Nanostructures on pipe walls to control regrowth

Nano- and microtechnology makes it possible to manipulate material structures at the molecular or atomic level. The macroscopic properties are thus determined not only by the material, but also by the modified nano- or microstructure. The result is known as a ‘metamaterial’. The multidisciplinary field of metamaterials has generated basic new insights, for example, in nano-electronics, renewable energy, nanomedicine, food technology and for the improvement of consumer products. This research project examined whether the concept can be applied to materials that come into contact with drinking water.

Reducing regrowth potential of materials

The growth of microorganisms on pipe walls in the drinking water distribution network can lead to a deterioration of the microbial water quality and of the water’s coloration or odour. KWR researched the regrowth potential of pipe materials, with the aim of assessing the risks involved and advising drinking water utilities. Regrowth potential plays a role in the selection of pipe materials by the utilities.

One interesting question is whether the regrowth potential of pipes can be reduced through the application of nanotechnology; for instance, through the production of surfaces upon which microbiological organisms cannot, or can less easily, attach themselves. Successful uses of this approach already exist in the form of antifouling paint and coatings.

Nanotechnology application

The safe application of nanotechnology in drinking water pipes requires that no leaching of undesirable chemicals takes place. Pipe materials with no regrowth might moreover contribute to reducing particle accumulation and reports of discoloured water, which is caused by the interaction of particles with biofilms; this means that pipes will need to be flushed less frequently.

Opportunities and risks

In this project we mapped out the opportunities and risks associated with nanotechnology and metamaterials in general, and with their application in pipe materials in particular. Specifically, the research assessed and determined:

  1. the chances of using nanotechnology to reduce microbiological regrowth and resistance in pipes;
  2. the safety risks associated with nanomaterials coming into contact with drinking water;
  3. the implementation potential and recommendations for follow-up steps towards application, such as lab testing.