Removal of aqueous rare earth elements (REEs) using nano-iron based materials

The uptake of REEs was investigated using nano-zero valent iron (nZVI) and alumina-supported nZVI (Al-nZVI). The results indicated fast uptake, with saturation approached within 10 min of contact between solutions and solids. Upon using nZVI, the uptake of REEs seemed to be quantitative over the studied range of concentration; 1.0–100.0 mg L−1. When Al-nZVI was used, complete removal was achieved within the range of 1.0–10.0 mg L−1. The solids demonstrated stable performance beyond pH of 2.0, up to neutral pH conditions. Fractionation of REEs on Al-nZVI was observed. The REE ions seem to be fixed to oxide and oxyhydroxide surface groups.