Efficient electrosorption of uranyl ions by a homemade amidoxime‐modified carbon paper‐based electrode in acidic aqueous condition

Abstract

BACKGROUND Electrosorption efficiency for uranyl ion (UO22+) capture is low in acid solution due to the adverse effect caused by protons. This requires novel electrodes effective at acid conditions for UO22+ electrosorption in highly acidic industrial effluents such as spent nuclear fuel treatment. RESULTS In the current study, UO22+ electrosorption was conducted using an amidoxime‐modified carbon paper (CP‐AO) electrode. The effects of voltage and frequency, pH, UO22+ initial concentration, and competing ions on UO22+ electrosorption were investigated. The reusability and electrochemical properties of the CP‐AO electrode were studied. The experimental results showed that the current CP‐AO electrode worked well in acidic conditiona (pH = 3) with a square wave periodic voltage (SWPV, −4 V, 1000 Hz), and outperformed a previously used carbon felt‐based electrode. The CP‐AO electrode showed considerable selectivity toward UO22+ in the presence of competitive ions. After seven rounds of continuous electrosorption–desorption, the CP‐AO electrode still showed good UO22+ uptake efficiency. The electrosorption mechanisms were studied in‐depth based on experimental and characterization results. The electrosorption of UO22+ by the CP‐AO electrode was due mainly to the electric field force moving UO22+ to the surface of the electrode, leading to electrodeposition of uranium compounds and the formation of electrically neutral substances. CONCLUSIONS The results indicated that based on SWPV electrosorption the CP‐AO could be a desirable treatment approach for acidic uranium‐containing wastewater with promising practical applications.

Electrochemical Techniques for Uranium Extraction from Water

“…For example, by incorporating phytic acid into a polypyrrole-carbon felt electrode, Huang et al were able to increase the equilibrium adsorption of uranyl nitrate from 372.8 to 1562.0 mg/g under alternating voltage conditions (Figure 3) [41]. However, the most common uranyl-ion-selective functional groups used are amidoximes [29,54,[66][67][68][69][70][71].…”

Synthesis of Pillar[5]arene- and Phosphazene-Linked Porous Organic Polymers for Highly Efficient Adsorption of Uranium

“…Recently, various approaches were used for uranium extraction from aqueous solutions, i.e., membrane filtration [ 7 ], ion exchange [ 8 ], electrochemical [ 9 ], solvent extraction [ 6 ], and adsorption [ 10 , 11 , 12 , 13 ]. In these processes, adsorption shows great potential in uranium separation and recovery because of its environmental friendliness, easy operation, low cost, and wide adaptability.…”