Undoubtedly some of the greatest challenges of this century will revolve around the adequate provision of clean water. With an estimated 5.7 billion people living under the threat of water-scarcity by 2050,1 driven largely by increasing urbanisation, rapid population growth and climate change, it is essential that water sanitation infrastructure and services are adapted to ensure sustainability and resilience. This is of utmost importance in communities that have no or limited access to traditional means of water decontamination. Clearly, approaches that promote a localised circular water economy will be favoured, minimising financial and environmental costs.2,3
Indeed, the growing health concerns associated with chlorination by-products will likely lead to a major overhaul in existing water infrastructure and a shift towards approaches that avoid the formation of harmful chemical residues. Theoretically H2O2 would be an attractive alternative to chlorination, however in practice the use of toxic stabilizing agents to prolong shelf-life would prevent the application of commercially generated H2O2 in water treatment.
In this work we demonstrate that the generation of H2O2, through the combination of dilute streams of H2 and O2 over AuPd alloyed catalysts, and more importantly surface bound intermediate species such as OH and OOH, whose desorption are promoted by the presence of Au are able to achieve bactericidal and virucidal efficacy several orders of magnitude greater than that observed when using chlorination or commercial H2O2. Furthermore, the low levels of residual H2O2 generated via our in situ approach also offers the opportunity for prolonged disinfection and inhibits the formation of biofilms, which are at the core of many pathogens persistence and propagation.
While this technology is in its infancy, we are excited by its potential to revolutionise water disinfection and with a highly motivated, multi-disciplined team that involves chemists, microbiologist, surface scientists and microscopists in addition to process engineers and industrialists we are confident that future hurdles can be overcome.
Further details can be found at https://www.nature.com/articles/s41929-021-00642-w
- Climate Change and Water, United Nations Water Policy Brief available from https://www.unwater.org/publications/un-water-policy-brief-on-climate-change-and-water/
- Larsen, T.A., Hoffmann, S., Luthi, C., Truffer, B., & Maurer M., Emerging solutions to the water challenges of an urbanizing world. Science, 352, 928-933, (2016).
- Grant S.B. et al., Taking the “waste” out of “wastewater” for human water security and ecosystem sustainability. Science, 337, 681-686 (2012).