A study on treatment of microorganisms using underwater shock waves by gas imploding detonation

Abstract

Ballast water is used to stabilize an empty ship on the open sea. It often contains various microorganisms such as plankton and bacteria, and causes serious damage to aquatic ecosystems when it is discharged. Ultra-high pressure underwater shock waves were applied to treat those microorganisms. The imploding detonation of propane-oxygen mixture was used to generate the underwater shock waves in a sample holder having an inner diameter of 10.9 mm. We investigated the imploding detonation wave in approximately hemisphere-shaped combustion chamber having maximum inner diameter of 60 mm and generated underwater shock waves of 100 MPa. As microorganisms of the high pressure treatment experiments Artemia salina, Heterosigma akashiwo and Coliform group were used. We could completely treat Artemia salina and Coliform group by 5 shots and Heterosigma akashiwo by 1 shot of the underwater shock wave that maximum pressure was about 100 MPa. © 2013 The Japan Society of Mechanical Engineers.