The authors investigated the leaching rate of antifouling agents from marine paint using an instrument that allows direct measurement from the flat bottom of ship hulls shortly after dry dock. A similar procedure was ...The authors investigated the leaching rate of antifouling agents from marine paint using an instrument that allows direct measurement from the flat bottom of ship hulls shortly after dry dock. A similar procedure was also used for painted flat panels that were immersed in the ocean. The relationship between leaching rate and fouling condition was considered by quantifying the amount of ATP （adenosine triphosphate） on the surface of immersed flat panel using fluorescence spectroscopy. The leaching rate results from ship hulls showed good agreement with the value by reporting of leaching rate of antifouling agents. The fluorescence spectroscopy results showed that the amount of ATP on the surface of the panel increased over time as the leaching rate fell, which implies an inverse relationship between leaching rate and fouling index. Fluorescence spectroscopy was also seen to be a simple method for evaluating the relationship between biofouling indexes and leaching rate.展开更多
The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, ...The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.展开更多
Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as ...Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that Sea Nine 211 is actually not degraded equally fast around the world（half-life between〈 1 day and 13.1 days）. Large-scale application of Sea Nine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of Sea Nine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. Considering that Sea Nine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by Sea Nine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population stability.Therefore, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, Sea Nine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of Sea Nine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.展开更多
文摘The authors investigated the leaching rate of antifouling agents from marine paint using an instrument that allows direct measurement from the flat bottom of ship hulls shortly after dry dock. A similar procedure was also used for painted flat panels that were immersed in the ocean. The relationship between leaching rate and fouling condition was considered by quantifying the amount of ATP （adenosine triphosphate） on the surface of immersed flat panel using fluorescence spectroscopy. The leaching rate results from ship hulls showed good agreement with the value by reporting of leaching rate of antifouling agents. The fluorescence spectroscopy results showed that the amount of ATP on the surface of the panel increased over time as the leaching rate fell, which implies an inverse relationship between leaching rate and fouling index. Fluorescence spectroscopy was also seen to be a simple method for evaluating the relationship between biofouling indexes and leaching rate.
文摘The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.
文摘Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that Sea Nine 211 is actually not degraded equally fast around the world（half-life between〈 1 day and 13.1 days）. Large-scale application of Sea Nine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of Sea Nine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. Considering that Sea Nine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by Sea Nine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population stability.Therefore, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, Sea Nine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of Sea Nine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.
