Mitsui O.S.K. Lines (MOL) and Miura July 5 announced the development of a new centrifugal-type microplastic (MP) collection device, which can continuously collect MPs while a vessel is underway, by leveraging their technology and knowledge of an earlier MP collection device they co-developed. The new device was installed on the MOL-operated car carrier EMERALD ACE last month for a demonstration test.
With the aim of collecting MPs, which are a source of ocean pollution, MOL and Miura have developed a collection device that captures MPs collected and trapped in a filter with a backwashing function, which constitutes the ballast water treatment system, and installed it on a total of five vessels-three bulk carriers and two wood chip carriers.
While these vessels were at unloading ports, the systems treated a total of about 16,000m3 of seawater. The development of this new model was intended to further increase treatment times, area, and capacity.
The addition of a centrifuge allows the device to efficiently separate floating MPs from concentrated seawater with a high density of floating debris, without closed plumbing. This enables it to treat sea water line, which continually draws in seawater, and even treat the full amount of discharge water after passing through the filter with the backwashing function of the ballast water treatment system, which was limited to a part of treatment in the previous device.
On EMERALD ACE, MPs can be continuously collected while sailing, by connecting the system to the cooling seawater line, which always draws in seawater. This gives the system an annual seawater treatment capacity about 70 times that of the previous device. As car carriers operate all over the world (lower right figure), the vessel contributes to the conservation of the marine environment by cleaning all sea areas while operating this device.
Today, demand for data regarding the amount of floating microplastics in seawater is growing among research institutes, as this data can be applied to research on MP movement and measurement of the effects of various approaches to MP reduction. MOL takes into consideration data such as components, amounts, places, and periods of MPs collected with the device for future research.
Miura is moving ahead with development of the product, which has a larger treatment capacity, and a full treatment system for ballast discharge water by combining a ballast water treatment system and MP collection device and cooling seawater.
Photo credit: iStock/ pcess609