Conventional water treatment processes are very well suited to remove particles. However, the smaller particles get (micro- and nanometre sized), the harder they are to remove. Still a significant part ends up in effluent and eventually in the environment. Not only the chemical composition (e.g. plastic particles) but also the size cause these particles to be unwanted in the environment. Their small size allows uptake and accumulation in aquatic life, and eventually poses a risk to human health. New technologies are urgently required to address the problem of nanoparticles and to effectively remove them from water.
The main challenge in removing nanoparticles stems from their small and varied size, and (chemical) material properties. Where the larger sized nanoparticles can still be removed through flocculation, the smallest nanoparticles would require technologies such as adsorption or membrane technology. While combining various technologies is a possibility, it would add significant extra costs to existing water treatment processes. It would be much more efficient to achieve an enhanced coagulation of the smallest nanoparticles, to bring them into a size range where easy removal becomes possible.
This theme focuses on a more sustainable approach in conventional water treatment techniques, such as coagulation/flocculation, for removal of nanoparticles. We will develop enhanced coagulation approaches to aggregate especially the smallest fraction of nanoparticles, thereby allowing their effective removal through standard flocculation and floatation approaches. Additives based on charged polymers and/or particles will be selected and/or developed to maximize the destabilization of nanoparticles, while these additives should themselves be biodegradable and completely non-toxic.