Delta Life 11

2011 Study by Deltares and VU-University of the presence of plastics/microplastics in the North Sea. 2012 Deltares and VU-Univer­ sity conduct a study as part of a European project looking at toxic substances and the spread of microplastics. 2014 Exploratory monitoring of microplastics in rivers to improve transport models. 2015 The Ocean Cleanup tests floating plastic traps in the Deltares flumes. 2015 Participation in Clean­ Sea: integrated European study of plastics in the food chain and ecological modelling. 2016 Continuation of model testing with The Ocean Cleanup. 2016 Study of the removal frommicroplastics in sewage treatment plants. 2017 The Great Bubble Barrier tests a bubble screen in the Deltares flumes. The bubble barrier was tested late last year in the IJssel river. 2018 Capturing plastics with a scoop wheel in flood defences was tested in a Deltares basin. 2018 Deltares models the spread of plastic particles from car tyres with software. 2019 The Ocean Cleanup conducts model tests again at Deltares. 26 DELTARES, MARCH 2019 plastic pollution ends up where. If we combine these insights with our understanding of microbiology, a model of this kind makes a valuable contribution to learning more about how plastics contribute to the spread of disease. This is exceptionally useful information, especially in the context of river flooding in urban areas. The international scope Several studies have shown that Asia is a major producer of plastic pollution. Eighty percent of the plastic floating in the oceans comes from this region. Which is why Deltares, in collaboration with the National University of Singapore (NUS), wants to investigate the ecological impact of plastics on the marine environment of Southeast Asia. Plastics for one-off use are also banned in Singapore , and Bali imposed a similar ban in late 2018. Indonesia has now also told Deltares, among others, that it wants to know how much plastic from the big cities ends up in rivers and coasts. The hope is, of course, that more Asian countries will follow. Not only do we need to cut back plastics worldwide as much as possible, we also need to pull out all the stops to clear up the plastics in our environment now. For example, in the coming years, we will be working on modelling the transport of macro- and microplastics in rivers and waterways. We teamed up with Delft University of Technology in late 2018 on a project proposal for 'plastic-free rivers'. To clear up plastic intelligently, we need to know where it is in the water system. The models will help government authorities and managers to prevent the further spread of, in particular, larger plastic waste. In recent years, Deltares has supported three initiatives for studies of how to capture plastics in rivers and lakes. We have conducted tests in our research facilities to see whether these 'plastic traps' actually work. And we have had a plastic soup floating in one of the installations at our Utrecht environmental laboratory Castel for five years now. This more fundamental research shows that plastic does not disintegrate as quickly as was initially thought. That is good news. It means there is still time to prevent micro­ plastics forming in the future. Staring down the many- headed monster It is clear that plastic pollution is a stubborn worldwide problemwith many facets. There are still a lot of gaps in our knowledge about contamination with micro- and nanoplastics and the possible impact on our ecosystems and our health. This should be a focus area in the years to come. More information: dick.vethaak@deltares.nl DELTARES & PLASTICS RESEARCH: AN OVERVIEW PHOTO: THE OCEAN CLEANUP