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Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
Microbial formation of manganese oxides
1Department of Biotechnology, University of New South Wales, P.O. Box 1, Kensington, New South Wales 2033, Australia.
Applied and Environmental Microbiology
|April 1, 1991
Summary
Microalgae and bacteria can efficiently remove high manganese concentrations, producing manganese oxides. This process, optimized using specific bacterial strains and culture conditions, yields valuable manganese oxide products for potential applications.
Area of Science:
- Environmental Microbiology
- Biomineralization
- Materials Science
Background:
- Microbial manganese oxidation is crucial for biogeochemical cycling.
- High manganese concentrations pose environmental challenges.
- Algal-bacterial interactions can influence mineral formation.
Purpose of the Study:
- To investigate microbial manganese oxidation at high concentrations (5 g/liter).
- To characterize the manganese oxides produced by algal-bacterial cultures.
- To identify key microbial players and optimal conditions for manganese removal and oxide formation.
Main Methods:
- Culturing of bacterial strains with a microalga (Chlamydomonas sp.) in bioreactors.
- Analysis of manganese oxide structure using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy.
- Optimization of medium components (algal biomass, urea) and scale-up of the culture process.
Main Results:
- Bacterial cultures with microalgae effectively removed high manganese concentrations, forming disordered gamma-MnO(2).
- Yields of semipure manganese oxide reached 22.3 g in scaled-up cultures.
- Manganite (gamma-MnOOH) was identified as a potential intermediate in the formation of disordered gamma-MnO(2).
Conclusions:
- Algal-bacterial consortia are effective in precipitating manganese oxides from high-concentration solutions.
- Pseudomonas sp. played a primary role in manganese precipitation, mediated by the microalga.
- The produced manganese oxide contained biological and inorganic contaminants, affecting its Mn(IV) content.
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