School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
Environ Pollut. 2019 Jul;250:155-165. doi: 10.1016/j.envpol.2019.04.021. Epub 2019 Apr 10.
Concerns have been raised regarding the ecotoxicity of ionic liquids (ILs) owing to their wide usage in numerous fields. Three imidazolium chloride ILs with different numbers of methyl substituents, 1-decyl-imidazolium chloride ([CIM]Cl), 1-decyl-3-methylimidazolium chloride ([CMIM]Cl), and 1-decyl-2,3-dimethylimidazolium chloride ([CDMIM]Cl), were examined to assess their effects on growth, photosynthesis pigments content, chlorophyll fluorescence, photosynthetic and respiration rate, and cellular ultrastructure of Scenedesmus obliquus. The results showed that algal growth was significantly inhibited by ILs treatments. The observed IC doses were 0.10 mg/L [CIM]Cl, 0.01 mg/L [CMIM]Cl, and 0.02 mg/L [CDMIM]Cl. The chlorophyll a, chlorophyll b, and total chlorophyll content declined, and the chlorophyll fluorescence parameters, minimal fluorescence yield (F), maximal fluorescence yield (F), maximum quantum yield of PSII photochemistry (F/F), effective quantum yield of PSII [Y(II)], non-photochemical quenching (NPQ) and non-photosynthetic losses yield [Y(NO)] were notably affected by ILs in a dose-dependent manner. ILs affected the primary photosynthetic reaction, impaired heat dissipation capability, and diminished photosynthetic efficiency, indicating negative effects on photosystem II. The photosynthetic and respiration rates of algal cells were also reduced due to the ILs treatments. The adverse effects of ILs on plasmolysis and chloroplast deformation were examined using ultrastructural analyses; chloroplast swelling and lamellar structure almost disappeared after the [CMIM]Cl treatment, and an increased number of starch grains and vacuoles was observed after all ILs treatments. The results indicated that one-methyl-substituted ILs were more toxic than non-methyl-substituted ILs, which were also more toxic than di-methyl-substituted ILs. The toxicity of the examined ILs showed the following order: [CIM]Cl < [CDMIM]Cl ≤ [CMIM]Cl.
由于离子液体（ILs）在许多领域的广泛应用，人们对其生态毒性产生了担忧。本研究选用三种不同取代甲基数目的咪唑氯盐离子液体，1-癸基-3-甲基咪唑氯盐([CMIM]Cl)、1-癸基-2,3-二甲基咪唑氯盐([CDMIM]Cl)和 1-癸基咪唑氯盐([CIM]Cl)，研究它们对斜生栅藻生长、光合作用色素含量、叶绿素荧光、光合和呼吸速率及细胞超微结构的影响。结果表明，ILs 处理显著抑制藻类生长。观察到的半效应浓度（IC）分别为 0.10mg/L [CIM]Cl、0.01mg/L [CMIM]Cl 和 0.02mg/L [CDMIM]Cl。叶绿素 a、叶绿素 b 和总叶绿素含量下降，叶绿素荧光参数最小荧光产量（F）、最大荧光产量（F）、PSII 光化学最大量子产量（F/F）、PSII 有效量子产量[Y(II)]、非光化学猝灭（NPQ）和非光合损失产量[Y(NO)]均受 ILs 影响呈剂量依赖性显著降低。ILs 影响初级光合作用反应，损害热耗散能力，降低光合作用效率，表明对 PSII 有负面影响。藻类细胞的光合和呼吸速率也因 ILs 处理而降低。通过超微结构分析检测 ILs 对质壁分离和叶绿体变形的影响；[CMIM]Cl 处理后叶绿体肿胀，片层结构几乎消失，所有 ILs 处理后淀粉粒和液泡数量增加。结果表明，一甲基取代的 ILs 比非甲基取代的 ILs 毒性更大，而二甲基取代的 ILs 比非甲基取代的 ILs 毒性更大。研究中三种 ILs 的毒性顺序为：[CIM]Cl < [CDMIM]Cl ≤ [CMIM]Cl。
