Can the IMO solve the microplastics problem?

Last week, two giants in international shipping?announced a novel plan?to tackle microplastics in the ocean. Finnish technology firm W?rtsil? will integrate into its new scrubbers a microplastics filtration system patented by Italian logistics company Grimaldi Group.

Scrubbers?are exhaust gas cleaning systems for ships. They remove dangerous particles – mostly sulphur oxides – from the exhaust gas of vessels using a mix of seawater or alkaline water and chemicals. Demand for scrubbers exploded after the International Maritime Organization (IMO) announced its plan to cap the amount of sulphur oxides ships can release. This “sulphur cap” went into effect on Jan. 1, 2020.??

Scrubbers are a popular way to meet the sulphur cap because they are less expensive than other options, such as converting to low-sulphur fuel or LNG. They also are fairly easy to retrofit onto existing ships – an important point as most container ships have a lifespan of 30-50 years.?

But scrubbers have?faced some pushback?from environmental activists because while they improve air quality, they make water quality worse. Once the exhaust has been “scrubbed” of sulphur, the wastewater – which now contains sulfuric acid among other pollutants – is discharged into the sea.?

While the addition of this new system doesn’t solve that problem, it does offer the possibility for scrubbers to be used to tackle a different environmental challenge. Before the wastewater is discharged, it will be put through a filter that captures microparticles. These microparticles can then be disposed of properly when the ship reaches port. Grimaldi Group reported the system captured nearly 65,000 microplastic particles during a test run on the relatively short trip between Civitavecchia and Barcelona.

The problem of microplastics is a serious one. Scientists estimate that?more than 5 trillion?of these particles are in the world’s oceans. And as they become part of the marine ecosystem, they make their way into humans. Microplastics have been found in?seafood, beer, and sea salt.

The IMO is aware of the issue. Since 2010, the organization has regularly released press reports on the dangers of microplastics, citing studies from?GESAMP, the UN agency that monitors ocean pollution. And at the?IMO 73rd Marine Environment Protection Committee?meeting, held in 2018, a resolution was adopted that contains 30 action points on the reduction of plastic litter from ships. But 85% of all plastic in the ocean?comes from land-based sources. So, while this move is admirable, it isn’t especially effective.?

In January 2021, just over a year after the sulphur cap went into effect, a?survey from the Maritime Port Authority of Singapore?revealed that over 96% of ships arriving at the port in the first quarter of 2020 were in compliance with the new rule. According to the IMO, the sulphur cap resulted in a?70% decrease?in sulphur emissions from ships in 2020. The results of the sulphur cap have encouraged the organization to move forward with other programs to reduce the environmental impact of the shipping industry, including research into alternative fuels and energy-efficient ship design.?

The success of the IMO’s emission-reduction efforts demonstrates what could be possible if the organization made tackling plastic pollution a priority.?An IMO requirement for ships to take steps toward removing microplastics could expand the use of the kind of filtration system developed by W?rtsil? and Grimaldi and act as a catalyst for developing other solutions.