component is independent therefore they can be adapted or interchanged with another component that may be potentially more suited to the situation that the filtration system is being used in. For example if an alternative biosecurity mechanism is required, potentially due to materials available or limited funds, then since it is not incorporated directly within the other components this would be feasible to change.

Our novel filtration system is comprised of three modular parts:

  • The first component is a Hydrocyclone this is used to separate sediment from the water. The video, shows a sediment particle (brown) gets separated, while the metal ions (pink) do not get separated and flows up the inner vortex with the water.
  • The second component is a Metal Binding Reactor which houses the genetically modified E. coli. This is where the metal ions (pink) bind to the pili.
  • The third component is a Biosecurity Mechanism which is used to kill the E. coli to prevent the genetically modified organisms from escaping into the environment.

Stakeholder Collaboration

We would like to thank the following stakeholders for sparing their time and offering invaluable suggestions, advice and equipment to help with the progression of our filtration system. Click here to find out more about our continual collaboration with these external stakeholders.


  • Wolkersdorfer, C., Chapter 11: Mine Water Treatment and Ground Water Protection in Water Management at Abandoned Flooded Underground Mines: Fundamentals, Tracer Tests, Modelling, Water Treatment, A. International Mine Water and I. ebrary, Editors. 2008, Springer: Berlin. p. 235.