‘This discovery also shows that nature is leading the way, pointing to solutions to what is a very significant problem…’
Researchers from Trinity College, Dublin, and University College Dublin, Ireland, have found that tap water produces a natural protective shield against microplastics, which can help prevent household objects, such as kettles, from releasing them. The research, which has been published in the Chemical Engineering Journal, indicates that tap water’s trace elements and minerals prevent plastics from degrading in water and therefore releasing microplastics.
The researchers noted that previous studies investigating microplastics release involved the use of deionised water, used mainly in laboratory settings, and did not account for the ions and impurities found in tap water. The researchers found that in contrast to deionised water, plastics exposed to hot (40 degrees centigrade to 100 degrees centigrade) local tap drinking water, showed the progressive development of a Copper (II) oxide passivation film, due to the presence of Cu2+ ions in the water samples.
Further studies showed that polypropylene kettles exposed to boiling tap drinking water during normal use resulted in the continuous growth of copper (II) oxide passivation films, ultimately yielding a 99.8% reduction in the release of microplastics.
Professor John Boland, Professor of Chemistry, SFI Research Centre for Advanced Materials and BioEngineering Research, Trinity College, and co-leader of the research team commented; ‘What we showed is that if you include trace elements and minerals, the degradation of plastics in tap water is completely different…The minerals coat the plastic and prevent any kind of degradation and so the product becomes microplastics free.’
Professor Boland added: ‘This discovery is important, because we have learned that these types of protective skins can be manufactured in the laboratory and directly applied to the plastic without having to wait for it to build up naturally. This discovery also shows that nature is leading the way, pointing to solutions to what is a very significant problem facing our modern high-tech society.’
DOI: 10.1016/j.cej.2021.132466