| Title |
Biorefining of green macroalgal (Ulva sp.) biomass and its application in the adsorptive recovery of rare earth elements (REEs) |
| ID_Doc |
24273 |
| Authors |
Manikandan, NA; Lens, PNL |
| Title |
Biorefining of green macroalgal (Ulva sp.) biomass and its application in the adsorptive recovery of rare earth elements (REEs) |
| Year |
2022 |
| Published |
|
| DOI |
10.1016/j.seppur.2022.122200 |
| Abstract |
The growing gap in the supply and demand of rare earth elements (REEs) calls for the recovery and reuse of REEs from waste streams and secondary sources like e-waste. The present study strategically utilised Ulva sp. and waste derived from Ulva sp. biorefining as a sustainable biosorbent for the recovery of lanthanum, neodymium and dysprosium. NaOH-assisted ulvan extracted biomass outperformed the other biosorbents investigated with a recovery efficiency of 90.71 (+/- 0.4) %, 95.12 (+/- 0.62) % and 93.83 (+/- 0.63) % for lanthanum, neodymium and dysprosium, respectively. Zeta potential (-18.9 +/- 0.5 mV) and zero-point charge (6.71 pH) analysis portrayed that the high surface charge negativity aided in the superior performance of NaOH-assisted ulvan extracted biomass. Thus, NaOH-assisted ulvan extracted biomass was selected and optimised to perform well at a solution pH of 7 and temperature of 293-313 K. Biosorption followed Langmuir isotherm and pseudo-second-order ki-netics adsorption with an R2 value of 0.99. Thermodynamic analysis portrayed biosorption to be an exothermic and spontaneous process. Fourier transform infrared spectroscopy (FTIR) described the involvement of hydroxyl (-OH), carboxylic (-COOH), and amide (N-H) groups present in the biomass for the recovery of REEs. Finally, desorption using HCl and EDTA gave stable adsorption and desorption efficiency of more than 40% up to six adsorption and desorption cycles. Thus, the present study developed a circular bioeconomy strategy by involving refused macroalgal biomass as a green and low-cost adsorbent to recover REEs. |
| Author Keywords |
Adsorption; Rare earth elements; Circular economy; Extraction; Ulva sp |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000871110200001 |
| WoS Category |
Engineering, Chemical |
| Research Area |
Engineering |
| PDF |
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