Enhanced Feammox activity and perfluorooctanoic acid (PFOA) degradation by Acidimicrobium sp. Strain A6 using PAA-coated ferrihydrite as an electron acceptor.
Enhanced Feammox activity and perfluorooctanoic acid (PFOA) degradation by Acidimicrobium sp. Strain A6 using PAA-coated ferrihydrite as an electron acceptor.
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DOI：
10.1016/j.jhazmat.2023.132039
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发表时间：
2023-07
影响因子：
13.6
通讯作者：
Jinhee Park;Shan Huang;B. Koel;P. Jaffé
中科院分区：
文献类型：
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作者：
Jinhee Park;Shan Huang;B. Koel;P. Jaffé
酸性微生物属菌株A6（A6）可以通过氧化NH4+同时还原Fe（Ⅲ）来降解全氟烷基酸（PFAA）。然而，在沉积物中供应和分布 Fe(III) 相具有挑战性，因为 Fe(III) 相的表面电荷通常为正，而沉积物的表面电荷为负。因此，水铁矿颗粒被四种不同分子量的聚丙烯酸（PAA）包覆，导致其表面具有负的zeta电位。 Zeta 电位被确定为 pH 值和 PAA 负载量的函数，当 pH 值为 5.5 时，PAA/水铁矿比率 > 1/5 (w/w) 时观察到最低值。与 A6 富集培养物一起进行几次 50 天的培养，以确定 PAA 包被的水铁矿作为 A6 的电子受体对 Feammox 活性和 PFOA 降解的影响。在所有 PAA 涂层样品中均观察到 NH4+ 氧化、PFOA 降解、短链 PFAS 和 F- 的产生。与使用裸水铁矿孵育相比，6 K 和 450 K 处理的 PFOA 浓度显着降低，并且 F 产量显着降低。电化学阻抗谱显示，PAA 包覆的水铁矿存在时，电荷转移电阻降低，表明 PAA 促进了电子向水铁矿的转移。这项研究强调了 PAA 包覆的水铁矿在加速 PFAS 脱氟方面的潜力，为基于 A6 的生物修复策略提供了新的见解。
Acidimicrobiumsp. Strain A6 (A6) can degrade perfluoroalkyl acids (PFAAs) by oxidizing NH4+while reducing Fe(Ⅲ). However, supplying and distributing Fe(III) phases in sediments is challenging since surface charges of Fe(III)-phases are typically positive while those of sediments are negative. Therefore, ferrihydrite particles were coated with polyacrylic acid (PAA) with four different molecular weights, resulting in a negative zeta potential on their surface. Zeta potential was determined as a function of pH and PAA loading, with the lowest value observed when the PAA/ferrihydrite ratio was > 1/5 (w/w) at a pH of 5.5. Several 50-day incubations with an A6-enrichment culture were conducted to determine the effect of PAA-coated ferrihydrite as the electron acceptor of A6 on the Feammox activity and PFOA degradation. NH4+oxidation, PFOA degradation, production of shorter-chain PFAS, and F-were observed in all PAA-coated samples. The 6 K and 450 K treatments exhibited significant reductions in PFOA concentration and substantial F-production compared to incubations with bare ferrihydrite. Electrochemical impedance spectroscopy showed lowered charge transfer resistance in the presence of PAA-coated ferrihydrite, indicating that PAAs facilitated electron transfer to ferrihydrite. This study highlights the potential of PAA-coated ferrihydrite in accelerating PFAS defluorination, providing novel insights for A6-based bioremediation strategies.