Common wisdom once held that UV ballast water treatment systems were simpler and better for smaller ballast water flows, while electrochlorination systems were more practical for larger flows. In recent years, however, there has been evidence of a shift in thinking. Today it is not uncommon for UV to be chosen in any flow range. A clear reason for this is the fact that even large-flow UV treatment systems can now be compact and cost-effective. Through larger UV reactor sizes and other advances, UV solutions such as Alfa Laval PureBallast 3 have put themselves on a highly competitive footing with electrochlorination.
With factors like footprint now largely equal among largeflow systems, others come into sharper focus. Today many ship owners are finding reason to re-examine the safety, complexity and cost issues associated with electrochlorination. This white paper provides a brief overview of those issues and their implications
UV treatment and electrochlorination have been the dominant technologies for ballast water treatment since long before the IMO Ballast Water Management Convention entered into force. UV treatment uses ultraviolet light to inactivate organisms as they pass through a reactor, whereas electrochlorination passes an electric current through saline water to produce oxidizing disinfectants. These disinfectants are active substances that inactivate the organisms in turn.
Both technologies are proven and simple in principle. However, electrochlorination involves a wide range of safety, logistical and cost considerations that UV treatment does not. As UV solutions continue to grow smaller and more cost-effective, these considerations are leading many to re-evaluate electrochlorination’s merits – even for large flows.