Acid cleaning solutions for barnacle-covered surfaces

In this preliminary study dealing with acid cleaning solutions for barnacle-covered immersed surfaces, chemical treatments for the removal of calcium carbonate residues were investigated. They are based on acid mixtures that dissolve calcium carbonate, leaving the residual bioadhesive. The two most efficient acid treatments are a solution of 50 vol% hydrochloric acid in water, and a mixture of water, hydrochloric and formic acids and hydrogen peroxide. The barnacle dissolution amount (normalized mass) and rate (normalized mass per unit time) in both solutions were compared, and the results showed that both treatments dissolved most of the barnacles in <2 min at room temperature. The effects of acid depletion, of barnacle/solution mass ratio and of the temperature have also been measured.