Inactive cells of Rhizopus arrhizus have been documented to exhibit a high thorium biosorptive uptake (170 mg/g) from aqueous solutions. The mechanism of thorium sequestering by this biomass type was investigated following the same method as for the uranium biosorption mechanism. The thorium sequestering mechanism appeared somewhat different from that of uranium. Experimental evidence is presen...

Recently, interest in thorium’s potential use in a nuclear fuel cycle has been renewed. Thorium is more abundant, at least on average, than uranium in the earth’s crust and, therefore, could theoretically extend the use of nuclear energy technology beyond the economic limits of uranium resources. This paper provides an economic assessment of thorium availability by creating cumulative-availabil...

Thorium concentrations at Kirtland Air Force Base training sites in Albuquerque, NM, have been previously described; however, the mechanisms of thorium migration were not fully understood. This work describes the processes affecting thorium mobility in this semiarid soil, which has implications for future remedial action. Aqueous extraction and filtration experiments have demonstrated the collo...

The largest two sectors emitting CO2 in the world are electricity generation and land-transportation. Therefore, nuclear power plays an important role in generating electricity with low CO2 emission. An important aspect needs to be considered to ensure environmental sustainability is nuclear non-proliferation and less amount of radioactive waste generated. Thus the use of “thorium” as nuclear f...

The reaction of phosgene with thorium oxide has been shown to be a good method for preparing thorium tetrachloride. The equilibria of the reaction showed that nearly complete utilization of phosgene could be attained in a properly designed reactor. The kinetics of the reaction could not be represented by a simple rate law but the effects of bed depth, particle size, mode of oxide preparation an...

The long-lived radioactive element thorium can potentially provide a simple and direct clock to determine the age of our Galaxy. Spectroscopic investigations of thorium in metal-poor stars have yielded some promising initial results. We discuss the major observational and theoretical limitations in thorium cosmochronometry, and point out the ways in which the implied Galactic ages from thorium ...

Toxicity of thorium by Monoraphidium sp. and Scenedesmus sp. was studied. Microalgal cultures were inoculated in ASM-1 medium in presence and absence of thorium. Its effect was monitored by direct counting on Fuchs-Rosenthal chamber and with software. The toxicity of thorium over the species was observed for concentrations over 50.0 mg/L. After 30 days, Monoraphidium cells decreased their conce...

The separation of rare metals from the ores and commercially available compounds is an important issue due to the need of their high purity in advanced materials and devices. Important examples of two highly important elements that co-exist in the ores are scandium and thorium. Scandium containing ores and consequently also commercially available scandium compounds often contain traces of thori...

A new calix[4]resorcinarene bearing eight hydroxamic acid groups (C4RAHA) has been synthesized and characterized by FT-IR, 1H-NMR and elemental analysis. Its analytical properties were investigated, and showed high affinity and selectivity toward thorium(IV) in the presence of large quantities of associated metal ions. Thorium(IV) was extracted from an ethyl acetate solution of C4RAHA at pH 4.5...

A flow injection system for the simultaneous determination of uranium and thorium has been developed by using selective masking and a spectrophotometric detector with two flow cells aligned with the same optical path. The injected sample solution was first mixed with a reagent solution containing Chromazurol S (CAS) and cetyltrimethylammonium chloride (CTMAC), and the total absorbance of uraniu...