Purple phototrophic bacteria for resource recovery: Challenges and opportunities
Résumé
Sustainable development is driving a rapid focus shift in the wastewater and organic waste treatment sectors, from a "removal and disposal" approach towards the recovery and reuse of water, energy and materials (e.g. carbon or nutrients). Purple phototrophic bacteria (PPB) are receiving increasing attention due to their capability of growing photoheterotrophically under anaerobic conditions. Using light as energy source, PPB can simultaneously assimilate carbon and nutrients at high efficiencies (with biomass yields close to unity (1 g COD biomass •g COD removed −1)), facilitating the maximum recovery of these resources as different value-added products. The effective use of infrared light enables selective PPB enrichment in non-sterile conditions, without competition with other phototrophs such as microalgae if ultraviolet-visible wavelengths are filtered. This review reunites results systematically gathered from over 177 scientific articles, aiming at producing generalized conclusions. The most critical aspects of PPB-based production and valorisation processes are addressed, including: (i) the identification of the main challenges and potentials of different growth strategies, (ii) a critical analysis of the production of value-added compounds, (iii) a comparison of the different value-added products, (iv) insights into the general challenges and opportunities and (v) recommendations for future research and development towards practical implementation. To date, most of the work has not been executed under real-life conditions, relevant for full-scale application. With the savings in wastewater discharge due to removal of
Mots clés
Coenzyme Q10
CSTR
Continuous stirred-tank reactor
Dark fermentation
Dissolved oxygen
HRAS
High-rate activated sludge
HRT
Hydraulic retention time
HSD
Honestly significant difference
Internal circulation
Interquartile range
LED
Light-emitting diode
MSBR
Membrane sequencing batch reactor
Number of independent members of a statistical population/sample
NADH
Nicotinamide adenine dinucleotide
NADPH
Nicotinamide adenine dinucleotide phosphate
NIR
Near infrared
OLR
Organic loading rate
ORP
Oxidation reduction potential
PAnMBR
Photoanaerobic membrane bioreactor
PBR
Photo-bioreactor
PHA
Polyhydroxyalkanoate
PHB
Poly(3-hydroxybutyrate)
PHBV
Poly(3-hydroxy-butyrate-co-3-hydroxyvalerate)
PF
Photofermentation
PNSB
Purple non-sulfur bacteria
PPB
Purple phototrophic bacteria
PRBC
Photorotating biological contractor
PSB
Purple sulfur bacteria
SBR
Sequencing batch reactor
SCP
Single-cell protein
STP
Standard temperature and pressure
SRT
Solid retention time
TCA
Tricarboxylic acid
TCOD
Total chemical oxygen demand
TS
Total solids
UASB
Up-flow anaerobic sludge blanket
UV
Ultra violet
VFA
Volatile fatty acid
VIS
Visible
VSS
Volatile suspended solids
VS
Volatile solids
VS frac
Organic fraction of total solids
Wastewater
5-ALA
5-Animolevulinic acid ⁎ Corresponding author
Carotenoids Hydrogen Nutrient recovery Polyhydroxyalkanoates Purple non-sulfur bacteria Purple sulfur bacteria Single-cell protein Waste Wastewater AMBR
Aerobic membrane reactor
AnMBR
Anaerobic membrane bioreactor
ANOVA
Analysis of variance
ATP
Adenosine triphosphate
BChl
Bacteriochlorophylls
BOD
Biochemical oxygen demand
CAGR
Compound annual growth rate
CAS
Conventional activated sludge
CBB
Calvin-Benson-Bassham
COD
Chemical oxygen demand
CoQ10
Domaines
Ingénierie de l'environnement| Origine | Fichiers produits par l'(les) auteur(s) |
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