The RepescaPlas project has ended its third year with a total of 4 218 kg of marine litter recovered from the ports of Marín (Galicia), La Restinga (El Hierro) and Gandia (Valencia) in Spain by fishermen’s guilds and associations.
As in previous years, the ports used the MARNOBA platform to classify recovered items by marine litter class. Samples of the most abundant type, i.e. plastics, were sent to AIMPLAS and the Universidade de Vigo. The first to categorise by materials' nature, to gain more knowledge about the plastics, and the latter for toxicological analysis. Boats delivering most marine litter to the port took monitored routes to allow Asociación Vertidos Cero (Zero Waste Association) to draw up a map of the litter recovery areas and establish the litter density (items/km2).
AIMPLAS' samples, mostly PET and low-density polyethene, have helped the institute progress towards developing technologies to recover these materials and convert them into new resources. Despite their extreme damage from exposure to the marine environment and the difficulty of reintroducing them into the value chain through mechanical recycling. To that end, AIMPLAS used optical sorting equipment to classify the items before they undergo a pyrolysis process. The process resulted in a solid fraction suitable for the synthesis of activated carbon or lampblack and a liquid fraction whose composition allowed it to be recovered as a fuel and thus used on the fishing vessels themselves. This pyrolysis liquid can be subjected to different chemical processes to obtain monomers of particular interest to the plastics industry.
Meanwhile, the Universidade de Vigo carried out a toxicological analysis. Two versions of the same product, one new and one recovered from the sea, were compared. The results did not detect toxicity levels for any of the marine organisms that usually come into contact with this waste.
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