Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Department of Environmental Engineering, Yonsei University, Wonju, 26493, Republic of Korea.
Chemosphere. 2019 Jun;225:696-704. doi: 10.1016/j.chemosphere.2019.03.086. Epub 2019 Mar 14.
Plants serve as appropriate markers of worldwide pollution because they are present in almost every corner of the globe and bioaccumulate xenobiotic chemicals from their environment. The potential of a semi-aquatic plant, Ipomoea aquatica, to uptake and metabolize sulfamethoxazole (SMX) was investigated in this study. I. aquatica exhibited 100% removal of 0.05 mg L SMX from synthetic media within 30 h. The I. aquatica achieved 93, 77 and 72% removal of SMX at 0.2, 0.5 and 1 mg L, respectively, after 48 h. This indicated that removal efficiency of I. aquatica was deteriorating at high concentrations of SMX. The chlorophyll and carotenoid content of I. aquatica was insignificantly influenced by SMX irrespective of its high concentration. Similarly, scanning electron microscopy (SEM) showed that exposure to SMX had an insignificant impact on morphology of the plant organelles. The mechanisms of removal by I. aquatica were explored by evaluating contributions of bioadsorption, bioaccumulation and biodegradation. There was negligible adsorption of SMX to plant roots. Accumulation of SMX within plant roots and stems was not observed; however, I. aquatica accumulated 17% of SMX in leaves. Thus, the major mechanism of elimination of SMX was biodegradation, which accounted for 82% removal of SMX. Gas chromatography-mass spectrometry (GC-MS) confirmed that I. aquatica biodegraded SMX into simpler compounds, and generated 4-aminophenol as its final product. A laboratory scale phytoreactor was used to investigate the application of I. aquatica in a simulated system, where it achieved 49% removal of SMX (0.2 mg L) in 10 d.
植物是全球污染的合适标志物，因为它们几乎存在于地球的每一个角落，并从环境中生物累积异生物质化学物质。本研究考察了半水生植物Ipomoea aquatica 对磺胺甲恶唑 (SMX) 的吸收和代谢能力。Ipomoea aquatica 在 30 小时内从合成介质中去除了 0.05mg/L SMX 的 100%。在 48 小时内，Ipomoea aquatica 分别以 0.2、0.5 和 1mg/L 的浓度去除 SMX 的效率达到 93%、77%和 72%。这表明随着 SMX 浓度的升高，Ipomoea aquatica 的去除效率在下降。无论 SMX 浓度高低，叶绿素和类胡萝卜素的含量对 Ipomoea aquatica 的影响都不显著。同样，扫描电子显微镜（SEM）显示，SMX 暴露对植物细胞器的形态没有显著影响。通过评估生物吸附、生物积累和生物降解的贡献，探讨了 Ipomoea aquatica 的去除机制。SMX 对植物根系的吸附可忽略不计。在植物的根和茎中未观察到 SMX 的积累，但 Ipomoea aquatica 在叶片中积累了 17%的 SMX。因此，SMX 的主要消除机制是生物降解，占 SMX 去除的 82%。气相色谱-质谱联用仪（GC-MS）证实，Ipomoea aquatica 将 SMX 生物降解为更简单的化合物，并生成 4-氨基酚作为最终产物。实验室规模的植物修复器用于研究 Ipomoea aquatica 在模拟系统中的应用，在 10 天内实现了 49%的 SMX（0.2mg/L）去除率。
