ANTIFOULING STUDY OF ZINC TANNATE (TZn) FOR MILD STEEL IN TROPICAL SEAWATER

Abstract

This study was coordinated to investigate the potential of tannin extracted from mangrove bark (Rhizophora apiculata sp.) as an antifouling agent. Using natural resources as antifouling agents is an environmentally friendly alternative in industrial applications. Extracted tannin was formulated in a readily available epoxy coating and then coated on the mild steel samples. The samples were immersed in seawater for 60 days in Chendering Port and Marang Jetty. A screening test was performed via the anti-biofilm assay method to characterise the antimicrobial abilities. The IC50 of zinc tannate extract against Bacillus Cereus and Salmonella sp was 2.6 mg/ml and 28.75 mg/ml, respectively.  It was discovered that fouling attachment is more noticeable in Chendering Port due to the physical parameters of the surrounding waters. Furthermore, the percentage of the weight acquired at Chendering port is higher than at Marang jetty. Surface inspection using digital photographs and scanning electron microscopy (SEM) reveals a denser tubeworm and mollusc attachment on the substrate without TZn. Higher tannin concentration has resulted in greater antifouling potential. Overall, the findings implicate that TZn has great potential as an antifouling additive in commercial marine coating.