Recovery of uranium from ammonium uranyl carbonate (AUC) effluents by combined ion exchange and membrane separation

Ammonium uranyl carbonate (AUC) production processes have effluents with a high uranium content (5 g/L), which is conventionally recovered by evaporation. In this study, an alternative process, recovery of uranium by strong anion exchange (AE) membranes is investigated. Solutions were modeled by MINTEQA2 for determining the species present. Laboratory scale AUC precipitations with three different C/U mole ratios were carried out using uranyl nitrate (UNH) feed solution from the pilot plant for the purpose of determining the remaining concentration of uranium in the effluents. Strongly basic AE membrane separations of these effluents were carried out, but separation was not effective because of the limited surface area of the membranes. Synthetic solutions of three different C/U mole ratios were prepared and passed through a column of strongly basic AE resin. Membrane separations were then carried out on the resulting Solutions. Membrane separations proved to be effective only in dilute solutions of uranium. There was a complementarity between the AE resins and membranes for U(VI) recovery from carbonate solutions in that different uranyl carbonate anionic species were extracted to differing extents with the two procedures

Dermoid cyst with cerebellar meningoencephalocele at different locations accompanied by posterior fossa abnormalities: case report

CONTEXT: Dermoid cysts are well-defined cysts containing sebaceous glands and dermal structures. In the literature, dermoid cysts and associated closure defects have been described in the same locations

Dermoid cyst with cerebellar meningoencephalocele at different locations accompanied by posterior fossa abnormalities: case report

ABSTRACT CONTEXT: Dermoid cysts are well-defined cysts containing sebaceous glands and dermal structures. In the literature, dermoid cysts and associated closure defects have been described in the same locations. CASE REPORT: In this case, a dermoid cyst was found at the base of the mouth with a coexisting closure defect in the occipital calvarium. Additional abnormalities were also observed, including posterior myeloschisis, right cerebellar dysgenesis, vermian hypogenesis and posterior fusion of the second and third vertebrae. The finding of a dermoid cyst located at the base of the mouth is discussed here, with additional imaging findings. CONCLUSION: Dermoid cysts in the head and neck region may be accompanied by posterior fossa abnormalities