الفهرس | Only 14 pages are availabe for public view |
Abstract I hydrogel in spite of its relatively NP02+ can be fixed in Al(011)3 hydroge Solubility in neutral to slightly alkaline solutions. The loss of Np due to washing the Np-Containing gel with water is below 2%.This loss is I dy caused by fine gel fragments suspended in and discharged with primarl fin wash water. The amount of genuinely dissolved Np(V) is approximately one order of magnitude lower than that present in the Suspended gel particles. ’Pie low concentration compared to that expected according to the solubility product is caused by strong adsorptive properties of the Al(OH)3 hydrogel. This has been proved both by leaching and loading tests. However, adsorption was found to be weaker in strong ammonia solutions than in weak ones. The adsorption mechanism is discussed. It is assumed that NpO,’ is attached to hydroxyl ions which on their part are bound to the gel. Dissolution of NP020H in both NHOH and NaOH Solutions was investigated mainly in a CO,-free atmosphere. Results show that solubility of NP0201-1 in NH4011 solution increases with the increase of N1-140H concentration . Absorption spectra of Np(V) in NH.,OH solution shows a characteristic absorption peak at 1002 nm, suggesting its presence as ammino complex having the formula NP020H(NHA, (H20)y |