Roles of natural organic matter in fixing uranium: Evidences from uranium oxidation state and functional groups of organic matter

By the correlation of TOC and uranium contents, as well as correlations of the relative atomic content of different chemical valence states of elements U and C, i.e., (U (IV) and U(VI)) vs C-O, and (U (IV) and U(VI)) vs ((O-C=O)+(C=O)) in attempt to obtain the information about roles of natural organic matter in fixing uranium from the views of uranium oxidation state and functional groups of organic matter.

Moreover, the data about mineral composition of uranium-bearing mineral around pyrites is used to identify autunite, indicating that pyrite and microbial activities may participate in uranium mineralization. Analyzing the relationship between Y2O3 and P2O5 is used to evidence the sedimentary environment during the mineralization period.