Abstract
ABSTRACTIt is necessary to assess the impact of nitrate salts and their reduction products (e.g. NH3(aq)/NH4+) contained in low-level radioactive waste generated from nuclear reprocessing process for the safety assessment of geological disposal of the waste. In the present study, sorption behavior of Ni and Pd on pumice tuff was investigated in the presence of NH3(aq)/NH4+. Under various NH3(aq)/NH4+ concentration, pH and ionic strength conditions, distribution coefficient (Kd) of Ni and Pd on pumice tuff was determined by a batch experiment. For Ni system, the Kd values showed no significant dependence on initial NH4+ concentration ([NH4+]ini < 1 M) in neutral pH region, which agreed with the prediction from thermodynamic data. For Pd system, the Kd values decreased with an increase of [NH4+]ini, suggesting the formation of stable ammine complexes (Pd(NH3)m2+ (m: 1 – 4)). The obtained Kd values for Ni and Pd were analyzed using a surface complexation model. By taking complexes predicted by thermodynamic data into account, sorption behavior of Ni and Pd in the presence of NH3(aq)/NH4+ were well explained.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
