Phosphonates, featuring organic skeletons binding phosphonic acid group, are ubiquitous in wastewaters and natural waters. Highly efficient removal of trace phosphonates is desirable to ensure the water quality and to prevent eutrophication. Commercially available hyper-cross-linked resins modified by amino groups have been proved to exhibit preferable adsorption of various organic acids from aqueous systems via synergetic effect of various interactions (electrostatic interaction, van der Waals interaction, π-π interaction, etc.) but seem relatively ineffective for phosphonates. In this study, we proposed a new strategy via coupling a commercial resin NDA88 with nanoconfinement of Hydrated ferric oxide (HFO) for selective removal of phosphonates. The resultant HFO@NDA88 shows an adsorption capacity of 15.0 mg P/g towards a model phosphonate (nitrilotris(methylenephosphonic acid)), higher than those of the NDA88 host (7.9 mg P/g) and the bare HFO (7.4 mg P/g). Remarkably, compared to NDA88 and HFO, HFO@NDA88 exhibits much higher resistance to the interference of various anions and other substances at much greater levels, particularly the organic analogue nitrilotriacetic acid and phosphate. Such superior selectivity is believed to result from the cooperative contributions of the host NDA88 as well as the embedded nano-HFO. Moreover, HFO@NDA88 shows excellent reusability and satisfactory performance in fixed-bed water treatment. This work provides a rational design of nanocomposite adsorbents for highly selective removal of phosphonates from complicated water matrix.

中文翻译：

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通过超交联树脂与纳米水合氧化物的耦合选择性去除有机膦酸盐

膦酸盐具有结合膦酸基团的有机骨架，在废水和天然水中普遍存在。为了确保水质并防止富营养化，需要高效去除痕量膦酸盐。市售的氨基改性超交联树脂已被证明通过各种相互作用（静电相互作用、范德华相互作用、π-π相互作用等）的协同效应，对水体系中的各种有机酸表现出更好的吸附作用，但似乎对膦酸盐相对无效。在这项研究中，我们提出了一种新策略，通过将商业树脂 NDA88 与水合氧化铁 (HFO) 的纳米限制耦合来选择性去除膦酸盐。所得的 HFO@NDA88 对模型膦酸盐（次氮基膦酸）的吸附能力为 15.0 mg P/g，高于 NDA88 宿主（7.9 mg P/g）和裸 HFO（7.4 mg P/g）的吸附能力。 G）。值得注意的是，与 NDA88 和 HFO 相比，HFO@NDA88 对各种阴离子和其他物质（特别是有机类似物次氮基三乙酸和磷酸盐）的干扰表现出更高的抵抗力。这种优异的选择性被认为是主体 NDA88 以及嵌入的纳米 HFO 的共同贡献的结果。此外，HFO@NDA88在固定床水处理中表现出优异的可重复使用性和令人满意的性能。这项工作提供了纳米复合吸附剂的合理设计，用于从复杂的水基质中高选择性地去除膦酸盐。