Cesium and Strontium Uptake Utilizing a New Ternary Solid-State Supramolecular Adsorbent under a Framework of Group Partitioning

Abstract

To simultaneously remove Sr and Cs from a simulated highly active liquid waste, a new ternary solid-state supramolecular adsorbent BnPC6DTXAD-7 (BnPDTX7), based on organic chelating agents 25,27-bis­(1-n-propoxy)-calix­[4]­26,28-crown-6 (BnPC6), 4,4′(5′)-di-tert-butyldicyclohexano-18-crown-6 (DT), and polymeric carrier XAD-7 was prepared for the first time. Scanning electronic microscopy and Brunauer–Emmett–Teller analysis demonstrated that BnPDTX7 is a macroporous adsorbent. The adsorption of 20 metals onto BnPDTX7 were studied. Under the optimal adsorption conditions of 3.0 M HNO3, 298 K, and contact time of 60 min, the adsorption capacity toward Cs and Sr were 0.1396 mM/g and 0.1289 mM/g, respectively. The experimental data fit well with the Langmuir model, indicative of the monolayer adsorption mechanism. The thermodynamic parameters, ΔH°, ΔG°, and ΔS° of Cs and Sr adsorption and other valuable chemical engineering data were obtained. BnPDTX7 proves to be a promising adsorbent for the simultaneous removal of Sr and Cs because of its high selectivity, fast kinetics, and high stability.

Selective Adsorption of Rubidium onto a New 1,3-Alternate Calix[4]crown-5 Mesoporous Adsorbent with a Polar Carrier Containing Polyalkyl Ester

“…Calix­[ n ]­crown is a derivative of calix­[ n ]­arene, which comprises a cavity of calix­[ n ] arene and one or two crown ether cycles. , Over the past three decades, it has been used as a host for recognizing guest metals through noncovalent bond interactions such as CH-p or p–p-stacking interactions. , Based on the investigations that have shown that the cavity of calix[4]­crown-6 families matches well with the size of Cs­(I). This provides a possibility for removing Cs­(I) from highly active liquid wastes. − However, it was found that under the framework of SPEC, GPSC, or FPEX process, − monovalent Rb­(I) was always separated from Cs-containing effluents due to similar chemical properties. − It would have a negative influence on the removal of Cs­(I). Moreover, Rb­(I) is an important resource used in energy, electronics, special glass, medicine, and many other fields.…”

Highly Selective Adsorption of New Bis-Opened-Triazine Materials Hybridized with a Cross-Linked Polymer Support for Palladium and Some Typical Coexisting Metals

“…MA was directly partitioned only along with Pd through one separation unit. It has following advantages: − (1) Cs and/or Sr, two heat generators, were removed first by new hybrid silica-based adsorbents hybridized with a highly selective calixcrown derivative such as 1,3-[(2,4-di­ethyl-heptyl­ethoxy)­oxy]-2,4-crown-6-calix­[4]­arene or 25,27-bis­(1-hexyloxy)-calix­[ 4 ]­arene-26,28-crown-6, and 4,4′,(5′)-di­( tert -butyl­cyclo­hexano)-18-crown-6 by host–guest recognition. This makes subsequent MA removal convenient because of the significant decrease in radioactivity.…”