Ballast water treatment by ozone nanobubbles

BACKGROUND The uncontrolled discharge of untreated ballast water, which is essential for a ship's optimal operation, one the major causes sea environmental pollution by shipping. Among disinfection methods available water treatment, ozonation commonly used method, but its performance limited rapid ozone auto-decomposition rate. Nanobubbles (NBs) technology has attracted much scientific interest as it characterized long residence time in aqueous phase and high surface area; therefore, nanobubbles (OzNBs) are expected to enhance capacity residual activity. present study was designed provide further insight into inactivation heterotrophic bacteria saline examine use OzNBs water. RESULTS survival rate Escherichia coli (E. coli), indicator microorganism, along with consumption at different salinities (1.5, 4, 8 15 PSU) bacterial concentrations (107, 106, 105 CFU mL−1) without supplementation were investigated. results indicated statistical difference concentration total oxidants (TRO) presence salinity level 1.5 PSU 4 only lowest content. At low concentration, TRO 6-fold higher OzNBs. CONCLUSION strong impact on ozone. When increased, reacts more rapidly bromide chloride ions. exhibited greater © 2023 Authors. Journal Chemical Technology Biotechnology published John Wiley & Sons Ltd behalf Society Industry (SCI).