The technology group Wärtsilä and the shipping company Grimaldi Group have unveiled a new system that uses exhaust gas scrubber wash water to tackle the number of microplastics in the oceans.
Approximately 368 million tonnes of plastic were produced in 2019 worldwide, and around 3%, or 11.4 million tonnes, of this, ultimately ends up in the ocean, according to the association Plastic Europe.
To tackle the growing amount of microplastics in the world’s seas, Grimaldi has developed a system that filters out microplastics from open-loop scrubber wash water.
Wärtsilä, in partnership with the Neapolitan group, will take to market the microplastics filtration system, which traps plastic particles before the wash water is returned to the ocean.
The capability to filter microplastics will be an integrated feature of Wärtsilä’s future wash-water treatment system that requires very little changes to onboard procedure and uses the natural capabilities of an open-loop scrubber that contributes to cleaning the oceans during each voyage.
A 10-megawatt engine will require scrubbers to process approximately 450m3 of water per hour, potentially resulting in a large amount of microplastics being captured from seawater.
According to early test results, the microplastics filtration system is efficient in capturing particles smaller than 10 micrometres (µm) and the captured concentration by volume equals around 76 particles/m3.
“The idea for this innovative technology originated from recognising that open-loop exhaust gas cleaning systems can draw seawater for exhaust scrubbing and simultaneously collect microplastic present in the oceans as part of their normal operation,” explained Emanuele Grimaldi, managing director of the Grimaldi Group.
A pilot testing of this system has been already completed onboard one of Grimandi’s vessels, deployed between Civitavecchia in Italy and Barcelona in Spain. The results, according to Grimaldi, are promising, with 64,680 microplastic particles collected on a single voyage between these two ports.
