1
|
Weng H, Wang Y, Li F, Muroya Y, Yamashita S, Cheng S. Recovery of platinum group metal resources from high-level radioactive liquid wastes by non-contact photoreduction. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131852. [PMID: 37331059 DOI: 10.1016/j.jhazmat.2023.131852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/29/2023] [Accepted: 06/12/2023] [Indexed: 06/20/2023]
Abstract
Recovery of platinum group metals (PGMs) including palladium (Pd), rhodium (Rh), and ruthenium (Ru) from high-level radioactive liquid waste (HLLW) possesses enormous environmental and economic benefits. A non-contact photoreduction method was herein developed to selectively recover each PGM from HLLW. Soluble Pd(II), Rh(III), and Ru(III) ions were reduced to insoluble zero-valent metals and separated from simulated HLLW containing neodymium (Nd) as a representative for lanthanides, another main component in HLLW. Detailed investigation on the photoreduction of different PGMs revealed that Pd(II) could be reduced under 254- or 300-nm UV exposure using either ethanol or isopropanol as reductants. Only 300-nm UV light enabled the reduction of Rh(III) in the presence of ethanol or isopropanol. Ru(III) was the most difficult to reduce, which was only realized by 300-nm UV illumination in isopropanol solution. The effects of pH was also studied, suggesting that lower pH favored the separation of Rh(III) but hindered the reduction of Pd(II) and Ru(III). A delicate three-step process was accordingly designed to achieve the selective recovery of each PGM from simulated HLLW. Pd(II) was reduced by 254-nm UV light with the help of ethanol in the first step. Then Rh(III) was reduced by 300-UV light in the second step after the pH was adjusted to 0.5 to suppress the Ru(III) reduction. In the third step, Ru(III) was reduced by 300-nm UV light after isopropanol was added and the pH was adjusted to 3.2. The separation ratios of Pd, Rh, and Ru exceeded 99.8%, 99.9%, and 90.0%, respectively. Meanwhile, all Nd(III) still remained in the simulated HLLW. The separation coefficients between Pd/Rh and Rh/Ru exceeded 56,000 and 75,000, respectively. This work may provide an alternative method to recover PGMs from HLLW, which minimize the secondary radioactive wastes compared with other approaches.
Collapse
Affiliation(s)
- Hanqin Weng
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China; Department of Beam Material Science, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan; Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan.
| | - Yi Wang
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China; Reactor Operation and Application Research Sub-Institute, Nuclear Power Institute of China, Chengdu, Sichuan 610041, China
| | - Fuhai Li
- Suzhou Nuclear Power Research Institute Co. Ltd., Suzhou, Jiangsu 215004, China
| | - Yusa Muroya
- Department of Beam Material Science, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Shinichi Yamashita
- Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan; Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 4-7-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Sheng Cheng
- Instrumental Analysis Center, Hefei University of Technology, Hefei, Anhui 230009, China
| |
Collapse
|
2
|
Hamilton HSC, Bradley LC. Probing the morphology evolution of chemically anisotropic colloids prepared by homopolymerization- and copolymerization-induced phase separation. Polym Chem 2020. [DOI: 10.1039/c9py01166h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chemically anisotropic colloids prepared by polymerization-induced phase separation during seeded emulsion polymerization with non-crosslinked seeds reveals tunability in both surface and interior properties based on the morphology evolution.
Collapse
Affiliation(s)
- Heather S. C. Hamilton
- Department of Polymer Science and Engineering
- University of Massachusetts Amherst
- Amherst
- USA
| | - Laura C. Bradley
- Department of Polymer Science and Engineering
- University of Massachusetts Amherst
- Amherst
- USA
| |
Collapse
|