Sonication of bacteria, phytoplankton and zooplankton: Application to treatment of ballast water.
We investigated the effect of high power ultrasound, at a frequency of 19 kHz, on the survival of bacteria, phytoplankton and zooplankton, in order to obtain estimates of effective exposure times and energy densities that could be applied to design of ultrasonic treatment systems for ballast water. Efficacy of ultrasonic treatment varied with the size of the test organism. Zooplankton required only 3-9s of exposure time and 6-19 J/mL of ultrasonic energy to realize a 90% reduction in survival. In contrast, decimal reduction times for bacteria and phytoplankton ranged from 1 to 22 min, and decimal reduction energy densities from 31 to 1240 J/mL. Our results suggest that stand-alone ultrasonic treatment systems for ballast water, operating at 19-20 kHz, may be effective for planktonic organisms >100 microm in size, but smaller planktonic organisms such as phytoplankton and bacteria will require treatment by an additional or alternative system.
Holm
Eric R
ER
Non-Metallic Materials Research and Engineering Branch, Code 617, Naval Surface Warfare Center, Carderock Division, 9500 MacArthur Boulevard, West Bethesda, MD 20817, USA. eric.holm@navy.mil
Stamper
David M
DM
Brizzolara
Robert A
RA
Barnes
Laurie
L
Deamer
Nora
N
Burkholder
Joann M
JM
D000818:Animals; D001419:Bacteria; D010839:Phytoplankton / Q000502:physiology*; D012767:Ships; D013010:Sonication; D015048:Zooplankton / Q000502:physiology*