2169-2174<span style="font-size:9.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;mso-bidi-font-family:="" "times="" roman";background:white;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">Ultrasonic technique is one of the promising
non-invasive technologies to control biofilm formation on the marine
substratum. A prototype ultrasonic
system was designed and developed to control biofouling in the marine
environment. The Ultrasonic technique was utilized to control the biofilm
formation on copper test coupons suspended in a continuous seawater flow
through system. The colonization of microorganisms promotes settlement of higher
order organisms; therefore, deactivation of microorganisms is likely to affect
the fouling density. <span style="font-size:9.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">Ultrasonic sound waves at 25 kHz with an
electric drive power of 500 watts were used to control aquatic biofouling and
growth in an open seawater circulation experimental setup. The ultrasonic waves
create microscopic cavitations which damages the outer cell structure of
microorganisms destroying them and preventing them from growing around the
ultrasound exposure areas.<span style="font-size:9.0pt;
line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;="" mso-bidi-font-family:"times="" roman";background:white;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> The experiments were
conducted continuously over a period of 21 days and were repeated several times
to ensure reliability. A reduction in the microorganism activation was observed
on the ultrasound exposed area besides preventing damages to the structure of
the test coupon. Based on the encouraging results, a low cost prototype
ultrasonic digital system controlled by pre-programmed microchips was custom
built and the same is being planned for further studies in the frequency range
20 – 40 kHz. </span