Abstract: Biofilm on glass beads deposited within a bottom portion of a vertically elongated bioreactor housing for possible experimental evaluation through a testing port in the housing which is also provided with inlet ports for aeration and infeed of nutrients with liquid. The biofilm collected within the housing chamber undergoes growth on glass slides within a cross-sectionally rectangular portion of the bioreactor housing from which the slides may be upwardly withdrawn under selective control without biofilm damage. The bioreactor housing arrangement also provides a high length to width ratio designed to enhance aeration.

Abstract: Acoustical shock waves are generated by electrical sparks within a gap between electrodes adjustably positioned for exposure to water adjacent a surface immersed therein. High voltage electrical energy derived from a constant current power supply, is stored in a capacitor for rapid. application to the electrodes by discharge during cyclic periods of short duration under remote control in order to render the acoustical shock waves so generated effective in preventing biofouling of the surface by organisms in the water.