Sorption of neptunium onto goethite in the presence of humic acids with different hydroquinone group content

摘要

Neptunyl sorption in the ternary system of goethite-humic acid (HA)-Np was studied in a series of batch experiments with natural leonardite HA and a hydroquinone enriched derivative. The reduction of Np(V) at low pH has been observed by XPS upon interaction with hydroquinone-enriched leonardite HA-goethite suspension. Under these low pH conditions the formation of humate coatings at the goethite mineral surface has been identified using scanning transmission X-ray microscopy (STXM) at the carbon K-edge.