Progress in tailor-made of anti-fouling coating strategies for marine fish farming cages based on green synthesis of zinc oxide nanoparticles from Avicennia marina leaves

Abstract

The development of environmentally friendly paints has become a significant goal for researchers. In this study, zinc oxide nanoparticles were synthesized using a green method involving mangrove plants and evaluated as a paint additive to control marine fouling on fish farming cages. The size and characteristics of zinc oxide nanoparticles were evaluated using XRD, FTIR, and TEM analyses. The effectiveness of the nanoparticles was assessed through antibacterial and antialgal tests, as well as by examining their lethal effects on two species, Amphibalanus amphitrite and Artemia salina, in laboratory settings. The minimum inhibitory concentration (MIC) of zinc oxide nanoparticles against the bacteria Staphylococcus aureus and Escherichia coli was determined to be 6.25 and 25 mg/L, respectively, after 48 h. At a concentration of 800 mg/L, zinc oxide nanoparticles inhibited the growth rates of the algae Spirulina platensis, Dunaliella salina, and Chaetoceros muelleri by 90.88 %, 94.06 %, and 92.49 %, respectively, demonstrating their high potential as an effective inhibitor. An epoxy resin paint containing 2 %, 4 % or 8 % zinc oxide nanoparticles was used as an antifouling solution. The tests were conducted in a sea environment at depths of 1 m, 5 m and 10 m below the surface, with the samples left for 90 days to evaluate their performance over time. Increasing the concentration of zinc nanoparticles in the paint enhanced its the antifouling performance of the paint increases. By the end of the experiment, seven groups of organisms were identified: Ascidiacea (1 species), Polychaeta (1 species), Gastropoda (2 species), Globothalamea (1 species), Tubothalamea (1 species), Thecostraca (1 species), and Bivalva (9 species). At all three depths tested, the fewest species were found on the paint containing 8 % zinc oxide nanoparticles. Given their strong antifouling effectiveness, zinc oxide nanoparticles could be a promising solution for marine biofouling.