ABSTRACT
As a method for separating tritiated water from radioactively contaminated water, an additive was mixed into the contaminated water and their treatments of agitation/circulation and electrolytic was considered to improve of the separation efficiency. Carbide powder and ore (silica stone) powder were used as additives. The radioactivity concentration of the tritium-contaminated water (tritiated water; HTO) was 366 Bq/mL before treatment, however it obtained 333 Bq/mL and decreasing rate of 9.02%, and a high separation efficiency after treatment. Furthermore, in the reproducibility experiments (five times) using high content of HTO, the average HTO/H2O separation efficiency was obtained about 5.59% indicating good reproducibility. The agitation/circulation treatment process was dissociated and ionized HTO, and was prepared colloidal particles by OT- and 3T+. In the electrolytic treatment process, the colloidal particles in HTO were deposited on the both electrodes applied DC voltage, and was efficiently removed tritium. These treatment processes using additives were found to be useful for removal of tritium.
ABSTRACT
Monodispersed PLGA microspheres containing rifampicin (RFP) have been prepared by solvent evaporation method using a Shirasu porous glass (SPG) membrane. The microspheres were spherical and their average diameter was about 2 microm. The loading efficiency of rifampicin was dependent on the molecular weight of PLGA. The higher loading efficiency was obtained by the usage of PLGA with the lower molecular weight, which may be caused by the interaction of the amino groups of rifampicin with the terminal carboxyl groups of PLGA. PLGA with the monomer compositions of 50/50 and 75/25, of lactic acid/glycolic acid, were used in this study. From rifampicin-loaded PLGA microspheres formulated using PLGA with the molecular weight of 20,000, rifampicin was released with almost constant rate for 20 days after the lag phase was observed for the initial 7 days at pH 7.4. On the other hand, from rifampicin-loaded PLGA microspheres formulated using PLGA with the molecular weight of 5000 or 10,000, almost 90% of rifampicin-loaded in the microspheres was released in the initial 10 days. Highly effective delivery of rifampicin to alveolar macrophages was observed by the usage of rifampicin-loaded PLGA microspheres. Almost 19 times higher concentration of rifampicin was found to be incorporated in alveolar macrophages when rifampicin-loaded PLGA microspheres were added to the cell culture medium than when rifampicin solution was added.
