Redox interactions of Pu(V) in solutions containing different humic substances

Humic substances play an important role in the speciation of actinides in the environment due to complexing, redox and sorptive interactions. This work is devoted to plutonium(V) reduction studies in solutions containing different humic substances, eluted from Mollisol and Sod-podzolic soil samples, as compared to real Pu distribution is contaminated soils. On the basis of kinetic curve slopes, the reducing ability is increased in the order: HA < FA ∼ low molecular weight fraction. The data obtained show that the different humic compounds play different roles in Pu(V) migration ability due to differing reducing and complexing properties.