Fluorous and Organic Extraction Systems: A Comparison from the Perspectives of Coordination Structures, Interfaces, and Bulk Extraction Phases.

Microscopic structures in liquid-liquid extraction, such as structuration between extractants or extracted complexes in bulk organic phases and at interfaces, can influence macroscopic phenomena, such as the distribution behavior of solutes, including extraction efficiency and selectivity. In this study, we correlated the macroscopic behavior of the Zr(IV) extraction from nitric acid solutions with microscopic structural information to understand at the molecular level the key factors contributing to the higher metal ion extraction performance in the fluorous extraction system as compared to the analogous organic extraction system. The fluorous and organic extraction systems consist of tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) phosphate (TFP) in perfluorohexane and tri--heptyl phosphate (THP) in -hexane, respectively.

Microbially formed Mn(IV) oxide as a novel adsorbent for removal of Radium.

Radioactivity of Ra isotopes in natural waters is of serious concern. Control of Ra concentrations in tailings ponds, which store waste from U ore extraction processes, is an important issue in mill tailings management. In this study, we tested microbially formed Mn(IV) oxide as an adsorbent for removal of Ra in water treatment.

Improvement of the Stability of IO-, SeO-, and SeO-Coprecipitated Barite after Treatment with Phosphate.

Coprecipitation of radionuclides with barite has been studied to remove radionuclides from radioactive liquid waste because of its excellent removal efficiency; however, little information exists concerning the stability of the ions coprecipitated with barite. This study systematically investigated the stability of iodate, selenite, and selenate coprecipitated with barite via leaching tests. These oxyanions were gradually leached from the oxyanion-bearing barite into ultrapure water over time.

Effective removal of iodate by coprecipitation with barite: Behavior and mechanism.

Radioactive iodine (I) is of great concern owing to its high mobility in the environment and long-term radiotoxicity. However, there is a lack of effective techniques for removing iodate (IO) from aqueous solution. This study aims to develop a new technique for removing radioactive iodate from contaminated solution by using barite (BaSO).

A new technique for removing strontium from seawater by coprecipitation with barite.

Strontium (Sr) removal from seawater has recently attracted attention from an environmental perspective after the Fukushima Nuclear Power Plant accident, but there is a lack of effective removal techniques for removing Sr from seawater. In the present study, we looked at the removal efficiency of Sr by using barite (BaSO) under various experimental conditions to develop techniques for the direct removal of Sr from seawater. The effects of pH, saturation state, ionic strength, competitive ions, and [Ba]/[SO] ratio in the initial aqueous solution were examined.

Effective Removal of Selenite and Selenate Ions from Aqueous Solution by Barite.

In the present study, we explore a new application of Barite (BaSO) as a sequestering phase for selenite (Se(IV)) and selenate (Se(VI)) ions from aqueous solutions because of the low solubility and high stability of Barite with its ability to selectively incorporate a large amount of various ions. The uptake of Se(IV) and Se(VI) during coprecipitation with Barite was investigated through batch experiments to understand the factors controlling effective removal of Se(IV) and Se(VI) from polluted water to Barite. The factors include (i) chemical affinity related to the degree of surface complexation between Barite surface and Se(IV)/Se(VI) ion and (ii) structural similarity related to the structural geometry of incorporated ions into the substituted site.