Background

Cathodic protection by sacrificial anodes composed of aluminum-zinc-indium alloys is often applied to protect offshore support structures of wind turbines from corrosion. Given the considerable growth of renewable energies and thus offshore wind farms in Germany over the last decade, increasing levels of aluminum, indium and zinc are released to the marine environment. Although these metals are ecotoxicologically well-studied, data regarding their impact on marine organisms, especially sediment-dwelling species, as well as possible ecotoxicological effects of galvanic anodes are scarce. To investigate possible ecotoxicological effects to the marine environment, the diatom Phaedactylum tricornutum, the bacterium Aliivibrio fischeri and the amphipod Corophium volutator were exposed to dissolved galvanic anodes and solutions of aluminum and zinc, respectively, in standardized laboratory tests using natural seawater. In addition to acute toxicological effects, the uptake of these elements by C. volutator was investigated.

Results

The investigated anode material caused no acute toxicity to the tested bacteria and only weak but significant effects on algal growth. In case of the amphipods, the single elements Al and Zn showed significant effects only at the highest tested concentrations. Moreover, an accumulation of Al and In was observed in the crustacea species.

Conclusions

Overall, the findings of this study indicated no direct environmental impact on the tested marine organisms by the use of galvanic anodes for cathodic protection. However, the accumulation of metals in, e.g., crustaceans might enhance their trophic transfer within the marine food web.

中文翻译：

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铝阳极的电化学阴极保护会影响海洋生物吗？

背景

由铝-锌-铟合金组成的牺牲阳极的阴极保护通常用于保护风力涡轮机的海上支撑结构不受腐蚀。鉴于过去十年来德国可再生能源和海上风电场的大量增长，铝，铟和锌的释放量不断增加到海洋环境中。尽管对这些金属进行了生态毒理学研究，但仍缺乏有关其对海洋生物（特别是沉积物物种）的影响以及电阳极可能产生的生态毒理学影响的数据。为了研究对海洋环境的可能的生态毒理影响，硅藻Phaedactylum tricornutum，细菌Aliivibrio fischeri和两栖动物Corophium v​​olutator在使用天然海水的标准化实验室测试中，分别将其暴露于溶解的电阳极和铝和锌的溶液中。除急性毒理作用外，还研究了C. volutator对这些元素的吸收。

结果

被研究的阳极材料对被测细菌没有急性毒性，仅对藻类生长产生了微弱但显着的影响。在两栖动物的情况下，仅在最高测试浓度下，单元素Al和Zn才显示出显着效果。此外，在甲壳动物中观察到Al和In的积累。

结论

总体而言，这项研究的结果表明，使用电化学阳极进行阴极保护不会对测试的海洋生物产生直接的环境影响。但是，金属在甲壳类动物中的积累可能会增强其在海洋食物网中的营养传递。