Kinetic studies on the extraction of uranium(VI) from phosphoric acid medium by bulk liquid membrane containing di-2-ethylhexyl phosphoric acid

Highly sensitive and selective determination of uranium in natural waters through a novel solidified floating organic drop microextraction method coupled with spectrophotometric determination

“…In recent years several techniques have been used to extract and measure uranyl ions from aqueous samples, including solvent extraction (SE) [3], ultrafiltration [4] solid phase extraction (SPE) [5][6][7][8], supercritical fluid extraction (SFE) [9], cloud-point extraction (CPE) [10-3 12], homogeneous liquid-liquid extraction (HLLE) [13], dispersive liquid-liquid microextraction (DLLME) [14] and membrane methods consisting of bulk liquid membrane (BLM) [15] emulsion liquid membrane (ELM) [16] and supported liquid membrane (SLM) [17]. In recent years several techniques have been used to extract and measure uranyl ions from aqueous samples, including solvent extraction (SE) [3], ultrafiltration [4] solid phase extraction (SPE) [5][6][7][8], supercritical fluid extraction (SFE) [9], cloud-point extraction (CPE) [10-3 12], homogeneous liquid-liquid extraction (HLLE) [13], dispersive liquid-liquid microextraction (DLLME) [14] and membrane methods consisting of bulk liquid membrane (BLM) [15] emulsion liquid membrane (ELM) [16] and supported liquid membrane (SLM) [17].…”

“…1,2 Due to elevated levels of uranyl ions in natural waters and the requirement for proper storage and disposal of uranium nuclear fuel wastes, its extraction and determination techniques need to be improved. In recent years, several techniques have been used to extract and measure uranyl ions from aqueous samples, including solvent extraction (SE), 3 ultraltration, 4 solid phase extraction (SPE), [5][6][7][8] supercritical uid extraction (SFE), 9 cloud-point extraction (CPE), [10][11][12] homogeneous liquid-liquid extraction (HLLE), 13 dispersive liquidliquid microextraction (DLLME) 14 and membrane methods consisting of bulk liquid membrane (BLM), 15 emulsion liquid membrane (ELM) 16 and supported liquid membrane (SLM). 17 However, there are still difficulties due to increasing uranium in natural waters.…”

Liquid Membranes: Basic Concepts and Applications to Nuclear Industry

“…The use of calixarene in conjunction with TOPO gave a complete and highly selective of uranyl ion even from seawater samples [28,29]. The use of bis(2-ethyl hexyl) phosphoric acid (D2EHPA) as carrier could result in excellent separation of uranium even from phosphoric acid medium [30,31]. The transport study of uranyl ion with equimolar concentrations of thenoyltrifluoroacetone (HTTA) and dicyclohexyl-18C6 as carriers showed that most of the ions did not interfere while the interference from Th (IV) could be reduced by masking [32].…”