Phosphate removal and recovery from wastewater play a vital role in controlling water eutrophication and facilitating resource recycling. Adsorbents of layered double hydroxides (LDHs) exhibit promising potential in the removal of phosphate; however, the removal efficiency often suffers insufficient as easy aggregation and inevitable loss of LDHs. Herein, a novel N, N–bis (carboxymethyl)–L–glutamic acid intercalated magnesium–aluminum LDH (GLDA@MgAl–LDH) were successfully synthesized. Intercalating with GLDA spawned dual functionality, i.e., the layer spacing expansion elevated the loading of phosphate, while GLDA also acted as additional binding sites toward phosphate. A higher phosphate capture (＞90%) was obtained in pH 5.0–8.0. Phosphate uptake was predominantly observed within the first1h, reaching equilibrium in approximately 4 h. The maximum adsorption capacity of 44.17 mg g was attained for GLDA@MgAl–LDH at pH 6.70, which are far higher than that of pristine MgAl–LDH. GLDA@MgAl–LDH also had the excellent stability and reusability in five adsorption/desorption experiments. The GLDA@MgAl–LDH demonstrated significant efficacy in treating actual phosphate-containing wastewater in the fixed–bed adsorption column. Spectroscopic analysis, in conjunction with density functional theory, elucidated that GLDA intercalation enhanced the adsorption efficiency of MgAl–LDH. The key mechanisms facilitating phosphate removal included electrostatic attraction, anion and ligand exchange, and surface complexation. The above results highlight that GLDA@MgAl–LDH could serve as a promising and environmentally friendly candidate for phosphate treatment from the real wastewater.

中文翻译：

---

可生物降解的螯合剂 GLDA 插层镁/铝层状双氢氧化物，可有效捕获和去除废水中的磷酸盐


废水中磷酸盐的去除和回收对于控制水体富营养化和促进资源循环利用起着至关重要的作用。层状双氢氧化物（LDH）吸附剂在去除磷酸盐方面表现出良好的潜力；然而，由于LDHs容易聚集和不可避免的损失，去除效率往往不足。在此，成功合成了一种新型N，N-双（羧甲基）-L-谷氨酸插层镁铝LDH（GLDA@MgAl-LDH）。 GLDA 的插层产生了双重功能，即层间距扩大提高了磷酸盐的负载量，同时 GLDA 还充当了磷酸盐的额外结合位点。在 pH 5.0–8.0 范围内获得了较高的磷酸盐捕获率 (>90%)。磷酸盐的吸收主要在最初的 1 小时内观察到，在大约 4 小时内达到平衡。 GLDA@MgAl-LDH在pH 6.70时获得最大吸附容量44.17mgg，远高于原始MgAl-LDH。 GLDA@MgAl-LDH在五次吸附/解吸实验中也具有优异的稳定性和可重复使用性。 GLDA@MgAl-LDH 在固定床吸附塔中处理实际含磷酸盐废水方面表现出显着的功效。光谱分析与密度泛函理论相结合，阐明了 GLDA 插层增强了 MgAl-LDH 的吸附效率。促进磷酸盐去除的关键机制包括静电吸引、阴离子和配体交换以及表面络合。上述结果表明，GLDA@MgAl-LDH 可以作为一种有前景且环保的候选材料，用于处理实际废水中的磷酸盐。