Using electric pulses to treat ballast water The introduction of invasive marine microorganisms by ballast water is a growing problem that has prompted researchers to develop a new water treatment unit. Industrial Technologies © Thinkstock Invasive marine organisms have a major global economic impact, with an estimated cost of USD 500 billion annually. Due to the increasing introduction of invasive species through ballast water, new regulations require more stringent treatment processes. The EU funded the ECOSEASAFE project to develop a ballast water treatment system that uses electrical pulses. The system is environmentally friendly, easy to use and cost effective. A shaped electrical pulse with an instant reversal of pulse direction is key to how the system works. This approach kills microorganisms in the water without the introduction of unstable chemicals such as free chlorine. Researchers developed necessary hardware and software for the system in the laboratory after testing various electrodes and metal alloys. They were able to obtain good inactivation of bacteria without generating any detectable free chlorine. A scaled-up device was built that included a user interface and data logging capabilities. It was tested at a ballast water treatment test site and, over a month of operation, it functioned according to international regulatory guidelines. ECOSEASAFE has thus developed a cost-effective and safe system for ballast water treatment. It is expected to take a sizeable market share over the next few years.
