TY - JOUR
T1 - Nanoengineering cellulose for the selective removal of neodymium
T2 - Towards sustainable rare earth element recovery
AU - Wamea, Patricia
AU - Pitcher, Mica L.
AU - Muthami, Joy
AU - Sheikhi, Amir
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/1/15
Y1 - 2022/1/15
N2 - Rare earth elements (REE) have exceedingly become critical in advanced industries. Despite the high demand for REE, the world is still experiencing a shortage in ready-to-exploit resources, environmentally friendly processing, and reliable recovery strategies, rendering sustainable REE removal an immediate and unmet environmental, industrial, and economical challenge worldwide. We nanoengineered cellulose, the most abundant biopolymer in the world, to develop a sustainable bio-based technology named anionic hairy nanocellulose (AHNC) for the high-capacity and selective removal of neodymium ions (Nd3+), one of the most widely used REE, from aqueous media. AHNC comprises fully solubilized dicarboxylated cellulose (DCC) chains and cellulose nanocrystals (CNC) decorated with DCC (hairs) bearing a charge density that is about one order of magnitude higher than conventional CNC. The unique colloidal properties of AHNC, particularly the polyanionic hairs, enable the removal of ~ 264 ± 14 mg of Nd3+ per gram of the nanoadsorbent within seconds, which, to the best of our knowledge, place this advanced material among the adsorbents with the highest removal capacity at the shortest contact time. We investigated the roles of ionic strength, pH, and competing iron species on the performance of AHNC. Besides Nd3+ removal at high initial Nd3+ concentrations (C0 > 150 ppm) wherein AHNC is fully neutralized and precipitated, we show, for the first time, that at C0 ≤ 100 ppm wherein AHNC maintains its partial colloidal stability, Nd3+ removal can be enhanced via complementary calcium ion-mediated colloidal bridging. Together, our colloidal engineering approach combined with the biorenewability of cellulose and an ambient, low-cost unit operation, renders AHNC a promising sustainable nanotechnology for the removal of Nd3+ from industrial wastewater, mining tails, e-waste, and NdFeB permanent magnet leachates.
AB - Rare earth elements (REE) have exceedingly become critical in advanced industries. Despite the high demand for REE, the world is still experiencing a shortage in ready-to-exploit resources, environmentally friendly processing, and reliable recovery strategies, rendering sustainable REE removal an immediate and unmet environmental, industrial, and economical challenge worldwide. We nanoengineered cellulose, the most abundant biopolymer in the world, to develop a sustainable bio-based technology named anionic hairy nanocellulose (AHNC) for the high-capacity and selective removal of neodymium ions (Nd3+), one of the most widely used REE, from aqueous media. AHNC comprises fully solubilized dicarboxylated cellulose (DCC) chains and cellulose nanocrystals (CNC) decorated with DCC (hairs) bearing a charge density that is about one order of magnitude higher than conventional CNC. The unique colloidal properties of AHNC, particularly the polyanionic hairs, enable the removal of ~ 264 ± 14 mg of Nd3+ per gram of the nanoadsorbent within seconds, which, to the best of our knowledge, place this advanced material among the adsorbents with the highest removal capacity at the shortest contact time. We investigated the roles of ionic strength, pH, and competing iron species on the performance of AHNC. Besides Nd3+ removal at high initial Nd3+ concentrations (C0 > 150 ppm) wherein AHNC is fully neutralized and precipitated, we show, for the first time, that at C0 ≤ 100 ppm wherein AHNC maintains its partial colloidal stability, Nd3+ removal can be enhanced via complementary calcium ion-mediated colloidal bridging. Together, our colloidal engineering approach combined with the biorenewability of cellulose and an ambient, low-cost unit operation, renders AHNC a promising sustainable nanotechnology for the removal of Nd3+ from industrial wastewater, mining tails, e-waste, and NdFeB permanent magnet leachates.
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U2 - 10.1016/j.cej.2021.131086
DO - 10.1016/j.cej.2021.131086
M3 - Article
AN - SCOPUS:85111572870
SN - 1385-8947
VL - 428
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 131086
ER -