An exopolysaccharide substances produced by Vibrio neocaledonicus sp. was introduced as a novel green inhibitor against the corrosion of carbon steel in artificial seawater and acidic media. The produced extracellular...An exopolysaccharide substances produced by Vibrio neocaledonicus sp. was introduced as a novel green inhibitor against the corrosion of carbon steel in artificial seawater and acidic media. The produced extracellular polymeric substance（EPS） is heterogeneous with composition of polysaccharides, nucleic acids and protein and average molecular weight of 29,572 Da. Adsorption of EPS on the metal surfaces and formation of Fe-EPS complexes acted as a barrier to prevent the oxygen penetration and hindered anodic and cathodic reactions. The inhibitory effect increases with increasing EPS concentration and exposure time. The highest corrosion inhibitory effect（95.1%） was observed for 10 g/L of EPS after 5 days of exposure in seawater. This is the highest inhibitory effect ever been reported by EPSs. While, the optimum concentration of EPS with the highest inhibition efficiency in 1 N H;SO;was 1000 ppm. The influence of different parameters, such as initial pH, growth phase, various nitrogen and carbon sources on the production of EPS and its corrosion inhibitory effect were also investigated. According to results,the optimum culture medium for EPS production is contained artificial seawater including 5% mannitol as carbon source and 0.1%（NH;）;SO;as nitrogen source at pH = 8. This medium could produce 22.24 g/L EPS during 3 days’ incubation at 30 ℃. The corrosion inhibitory efficiency of obtained EPS was 95.97%.展开更多
基金financially supported by the National Natural Science Foundation of China(No.5161101078)CAS President’s International Fellowship Initiative(PIFI)(No.Y60708WP08)+1 种基金the Public welfare project of Zhejiang Province(No.2015C31031)the Natural Science Foundation of Ningbo,China(No.2015A610070)
文摘An exopolysaccharide substances produced by Vibrio neocaledonicus sp. was introduced as a novel green inhibitor against the corrosion of carbon steel in artificial seawater and acidic media. The produced extracellular polymeric substance（EPS） is heterogeneous with composition of polysaccharides, nucleic acids and protein and average molecular weight of 29,572 Da. Adsorption of EPS on the metal surfaces and formation of Fe-EPS complexes acted as a barrier to prevent the oxygen penetration and hindered anodic and cathodic reactions. The inhibitory effect increases with increasing EPS concentration and exposure time. The highest corrosion inhibitory effect（95.1%） was observed for 10 g/L of EPS after 5 days of exposure in seawater. This is the highest inhibitory effect ever been reported by EPSs. While, the optimum concentration of EPS with the highest inhibition efficiency in 1 N H;SO;was 1000 ppm. The influence of different parameters, such as initial pH, growth phase, various nitrogen and carbon sources on the production of EPS and its corrosion inhibitory effect were also investigated. According to results,the optimum culture medium for EPS production is contained artificial seawater including 5% mannitol as carbon source and 0.1%（NH;）;SO;as nitrogen source at pH = 8. This medium could produce 22.24 g/L EPS during 3 days’ incubation at 30 ℃. The corrosion inhibitory efficiency of obtained EPS was 95.97%.
