Achieving Rapid and Effective Europium Enrichment from Aqueous Solution by a Rigid Layered Silicate

High-level radioactive wastewater containing 152Eu and 154Eu radionuclides poses severe threats to ecological security and human health, necessitating the development of high-performance adsorbents for targeted remediation. Herein, we systematically demonstrated the europium enrichment adaptability of a two-dimensional layered silicate by ion exchange, namely, [N(CH3)4]8[Si24O52(OH)4]·20H2O (denoted as RUB-15). It has been found that RUB-15 delivers a remarkable europium saturation capacity of 105.63 mg/g, most notably featuring ultrafast adsorption kinetics with equilibrium accomplished within merely 5 min. Benefiting from its unique structural characteristics, RUB-15 presents prominent acid-base resistance across a wide pH range (2.7-9.8), exhibiting excellent Eu3+ preference against various individual interfering species like Na+, Cs+, Ca2+, and HA. Impressively, its maximum distribution coefficient and europium removal efficiency separately reach up to 3.2 × 105 mL/g and 99.69%, which obviously outperform those of most state-of-the-art counterparts. In addition, its good europium adsorption is well-validated in the competitive multicomponent Na+/K+/Mg2+/Ca2+ system, real water matrices, coexisting rare-earth ion solution, and recycling study. These merits, combined with its feasible teabag and column applications, render RUB-15 as a highly promising candidate for the fast and efficient incarceration of Eu3+ ions in a practical engineering scenario.