Ballast water is used by cargo ships to help stabilize the ship and help maneuverability during long voyages. Generally, ships intake ballast water while in port, and release it once they’ve reached the destination. During this process, the sediment and everything else in the water is released into the port along with it. We now know that this is a very common pathway for aquatic invasive species to spread across the globe and establish themselves in new habitats. The introduced species can range from microscopic zooplankton to animals like crabs and mussels, all of which can have negative impacts in new habitats. Because of the danger posed by ballast water transfer around the globe, various treatments are being developed to prevent the introduction of invasive species. The International Marine Organization (IMO) has headed the regulation of ballast water issues and treatments since 2004, and currently approves 30 different treatment methods being used and developed across the world (Kim and Lee, 2009). Unfortunately, the best combination of ballast water treatment methods is still yet to be found. This is a problem that Andre May hopes to solve.
Having an interest in civil engineering and shipbuilding, May also has an interest in the ballast water issue. He felt that there is a knowledge gap as far as economic and energy efficiencies are concerned. May says that as far as what has currently been looked at, “Cost was more on consumer side, not manufacturer’s side”, and he hopes to delineate the latter half. In his proposed study, May will look at the following criteria for ballast water treatment: “the method’s cost and effectiveness, ease of installation and operation, health and environmental risks, corrosive potential (to the ballast tank’s walls), and ease of monitoring and regulation.” In particular, May will focus on three of the most auspicious treatment combinations supported by the IMO. They are filtration and water heating, electrochemical treatment and water heating, and filtration and UV radiation. By measuring the energy usage per amount of invasive species removed in laboratory conditions, May will determine the best combination for use after subsequent analysis and comparison of economic and mechanical efficiency.
Ultimately, May hopes that the proposed experiment will shed light on the most useful and practical ballast water treatment combinations. While his study will illuminate the cost-benefits of three treatment combinations, there are still many more that can be researched. However, the results of his study should give future research a strong direction, regardless of the outcome. When asked how realistic he thought implementing the best combination or combinations for ballast water treatment globally would be, he replied, “Each region has to tailor a product. It’s not something that can be mass produced easily. Different countries use the same equipment, same combinations, but don’t get the same efficiency. It depends on the environment, Arctic versus Mediterranean, etc., and geographic location for the efficiency.” Personally, his method of choice is filtration. There are few risks to consider, and there is a higher level of control in screening for invasive species. However, May also advocated for water heating as a potential treatment. He thinks that the water used to cool the engines can be recycled for use in ballast water treatment. Finally, when asked about the future of ballast water treatment and privatization versus nationalization, he supported nationalization, because in his mind it is more efficient. But those are debates for the future, and we look forward to the results of his study to lead ballast water treatment on.
Reference: Kim EC and Lee KP. 2009. Development of ballast water treatment system based on electrochemical disinfection technology. Oceans-Europe. 2009: 1-8.