New insights on Uranium recovery from seawater and aqueous media

Abstract

Oceans uranium reserve of 4.5 billion tons can be the answer for the next-generation sustainable nuclear energy. However, extracting the extremely diluted uranium (3.3 ppb) is a difficult task and adsorption materials with high selectivity and uptake capacity are still to be found. Here, we propose the use of poly(4-vinyldipicolinic acid) (PVDPA) as a new highly promising polymer for uranium harvesting from seawater. PVDPA showed a uranium uptake capacity of 597 mg/g in simulated seawater conditions, even at high ionic strength and in the presence of the challenging vanadium species, that tend to limit the performance of other existing materials. PVDPA is also built from a solid PVC-based substrate using an easy and oxygen tolerant strategy. The used PVDPA-modified fibers showed a uranium uptake capacity of 392 mg/g and reached the adsorption equilibrium in less than 3 h, the fastest and highest reported, to the best of our knowledge. The cheap, easy and fast preparation, combined with fast and high uranium recovery, make PVDPA highly promising, not only for uranium harvesting from seawater, but also for treating waters contaminated with uranium.