Antifouling with Chloride Ion Electrolytic Recycling through a Momentum Boundary Layer

Abstract

AbstractSeaLite Engineering, after a 10-yr research and development program, has produced an operational antifouling system for ocean sensors and instruments designed for low power consumption and long (>1 yr) deployments. The important innovation is the replacement of pumps by gravity and external motion to significantly reduce energy consumption. Also, a prototype system for autonomous underwater vehicle control surfaces is now undergoing laboratory testing. The effectiveness of SeaLite’s technology has been demonstrated year-round in northern estuaries and in the Gulf of Mexico, the latter by an independent agency. The process leading to this result was, first starting in 2010, an extensive laboratory evaluation of electrode alloys, calibration of chlorine production versus electric power input, and the location for attaching electrodes to various objects requiring protection from fouling. After 2015 the experimentation moved to the ocean, first in a Cape Cod estuary and then to the Gulf of Mexico. Comparisons with a mechanical antifouling system were done in situ, and with a UV antifouling system from AML Oceanographic, Ltd., by comparing the data. Starting in 2019, the development of biofilms, from their initial deposition through the extra polysaccharide substance stage, were experimentally investigated by taking samples from an estuary near SeaLite’s laboratory. Biofilms on microscope slides and water column samples were collected. This was done in different seasons, from spring bloom, summer doldrums, autumn temperature decline, and the winter freeze. The objective was to determine the level of biofilm growth that would require antifouling, and its’ seasonal, temperature, and solar radiation dependence, and thus to conserve power.