Metal-organic frameworks (MOFs) are an emerging class of materials which have garnered increasing attention for their utility as adsorbents and photocatalysts in water treatment. Nevertheless, the environmental risks of MOFs, especially their underlying impacts on aquatic organisms, are not fully explored. Herein, the toxicity of multiple representative MOFs was systematically assessed using a freshwater green alga (Chlamydomonas reinhardtii) model. Six typical MOFs with different metal nodes or organic linkers, including four transition metal incorporated aluminum-based porphyrin MOFs [pristine Al-PMOF, Al-PMOF (Cu), Al-PMOF (Ni), and Al-PMOF (Co)], one amine-functionalized MOF NH₂-MIL-125 (Ti), and one bimetallic Hofmann MOF (NiCo-PYZ), were successfully synthesized and characterized. All the tested MOFs significantly reduced the chlorophyll content and inhibited the algal growth, with the most toxic materials being NiCo-PYZ and Al-PMOF (Cu). Distinct toxic mechanisms were observed for the tested MOFs. Metal ion release was the primary cause for algal toxicity induced by NiCo-PYZ. The algal toxicity induced by porphyrin MOFs could be explained by the combined effects of metal ion release and nutrient adsorption, agglomeration and physical interactions, and reactive oxygen species generation. NH₂-MIL-125 (Ti) showed higher stability and more biocompatibility than the other tested MOFs. MOFs concentrations with no harmful effects to algae can be taken as the threshold values for safe use and discharge of MOFs. The ecotoxicological risks of MOFs should be considered as the applied concentrations of MOFs at mg/mL levels in environmental remediation were much higher than the no harmful effect thresholds.

金属有机框架 (MOF) 是一类新兴材料，因其在水处理中作为吸附剂和光催化剂的实用性而受到越来越多的关注。然而，MOFs 的环境风险，尤其是它们对水生生物的潜在影响，尚未得到充分探讨。在此，使用淡水绿藻（莱茵衣藻）模型系统地评估了多种代表性 MOF 的毒性。六种具有不同金属节点或有机连接体的典型 MOF，包括四种过渡金属掺入铝基卟啉 MOF [原始 Al-PMOF、Al-PMOF (Cu)、Al-PMOF (Ni) 和 Al-PMOF (Co)]，一种胺官能化的 MOF NH ₂-MIL-125 (Ti) 和一种双金属霍夫曼 MOF (NiCo-PYZ) 被成功合成和表征。所有测试的 MOF 都显着降低了叶绿素含量并抑制了藻类生长，其中毒性最大的材料是 NiCo-PYZ 和 Al-PMOF (Cu)。对测试的 MOF 观察到了不同的毒性机制。金属离子释放是 NiCo-PYZ 诱导藻类毒性的主要原因。卟啉 MOF 诱导的藻类毒性可以通过金属离子释放和养分吸附、团聚和物理相互作用以及活性氧产生的综合作用来解释。NH ₂-MIL-125 (Ti) 显示出比其他测试的 MOF 更高的稳定性和更高的生物相容性。MOFs 对藻类无有害影响的浓度可作为 MOFs 安全使用和排放的阈值。应考虑 MOF 的生态毒理学风险，因为在环境修复中应用的 MOF 浓度为 mg/mL，远高于无害影响阈值。