Precious metals recovery from aqueous solutions using a new adsorbent material
Oana Grad1, Mihaela Ciopec2, Adina Negrea3
1Faculty of Industrial Chemistry and Environmental Engineering, Polytechnic University of Timişoara, Victoriei Square, No. 2, 300006, Timisoara, Romania.
Scientific Reports
|January 22, 2021
Summary
Recycling platinum group metals (PGMs) from spent catalysts is crucial. A new Chitosan-DB18C6 adsorbent efficiently recovers PGMs from aqueous solutions, offering a promising method for valuable metal recovery.
Area of Science:
- Materials Science
- Environmental Chemistry
- Chemical Engineering
Background:
- Platinum group metals (PGMs) like palladium, platinum, and ruthenium are essential for automotive exhaust treatment.
- The rising importance and high value of PGMs necessitate efficient recycling methods from spent catalysts.
- Adsorption is an effective PGM recovery technique, but relies heavily on adsorbent material performance.
Purpose of the Study:
- To develop and evaluate a novel adsorbent material for the efficient recovery of PGMs from aqueous solutions.
- To investigate the adsorption properties and mechanism of the Chitosan-DB18C6 adsorbent for PGMs.
- To assess the viability of the Chitosan-DB18C6 adsorbent for industrial PGM recycling applications.
Main Methods:
- A new adsorbent, Chitosan-DB18C6, was synthesized using the Solvent Impregnated Resin (SIR) method, impregnating Chitosan with dibenzo-18-crown-6-ether.
- Equilibrium and kinetic studies were conducted to evaluate the PGM recovery efficiency of the Chitosan-DB18C6 adsorbent.
- Adsorption mechanism was studied by modeling experimental data using pseudo-first-order and pseudo-second-order kinetic models and Langmuir, Freundlich, and Sips isotherm models.
Main Results:
- The Chitosan-DB18C6 adsorbent demonstrated high efficiency in recovering PGMs from aqueous solutions.
- Kinetic modeling indicated the adsorption process followed pseudo-second-order kinetics, suggesting chemisorption.
- Isotherm modeling suggested a complex adsorption mechanism, with Sips model providing the best fit, indicating heterogeneous surface interactions.
Conclusions:
- The Chitosan-DB18C6 adsorbent is a highly efficient material for the recovery of platinum group metals from aqueous solutions.
- The developed adsorbent shows significant potential for application in the recycling of valuable PGMs from industrial waste streams.
- Further research into optimizing the adsorbent synthesis and exploring its performance with real spent catalyst leachates is warranted.
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