Recent research from the University of Ghent, Belgium, has demonstrated there is a large variability in micro plastics removal by water purification systems, which made it conclude that the Scheldt river contains a lot of micro plastics.
Plague of plastics
Plastic debris in the marine environment is more than an unsightly problem. Images of beach litter and large floating debris may first come to mind, but recent concern about plastic pollution focused on micro plastic particles, too small to be easily detected by eye, and likely the most numerically abundant items of plastic debris in the ocean today and increasing as large, single plastic items ultimately degrade into millions of micro plastic pieces. Micro plastics are of environmental concern because their size (millimeters or smaller) render them accessible to lower trophic organisms introducing them into the food web.
Research and river pollution
Recent research from the Ghent University in Belgium demonstrated there is a large variety in the removal of micro plastics by water purification systems. It seems that water treatment systems in Belgium are doing not as good as the ones in the neighbouring countries, removing only 45% of the micro plastics, compared to 90% in the Netherlands and even 97% in Germany. It is believed that rivers are significant contributors to the plastic pollution of the oceans due to their estuarine connection. Therefore, focus on rivers in order to assess ocean pollution matters.
Based on this research, the Ghent University concluded that the Scheldt river is a highly polluted freshwater ecosystem containing a lot of micro plastics. Similar research in Switzerland led to the same conclusion as to the Rhine river. As such, it can be said that rivers are the main source of marine litter pollution and appropriated steps are needed to also reduce the plastics in the seas (source: De Standaard).