Electrochemical disinfection for ballast water management: Technology development and risk assessment

► A cost-effective electro-chlorination ballast water treatment system was developed. ► To meet the IMO standard, the energy consumption is as low as 0.006 kWh/m3. ► The discharged ballast water treated showed no negative effect to marine organism. ► The treated ballast water discharge didn’t enhance corrosion on the ship. Ballast water is essential in maintaining the balance and structural integrity of ships during voyage. However, it has created biological invasion threats to the ocean environment. An innovative electrochemical technology was developed in this study. The microorganisms regulated by the International Maritime Organization (D2) were used as the target organisms. It was found that the required energy to meet the D2 was below 0.006kWh/m3. The size of disinfector (m3) was about 0.5% of treatment flow rate (m3/h). The complete disappearance of chlorine in seawater was achieved after three days. The ballast tank corrosion was not worsened due to the application of technology. The ecotoxicity studies showed no toxic effect on fish, invertebrate, and algae. Finally, the environmental risk assessment showed the treated water did not pose threats to the environment. It can therefore be concluded that the technology provides a cost-effective and environmental friendly solution to ballast water management.