STUDIES ON THE PHOTOCHEMISTRY OF URANYL ION Ⅳ.PHOTOCHEMICAL REDUCTION OF U(Ⅵ) IN UO_2~(2+)-HCOOH-HNO_3 SYSTEM WITH GALLIUM LAMP IRRADIATION

The photochemical reactions of uranyl ion in UO2(NO3)2-HCOOH and UO2(NO2)2-HCOOH-HCOONa systems are investigated using gallium lamp as a light source. Its emission spectrum is well consistent with absorption spectrum of uranyl ion in solution at wave length 400 - 420 nm. Analytical results of gas chromatography show that the ratio of CO2 and CO is approximately 15/1.Stoi-chiometric studies of the photochemical reduction show that the mole ratio of produced U(Ⅳ) , gas products and consumed formic acid is 1:1:1. The photochemical reaction equation can be expressed byThe effects of different conditions on the quantity of U(Ⅳ) formed are also reported.