Institute of Grass Science, Northeast Normal University, Changchun, 130024, People's Republic of China.
Department of Environment, Northeast Normal University, Changchun, 130024, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Sep;25(27):27545-27560. doi: 10.1007/s11356-018-2773-9. Epub 2018 Jul 27.
Rivers act as carriers where active cycling of chromophoric dissolved organic matter (CDOM) affected by anthropogenic activities and land cover variation may occur. Little is known about the optical properties of CDOM in relation to antibiotics; these properties could provide valuable insights into CDOM transformation processes and biogeochemical reactivity. The spatial distribution of CDOM absorption, fluorescence intensities of CDOM components, and correlations between fluorescence indices (FI, humification index (HIX)) and biological index (BIX)) with water quality and antibiotics were investigated in three rivers, namely, two rivers (Yalu River and Tumen River) dividing China and North Korea, and the Songhua River. Four humic-like components (C1 and C3-5), and one tryptophan-like component (C2), were identified via fluorescence excitation-emission matrices-parallel factor analysis (EEM-PARAFAC). The correlation between F for five EEM-PARAFAC extracted CDOM components, C1-C5, FI, HIX, BIX, and water quality parameters, and four antibiotics (i.e., Norfloxacin, Enrofloxacin, Sulfamethoxazole and Metronidazole), were determined through a redundancy analysis (RDA), with species-environment correlations of 0.887 and 0.833, respectively. The results showed that spatial variation in land cover, pollution sources, and terrestrial contribution in water quality affected F for the fluorescent components C1-C5 and the fluorescence indices, indicating a high diverse chemical composition and transformation history. The F for terrestrial humic-like components, C4 and C5, showed spatial variation depending on land cover and anthropogenic impacts. Further correlation and regression analyses indicated that CDOM soil fulvic-like component C5 correlated with Sulfamethoxazole and Metronidazole (t test, p < 0.01). Our results indicate that the spatial distributions of F for CDOM fluorescent terrestrial components, evaluated by EEM-PARAFAC, have potential implications for the monitoring of Sulfamethoxazole and Metronidazole in surface waters. Further, these findings can be used to understand the biogeochemical cycling of CDOM and its effects on antibiotics pollution in the environment.
河流是活性循环的色溶解有机质（CDOM）的载体，这种活性循环受到人为活动和土地覆盖变化的影响。关于抗生素与 CDOM 的光学性质知之甚少；这些性质可以为 CDOM 转化过程和生物地球化学反应性提供有价值的见解。本研究在鸭绿江和图们江（中朝界河）和松花江三条河流中，调查了 CDOM 吸收的空间分布、CDOM 成分的荧光强度以及荧光指数（FI，腐殖化指数（HIX））和生物指数（BIX）与水质和抗生素之间的相关性。通过荧光激发-发射矩阵-平行因子分析（EEM-PARAFAC）鉴定了四个腐殖质类似物（C1 和 C3-5）和一个色氨酸类似物（C2）。通过冗余分析（RDA）确定了五个从 EEM-PARAFAC 提取的 CDOM 成分（C1-C5）、FI、HIX、BIX 和水质参数与四种抗生素（诺氟沙星、恩诺沙星、磺胺甲恶唑和甲硝唑）之间的相关性，物种-环境相关性分别为 0.887 和 0.833。结果表明，水质中土地覆盖、污染源和陆地贡献的空间变化影响了荧光成分 C1-C5 和荧光指数的 F 值，表明其具有高度多样化的化学组成和转化历史。陆地腐殖质类似物 C4 和 C5 的 F 值随土地覆盖和人为影响的空间变化而变化。进一步的相关和回归分析表明，CDOM 土壤富里酸类似物 C5 与磺胺甲恶唑和甲硝唑呈正相关（t 检验，p<0.01）。本研究结果表明，通过 EEM-PARAFAC 评价的 CDOM 荧光陆地成分的 F 值的空间分布可能对监测地表水中的磺胺甲恶唑和甲硝唑具有重要意义。此外，这些发现可以帮助我们了解 CDOM 的生物地球化学循环及其对环境中抗生素污染的影响。
