Recovery of Rare Earth Ions by Electro-Sorption with Sodium Diphenylamine Sulfonate Modified Activated Carbon Electrode

Electro-sorption is an effective strategy to remove metal ions from aqueous solution without being polluted by chemical reagents. It has been used in water purification and desalination, but there is little research on the recovery of rare earth. In this article, sodium diphenylamine sulfonate (SDAS) modified activated carbon (AC) was coated on carbon felt (CF) and used as working electrode (SDAS/AC-CF). The recoveries of La(III), Nd(III) and Ce(III) on the SDAS/AC-CF were studied by electro-sorption. The effects of reactive time, concentrations and temperature on the recovery of La(III) were evaluated. Meanwhile, the adsorptive capacity, kinetics and isotherm of aqueous La(III) were determined. As shown in the studies, La(OH) 3 is formed on the surface of modified SDAS/AC-CF electrode. After 500 minutes of reaction, the adsorption capacity reaches nearly 600 mg g -1 . In the three adsorption-desorption cycles, the adsorption capacity remains stable. The obtained rare earth products are La(OH) 3, Nd(OH) 3 and CeO 2 , respectively. After nearly 180 minutes of reaction, the corresponding adsorption capacities are 275 mg g -1 and 365 mg g -1 , respectively. The electro-sorption has revealed potential application value in the recovery of rare earth from wastewater