Autotrophic sulfide removal by mixed culture purple phototrophic bacteria

Egger, Felix and Hulsen, Tim and Tait, Stephan and Batstone, Damien J. (2020) Autotrophic sulfide removal by mixed culture purple phototrophic bacteria. Water Research, 182:115896. pp. 1-15. ISSN 0043-1354


Abstract

Current H2S treatment methods for sour gases require considerable amounts of chemicals and energy, or in case of biological treatment, unwanted diluents such as oxygen or nitrogen may be introduced. In order to reduce those requirements, the viability of an anaerobic biological H2S removal process using purple phototrophic bacteria (PPB) was investigated in this study. PPB can use sunlight, and centrate as nutrient source, thus potentially reducing energy and chemical requirements. An added benefit is the production of biomass with potential uses, such as single cell protein. An inoculum of PPB enriched from domestic wastewater was grown photoautotrophically with sulfide as the electron donor and inorganic carbon in a mixed culture. Additionally, synthetic medium and centrate as well as high (56 +/- 11 Wm(-2)) and low (27 +/- 3 Wm(-2)) IR irradiation were trialled. Finally, a process model was developed to study biomass specific removal rates and yield. The results showed that a mixed culture of PPB removed sulfide completely in synthetic media (121 9 mg-S.L-1) at a maximum rate of 1.79 0.16 mg-S(Lh)(-1) (low irradiance) and 2.9 mg-S(Lh)(-1) (high irradiance). The pH increased in both experiments from about 8.5 to 9. Sulfide removal rates using centrate and low irradiance were similar. However Fe and Mn were found to be limiting growth and sulfide removal. In all experiments, Chromatiaceae (purple sulfur bacteria) were most abundant at the end of the experiment, while at the start purple non-sulfur bacteria were most abundant (from the inoculum). Process modelling and experimental work identified the sulfide oxidation to be a multi-step process with accumulation of intermediates. Specific rates were directly dependent on light input, doubling at high irradiance. Sulfide oxidation was estimated at 0.100 +/- 0.014 h(-1) (0.085 0.012 g-S(g-VS.h)(-1)) at low irradiance, and the biomass yield at 0.86 0.05 mg-COD.mg-COD-1. This process model enables the virtual evaluation of autotrophic sulfide removal by PPB in a continuous scaled-up process. Overall, the photoautotrophic removal of sulfide seems to be a viable option, especially because of the possibility of using sunlight as an energy source and centrate as a nutrient source.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Agricultural Engineering (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Agricultural Engineering (1 Aug 2018 -)
Date Deposited: 16 Feb 2021 05:24
Last Modified: 17 Feb 2021 01:28
Uncontrolled Keywords: Purple Phototrophic Bacteria; Biological sulfide removal; Biogas treatment; Allochromatium vinosum; Anaerobic process modelling
Fields of Research (2008): 09 Engineering > 0907 Environmental Engineering > 090702 Environmental Engineering Modelling
09 Engineering > 0907 Environmental Engineering > 090701 Environmental Engineering Design
09 Engineering > 0907 Environmental Engineering > 090703 Environmental Technologies
Fields of Research (2020): 40 ENGINEERING > 4011 Environmental engineering > 401106 Waste management, reduction, reuse and recycling
31 BIOLOGICAL SCIENCES > 3106 Industrial biotechnology > 310602 Bioprocessing, bioproduction and bioproducts
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9609 Land and Water Management > 960912 Urban and Industrial Water Management
D Environment > 96 Environment > 9606 Environmental and Natural Resource Evaluation > 960604 Environmental Management Systems
Socio-Economic Objectives (2020): 24 MANUFACTURING > 2406 Environmentally sustainable manufacturing activities > 240699 Environmentally sustainable manufacturing activities not elsewhere classified
24 MANUFACTURING > 2406 Environmentally sustainable manufacturing activities > 240605 Management of water consumption by manufacturing activities
Identification Number or DOI: https://doi.org/10.1016/j.watres.2020.115896
URI: http://eprints.usq.edu.au/id/eprint/41385

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