The reduction of plutonium(V) by aquatic sediments

Preparation and use of humic coatings covalently bound to silica gel for Np(V) and Pu(V) sequestration

“…This range is consistent with the redox potential of hydroquinone which suggests quinonoid structures are responsible for the redox properties of humic materials [14,15]. In the context of this study, it is of particular importance to stress that HS can reduce Pu(VI/V) to Pu(IV), Np(VI) to Np(V) [16,17], and that several investigations report enhanced sorption of actinides on humics-rich solids (silts and bottom sediments) [18,19]. Thus, humic PRBs could be an effective innovation in groundwater remediation.…”

Influence of some Seawater Components on the Sorption Behaviour of Neptunium(V)

“…Sorption of Pu(IV) was not found to be similarly affected. It has been suggested that Pu bound Brought to you by | University of California Authenticated Download Date | 6/12/15 5:03 AM to marine sediment is predominantly in the IV-valent state [23] and that binding of Pu(V) involves reduction to Pu(IV) on the particle surface [24], In contrast, Np(V) appears to largely persist in the V-valent state after uptake onto the type of particulate material used in the present study [9]. This information indicates that the presence of the major divalent seawater cations inhibits Pu(V) sorption in the +5 oxidation state rather than simply occupying reactive sites on the particles and suppressing the reduction mechanism.…”

Determination of plutonium in seawater using co-precipitation and inductively coupled plasma mass spectrometry with ultrasonic nebulisation

“…In the Irish Sea dissolved 239 + 240 Pu has been reported to be predominantly (70%-90%) in the V-valent state [3,4], whereas 239 + 240 Pu associated with particulate material exists almost entirely (Ͼ 98%) in the IV-valent state [5]. It has also been suggested that Pu(V) can bind to particulate material and that the uptake of Pu(V) species involves the reduction to Pu(IV) at the particle-solution interface [6]. Moreover, it has Spectrochimica Acta Part B 53 (1998) [1221][1222][1223][1224][1225][1226][1227][1228][1229][1230][1231][1232][1233] 0584-8547/98/$19.00 ᭧ 1998 Elsevier Science B.V. All rights reserved PII: S 05 84 -85 4 7( 9 8) 0 01 7 9-7 been shown that the distribution coefficient (partitioning between dissolved and particulate phases) for Pu(IV) (K d ϳ10 6 ) exceeds that of Pu(V) (K d ϳ10 4 ) [7].…”

“…It has also been suggested that Pu(V) can bind to particulate material and that the uptake of Pu(V) species involves the reduction to Pu(IV) at the particle-solution interface [6]. Moreover, it has Spectrochimica Acta Part B 53 (1998) [1221][1222][1223][1224][1225][1226][1227][1228][1229][1230][1231][1232][1233] 0584-8547/98/$19.00 ᭧ 1998 Elsevier Science B.V. All rights reserved PII: S 05 84 -85 4 7( 9 8) 0 01 7 9-7 been shown that the distribution coefficient (partitioning between dissolved and particulate phases) for Pu(IV) (K d ϳ10 6 ) exceeds that of Pu(V) (K d ϳ10 4 ) [7]. Therefore, it is evident that Pu(IV) is a highly particle reactive species, whilst Pu(V) is relatively soluble.…”