Lucas Manuelli with Rodolfo Perez and Professor Daniel Noguera

UW-Madison Department of Civil and Environmental Engineering

Biofouling, or the undesired adhesion of aquatic organisms to underwater surfaces, is a major problem for any artificial structure immersed in water. In particular, biofouling of ship hulls poses serious challenges to navigation, by causing dramatic decreases in fuel efficiency, shortening the hull’s lifetime, and enhancing the spread of aquatic invasive species (such as zebra mussels).  Current methods aimed at reducing biofouling employ coating a ship’s hull with toxic paints. These paints wear off as the ship moves through the water and release chemicals that are harmful to other non-targeted organisms. Our goal is to develop an alternative method of combating biofouling by employing a combination of special coatings capable of deliver low-voltage electric pulses.

Various different types of slides were immersed in a water reservoir connected to Lake Mendota for 8 days. We tested several different combinations of coating and pulse types. The slides were then analyzed for fouling using light microscopy, and later stained with a DNA-fluorescent dye for their observation under ultraviolet light. Results were varied, but generally indicated that very low currents were ineffective against biofouling, while relatively high currents (within the range tested) produced precipitation of calcium onto the slides. Slides treated with an intermediate current setting showed improvement in resistance to biofouling over controls. Thus it seems promising that a treatment involving low voltage electrodes may be feasible.