Department of Water Protection, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland.
Department of Chemistry, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 75, 60-625, Poznań, Poland.
J Environ Manage. 2022 Sep 15;318:115535. doi: 10.1016/j.jenvman.2022.115535. Epub 2022 Jun 16.
Iron (Fe) treatment is one of the most commonly used methods to restore eutrophic lakes and reservoirs. The Fe-based coagulants dosage results in an almost immediate improvement in water quality at a relatively low cost. However, the effects of the application of coagulants are not always predictable, and the scale of the risks is not fully understood. The dosage of coagulants changes the chemical and physical properties of water, thereby affecting aquatic biocenoses. In this study, several laboratory experiments were conducted to evaluate the effects of Fe-based coagulant dosage on two bivalves species: Anodonta anatina and Unio tumidus. Their ability to efficiently filter water and reduce seston makes them a key component of aquatic ecosystems in terms of maintaining proper ecological health and stable functioning. Behavioral response, biochemical parameters, and body chemistry changes in mussels exposed to different doses of coagulant were surveyed. A dose-dependent reduction in filtration activity of both species was observed. As early as 10 g Fe m (which is a moderate dose used in lakes restoration), mussels of both species almost completely reduced their filtration activity and remained with closed valves for several subsequent days. Significant Fe accumulation in muscles of bivalves exposed to coagulant was also observed. This was particularly the case when very high doses of coagulant were applied. Then, the iron content in leg muscles of both species increased over fourfold. At the same time, a decrease in muscles calcium and phosphorus content was observed. No symptoms of oxidative stress (TBARS, HO) after mussels exposure to coagulants were found. The results suggest that the application of Fe-based coagulant for water ecosystem restoration may be a threat to the mussels population. These findings are significant for decisions on the selection of restoration methods for a specific lake.
铁（Fe）处理是恢复富营养化湖泊和水库最常用的方法之一。Fe 基混凝剂的用量可以在相对较低的成本下几乎立即改善水质。然而，混凝剂的应用效果并不总是可以预测的，其风险规模也不完全了解。混凝剂的用量改变了水的化学和物理性质，从而影响水生生物群落。在这项研究中，进行了几项实验室实验，以评估 Fe 基混凝剂用量对两种双壳类动物物种的影响：Anodonta anatina 和 Unio tumidus。它们有效地过滤水和减少悬浮物的能力使它们成为维持适当生态健康和稳定功能的水生生态系统的关键组成部分。调查了暴露于不同剂量混凝剂的贻贝的行为反应、生化参数和身体化学变化。观察到两种物种的过滤活性都随剂量呈依赖性降低。早在 10g Fe m（这是湖泊修复中使用的中等剂量）时，两种贻贝的过滤活性几乎完全降低，并且随后的几天内都保持关闭。还观察到暴露于混凝剂的双壳类动物肌肉中 Fe 的大量积累。当使用非常高剂量的混凝剂时尤其如此。然后，两种贻贝腿肌中的铁含量增加了四倍以上。同时，肌肉中的钙和磷含量减少。未发现贻贝暴露于混凝剂后出现氧化应激（TBARS、HO）的症状。结果表明，应用 Fe 基混凝剂来恢复水生态系统可能对贻贝种群构成威胁。这些发现对于选择特定湖泊的恢复方法的决策具有重要意义。
