Which of the following is NOT commonly cited as a ballast water treatment option?

• A. Filtration
• B. Ultra-Violet Light
• C. Ultrasound
• D. Hyperbaric Filtration

Answer: (D)

Ballast water treatment aims to prevent moving invasive aquatic organisms by either removing them or inactivating them before discharge. Filtration is a common approach because it physically removes many organisms as water passes through a filter. Ultraviolet light is another widely used method; UV radiation damages the genetic material of microorganisms, stopping their ability to reproduce. Ultrasound has been explored as a disinfection or anti-fouling technique in some studies and pilot systems, leveraging cavitation to disrupt cells, but it’s not as universally adopted as filtration or UV.

Hyperbaric filtration isn’t a standard or practical option for ballast water in most real-world applications. Pushing ballast water under high pressure would require bulky, energy-intensive equipment and poses design and safety challenges on ships, with limited proven effectiveness across the range of organisms ballast water may carry. That’s why it isn’t commonly cited as a ballast water treatment method.