Ship Scrubbers: A Solution to Air Pollution or a New Environmental Problem?

by | Aug 15, 2023 | Editorial

FGN continuously monitors changes in regulations that may impact our customers and service offerings. The International Maritime Organization’s (IMO) adoption of a 2016 regulation aimed at reducing emissions is one that has had lasting effects on shipping costs.

The growing concern about the environmental impacts of shipping was the main reason for this regulation enactment. Many claim that ocean vessels are a major source of air pollution, emitting harmful pollutants that contribute to many chronic illnesses like respiratory problems, heart disease, and cancer.

The International Maritime Organization (IMO) adopted a regulation in 2016 that requires ships to either use low-sulfur fuel or install exhaust cleaning systems (scrubbers) by 2020. The decision resulted in increased freight rates as steamship lines looked to off-set the additional costs. Low-sulfur fuel is expensive, so many steamship companies opted to use scrubbers to reduce the expense; scrubbers are devices that remove sulfur dioxide from ship exhaust.

While scrubbers help reduce air pollution, they can have a negative environmental impact on marine life. Scrubbers operate by spraying water (seawater or fresh) mixed with a caustic chemical into the gas stream. After “scrubbing” the sulfur dioxide from the exhaust, the wastewater is often released back into the ocean. This wastewater contains a variety of pollutants, including metals, organic compounds, and biocides which harm marine life and contaminate oceanic waters.

A recent study by the International Council on Clean Transportation (ICCT) found that scrubber wastewater is a significant source of pollution in port waters, and that discharges from scrubbers can contain up to 100 times more copper and zinc than untreated ship exhaust. These metals can accumulate in the sediment of port waters, where they can be harmful to coastal water environments.

The ICCT study also found that scrubber wastewater contains organic compounds that disrupt the endocrine system of fish and other marine animals.

There are plenty of reasons for the environmental impact of scrubber wastewater to be a serious concern. As more research is conducted to understand the full extent of the problem, it is important to ensure a contingency plan is put in place.

Here are a few short-or-long term solutions that can be implemented to reduce the environmental impact of scrubber wastewater:

  • Treat scrubber wastewater to remove pollutants. There are a number of technologies that can be used to treat scrubber wastewater, including chemical precipitation, ion exchange, and activated carbon adsorption.
  • Reduce the use of biocides in scrubber paints. Biocides are used in scrubber paints to prevent the growth of algae and barnacles. However, these biocides can also be harmful to marine life. 
  • Switch to low-sulfur fuel. While this option is more expensive, it helps protect our environments and lessen the pollutants in our air and oceans.

The use of scrubbers is a complex issue with both environmental and economic impacts. At FGN, we continue to look for ways to maximize the value to our customers and hope the IMO will be more diligent in future decisions involving ship pollution and real impact on all the parties involved, including the environment.

Written by Juli Herndon

August 15, 2023