One step bioconversion of waste precious metals into Serratia biofilm-immobilized catalyst for Cr(VI) reduction
Research output: Contribution to journal › Article › peer-review
Authors
Colleges, School and Institutes
External organisations
- University of Cambridge
- School of Mechanical and Chemical Engineering
- University of Western Australia
Abstract
Objectives: For reduction of Cr(VI) the Pd-catalyst is excellent but costly. The objectives were to prove the robustness of a Serratia biofilm as a support for biogenic Pd-nanoparticles and to fabricate effective catalyst from precious metal waste. Results: Nanoparticles (NPs) of palladium were immobilized on polyurethane reticulated foam and polypropylene supports via adhesive biofilm of a Serratia sp. The biofilm adhesion and cohesion strength were unaffected by palladization and catalytic biofilm integrity was also shown by magnetic resonance imaging. Biofilm-Pd and mixed precious metals on biofilm (biofilm-PM) reduced 5 mM Cr(VI) to Cr(III) when immobilized in a flow-through column reactor, at respective flow rates of 9 and 6 ml/h. The lower activity of the latter was attributed to fewer, larger, metal deposits on the bacteria. Activity was lost in each case at pH 7 but was restored by washing with 5 mM citrate solution or by exposure of columns to solution at pH 2, suggesting fouling by Cr(III) hydroxide product at neutral pH. Conclusion: A ‘one pot’ conversion of precious metal waste into new catalyst for waste decontamination was shown in a continuous flow system based on the use of Serratia biofilm to manufacture and support catalytic Pd-nanoparticles.
Details
Original language | English |
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Pages (from-to) | 2181-2191 |
Number of pages | 11 |
Journal | Biotechnology Letters |
Volume | 37 |
Issue number | 11 |
Publication status | Published - 29 Nov 2015 |
Keywords
- Biofilm, Catalyst, Chromate reduction, Palladium, Precious metals, Serratia sp