In this research, a bimetallic compound of silver-modified nano zero-valent iron (Ag/Fe⁰) was synthesized and utilized to degrade pentabromophenyl ether (BDE209) under various environmental conditions with the presence of citric acid (CA). Liquid chromatography-mass spectrometry (LC-MS) analysis revealed twelve intermediate products formed during the degradation of BDE209. Both the Fe⁰–CA system and 0.2% Ag/Fe⁰–CA system showcased a degradation efficiency of 68.7% and 72.7% respectively in a liquid solution after 24 hours of treatment, along with a 9.1% and 18.2% total organic carbon (TOC) removal. Amid soil conditions, degradation rates reached 66.4%, 54.1%, and 50.5% respectively for initial BDE concentrations of 5 ppm, 10 ppm and 15 ppm in the presence of a degradation system comprising 30 g kg⁻¹ Ag/Fe⁰ and sodium citrate/CA (NaCA/CA) over 45 days. The potential environmental impacts of this process were assessed using ryegrass as a phytotoxicity marker in soil, wherein the measured chlorophyll and malondialdehyde (MDA) contents indicated that the addition of Ag/Fe⁰ successfully mitigated stress damage caused by BDE209. Furthermore, Ag/Fe⁰ has the capability to permeate the cell wall of ryegrass roots and establish interconnections. STEM-EDS patterns revealed that Ag was more readily accumulated inside of the cells compared to Fe. In conclusion, this study introduces an innovative approach for the safe and efficient oxidative degradation of BDE209 under both aquatic and terrestrial environmental conditions.

中文翻译：

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通过评估黑麦草，在各种环境和毒性评估中使用 Ag/Fe0 与柠檬酸盐复合来减弱十溴二苯醚 (BDE209)


本研究合成了银修饰的纳米零价铁双金属化合物（Ag/Fe ⁰ ），并在柠檬酸存在下，在各种环境条件下用于降解五溴苯醚（BDE209）。加利福尼亚州）。液相色谱-质谱 (LC-MS) 分析显示 BDE209 降解过程中形成了 12 种中间产物。 Fe ⁰ -CA 体系和 0.2% Ag/Fe ⁰ -CA 体系在处理 24 小时后在液体溶液中的降解效率分别为 68.7% 和 72.7%。总有机碳 (TOC) 去除率分别为 9.1% 和 18.2%。在土壤条件下，在包含 30 g kg ⁻¹ Ag/ 的降解系统存在下，初始 BDE 浓度为 5 ppm、10 ppm 和 15 ppm 时，降解率分别达到 66.4%、54.1% 和 50.5%。 Fe ⁰ 和柠檬酸钠/CA (NaCA/CA) 超过 45 天。使用黑麦草作为土壤中的植物毒性标记物评估了该过程的潜在环境影响，其中测量的叶绿素和丙二醛（MDA）含量表明Ag/Fe ⁰ 的添加成功减轻了BDE209造成的胁迫损害。此外，Ag/Fe ⁰ 具有渗透黑麦草根细胞壁并建立互连的能力。 STEM-EDS 模式显示，与 Fe 相比，Ag 更容易在细胞内积累。总之，本研究介绍了一种在水生和陆地环境条件下安全有效氧化降解 BDE209 的创新方法。