Potash abandoned mines cause severe environmental damage to their bordering environment, with significant impacts on freshwater ecosystems mostly through uncontrolled discharge of hypersaline effluents. This study aimed to evaluate the ecological impact caused by a hypersaline effluent from an abandoned potash mine (Menteroda, Germany) on freshwater biofilms and, specifically, on diatom communities. Biofilm from a pristine stream was exposed under controlled conditions in microcosms to a mining effluent (ME), and its structural (algal biomass, community composition, diatom metrics) and functional (photosynthetic activity, nutrient uptake) responses were evaluated over time and compared with unexposed biofilms used as control. Biofilm exposed to ME showed drastic functional responses after one day of exposure, with a significant decrease in photosynthetic efficiency and nutrient uptake, that were recovered over time. Biofilm exposed to ME showed a progressive increase in diatom metrics (abundance, density and growth rate) over time, compared to the control. However, a significant decrease in diatom species diversity, richness and cell size was also observed in biofilm exposed to ME. This study revealed that the ME affected the biofilm causing short-term functional responses, which were recovered simultaneously with a drastic diatom community structure shift.

废弃的钾肥矿山对其周围环境造成严重的环境破坏，主要是通过不加控制地排放高盐废水，对淡水生态系统产生了重大影响。这项研究旨在评估废弃钾肥矿（德国门特罗达）的高盐废水对淡水生物膜，尤其是对硅藻群落的生态影响。在受控条件下，将原始流中的生物膜暴露于采矿废水（ME）中，并随时间评估其结构（藻类生物量，群落组成，硅藻指标）和功能（光合活性，养分吸收）响应，并与未暴露的生物膜用作对照。暴露于ME的生物膜在暴露一天后显示出剧烈的功能反应，随着时间的推移，光合效率和养分吸收显着下降。与对照相比，暴露于ME的生物膜显示硅藻指标（丰度，密度和生长速率）随着时间的推移逐渐增加。然而，在暴露于ME的生物膜中也观察到硅藻物种多样性，丰富度和细胞大小的显着降低。这项研究表明，ME影响了生物膜，引起了短期功能性反应，并随着硅藻群落结构的剧烈变化而同时被恢复。在暴露于ME的生物膜中也观察到了丰富性和细胞大小。这项研究表明，ME影响了生物膜，引起了短期功能性反应，并随着硅藻群落结构的剧烈变化而同时被恢复。在暴露于ME的生物膜中也观察到了丰富性和细胞大小。这项研究表明，ME影响了生物膜，引起了短期功能性反应，并随着硅藻群落结构的剧烈变化而同时被恢复。