Characterization of Wastewater from Ship’s Hull Cleaning by Hyrdoblasting

Abstract

During periodic haul-out maintenance of ship, high-pressure water is sprayed to clear off foulants and antifouling paint on the ship’s hull. The sprayed water can be contaminated with particles and active substances released from the paints, and then introduced directly into the adjacent marine environment, if no further treatment of the waste was implemented. The particles and active substances can be sources of hazards to marine organisms in the environment. Wastewaters were collected for analyses of booster biocides and metals during ships’ hull cleanings. Total suspended solid and particle size distribution in the wastewater were also characterized. Copper and zinc were the most abundant metals in the wastewater, as were in the original composition of antifouling paint, exceeding local regulatory discharge standards and NOEC or LC50 values of almost all test species reported in the ECOTOX database. Zinc pyrithione and copper pyrithione were the most abundant booster biocides, exceeding the LC50s of 35