Samenvatting

Plastic pollution of rivers, seas, and oceans is currently one of the most pressing environmental issues. The litter traps constructed by CLEAR RIVERS provide a way to clean the rivers of litter by utilising winds and currents. CLEAR RIVERS wants to know how to improve the effectiveness of current litter traps. The methods used to find ways to improve the effectiveness of the litter traps are visual observation, weighing of litter, desk research, interviews, and experimental research.

This study has found that the litter trap of CLEAR RIVERS at the Coolhaven is able to catch around 11% of the litter in the targeted waterbody. The effectiveness of litter traps can be improved by choosing the best locations. The caught amount of litter is mostly impacted by the amount of litter in the targeted water body, the currents, and winds. Challenges with the current litter traps identified by experts are small plastic pieces cannot be retrieved during emptying, sticks and organic material occasionally block the plastic from entering the litter traps, it is straining to remove the organic material that is blocking the litter trap, and the litter traps alter the currents due to their resistance.
CLEAR RIVERS’ screens often cannot be used over the whole width of rivers or canals due to shipping lanes. This study found that using an engine on the opposite side of the water to create a waterflow and move plastic towards the litter traps can improve the effectiveness of the litter traps. The effect of using two of the engines to support litter traps at the Parksluizen would increase the expected caught percentage of the total plastic by 62% (from 22% to 84%).